【Socket网络编程进阶与实战】-----UDP辅助TCP实现点对点传输案例
前言
分享UDP辅助TCP实现点对点传输案例
UDP搜索IP与端口
- 构建基础口令消息
- 局域网广播口令消息（指定端口）
- 接收指定端口回送消息（得到客户端IP，Port）
UDP搜索取消实现
- 异步线程接收回送消息
- 异步线程等待完成（定时）
- 关闭等待-终止线程等待
package com.zcw.demo5.client.bean;
/**
* @ClassName : ServerInfo
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-07 19:47
*/
public class ServerInfo {
private String sn;
private int port;
private String address;
public ServerInfo(int port, String ip, String sn) {
this.port = port;
this.address = ip;
this.sn = sn;
}
public String getSn() {
return sn;
}
public void setSn(String sn) {
this.sn = sn;
}
public int getPort() {
return port;
}
public void setPort(int port) {
this.port = port;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
@Override
public String toString() {
return "ServerInfo{" +
"sn='" + sn + '\'' +
", port=" + port +
", address='" + address + '\'' +
'}';
}
}
package com.zcw.demo5.client;
import com.zcw.demo5.client.bean.ServerInfo;
/**
* @ClassName : Client
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-07 19:45
*/
public class Client {
public static void main(String[] args) {
ServerInfo info = ClientSearcher.searchServer(10000);
System.out.println("Server:" + info);
}
}
package com.zcw.demo5.client;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import com.zcw.demo5.client.bean.ServerInfo;
import com.zcw.demo5.clink.utils.ByteUtils;
import com.zcw.demo5.constants.UDPConstants;
/**
* @ClassName : ClientSearcher
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-07 19:46
*/
public class ClientSearcher {
private static final int LISTEN_PORT = UDPConstants.PORT_CLIENT_RESPONSE;
public static ServerInfo searchServer(int timeout) {
System.out.println("UDPSearcher Started.");
// 成功收到回送的栅栏
CountDownLatch receiveLatch = new CountDownLatch(1);
Listener listener = null;
try {
listener = listen(receiveLatch);
sendBroadcast();
receiveLatch.await(timeout, TimeUnit.MILLISECONDS);
} catch (Exception e) {
e.printStackTrace();
}
// 完成
System.out.println("UDPSearcher Finished.");
if (listener == null) {
return null;
}
List<ServerInfo> devices = listener.getServerAndClose();
if (devices.size() > 0) {
return devices.get(0);
}
return null;
}
private static Listener listen(CountDownLatch receiveLatch) throws InterruptedException {
System.out.println("UDPSearcher start listen.");
CountDownLatch startDownLatch = new CountDownLatch(1);
Listener listener = new Listener(LISTEN_PORT, startDownLatch, receiveLatch);
listener.start();
startDownLatch.await();
return listener;
}
private static void sendBroadcast() throws IOException {
System.out.println("UDPSearcher sendBroadcast started.");
// 作为搜索方，让系统自动分配端口
DatagramSocket ds = new DatagramSocket();
// 构建一份请求数据
ByteBuffer byteBuffer = ByteBuffer.allocate(128);
// 头部
byteBuffer.put(UDPConstants.HEADER);
// CMD命名
byteBuffer.putShort((short) 1);
// 回送端口信息
byteBuffer.putInt(LISTEN_PORT);
// 直接构建packet
DatagramPacket requestPacket = new DatagramPacket(byteBuffer.array(),
byteBuffer.position() + 1);
// 广播地址
requestPacket.setAddress(InetAddress.getByName("255.255.255.255"));
// 设置服务器端口
requestPacket.setPort(UDPConstants.PORT_SERVER);
// 发送
ds.send(requestPacket);
ds.close();
// 完成
System.out.println("UDPSearcher sendBroadcast finished.");
}
private static class Listener extends Thread {
private final int listenPort;
private final CountDownLatch startDownLatch;
private final CountDownLatch receiveDownLatch;
private final List<ServerInfo> serverInfoList = new ArrayList<ServerInfo>();
private final byte[] buffer = new byte[128];
private final int minLen = UDPConstants.HEADER.length + 2 + 4;
private boolean done = false;
private DatagramSocket ds = null;
private Listener(int listenPort, CountDownLatch startDownLatch, CountDownLatch receiveDownLatch) {
super();
this.listenPort = listenPort;
this.startDownLatch = startDownLatch;
this.receiveDownLatch = receiveDownLatch;
}
@Override
public void run() {
super.run();
// 通知已启动
startDownLatch.countDown();
try {
// 监听回送端口
ds = new DatagramSocket(listenPort);
// 构建接收实体
DatagramPacket receivePack = new DatagramPacket(buffer, buffer.length);
while (!done) {
// 接收
ds.receive(receivePack);
// 打印接收到的信息与发送者的信息
// 发送者的IP地址
String ip = receivePack.getAddress().getHostAddress();
int port = receivePack.getPort();
int dataLen = receivePack.getLength();
byte[] data = receivePack.getData();
boolean isValid = dataLen >= minLen
&& ByteUtils.startsWith(data, UDPConstants.HEADER);
System.out.println("UDPSearcher receive form ip:" + ip
+ "\tport:" + port + "\tdataValid:" + isValid);
if (!isValid) {
// 无效继续
continue;
}
ByteBuffer byteBuffer = ByteBuffer.wrap(buffer, UDPConstants.HEADER.length, dataLen);
final short cmd = byteBuffer.getShort();
final int serverPort = byteBuffer.getInt();
if (cmd != 2 || serverPort <= 0) {
System.out.println("UDPSearcher receive cmd:" + cmd + "\tserverPort:" + serverPort);
continue;
}
String sn = new String(buffer, minLen, dataLen - minLen);
ServerInfo info = new ServerInfo(serverPort, ip, sn);
serverInfoList.add(info);
// 成功接收到一份
receiveDownLatch.countDown();
}
} catch (Exception ignored) {
} finally {
close();
}
System.out.println("UDPSearcher listener finished.");
}
private void close() {
if (ds != null) {
ds.close();
ds = null;
}
}
List<ServerInfo> getServerAndClose() {
done = true;
close();
return serverInfoList;
}
}
}
package com.zcw.demo5.clink.utils;
/**
* @ClassName : ByteUtils
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-07 19:49
*/
public class ByteUtils {
/**
* Does this byte array begin with match array content?
*
* @param source Byte array to examine
* @param match Byte array to locate in source
* @return true If the starting bytes are equal
*/
public static boolean startsWith(byte[] source, byte[] match) {
return startsWith(source, 0, match);
}
/**
* Does this byte array begin with match array content?
*
* @param source Byte array to examine
* @param offset An offset into the source array
* @param match Byte array to locate in source
* @return true If the starting bytes are equal
*/
public static boolean startsWith(byte[] source, int offset, byte[] match) {
if (match.length > (source.length - offset)) {
return false;
}
for (int i = 0; i < match.length; i++) {
if (source[offset + i] != match[i]) {
return false;
}
}
return true;
}
/**
* Does the source array equal the match array?
*
* @param source Byte array to examine
* @param match Byte array to locate in source
* @return true If the two arrays are equal
*/
public static boolean equals(byte[] source, byte[] match) {
if (match.length != source.length) {
return false;
}
return startsWith(source, 0, match);
}
/**
* Copies bytes from the source byte array to the destination array
*
* @param source The source array
* @param srcBegin Index of the first source byte to copy
* @param srcEnd Index after the last source byte to copy
* @param destination The destination array
* @param dstBegin The starting offset in the destination array
*/
public static void getBytes(byte[] source, int srcBegin, int srcEnd, byte[] destination,
int dstBegin) {
System.arraycopy(source, srcBegin, destination, dstBegin, srcEnd - srcBegin);
}
/**
* Return a new byte array containing a sub-portion of the source array
*
* @param srcBegin The beginning index (inclusive)
* @param srcEnd The ending index (exclusive)
* @return The new, populated byte array
*/
public static byte[] subbytes(byte[] source, int srcBegin, int srcEnd) {
byte destination[];
destination = new byte[srcEnd - srcBegin];
getBytes(source, srcBegin, srcEnd, destination, 0);
return destination;
}
/**
* Return a new byte array containing a sub-portion of the source array
*
* @param srcBegin The beginning index (inclusive)
* @return The new, populated byte array
*/
public static byte[] subbytes(byte[] source, int srcBegin) {
return subbytes(source, srcBegin, source.length);
}
}
package com.zcw.demo5.clink;
/**
* @ClassName : Clink
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-07 19:49
*/
public class Clink {
}
package com.zcw.demo5.constants;
/**
* @ClassName : TCPConstants
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-07 19:42
*/
public class TCPConstants {
// 服务器固化UDP接收端口
public static int PORT_SERVER = 30401;
}
package com.zcw.demo5.constants;
/**
* @ClassName : UDPConstants
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-07 19:36
*/
public class UDPConstants {
//公用头部
public static byte[] HEADER = new byte[]{7,7,7,7,7,7,7,7};
//服务器固化UDP接收端口
public static int PORT_SERVER = 30201;
//客户端回送端口
public static int PORT_CLIENT_RESPONSE=30202;
}
package com.zcw.demo5.server;
import java.io.IOException;
import com.zcw.demo5.constants.TCPConstants;
/**
* @ClassName : Server
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-07 19:40
*/
public class Server {
public static void main(String[] args) {
ServerProvider.start(TCPConstants.PORT_SERVER);
try {
//noinspection ResultOfMethodCallIgnored
System.in.read();
} catch (IOException e) {
e.printStackTrace();
}
ServerProvider.stop();
}
}
package com.zcw.demo5.server;
import com.zcw.demo5.clink.utils.ByteUtils;
import com.zcw.demo5.constants.UDPConstants;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.nio.ByteBuffer;
import java.util.UUID;
/**
* @ClassName : ServerProvider
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-07 19:51
*/
public class ServerProvider {
private static Provider PROVIDER_INSTANCE;
static void start(int port) {
stop();
String sn = UUID.randomUUID().toString();
Provider provider = new Provider(sn, port);
provider.start();
PROVIDER_INSTANCE = provider;
}
static void stop() {
if (PROVIDER_INSTANCE != null) {
PROVIDER_INSTANCE.exit();
PROVIDER_INSTANCE = null;
}
}
private static class Provider extends Thread {
private final byte[] sn;
private final int port;
private boolean done = false;
private DatagramSocket ds = null;
// 存储消息的Buffer
final byte[] buffer = new byte[128];
Provider(String sn, int port) {
super();
this.sn = sn.getBytes();
this.port = port;
}
@Override
public void run() {
super.run();
System.out.println("UDPProvider Started.");
try {
// 监听20000 端口
ds = new DatagramSocket(UDPConstants.PORT_SERVER);
// 接收消息的Packet
DatagramPacket receivePack = new DatagramPacket(buffer, buffer.length);
while (!done) {
// 接收
ds.receive(receivePack);
// 打印接收到的信息与发送者的信息
// 发送者的IP地址
String clientIp = receivePack.getAddress().getHostAddress();
int clientPort = receivePack.getPort();
int clientDataLen = receivePack.getLength();
byte[] clientData = receivePack.getData();
boolean isValid = clientDataLen >= (UDPConstants.HEADER.length + 2 + 4)
&& ByteUtils.startsWith(clientData, UDPConstants.HEADER);
System.out.println("ServerProvider receive form ip:" + clientIp
+ "\tport:" + clientPort + "\tdataValid:" + isValid);
if (!isValid) {
// 无效继续
continue;
}
// 解析命令与回送端口
int index = UDPConstants.HEADER.length;
short cmd = (short) ((clientData[index++] << 8) | (clientData[index++] & 0xff));
int responsePort = (((clientData[index++]) << 24) |
((clientData[index++] & 0xff) << 16) |
((clientData[index++] & 0xff) << 8) |
((clientData[index] & 0xff)));
// 判断合法性
if (cmd == 1 && responsePort > 0) {
// 构建一份回送数据
ByteBuffer byteBuffer = ByteBuffer.wrap(buffer);
byteBuffer.put(UDPConstants.HEADER);
byteBuffer.putShort((short) 2);
byteBuffer.putInt(port);
byteBuffer.put(sn);
int len = byteBuffer.position();
// 直接根据发送者构建一份回送信息
DatagramPacket responsePacket = new DatagramPacket(buffer,
len,
receivePack.getAddress(),
responsePort);
ds.send(responsePacket);
System.out.println("ServerProvider response to:" + clientIp + "\tport:" + responsePort + "\tdataLen:" + len);
} else {
System.out.println("ServerProvider receive cmd nonsupport; cmd:" + cmd + "\tport:" + port);
}
}
} catch (Exception ignored) {
} finally {
close();
}
// 完成
System.out.println("UDPProvider Finished.");
}
private void close() {
if (ds != null) {
ds.close();
ds = null;
}
}
/**
* 提供结束
*/
void exit() {
done = true;
close();
}
}
}
- 测试
UDP辅助TCP实现点对点传输案例
- 多线程收发并行
- TCP多线程收发协作
package com.zcw.channel.client.bean;
/**
* @ClassName : ServerInfo
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:48
*/
public class ServerInfo {
private String sn;
private int port;
private String address;
public ServerInfo(int port, String ip, String sn) {
this.port = port;
this.address = ip;
this.sn = sn;
}
public String getSn() {
return sn;
}
public void setSn(String sn) {
this.sn = sn;
}
public int getPort() {
return port;
}
public void setPort(int port) {
this.port = port;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
@Override
public String toString() {
return "ServerInfo{" +
"sn='" + sn + '\'' +
", port=" + port +
", address='" + address + '\'' +
'}';
}
}
package com.zcw.channel.client;
import com.zcw.channel.client.TCPClient;
import com.zcw.channel.client.UDPSearcher;
import com.zcw.channel.client.bean.ServerInfo;
import java.io.IOException;
/**
* @ClassName : Client
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:47
*/
public class Client {
public static void main(String[] args) {
ServerInfo info = UDPSearcher.searchServer(10000);
System.out.println("Server:" + info);
if (info != null) {
try {
TCPClient.linkWith(info);
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
package com.zcw.channel.client;
import com.zcw.channel.client.bean.ServerInfo;
import com.zcw.channel.clink.utils.CloseUtils;
import java.io.*;
import java.net.Inet4Address;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.net.SocketTimeoutException;
/**
* @ClassName : TCPClient
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:47
*/
public class TCPClient {
public static void linkWith(ServerInfo info) throws IOException {
Socket socket = new Socket();
// 超时时间
socket.setSoTimeout(3000);
// 连接本地，端口2000；超时时间3000ms
socket.connect(new InetSocketAddress(Inet4Address.getByName(info.getAddress()), info.getPort()), 3000);
System.out.println("已发起服务器连接，并进入后续流程～");
System.out.println("客户端信息：" + socket.getLocalAddress() + " P:" + socket.getLocalPort());
System.out.println("服务器信息：" + socket.getInetAddress() + " P:" + socket.getPort());
try {
ReadHandler readHandler = new ReadHandler(socket.getInputStream());
readHandler.start();
// 发送接收数据
write(socket);
// 退出操作
readHandler.exit();
} catch (Exception e) {
System.out.println("异常关闭");
}
// 释放资源
socket.close();
System.out.println("客户端已退出～");
}
private static void write(Socket client) throws IOException {
// 构建键盘输入流
InputStream in = System.in;
BufferedReader input = new BufferedReader(new InputStreamReader(in));
// 得到Socket输出流，并转换为打印流
OutputStream outputStream = client.getOutputStream();
PrintStream socketPrintStream = new PrintStream(outputStream);
do {
// 键盘读取一行
String str = input.readLine();
// 发送到服务器
socketPrintStream.println(str);
if ("00bye00".equalsIgnoreCase(str)) {
break;
}
} while (true);
// 资源释放
socketPrintStream.close();
}
static class ReadHandler extends Thread {
private boolean done = false;
private final InputStream inputStream;
ReadHandler(InputStream inputStream) {
this.inputStream = inputStream;
}
@Override
public void run() {
super.run();
try {
// 得到输入流，用于接收数据
BufferedReader socketInput = new BufferedReader(new InputStreamReader(inputStream));
do {
String str;
try {
// 客户端拿到一条数据
str = socketInput.readLine();
} catch (SocketTimeoutException e) {
continue;
}
if (str == null) {
System.out.println("连接已关闭，无法读取数据！");
break;
}
// 打印到屏幕
System.out.println(str);
} while (!done);
} catch (Exception e) {
if (!done) {
System.out.println("连接异常断开：" + e.getMessage());
}
} finally {
// 连接关闭
CloseUtils.close(inputStream);
}
}
void exit() {
done = true;
CloseUtils.close(inputStream);
}
}
}
package com.zcw.channel.client;
import com.zcw.channel.client.bean.ServerInfo;
import com.zcw.channel.clink.utils.ByteUtils;
import com.zcw.channel.constants.UDPConstants;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
/**
* @ClassName : UDPSearcher
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:48
*/
public class UDPSearcher {
private static final int LISTEN_PORT = UDPConstants.PORT_CLIENT_RESPONSE;
public static ServerInfo searchServer(int timeout) {
System.out.println("UDPSearcher Started.");
// 成功收到回送的栅栏
CountDownLatch receiveLatch = new CountDownLatch(1);
Listener listener = null;
try {
listener = listen(receiveLatch);
sendBroadcast();
receiveLatch.await(timeout, TimeUnit.MILLISECONDS);
} catch (Exception e) {
e.printStackTrace();
}
// 完成
System.out.println("UDPSearcher Finished.");
if (listener == null) {
return null;
}
List<ServerInfo> devices = listener.getServerAndClose();
if (devices.size() > 0) {
return devices.get(0);
}
return null;
}
private static Listener listen(CountDownLatch receiveLatch) throws InterruptedException {
System.out.println("UDPSearcher start listen.");
CountDownLatch startDownLatch = new CountDownLatch(1);
Listener listener = new Listener(LISTEN_PORT, startDownLatch, receiveLatch);
listener.start();
startDownLatch.await();
return listener;
}
private static void sendBroadcast() throws IOException {
System.out.println("UDPSearcher sendBroadcast started.");
// 作为搜索方，让系统自动分配端口
DatagramSocket ds = new DatagramSocket();
// 构建一份请求数据
ByteBuffer byteBuffer = ByteBuffer.allocate(128);
// 头部
byteBuffer.put(UDPConstants.HEADER);
// CMD命名
byteBuffer.putShort((short) 1);
// 回送端口信息
byteBuffer.putInt(LISTEN_PORT);
// 直接构建packet
DatagramPacket requestPacket = new DatagramPacket(byteBuffer.array(),
byteBuffer.position() + 1);
// 广播地址
requestPacket.setAddress(InetAddress.getByName("255.255.255.255"));
// 设置服务器端口
requestPacket.setPort(UDPConstants.PORT_SERVER);
// 发送
ds.send(requestPacket);
ds.close();
// 完成
System.out.println("UDPSearcher sendBroadcast finished.");
}
private static class Listener extends Thread {
private final int listenPort;
private final CountDownLatch startDownLatch;
private final CountDownLatch receiveDownLatch;
private final List<ServerInfo> serverInfoList = new ArrayList<ServerInfo>();
private final byte[] buffer = new byte[128];
private final int minLen = UDPConstants.HEADER.length + 2 + 4;
private boolean done = false;
private DatagramSocket ds = null;
private Listener(int listenPort, CountDownLatch startDownLatch, CountDownLatch receiveDownLatch) {
super();
this.listenPort = listenPort;
this.startDownLatch = startDownLatch;
this.receiveDownLatch = receiveDownLatch;
}
@Override
public void run() {
super.run();
// 通知已启动
startDownLatch.countDown();
try {
// 监听回送端口
ds = new DatagramSocket(listenPort);
// 构建接收实体
DatagramPacket receivePack = new DatagramPacket(buffer, buffer.length);
while (!done) {
// 接收
ds.receive(receivePack);
// 打印接收到的信息与发送者的信息
// 发送者的IP地址
String ip = receivePack.getAddress().getHostAddress();
int port = receivePack.getPort();
int dataLen = receivePack.getLength();
byte[] data = receivePack.getData();
boolean isValid = dataLen >= minLen
&& ByteUtils.startsWith(data, UDPConstants.HEADER);
System.out.println("UDPSearcher receive form ip:" + ip
+ "\tport:" + port + "\tdataValid:" + isValid);
if (!isValid) {
// 无效继续
continue;
}
ByteBuffer byteBuffer = ByteBuffer.wrap(buffer, UDPConstants.HEADER.length, dataLen);
final short cmd = byteBuffer.getShort();
final int serverPort = byteBuffer.getInt();
if (cmd != 2 || serverPort <= 0) {
System.out.println("UDPSearcher receive cmd:" + cmd + "\tserverPort:" + serverPort);
continue;
}
String sn = new String(buffer, minLen, dataLen - minLen);
ServerInfo info = new ServerInfo(serverPort, ip, sn);
serverInfoList.add(info);
// 成功接收到一份
receiveDownLatch.countDown();
}
} catch (Exception ignored) {
} finally {
close();
}
System.out.println("UDPSearcher listener finished.");
}
private void close() {
if (ds != null) {
ds.close();
ds = null;
}
}
List<ServerInfo> getServerAndClose() {
done = true;
close();
return serverInfoList;
}
}
}
package com.zcw.channel.clink.utils;
/**
* @ClassName : ByteUtils
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:50
*/
public class ByteUtils {
/**
* Does this byte array begin with match array content?
*
* @param source Byte array to examine
* @param match Byte array to locate in source
* @return true If the starting bytes are equal
*/
public static boolean startsWith(byte[] source, byte[] match) {
return startsWith(source, 0, match);
}
/**
* Does this byte array begin with match array content?
*
* @param source Byte array to examine
* @param offset An offset into the source array
* @param match Byte array to locate in source
* @return true If the starting bytes are equal
*/
public static boolean startsWith(byte[] source, int offset, byte[] match) {
if (match.length > (source.length - offset)) {
return false;
}
for (int i = 0; i < match.length; i++) {
if (source[offset + i] != match[i]) {
return false;
}
}
return true;
}
/**
* Does the source array equal the match array?
*
* @param source Byte array to examine
* @param match Byte array to locate in source
* @return true If the two arrays are equal
*/
public static boolean equals(byte[] source, byte[] match) {
if (match.length != source.length) {
return false;
}
return startsWith(source, 0, match);
}
/**
* Copies bytes from the source byte array to the destination array
*
* @param source The source array
* @param srcBegin Index of the first source byte to copy
* @param srcEnd Index after the last source byte to copy
* @param destination The destination array
* @param dstBegin The starting offset in the destination array
*/
public static void getBytes(byte[] source, int srcBegin, int srcEnd, byte[] destination,
int dstBegin) {
System.arraycopy(source, srcBegin, destination, dstBegin, srcEnd - srcBegin);
}
/**
* Return a new byte array containing a sub-portion of the source array
*
* @param srcBegin The beginning index (inclusive)
* @param srcEnd The ending index (exclusive)
* @return The new, populated byte array
*/
public static byte[] subbytes(byte[] source, int srcBegin, int srcEnd) {
byte destination[];
destination = new byte[srcEnd - srcBegin];
getBytes(source, srcBegin, srcEnd, destination, 0);
return destination;
}
/**
* Return a new byte array containing a sub-portion of the source array
*
* @param srcBegin The beginning index (inclusive)
* @return The new, populated byte array
*/
public static byte[] subbytes(byte[] source, int srcBegin) {
return subbytes(source, srcBegin, source.length);
}
}
package com.zcw.channel.clink.utils;
import java.io.Closeable;
import java.io.IOException;
/**
* @ClassName : CloseUtils
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:50
*/
public class CloseUtils {
public static void close(Closeable... closeables) {
if (closeables == null) {
return;
}
for (Closeable closeable : closeables) {
try {
closeable.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
package com.zcw.channel.clink;
/**
* @ClassName : Clink
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:49
*/
public class Clink {
}
package com.zcw.channel.constants;
/**
* @ClassName : TCPConstants
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:51
*/
public class TCPConstants {
// 服务器固化UDP接收端口
public static int PORT_SERVER = 30401;
}
package com.zcw.channel.constants;
/**
* @ClassName : UDPConstants
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:53
*/
public class UDPConstants {
// 公用头部
public static byte[] HEADER = new byte[]{7, 7, 7, 7, 7, 7, 7, 7};
// 服务器固化UDP接收端口
public static int PORT_SERVER = 30201;
// 客户端回送端口
public static int PORT_CLIENT_RESPONSE = 30202;
}
package com.zcw.channel.server.handle;
import com.zcw.channel.clink.utils.CloseUtils;
import java.io.*;
import java.net.Socket;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
/**
* @ClassName : ClientHandler
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:56
*/
public class ClientHandler {
private final Socket socket;
private final ClientReadHandler readHandler;
private final ClientWriteHandler writeHandler;
private final CloseNotify closeNotify;
public ClientHandler(Socket socket, CloseNotify closeNotify) throws IOException {
this.socket = socket;
this.readHandler = new ClientReadHandler(socket.getInputStream());
this.writeHandler = new ClientWriteHandler(socket.getOutputStream());
this.closeNotify = closeNotify;
System.out.println("新客户端连接：" + socket.getInetAddress() +
" P:" + socket.getPort());
}
public void exit() {
readHandler.exit();
writeHandler.exit();
CloseUtils.close(socket);
System.out.println("客户端已退出：" + socket.getInetAddress() +
" P:" + socket.getPort());
}
public void send(String str) {
writeHandler.send(str);
}
public void readToPrint() {
readHandler.start();
}
private void exitBySelf() {
exit();
closeNotify.onSelfClosed(this);
}
public interface CloseNotify {
void onSelfClosed(ClientHandler handler);
}
class ClientReadHandler extends Thread {
private boolean done = false;
private final InputStream inputStream;
ClientReadHandler(InputStream inputStream) {
this.inputStream = inputStream;
}
@Override
public void run() {
super.run();
try {
// 得到输入流，用于接收数据
BufferedReader socketInput = new BufferedReader(new InputStreamReader(inputStream));
do {
// 客户端拿到一条数据
String str = socketInput.readLine();
if (str == null) {
System.out.println("客户端已无法读取数据！");
// 退出当前客户端
ClientHandler.this.exitBySelf();
break;
}
// 打印到屏幕
System.out.println(str);
} while (!done);
} catch (Exception e) {
if (!done) {
System.out.println("连接异常断开");
ClientHandler.this.exitBySelf();
}
} finally {
// 连接关闭
CloseUtils.close(inputStream);
}
}
void exit() {
done = true;
CloseUtils.close(inputStream);
}
}
class ClientWriteHandler {
private boolean done = false;
private final PrintStream printStream;
private final ExecutorService executorService;
ClientWriteHandler(OutputStream outputStream) {
this.printStream = new PrintStream(outputStream);
this.executorService = Executors.newSingleThreadExecutor();
}
void exit() {
done = true;
CloseUtils.close(printStream);
executorService.shutdownNow();
}
void send(String str) {
executorService.execute(new WriteRunnable(str));
}
class WriteRunnable implements Runnable {
private final String msg;
WriteRunnable(String msg) {
this.msg = msg;
}
@Override
public void run() {
if (ClientWriteHandler.this.done) {
return;
}
try {
ClientWriteHandler.this.printStream.println(msg);
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
}
package com.zcw.channel.server;
import com.zcw.channel.constants.TCPConstants;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
/**
* @ClassName : Server
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:54
*/
public class Server {
public static void main(String[] args) throws IOException {
TCPServer tcpServer = new TCPServer(TCPConstants.PORT_SERVER);
boolean isSucceed = tcpServer.start();
if (!isSucceed) {
System.out.println("Start TCP server failed!");
return;
}
UDPProvider.start(TCPConstants.PORT_SERVER);
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
String str;
do {
str = bufferedReader.readLine();
tcpServer.broadcast(str);
} while (!"00bye00".equalsIgnoreCase(str));
UDPProvider.stop();
tcpServer.stop();
}
}
package com.zcw.channel.server;
import com.zcw.channel.server.handle.ClientHandler;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.List;
/**
* @ClassName : TCPServer
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:55
*/
public class TCPServer {
private final int port;
private ClientListener mListener;
private List<ClientHandler> clientHandlerList = new ArrayList<ClientHandler>();
public TCPServer(int port) {
this.port = port;
}
public boolean start() {
try {
ClientListener listener = new ClientListener(port);
mListener = listener;
listener.start();
} catch (IOException e) {
e.printStackTrace();
return false;
}
return true;
}
public void stop() {
if (mListener != null) {
mListener.exit();
}
for (ClientHandler clientHandler : clientHandlerList) {
clientHandler.exit();
}
clientHandlerList.clear();
}
public void broadcast(String str) {
for (ClientHandler clientHandler : clientHandlerList) {
clientHandler.send(str);
}
}
private class ClientListener extends Thread {
private ServerSocket server;
private boolean done = false;
private ClientListener(int port) throws IOException {
server = new ServerSocket(port);
System.out.println("服务器信息：" + server.getInetAddress() + " P:" + server.getLocalPort());
}
@Override
public void run() {
super.run();
System.out.println("服务器准备就绪～");
// 等待客户端连接
do {
// 得到客户端
Socket client;
try {
client = server.accept();
} catch (IOException e) {
continue;
}
try {
// 客户端构建异步线程
ClientHandler clientHandler = new ClientHandler(client,
handler -> clientHandlerList.remove(handler));
// 读取数据并打印
clientHandler.readToPrint();
clientHandlerList.add(clientHandler);
} catch (IOException e) {
e.printStackTrace();
System.out.println("客户端连接异常：" + e.getMessage());
}
} while (!done);
System.out.println("服务器已关闭！");
}
void exit() {
done = true;
try {
server.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
package com.zcw.channel.server;
import com.zcw.channel.clink.utils.ByteUtils;
import com.zcw.channel.constants.UDPConstants;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.nio.ByteBuffer;
import java.util.UUID;
/**
* @ClassName : UDPProvider
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:55
*/
public class UDPProvider {
private static Provider PROVIDER_INSTANCE;
static void start(int port) {
stop();
String sn = UUID.randomUUID().toString();
Provider provider = new Provider(sn, port);
provider.start();
PROVIDER_INSTANCE = provider;
}
static void stop() {
if (PROVIDER_INSTANCE != null) {
PROVIDER_INSTANCE.exit();
PROVIDER_INSTANCE = null;
}
}
private static class Provider extends Thread {
private final byte[] sn;
private final int port;
private boolean done = false;
private DatagramSocket ds = null;
// 存储消息的Buffer
final byte[] buffer = new byte[128];
Provider(String sn, int port) {
super();
this.sn = sn.getBytes();
this.port = port;
}
@Override
public void run() {
super.run();
System.out.println("UDPProvider Started.");
try {
// 监听20000 端口
ds = new DatagramSocket(UDPConstants.PORT_SERVER);
// 接收消息的Packet
DatagramPacket receivePack = new DatagramPacket(buffer, buffer.length);
while (!done) {
// 接收
ds.receive(receivePack);
// 打印接收到的信息与发送者的信息
// 发送者的IP地址
String clientIp = receivePack.getAddress().getHostAddress();
int clientPort = receivePack.getPort();
int clientDataLen = receivePack.getLength();
byte[] clientData = receivePack.getData();
boolean isValid = clientDataLen >= (UDPConstants.HEADER.length + 2 + 4)
&& ByteUtils.startsWith(clientData, UDPConstants.HEADER);
System.out.println("UDPProvider receive form ip:" + clientIp
+ "\tport:" + clientPort + "\tdataValid:" + isValid);
if (!isValid) {
// 无效继续
continue;
}
// 解析命令与回送端口
int index = UDPConstants.HEADER.length;
short cmd = (short) ((clientData[index++] << 8) | (clientData[index++] & 0xff));
int responsePort = (((clientData[index++]) << 24) |
((clientData[index++] & 0xff) << 16) |
((clientData[index++] & 0xff) << 8) |
((clientData[index] & 0xff)));
// 判断合法性
if (cmd == 1 && responsePort > 0) {
// 构建一份回送数据
ByteBuffer byteBuffer = ByteBuffer.wrap(buffer);
byteBuffer.put(UDPConstants.HEADER);
byteBuffer.putShort((short) 2);
byteBuffer.putInt(port);
byteBuffer.put(sn);
int len = byteBuffer.position();
// 直接根据发送者构建一份回送信息
DatagramPacket responsePacket = new DatagramPacket(buffer,
len,
receivePack.getAddress(),
responsePort);
ds.send(responsePacket);
System.out.println("UDPProvider response to:" + clientIp + "\tport:" + responsePort + "\tdataLen:" + len);
} else {
System.out.println("UDPProvider receive cmd nonsupport; cmd:" + cmd + "\tport:" + port);
}
}
} catch (Exception ignored) {
} finally {
close();
}
// 完成
System.out.println("UDPProvider Finished.");
}
private void close() {
if (ds != null) {
ds.close();
ds = null;
}
}
/**
* 提供结束
*/
void exit() {
done = true;
close();
}
}
}
测试：数据发送与接收并行
TCP-Channel
package com.zcw.tcp.ckink.utils;
/**
* @ClassName : ByteUtils
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:26
*/
public class ByteUtils {
/**
* Does this byte array begin with match array content?
*
* @param source Byte array to examine
* @param match Byte array to locate in source
* @return true If the starting bytes are equal
*/
public static boolean startsWith(byte[] source, byte[] match) {
return startsWith(source, 0, match);
}
/**
* Does this byte array begin with match array content?
*
* @param source Byte array to examine
* @param offset An offset into the source array
* @param match Byte array to locate in source
* @return true If the starting bytes are equal
*/
public static boolean startsWith(byte[] source, int offset, byte[] match) {
if (match.length > (source.length - offset)) {
return false;
}
for (int i = 0; i < match.length; i++) {
if (source[offset + i] != match[i]) {
return false;
}
}
return true;
}
/**
* Does the source array equal the match array?
*
* @param source Byte array to examine
* @param match Byte array to locate in source
* @return true If the two arrays are equal
*/
public static boolean equals(byte[] source, byte[] match) {
if (match.length != source.length) {
return false;
}
return startsWith(source, 0, match);
}
/**
* Copies bytes from the source byte array to the destination array
*
* @param source The source array
* @param srcBegin Index of the first source byte to copy
* @param srcEnd Index after the last source byte to copy
* @param destination The destination array
* @param dstBegin The starting offset in the destination array
*/
public static void getBytes(byte[] source, int srcBegin, int srcEnd, byte[] destination,
int dstBegin) {
System.arraycopy(source, srcBegin, destination, dstBegin, srcEnd - srcBegin);
}
/**
* Return a new byte array containing a sub-portion of the source array
*
* @param srcBegin The beginning index (inclusive)
* @param srcEnd The ending index (exclusive)
* @return The new, populated byte array
*/
public static byte[] subbytes(byte[] source, int srcBegin, int srcEnd) {
byte destination[];
destination = new byte[srcEnd - srcBegin];
getBytes(source, srcBegin, srcEnd, destination, 0);
return destination;
}
/**
* Return a new byte array containing a sub-portion of the source array
*
* @param srcBegin The beginning index (inclusive)
* @return The new, populated byte array
*/
public static byte[] subbytes(byte[] source, int srcBegin) {
return subbytes(source, srcBegin, source.length);
}
}
package com.zcw.tcp.ckink;
/**
* @ClassName : Clink
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:25
*/
public class Clink {
}
package com.zcw.tcp.client.bean;
/**
* @ClassName : ServerInfo
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:24
*/
public class ServerInfo {
private String sn;
private int port;
private String address;
public ServerInfo(int port, String ip, String sn) {
this.port = port;
this.address = ip;
this.sn = sn;
}
public String getSn() {
return sn;
}
public void setSn(String sn) {
this.sn = sn;
}
public int getPort() {
return port;
}
public void setPort(int port) {
this.port = port;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
@Override
public String toString() {
return "ServerInfo{" +
"sn='" + sn + '\'' +
", port=" + port +
", address='" + address + '\'' +
'}';
}
}
package com.zcw.tcp.client;
import com.zcw.tcp.client.bean.ServerInfo;
import java.io.IOException;
/**
* @ClassName : Client
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:23
*/
public class Client {
public static void main(String[] args) {
ServerInfo info = UDPSearcher.searchServer(10000);
System.out.println("Server:" + info);
if (info != null) {
try {
TCPClient.linkWith(info);
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
package com.zcw.tcp.client;
import com.zcw.tcp.client.bean.ServerInfo;
import java.io.*;
import java.net.Inet4Address;
import java.net.InetSocketAddress;
import java.net.Socket;
/**
* @ClassName : TCPClient
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:23
*/
public class TCPClient {
public static void linkWith(ServerInfo info) throws IOException {
Socket socket = new Socket();
// 超时时间
socket.setSoTimeout(3000);
// 连接本地，端口2000；超时时间3000ms
socket.connect(new InetSocketAddress(Inet4Address.getByName(info.getAddress()), info.getPort()), 3000);
System.out.println("已发起服务器连接，并进入后续流程～");
System.out.println("客户端信息：" + socket.getLocalAddress() + " P:" + socket.getLocalPort());
System.out.println("服务器信息：" + socket.getInetAddress() + " P:" + socket.getPort());
try {
// 发送接收数据
todo(socket);
} catch (Exception e) {
System.out.println("异常关闭");
}
// 释放资源
socket.close();
System.out.println("客户端已退出～");
}
private static void todo(Socket client) throws IOException {
// 构建键盘输入流
InputStream in = System.in;
BufferedReader input = new BufferedReader(new InputStreamReader(in));
// 得到Socket输出流，并转换为打印流
OutputStream outputStream = client.getOutputStream();
PrintStream socketPrintStream = new PrintStream(outputStream);
// 得到Socket输入流，并转换为BufferedReader
InputStream inputStream = client.getInputStream();
BufferedReader socketBufferedReader = new BufferedReader(new InputStreamReader(inputStream));
boolean flag = true;
do {
// 键盘读取一行
String str = input.readLine();
// 发送到服务器
socketPrintStream.println(str);
// 从服务器读取一行
String echo = socketBufferedReader.readLine();
if ("bye".equalsIgnoreCase(echo)) {
flag = false;
} else {
System.out.println(echo);
}
} while (flag);
// 资源释放
socketPrintStream.close();
socketBufferedReader.close();
}
}
package com.zcw.tcp.client;
import com.zcw.tcp.ckink.utils.ByteUtils;
import com.zcw.tcp.client.bean.ServerInfo;
import com.zcw.tcp.constants.UDPConstants;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
/**
* @ClassName : UDPSearcher
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:24
*/
public class UDPSearcher {
private static final int LISTEN_PORT = UDPConstants.PORT_CLIENT_RESPONSE;
public static ServerInfo searchServer(int timeout) {
System.out.println("UDPSearcher Started.");
// 成功收到回送的栅栏
CountDownLatch receiveLatch = new CountDownLatch(1);
Listener listener = null;
try {
listener = listen(receiveLatch);
sendBroadcast();
receiveLatch.await(timeout, TimeUnit.MILLISECONDS);
} catch (Exception e) {
e.printStackTrace();
}
// 完成
System.out.println("UDPSearcher Finished.");
if (listener == null) {
return null;
}
List<ServerInfo> devices = listener.getServerAndClose();
if (devices.size() > 0) {
return devices.get(0);
}
return null;
}
private static Listener listen(CountDownLatch receiveLatch) throws InterruptedException {
System.out.println("UDPSearcher start listen.");
CountDownLatch startDownLatch = new CountDownLatch(1);
Listener listener = new Listener(LISTEN_PORT, startDownLatch, receiveLatch);
listener.start();
startDownLatch.await();
return listener;
}
private static void sendBroadcast() throws IOException {
System.out.println("UDPSearcher sendBroadcast started.");
// 作为搜索方，让系统自动分配端口
DatagramSocket ds = new DatagramSocket();
// 构建一份请求数据
ByteBuffer byteBuffer = ByteBuffer.allocate(128);
// 头部
byteBuffer.put(UDPConstants.HEADER);
// CMD命名
byteBuffer.putShort((short) 1);
// 回送端口信息
byteBuffer.putInt(LISTEN_PORT);
// 直接构建packet
DatagramPacket requestPacket = new DatagramPacket(byteBuffer.array(),
byteBuffer.position() + 1);
// 广播地址
requestPacket.setAddress(InetAddress.getByName("255.255.255.255"));
// 设置服务器端口
requestPacket.setPort(UDPConstants.PORT_SERVER);
// 发送
ds.send(requestPacket);
ds.close();
// 完成
System.out.println("UDPSearcher sendBroadcast finished.");
}
private static class Listener extends Thread {
private final int listenPort;
private final CountDownLatch startDownLatch;
private final CountDownLatch receiveDownLatch;
private final List<ServerInfo> serverInfoList = new ArrayList<ServerInfo>();
private final byte[] buffer = new byte[128];
private final int minLen = UDPConstants.HEADER.length + 2 + 4;
private boolean done = false;
private DatagramSocket ds = null;
private Listener(int listenPort, CountDownLatch startDownLatch, CountDownLatch receiveDownLatch) {
super();
this.listenPort = listenPort;
this.startDownLatch = startDownLatch;
this.receiveDownLatch = receiveDownLatch;
}
@Override
public void run() {
super.run();
// 通知已启动
startDownLatch.countDown();
try {
// 监听回送端口
ds = new DatagramSocket(listenPort);
// 构建接收实体
DatagramPacket receivePack = new DatagramPacket(buffer, buffer.length);
while (!done) {
// 接收
ds.receive(receivePack);
// 打印接收到的信息与发送者的信息
// 发送者的IP地址
String ip = receivePack.getAddress().getHostAddress();
int port = receivePack.getPort();
int dataLen = receivePack.getLength();
byte[] data = receivePack.getData();
boolean isValid = dataLen >= minLen
&& ByteUtils.startsWith(data, UDPConstants.HEADER);
System.out.println("UDPSearcher receive form ip:" + ip
+ "\tport:" + port + "\tdataValid:" + isValid);
if (!isValid) {
// 无效继续
continue;
}
ByteBuffer byteBuffer = ByteBuffer.wrap(buffer, UDPConstants.HEADER.length, dataLen);
final short cmd = byteBuffer.getShort();
final int serverPort = byteBuffer.getInt();
if (cmd != 2 || serverPort <= 0) {
System.out.println("UDPSearcher receive cmd:" + cmd + "\tserverPort:" + serverPort);
continue;
}
String sn = new String(buffer, minLen, dataLen - minLen);
ServerInfo info = new ServerInfo(serverPort, ip, sn);
serverInfoList.add(info);
// 成功接收到一份
receiveDownLatch.countDown();
}
} catch (Exception ignored) {
} finally {
close();
}
System.out.println("UDPSearcher listener finished.");
}
private void close() {
if (ds != null) {
ds.close();
ds = null;
}
}
List<ServerInfo> getServerAndClose() {
done = true;
close();
return serverInfoList;
}
}
}
package com.zcw.tcp.constants;
/**
* @ClassName : TCPConstants
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:26
*/
public class TCPConstants {
// 服务器固化UDP接收端口
public static int PORT_SERVER = 30401;
}
package com.zcw.tcp.constants;
/**
* @ClassName : UDPConstants
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:27
*/
public class UDPConstants {
// 公用头部
public static byte[] HEADER = new byte[]{7, 7, 7, 7, 7, 7, 7, 7};
// 服务器固化UDP接收端口
public static int PORT_SERVER = 30201;
// 客户端回送端口
public static int PORT_CLIENT_RESPONSE = 30202;
}
package com.zcw.tcp.server;
import com.zcw.tcp.constants.TCPConstants;
import java.io.IOException;
/**
* @ClassName : Server
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:27
*/
public class Server {
public static void main(String[] args) {
TCPServer tcpServer = new TCPServer(TCPConstants.PORT_SERVER);
boolean isSucceed = tcpServer.start();
if (!isSucceed) {
System.out.println("Start TCP server failed!");
return;
}
UDPProvider.start(TCPConstants.PORT_SERVER);
try {
//noinspection ResultOfMethodCallIgnored
System.in.read();
} catch (IOException e) {
e.printStackTrace();
}
UDPProvider.stop();
tcpServer.stop();
}
}
package com.zcw.tcp.server;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;
/**
* @ClassName : TCPServer
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:28
*/
public class TCPServer {
private final int port;
private ClientListener mListener;
public TCPServer(int port) {
this.port = port;
}
public boolean start() {
try {
ClientListener listener = new ClientListener(port);
mListener = listener;
listener.start();
} catch (IOException e) {
e.printStackTrace();
return false;
}
return true;
}
public void stop() {
if (mListener != null) {
mListener.exit();
}
}
private static class ClientListener extends Thread {
private ServerSocket server;
private boolean done = false;
private ClientListener(int port) throws IOException {
server = new ServerSocket(port);
System.out.println("服务器信息：" + server.getInetAddress() + " P:" + server.getLocalPort());
}
@Override
public void run() {
super.run();
System.out.println("服务器准备就绪～");
// 等待客户端连接
do {
// 得到客户端
Socket client;
try {
client = server.accept();
} catch (IOException e) {
continue;
}
// 客户端构建异步线程
ClientHandler clientHandler = new ClientHandler(client);
// 启动线程
clientHandler.start();
} while (!done);
System.out.println("服务器已关闭！");
}
void exit() {
done = true;
try {
server.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
/**
* 客户端消息处理
*/
private static class ClientHandler extends Thread {
private Socket socket;
private boolean flag = true;
ClientHandler(Socket socket) {
this.socket = socket;
}
@Override
public void run() {
super.run();
System.out.println("新客户端连接：" + socket.getInetAddress() +
" P:" + socket.getPort());
try {
// 得到打印流，用于数据输出；服务器回送数据使用
PrintStream socketOutput = new PrintStream(socket.getOutputStream());
// 得到输入流，用于接收数据
BufferedReader socketInput = new BufferedReader(new InputStreamReader(
socket.getInputStream()));
do {
// 客户端拿到一条数据
String str = socketInput.readLine();
if ("bye".equalsIgnoreCase(str)) {
flag = false;
// 回送
socketOutput.println("bye");
} else {
// 打印到屏幕。并回送数据长度
System.out.println(str);
socketOutput.println("回送：" + str.length());
}
} while (flag);
socketInput.close();
socketOutput.close();
} catch (Exception e) {
System.out.println("连接异常断开");
} finally {
// 连接关闭
try {
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
System.out.println("客户端已退出：" + socket.getInetAddress() +
" P:" + socket.getPort());
}
}
}
package com.zcw.tcp.server;
import com.zcw.tcp.ckink.utils.ByteUtils;
import com.zcw.tcp.constants.UDPConstants;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.nio.ByteBuffer;
import java.util.UUID;
/**
* @ClassName : UDPProvider
* @Description :
* @Author : Zhaocunwei
* @Date: 2020-07-08 10:28
*/
public class UDPProvider {
private static Provider PROVIDER_INSTANCE;
static void start(int port) {
stop();
String sn = UUID.randomUUID().toString();
Provider provider = new Provider(sn, port);
provider.start();
PROVIDER_INSTANCE = provider;
}
static void stop() {
if (PROVIDER_INSTANCE != null) {
PROVIDER_INSTANCE.exit();
PROVIDER_INSTANCE = null;
}
}
private static class Provider extends Thread {
private final byte[] sn;
private final int port;
private boolean done = false;
private DatagramSocket ds = null;
// 存储消息的Buffer
final byte[] buffer = new byte[128];
Provider(String sn, int port) {
super();
this.sn = sn.getBytes();
this.port = port;
}
@Override
public void run() {
super.run();
System.out.println("UDPProvider Started.");
try {
// 监听20000 端口
ds = new DatagramSocket(UDPConstants.PORT_SERVER);
// 接收消息的Packet
DatagramPacket receivePack = new DatagramPacket(buffer, buffer.length);
while (!done) {
// 接收
ds.receive(receivePack);
// 打印接收到的信息与发送者的信息
// 发送者的IP地址
String clientIp = receivePack.getAddress().getHostAddress();
int clientPort = receivePack.getPort();
int clientDataLen = receivePack.getLength();
byte[] clientData = receivePack.getData();
boolean isValid = clientDataLen >= (UDPConstants.HEADER.length + 2 + 4)
&& ByteUtils.startsWith(clientData, UDPConstants.HEADER);
System.out.println("UDPProvider receive form ip:" + clientIp
+ "\tport:" + clientPort + "\tdataValid:" + isValid);
if (!isValid) {
// 无效继续
continue;
}
// 解析命令与回送端口
int index = UDPConstants.HEADER.length;
short cmd = (short) ((clientData[index++] << 8) | (clientData[index++] & 0xff));
int responsePort = (((clientData[index++]) << 24) |
((clientData[index++] & 0xff) << 16) |
((clientData[index++] & 0xff) << 8) |
((clientData[index] & 0xff)));
// 判断合法性
if (cmd == 1 && responsePort > 0) {
// 构建一份回送数据
ByteBuffer byteBuffer = ByteBuffer.wrap(buffer);
byteBuffer.put(UDPConstants.HEADER);
byteBuffer.putShort((short) 2);
byteBuffer.putInt(port);
byteBuffer.put(sn);
int len = byteBuffer.position();
// 直接根据发送者构建一份回送信息
DatagramPacket responsePacket = new DatagramPacket(buffer,
len,
receivePack.getAddress(),
responsePort);
ds.send(responsePacket);
System.out.println("UDPProvider response to:" + clientIp + "\tport:" + responsePort + "\tdataLen:" + len);
} else {
System.out.println("UDPProvider receive cmd nonsupport; cmd:" + cmd + "\tport:" + port);
}
}
} catch (Exception ignored) {
} finally {
close();
}
// 完成
System.out.println("UDPProvider Finished.");
}
private void close() {
if (ds != null) {
ds.close();
ds = null;
}
}
/**
* 提供结束
*/
void exit() {
done = true;
close();
}
}
}
- 启动Server
- 启动Client
- 发送信息
