视频:【零基础 快速学Java】韩顺平 零基础30天学会Java
SocketTCP01Server.java
package java学习.网络编程.TCP;
import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;
public class SocketTCP01Server {
public static void main(String[] args) throws IOException {
// 编写一个服务器端
// 服务器端在9999端口监听
// 在本机 的 9999 端口监听, 等待连接
// 要求在本机没有其它服务在监听 9999
// 这个 ServerSocket 可以通过 accept() 返回多个 Socket[多个客户端连接服务器的并发]
ServerSocket serverSocket = new ServerSocket(9999);
System.out.println( "服务端,在9999端口监听,等待连接..." );
// 当没有客户端连接 9999 端口时,程序会 阻塞, 等待连接
// 如果有客户端连接,则会返回 Socket 对象,程序继续
Socket socket = serverSocket.accept();
System.out.println( "服务端 socket=" + socket.getClass() );
// 服务器端接收到客户端发送的信息,输出,并退出
// 通过 socket.getInputStream() 读取客户端写入到数据通道的数据, 显示
InputStream inputStream = socket.getInputStream();
// IO 读取
byte[] buf = new byte[1024];
int readLen = 0;
while ( (readLen=inputStream.read(buf))!=-1 ) {
//根据读取到的实际长度,显示内容.
System.out.println( new String(buf, 0, readLen) );
}
// 关闭流和 socket
inputStream.close();
socket.close();
serverSocket.close();
}
}
SocketTCP01Client.java
package java学习.网络编程.TCP;
import java.io.IOException;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
public class SocketTCP01Client {
public static void main(String[] args) throws IOException {
// 连接服务端 (ip , 端口)
// 连接本机的 9999 端口, 如果连接成功,返回 Socket 对象
Socket socket = new Socket(InetAddress.getLocalHost(), 9999);
System.out.println( "客户端 socket=" + socket.getClass() );
// 连接上后,生成 Socket, 通过 socket.getOutputStream()
// 得到 和 socket 对象关联的输出流对象
OutputStream outputStream = socket.getOutputStream();
// 通过输出流,写入数据到 数据通道
outputStream.write("hello server".getBytes());
// 关闭流对象和 socket, 必须关闭
outputStream.close();
socket.close();
System.out.println( "客户端退出" );
}
}
SocketTCP02Server
package java学习.网络编程.TCP;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
public class SocketTCP02Server {
public static void main(String[] args) throws IOException {
ServerSocket serverSocket = new ServerSocket(9999);
System.out.println( "服务端在9999端口监听..." );
Socket socket = serverSocket.accept();
System.out.println( "服务端 socket=" + socket.getClass() );
// 输入流,读取
InputStream inputStream = socket.getInputStream();
byte[] buf = new byte[1024];
int readLen = 0;
while ( (readLen=inputStream.read(buf))!=-1 ) {
System.out.println( new String(buf, 0, readLen) );
}
// 输出流,输出
OutputStream outputStream = socket.getOutputStream();
outputStream.write( "hello client".getBytes() );
// 输出结束标志
socket.shutdownOutput();
// 关闭流
outputStream.close();
inputStream.close();
socket.close();
serverSocket.close();
}
}
SocketTCP02Client
package java学习.网络编程.TCP;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
public class SocketTCP02Client {
public static void main(String[] args) throws IOException {
Socket socket = new Socket(InetAddress.getLocalHost(), 9999);
System.out.println( "客户端 socket=" + socket.getClass() );
OutputStream outputStream = socket.getOutputStream();
outputStream.write("hello server".getBytes());
// 输出结束标志
socket.shutdownOutput();
InputStream inputStream = socket.getInputStream();
int readLen = 0;
byte[] buf = new byte[1024];
while ( (readLen=inputStream.read(buf))!=-1 ) {
System.out.println( new String(buf, 0, readLen) );
}
inputStream.close();
outputStream.close();
socket.close();
System.out.println("客户端退出...");
}
}
SocketTCP03Server
package java学习.网络编程.TCP;
import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
public class SocketTCP03Server {
public static void main(String[] args) throws IOException {
ServerSocket serverSocket = new ServerSocket(9999);
System.out.println( "服务端在9999端口监听" );
Socket accept = serverSocket.accept();
InputStream inputStream = accept.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
String s = bufferedReader.readLine();
System.out.println(s);
// 输出
OutputStream outputStream = accept.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream));
bufferedWriter.write("hello client 字符流");
// 插入一个换行符,表示回复内容的结束
bufferedWriter.newLine();
bufferedWriter.flush();
// 关闭
bufferedWriter.close();
bufferedReader.close();
accept.close();
serverSocket.close();
}
}
SocketTCP03Client
package java学习.网络编程.TCP;
import java.io.*;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
public class SocketTCP03Client {
public static void main(String[] args) throws IOException {
Socket socket = new Socket(InetAddress.getLocalHost(), 9999);
OutputStream outputStream = socket.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream));
bufferedWriter.write("hello server 字符流");
// 插入一个换行符,表示写入的内容结束, 注意,要求对方使用 readLine()!!!!
bufferedWriter.newLine();
bufferedWriter.flush();
InputStream inputStream = socket.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
String line = bufferedReader.readLine();
System.out.println(line);
// 关闭
bufferedReader.close();
bufferedWriter.close();
socket.close();
System.out.println("客户端退出...");
}
}
编写一个服务端,和一个客户端
服务器端在8888端口监听
服务器端接收到客户端发送的图片,保存到src下,发送"收到图片”再退出
客户端接收到服务端发送的“收到图片”,再退出
该程序要求使用StreamUtils.java,我们直接使用
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
/**
* 此类用于演示关于流的读写方法
*
*/
public class StreamUtils {
/**
* 功能:将输入流转换成byte[], 即可以把文件的内容读入到byte[]
* @param is
* @return
* @throws Exception
*/
public static byte[] streamToByteArray(InputStream is) throws Exception{
ByteArrayOutputStream bos = new ByteArrayOutputStream();//创建输出流对象
byte[] b = new byte[1024];//字节数组
int len;
while((len=is.read(b))!=-1){//循环读取
bos.write(b, 0, len);//把读取到的数据,写入bos
}
byte[] array = bos.toByteArray();//然后将bos 转成字节数组
bos.close();
return array;
}
/**
* 功能:将InputStream转换成String
* @param is
* @return
* @throws Exception
*/
public static String streamToString(InputStream is) throws Exception{
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
StringBuilder builder= new StringBuilder();
String line;
while((line=reader.readLine())!=null){
builder.append(line+"\r\n");
}
return builder.toString();
}
}
TCPFileUploadServer.java
TCPFileUploadClient.java
package java学习.网络编程.TCP;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
public class TCPFileUploadServer {
public static void main(String[] args) throws IOException {
// 服务器在8888端口监听
ServerSocket serverSocket = new ServerSocket(8888);
System.out.println("服务器在8888端口监听");
// 等待连接
Socket socket = serverSocket.accept();
System.out.println( "服务端 socket=" + socket.getClass() );
}
}
package java学习.网络编程.TCP;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
public class TCPFileUploadClient {
public static void main(String[] args) throws Exception {
// 连接服务端的8888端口
Socket socket = new Socket(InetAddress.getLocalHost(), 8888);
// 文件的路径
String filePath = "e:\\bg.jpg";
// 输入流,读取图片
BufferedInputStream bis = new BufferedInputStream(new FileInputStream(filePath));
// 调用StreamUtils.streamToByteArray读取图片,获取二进制数组
byte[] bytes = StreamUtils.streamToByteArray(bis);
// 通过 socket 获取到输出流, 将 bytes 数据发送给服务端
BufferedOutputStream bos = new BufferedOutputStream(socket.getOutputStream());
bos.write(bytes);//将文件对应的字节数组的内容,写入到数据通道
socket.shutdownOutput();//设置写入数据的结束标记
// 关闭流
bos.close();
bis.close();
socket.close();
}
}
package java学习.网络编程.TCP;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
public class TCPFileUploadServer {
public static void main(String[] args) throws Exception {
// 服务器在8888端口监听
ServerSocket serverSocket = new ServerSocket(8888);
System.out.println("服务器在8888端口监听");
// 等待连接
Socket socket = serverSocket.accept();
System.out.println( "服务端 socket=" + socket.getClass() );
// 输入流,读取流中数据
BufferedInputStream bis = new BufferedInputStream(socket.getInputStream());
// 调用StreamUtils.streamToByteArray将输入流中的数据读到数组中
byte[] bytes = StreamUtils.streamToByteArray(bis);
// 将得到 bytes 数组,写入到指定的路径,就得到一个文件了
// 路径
String filePath = "src\\bg.jpg";
// 输出流
BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(filePath));
bos.write(bytes);
// 关闭
bos.close();
bis.close();
socket.close();
serverSocket.close();
}
}
package java学习.网络编程.TCP;
import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
public class TCPFileUploadServer {
public static void main(String[] args) throws Exception {
// 服务器在8888端口监听
ServerSocket serverSocket = new ServerSocket(8888);
System.out.println("服务器在8888端口监听");
// 等待连接
Socket socket = serverSocket.accept();
System.out.println( "服务端 socket=" + socket.getClass() );
// 输入流,读取流中数据
BufferedInputStream bis = new BufferedInputStream(socket.getInputStream());
// 调用StreamUtils.streamToByteArray将输入流中的数据读到数组中
byte[] bytes = StreamUtils.streamToByteArray(bis);
// 将得到 bytes 数组,写入到指定的路径,就得到一个文件了
// 路径
String filePath = "src\\bg.jpg";
// 输出流
BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(filePath));
bos.write(bytes);
// 回复信息
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
bw.write("收到图片");
bw.flush();//把内容刷新到数据通道
// 客户端以字节流读取信息,可以设置如下结束标记
socket.shutdownOutput();//设置写入结束标记
// 关闭
bw.close();
bos.close();
bis.close();
socket.close();
serverSocket.close();
}
}
package java学习.网络编程.TCP;
import java.io.*;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
public class TCPFileUploadClient {
public static void main(String[] args) throws Exception {
// 连接服务端的8888端口
Socket socket = new Socket(InetAddress.getLocalHost(), 8888);
// 文件的路径
String filePath = "e:\\bg.jpg";
// 输入流,读取图片
BufferedInputStream bis = new BufferedInputStream(new FileInputStream(filePath));
// 调用StreamUtils.streamToByteArray读取图片,获取二进制数组
byte[] bytes = StreamUtils.streamToByteArray(bis);
// 通过 socket 获取到输出流, 将 bytes 数据发送给服务端
BufferedOutputStream bos = new BufferedOutputStream(socket.getOutputStream());
bos.write(bytes);//将文件对应的字节数组的内容,写入到数据通道
socket.shutdownOutput();//设置写入数据的结束标记
// 接收服务端回复的信息
InputStream inputStream = socket.getInputStream();
// 使用 StreamUtils 的方法,直接将 inputStream 读取到的内容 转成字符串
String s = StreamUtils.streamToString(inputStream);
System.out.println(s);
// 关闭流
inputStream.close();
bos.close();
bis.close();
socket.close();
}
}
说明:
(1) Listening表示某个端口在监听
(2)如果有一个外部程序(客户端)连接到该端口,就会显示一条连接信息.
(3)可以输入ctrl +c退出指令
netstat -an
netstat -an | more
netstat -anb
当客户端连接到服务端后,实际上客户端也是通过一个端口和服务端进行通讯的,这个端口是TCP/IP来分配的,是不确定的,是随机的.