名称∶Minicat
Minicat要做的事情∶作为一个服务器软件提供服务的，也即我们可以通过浏览器客户端发送http请求，Minicat可以接收到请求进行处理，处理之后的结果可以返回浏览器客户端。
1）提供服务，接收请求（Socket通信）
2）请求信息封装成Request对象（Response对象）
3）客户端请求资源，资源分为静态资源（html）和动态资源（Servlet ）
4）资源返回给客户端浏览器
我们递进式完成以上需求，提出V1.0、V2.0、V3.0版本的需求
V1.0需求∶浏览器请求nttp/localhost8080返回一个固定的字符串到页面"Hello Minicat!"
V2.0需求∶封装Request和Response对象，返回html静态资源文件
V3.0需求∶可以请求动态资源（Servlet）完成上述三个版本后，我们的代码如下
- Bootstrap 启动类
package com.study.server;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.*;
/**
* @author Qi XueSong
* Minicat 的主类
*/
public class Bootstrap {
/**定义socket监听的端口号*/
private int port = 8080;
public int getPort() {
return port;
}
public void setPort(int port) {
this.port = port;
}
Map map = new HashMap<>();
private void start() throws Exception {
// 加载解析相关的配置，web.xml
loadServlet();
int corePoolSize = 10;
int maximumPoolSize = 50;
long keepAliveTime = 100L;
TimeUnit unit = TimeUnit.SECONDS;
BlockingQueue workQueue = new ArrayBlockingQueue<>(50);
ThreadFactory threadFactory = Executors.defaultThreadFactory();
RejectedExecutionHandler handler = new ThreadPoolExecutor.AbortPolicy();
ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(
corePoolSize,
maximumPoolSize,
keepAliveTime,
unit,
workQueue,
threadFactory,
handler
);
ServerSocket serverSocket = new ServerSocket(port);
System.out.println("Minicat start on port：" + port);
/*
完成Minicat 1.0版本
需求：浏览器请求http://localhost:8080,返回一个固定的字符串到页面"Hello Minicat!"
*/
/*while (true){
Socket socket = serverSocket.accept();
// 有了socket , 接收到请求，获取输出流
OutputStream outputStream = socket.getOutputStream();
String data = "Hello Minicat!";
String responseText = HttpProtocolUtil.getHttpHeader200(data.getBytes().length)+data;
outputStream.write(responseText.getBytes());
socket.close();
}*/
/**
* 完成Minicat 2.0版本
* 需求：封装Request和Response对象，返回html静态资源文件
*/
/*while (true){
Socket socket = serverSocket.accept();
InputStream inputStream = socket.getInputStream();
// 封装Request对象和Response对象
Request request = new Request(inputStream);
Response response = new Response(socket.getOutputStream());
String url = request.getUrl();
response.outputHtml(url);
}*/
/**
* 完成Minicat 3.0版本
* 需求：可以请求动态资源（Servlet）
*/
/*while (true){
Socket socket = serverSocket.accept();
InputStream inputStream = socket.getInputStream();
// 封装Request对象和Response对象
Request request = new Request(inputStream);
Response response = new Response(socket.getOutputStream());
String url = request.getUrl();
// 静态资源处理
if(map.get(request.getUrl()) == null){
response.outputHtml(url);
} else {
// 动态资源servlet请求
map.get(url).service(request,response);
}
socket.close();
}*/
/**
* 多线程改造（不使用线程池）
*/
/*while (true){
Socket socket = serverSocket.accept();
RequestProcessor requestProcessor = new RequestProcessor(socket, map);
requestProcessor.start();
}*/
System.out.println("=========>>>>>>使用线程池进行多线程改造");
/*
多线程改造（使用线程池）
*/
while (true){
Socket socket = serverSocket.accept();
RequestProcessor requestProcessor = new RequestProcessor(socket, map);
threadPoolExecutor.execute(requestProcessor);
}
}
private void loadServlet() {
InputStream resourceAsStream = Bootstrap.class.getClassLoader().getResourceAsStream("web.xml");
SAXReader saxReader = new SAXReader();
try {
Document document = saxReader.read(resourceAsStream);
Element rootElement = document.getRootElement();
List list = rootElement.selectNodes("//servlet");
for (int i = 0; i < list.size(); i++) {
Element element = list.get(i);
// study
Element servletNameElement = (Element) element.selectSingleNode("servlet-name");
String servletName = servletNameElement.getStringValue();
// com.study.server.StudyServlet
Element servletclassElement = (Element) element.selectSingleNode("servlet-class");
String servletClass = servletclassElement.getStringValue();
// 根据servlet-name的值找到url-pattern
Element servletMapping = (Element) rootElement.selectSingleNode("/web-app/servlet-mapping[servlet-name='" + servletName + "']");
String urlPattern = servletMapping.selectSingleNode("url-pattern").getStringValue();
map.put(urlPattern,(HttpServlet) Class.forName(servletClass).newInstance());
}
} catch (DocumentException | ClassNotFoundException | InstantiationException | IllegalAccessException e) {
e.printStackTrace();
}
}
/**
* minicat 的启动入口
*/
public static void main(String[] args) {
Bootstrap bootstrap = new Bootstrap();
try {
// 启动 minicat
bootstrap.start();
} catch (Exception e) {
e.printStackTrace();
}
}
}
- Http协议工具类
package com.study.server;
/**
* http协议工具类，主要是提供响应头信息，这里我们只提供200和404的情况
* @author Qi XueSong
*/
public class HttpProtocolUtil {
/**
* 为响应码200提供请求头信息
*/
public static String getHttpHeader200(long contentLength){
return "HTTP/1.1 200 OK \n" +
"Content-Type: text/html \n" +
"Content-Length: " + contentLength + " \n" +
"\r\n";
}
/**
* 为响应码404提供请求头信息(此处也包含了数据内容)
*/
public static String getHttpHeader404(){
String str404 = "404 NOT Found
";
return "HTTP/1.1 404 NOT Found \n" +
"Content-Type: text/html \n" +
"Content-Length: " + str404.getBytes().length + " \n" +
"\r\n" + str404;
}
}
- Request封装类
package com.study.server;
import java.io.IOException;
import java.io.InputStream;
/**
* 把请求信息封装为Request对象（根据InputSteam输入流封装）
* @author Qi XueSong
*/
public class Request {
private String method; // 请求方式，比如GET/POST
private String url; // 例如 /,/index.html
private InputStream inputStream; // 输入流，其他属性从输入流中解析出来
public String getMethod() {
return method;
}
public void setMethod(String method) {
this.method = method;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public InputStream getInputStream() {
return inputStream;
}
public void setInputStream(InputStream inputStream) {
this.inputStream = inputStream;
}
public Request() {
}
// 构造器，输入流传入
public Request(InputStream inputStream) throws IOException {
this.inputStream = inputStream;
// 从输入流中获取请求信息
int count = 0;
while (count == 0) {
count = inputStream.available();
}
byte[] bytes = new byte[count];
inputStream.read(bytes);
String inputStr = new String(bytes);
// 获取第一行请求头信息
String firstLineStr = inputStr.split("\\n")[0]; // GET / HTTP/1.1
String[] strings = firstLineStr.split(" ");
this.method = strings[0];
this.url = strings[1];
System.out.println("=====>>method:" + method);
System.out.println("=====>>url:" + url);
}
}
- Response封装类
package com.study.server;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
/**
* 封装Response对象，需要依赖于OutputStream
* 该对象需要提供核心方法，输出html
*
* @author Qi XueSong
*/
public class Response {
private OutputStream outputStream;
public Response() {
}
public Response(OutputStream outputStream) {
this.outputStream = outputStream;
}
// 使用输出流输出指定字符串
public void output(String content) throws IOException {
outputStream.write(content.getBytes());
}
/**
*
* @param path url，随后要根据url来获取到静态资源的绝对路径，进一步根据绝对路径读取该静态资源文件，最终通过
* 输出流输出
* /-----> classes
*/
public void outputHtml(String path) throws IOException {
// 获取静态资源文件的绝对路径
String absoluteResourcePath = StaticResourceUtil.getAbsolutePath(path);
// 输入静态资源文件
File file = new File(absoluteResourcePath);
if(file.exists() && file.isFile()) {
// 读取静态资源文件，输出静态资源
StaticResourceUtil.outputStaticResource(new FileInputStream(file),outputStream);
}else{
// 输出404
output(HttpProtocolUtil.getHttpHeader404());
}
}
}
- 静态资源请求处理工具类
package com.study.server;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
public class StaticResourceUtil {
/**
* 获取静态资源文件的绝对路径
* @author Qi XueSong
*/
public static String getAbsolutePath(String path) {
String absolutePath = StaticResourceUtil.class.getResource("/").getPath();
return absolutePath.replaceAll("\\\\","/") + path;
}
/**
* 读取静态资源文件输入流，通过输出流输出
*/
public static void outputStaticResource(InputStream inputStream, OutputStream outputStream) throws IOException {
int count = 0;
while(count == 0) {
count = inputStream.available();
}
int resourceSize = count;
// 输出http请求头,然后再输出具体内容
outputStream.write(HttpProtocolUtil.getHttpHeader200(resourceSize).getBytes());
// 读取内容输出
long written = 0 ;// 已经读取的内容长度
int byteSize = 1024; // 计划每次缓冲的长度
byte[] bytes = new byte[byteSize];
while(written < resourceSize) {
if(written + byteSize > resourceSize) { // 说明剩余未读取大小不足一个1024长度，那就按真实长度处理
byteSize = (int) (resourceSize - written); // 剩余的文件内容长度
bytes = new byte[byteSize];
}
inputStream.read(bytes);
outputStream.write(bytes);
outputStream.flush();
written+=byteSize;
}
inputStream.close();
outputStream.close();
}
}
动态资源请求
- Servlet接口定义
package com.study.server;
public interface Servlet {
void init() throws Exception;
void destory() throws Exception;
void service(Request request, Response response) throws Exception;
}
- HttpServlet抽象类定义
package com.study.server;
/**
* @author Qi XueSong
*/
public abstract class HttpServlet implements Servlet{
public abstract void doGet(Request request, Response response);
public abstract void doPost(Request request, Response response);
@Override
public void service(Request request, Response response) throws Exception {
if("GET".equals(request.getMethod())){
doGet(request,response);
} else {
doPost(request,response);
}
}
}
- 业务类Servlet定义StudyServlet
package com.study.server;
import java.io.IOException;
/**
* @author Qi XueSong
*/
public class StudyServlet extends HttpServlet {
@Override
public void doGet(Request request, Response response) {
try {
Thread.sleep(10000000);
} catch (InterruptedException e) {
e.printStackTrace();
}
String content = "StudyServlet get
";
try {
response.output(HttpProtocolUtil.getHttpHeader200(content.getBytes().length)+content);
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
public void doPost(Request request, Response response) {
String content = "StudyServlet post
";
try {
response.output(HttpProtocolUtil.getHttpHeader200(content.getBytes().length)+content);
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
public void init() throws Exception {
}
@Override
public void destory() throws Exception {
}
}
- 多线程改造封装的RequestProcessor类
package com.study.server;
import java.io.IOException;
import java.io.InputStream;
import java.net.Socket;
import java.util.Map;
/**
* @author qixuesong
* @version 1.0
* @since 2020/10/7
*/
public class RequestProcessor extends Thread {
private Socket socket;
private Map map;
public RequestProcessor(Socket socket, Map map) {
this.socket = socket;
this.map = map;
}
public RequestProcessor() {
}
@Override
public void run() {
try {
InputStream inputStream = socket.getInputStream();
// 封装Request对象和Response对象
Request request = new Request(inputStream);
Response response = new Response(socket.getOutputStream());
String url = request.getUrl();
// 静态资源处理
if(!map.containsKey(request.getUrl())){
response.outputHtml(url);
} else {
// 动态资源servlet请求
map.get(url).service(request,response);
}
socket.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
- web.xml
study
com.study.server.StudyServlet
study
/study