封装Response:/** * 封装响应信息 */public class Response {    //两个常量    public static final String CRLF="\r\n";    public static final String BLANK=" ";    //流    private BufferedWriter bw ;        //正文    private StringBuilder content;            //存储头信息    private StringBuilder headInfo;    //存储正文长度    private int len = 0;    public Response(){        headInfo = new StringBuilder();        content = new StringBuilder();        len = 0;    }    public Response(Socket client){        this();        try {            bw = new BufferedWriter(new OutputStreamWriter(client.getOutputStream()));        } catch (IOException e) {            headInfo=null;        }    }    public Response(OutputStream os){        this();        bw = new BufferedWriter(new OutputStreamWriter(os));    }    /**     * 构建正文     */    public Response print(String info){        content.append(info);        len += info.getBytes().length;        return this;    }        /**     * 构建正文+回车     */    public Response println(String info){        content.append(info).append(CRLF);        len += (info+CRLF).getBytes().length;        return this;    }        /**     * 构建响应头     */    private void createHeadInfo(int code){        //1)  HTTP协议版本、状态代码、描述        headInfo.append("HTTP/1.1").append(BLANK).append(code).append(BLANK);        switch(code){            case 200:                headInfo.append("OK");                break;            case 404:                headInfo.append("NOT FOUND");                break;            case 505:                headInfo.append("SEVER ERROR");                break;            }        headInfo.append(CRLF);        //2)  响应头(Response Head)        headInfo.append("Server:bjsxt Server/0.0.1").append(CRLF);        headInfo.append("Date:").append(new Date()).append(CRLF);        headInfo.append("Content-type:text/html;charset=GBK").append(CRLF);        //正文长度 ：字节长度        headInfo.append("Content-Length:").append(len).append(CRLF);        headInfo.append(CRLF); //分隔符    }     //推送到客户端    void pushToClient(int code) throws IOException{        if(null==headInfo){            code =500;        }        createHeadInfo(code);        //头信息+分割符        bw.append(headInfo.toString());        //正文        bw.append(content.toString());        bw.flush();    }    public void close(){        CloseUtil.closeIO(bw);    }        }测试：/** * 创建服务器，并启动 * 1、请求 * 2、响应 */public class Server4 {    private ServerSocket server;    public static final String CRLF="\r\n";    public static final String BLANK=" ";        public static void main(String[] args) {        Server4 server = new Server4();        server.start();    }    /**     * 启动方法     */    public void start(){                try {            server = new ServerSocket(8888);            this.receive();        } catch (IOException e) {            e.printStackTrace();        }    }    /**     * 接收客户端     */    private void receive(){        try {            Socket client =server.accept();                        byte[] data=new byte[20480];            int len =client.getInputStream().read(data);                            //接收客户端的请求信息            String requestInfo=new String(data,0,len).trim();                System.out.println(requestInfo);            //响应            Response rep=new Response(client.getOutputStream());            rep.println("");            rep.println("Hello server!");            rep.pushToClient(200);                    } catch (IOException e) {        }    }    public void stop(){    }}封装Request：/** * 封装request */public class Request {    //请求方式    private String method;    //请求资源    private String url;    //请求参数    private Map
     
      
       > parameterMapValues;        //内部    public static final String CRLF="\r\n";    private InputStream is;    private String requestInfo;        public Request(){        method ="";        url ="";        parameterMapValues=new HashMap
       
        
         >();        requestInfo="";    }    public Request(InputStream is){        this();        this.is=is;        try {            byte[] data = new byte[20480];            int len = is.read(data);            requestInfo = new String(data, 0, len);        } catch (Exception e) {            return ;        }        //分析请求信息        parseRequestInfo();    }    /**     * 分析请求信息     */    private void parseRequestInfo(){        if(null==requestInfo ||(requestInfo=requestInfo.trim()).equals("")){            return ;        }                /**         * =====================================         * 从信息的首行分解出 :请求方式    请求路径   请求参数(get可能存在)         *   如:GET /index.html?name=123&pwd=5456 HTTP/1.1         *          * 如果为post方式，请求参数可能在 最后正文中         *          * 思路:         * 1)请求方式 :找出第一个/  截取即可         * 2)请求资源:找出第一个/   HTTP/          * =====================================         */        String paramString =""; //接收请求参数                 //1、获取请求方式        String firstLine =requestInfo.substring(0,requestInfo.indexOf(CRLF));        int idx =requestInfo.indexOf("/"); // /的位置        this.method=firstLine.substring(0, idx).trim();        String urlStr =firstLine.substring(idx,firstLine.indexOf("HTTP/")).trim();        if(this.method.equalsIgnoreCase("post")){            this.url=urlStr;                    paramString=requestInfo.substring(requestInfo.lastIndexOf(CRLF)).trim();                    }else if(this.method.equalsIgnoreCase("get")){            if(urlStr.contains("?")){ //是否存在参数                String[] urlArray=urlStr.split("\\?");                this.url=urlArray[0];                paramString=urlArray[1];//接收请求参数             }else{                this.url=urlStr;                        }        }                    //不存在请求参数        if(paramString.equals("")){            return ;        }        //2、将请求参数封装到Map中            parseParams(paramString);    }    private void parseParams(String paramString){        //分割 将字符串转成数组        StringTokenizer token=new StringTokenizer(paramString,"&");        while(token.hasMoreTokens()){            String keyValue =token.nextToken();            String[] keyValues=keyValue.split("=");            if(keyValues.length==1){                keyValues =Arrays.copyOf(keyValues, 2);                keyValues[1] =null;            }                        String key = keyValues[0].trim();            String value = null==keyValues[1]?null:decode(keyValues[1].trim(),"gbk");            //转换成Map 分拣            if(!parameterMapValues.containsKey(key)){                parameterMapValues.put(key,new ArrayList
         
          ());            }                        List
          
            values =parameterMapValues.get(key); values.add(value); } } /** * 解决中文 * @param value * @param code * @return */ private String decode(String value,String code){ try { return java.net.URLDecoder.decode(value, code); } catch (UnsupportedEncodingException e) { //e.printStackTrace(); } return null; } /** * 根据页面的name 获取对应的多个值 * @param args */ public String[] getParameterValues(String name){ List
           
             values=null; if((values=parameterMapValues.get(name))==null){ return null; }else{ return values.toArray(new String[0]); } } /** * 根据页面的name 获取对应的单个值 * @param args */ public String getParameter(String name){ String[] values =getParameterValues(name); if(null==values){ return null; } return values[0]; } public String getUrl() { return url; }}测试：/** * 创建服务器，并启动 * 1、请求 * 2、响应 */public class Server5 { private ServerSocket server; public static final String CRLF="\r\n"; public static final String BLANK=" "; public static void main(String[] args) { Server5 server = new Server5(); server.start(); } /** * 启动方法 */ public void start(){ try { server = new ServerSocket(8888); this.receive(); } catch (IOException e) { e.printStackTrace(); } } /** * 接收客户端 */ private void receive(){ try { Socket client =server.accept(); //请求 Request req=new Request(client.getInputStream()); //响应 Response rep=new Response(client.getOutputStream()); rep.println("
            "); rep.println(""); rep.println("欢迎:").println(req.getParameter("uname")).println("回来"); rep.println(""); rep.pushToClient(200); } catch (IOException e) { } } /** * 停止服务器 */ public void stop(){ }}加入Servlet：public class Servlet { public void service(Request req,Response rep){ rep.println("
            "); rep.println(""); rep.println("欢迎:").println(req.getParameter("uname")).println("回来"); rep.println(""); }}/** * 接收客户端 */private void receive(){ try { Socket client =server.accept(); Servlet serv =new Servlet(); Request req =new Request(client.getInputStream()); Response rep =new Response(client.getOutputStream()); serv.service(req,rep); rep.pushToClient(200); //通过流写出去 } catch (IOException e) { }}服务端利用多线程：/** * 创建服务器，并启动 * 1、请求 * 2、响应 */public class Server7 { private ServerSocket server; public static final String CRLF="\r\n"; public static final String BLANK=" "; private boolean isShutDown= false; public static void main(String[] args) { Server7 server = new Server7(); server.start(); } /** * 启动方法 */ public void start(){ start(8888); } /** * 指定端口的启动方法 */ public void start(int port){ try { server = new ServerSocket(port); this.receive(); } catch (IOException e) { //e.printStackTrace(); stop();//启动出错则stop。 } } /** * 接收客户端 */ private void receive(){ try { while(!isShutDown){ new Thread(new Dispatcher(server.accept())).start(); } } catch (IOException e) { stop(); } } /** * 停止服务器 */ public void stop(){ isShutDown=true; CloseUtil.closeSocket(server); }}/** * 一个请求与响应 就一个此对象 */public class Dispatcher implements Runnable{ private Socket client; private Request req; private Response rep; private int code=200; Dispatcher(Socket client){ this.client=client; try { req =new Request(client.getInputStream()); rep =new Response(client.getOutputStream()); } catch (IOException e) { code =500;//统一到推送地方去推送。 return ; } } @Override public void run() { Servlet serv =new Servlet(); serv.service(req,rep); try { rep.pushToClient(code); //流推送到客户端 } catch (IOException e) { } try { rep.pushToClient(500); } catch (IOException e) { e.printStackTrace(); } CloseUtil.closeSocket(client); }}public class CloseUtil { /** * 关闭IO流 */ /* public static void closeIO(Closeable... io){ for(Closeable temp:io){ try { if (null != temp) { temp.close(); } } catch (Exception e) { } } }*/ /** * 使用泛型方法实现关闭IO流 * @param io */ public static 
            
              void closeIO(T... io){ for(Closeable temp:io){ try { if (null != temp) { temp.close(); } } catch (Exception e) { } } } public static void closeSocket(ServerSocket socket){ try { if (null != socket) { socket.close(); } } catch (Exception e) { } } public static void closeSocket(Socket socket){ try { if (null != socket) { socket.close(); } } catch (Exception e) { }} public static void closeSocket(DatagramSocket socket){ try { if (null != socket) { socket.close(); } } catch (Exception e) { } }}