java21 封装Response:

封装Response:
/**
 * 封装响应信息
 */
public class Response {
    //两个常量
    public static final String CRLF="
";
    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="
";
    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("<html><head><title>HTTP响应示例</title>");
            rep.println("</head><body>Hello server!</body></html>");
            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<String,List<String>> parameterMapValues;
    
    //内部
    public static final String CRLF="
";
    private InputStream is;
    private String requestInfo;
    
    public Request(){
        method ="";
        url ="";
        parameterMapValues=new HashMap<String,List<String>>();
        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<String>());
            }            
            List<String> 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<String> 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="
";
    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("<html><head><title>HTTP响应示例</title>");
            rep.println("</head><body>");
            rep.println("欢迎:").println(req.getParameter("uname")).println("回来");
            rep.println("</body></html>");
            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("<html><head><title>HTTP响应示例</title>");
        rep.println("</head><body>");        rep.println("欢迎:").println(req.getParameter("uname")).println("回来");
        rep.println("</body></html>");
    }
}
/**
 * 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="
";
    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 <T extends Closeable> 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) {
            }
    }
}
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原文地址：https://www.cnblogs.com/yaowen/p/4833650.html