使用HttpClientdopost编写客户端、服务器与数据库Demo

原创

是丹凤呀 2022-08-19 13:18:21 博主文章分类：Java ©著作权

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一、原版代码

客户端：

package com.augtwleve;

import java.awt.BorderLayout;
import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.message.BasicNameValuePair;

import net.sf.json.JSONObject;

import javax.swing.JTextField;
import javax.swing.JLabel;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.util.ArrayList;
import java.util.concurrent.TimeUnit;
import java.awt.event.ActionEvent;

public class Httpclientpost extends JFrame {

    private JPanel contentPane;
    private JTextField textField;
    private JTextField textField_1;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    Httpclientpost frame = new Httpclientpost();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public Httpclientpost() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 450, 300);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(null);

        textField = new JTextField();
        textField.setBounds(139, 45, 66, 21);
        contentPane.add(textField);
        textField.setColumns(10);

        textField_1 = new JTextField();
        textField_1.setBounds(139, 104, 66, 21);
        contentPane.add(textField_1);
        textField_1.setColumns(10);

        JLabel label = new JLabel("用户名");
        label.setBounds(22, 48, 54, 15);
        contentPane.add(label);

        JLabel label_1 = new JLabel("密码");
        label_1.setBounds(22, 107, 54, 15);
        contentPane.add(label_1);

        JButton button = new JButton("登录");
        button.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {

                String urlstring="http://localhost:8080/MyserviceTestyuanchuang/MyserverletTestyuanchuang";
                HttpClientBuilder builder=HttpClientBuilder.create();
                builder.setConnectionTimeToLive(3000, TimeUnit.MILLISECONDS);
                HttpClient client=builder.build();
                HttpPost post=new HttpPost(urlstring);

                String type="login";
                String username=textField.getText();
                String password=textField_1.getText();

                Jsonobj jsonobj=new Jsonobj();
                String jsonstring=jsonobj.json(type, username, password);


                NameValuePair pair=new BasicNameValuePair("json", jsonstring);
                ArrayList<NameValuePair> param=new ArrayList<>();
                param.add(pair);
                 try {
                    post.setEntity(new UrlEncodedFormEntity(param,"UTF-8"));
                    post.setHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
                    HttpResponse response=client.execute(post);

                    int code=response.getStatusLine().getStatusCode();
                    if(code==HttpURLConnection.HTTP_OK){
                        HttpEntity entity=response.getEntity();
                        InputStream is=entity.getContent();
                        BufferedReader br=new BufferedReader(new InputStreamReader(is));
                        String line=br.readLine();
                        while(line!=null){
                            System.out.println(line);
                            line=br.readLine();
                        }

                    }
                } catch (UnsupportedEncodingException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (ClientProtocolException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }








            }
        });
        button.setBounds(139, 182, 93, 23);
        contentPane.add(button);

        JButton button_1 = new JButton("注册");
        button_1.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                String urlstring="http://localhost:8080/MyserviceTestyuanchuang/MyserverletTestyuanchuang";
                HttpClientBuilder builder=HttpClientBuilder.create();
                builder.setConnectionTimeToLive(3000, TimeUnit.MILLISECONDS);
                HttpClient client=builder.build();
                HttpPost post=new HttpPost(urlstring);

                String type="register";
                String username=textField.getText();
                String password=textField_1.getText();

                Jsonobj jsonobj=new Jsonobj();
                String jsonstring=jsonobj.json(type, username, password);


                NameValuePair pair=new BasicNameValuePair("json", jsonstring);
                ArrayList<NameValuePair> param=new ArrayList<>();
                param.add(pair);
                 try {
                    post.setEntity(new UrlEncodedFormEntity(param,"UTF-8"));
                    post.setHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
                    HttpResponse response=client.execute(post);

                    int code=response.getStatusLine().getStatusCode();
                    if(code==HttpURLConnection.HTTP_OK){
                        HttpEntity entity=response.getEntity();
                        InputStream is=entity.getContent();
                        BufferedReader br=new BufferedReader(new InputStreamReader(is));
                        String line=br.readLine();
                        while(line!=null){
                            System.out.println(line);
                            line=br.readLine();
                        }

                    }
                } catch (UnsupportedEncodingException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (ClientProtocolException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }




            }
        });
        button_1.setBounds(29, 182, 93, 23);
        contentPane.add(button_1);

        JButton button_2 = new JButton("查询");
        button_2.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {

                String urlstring="http://localhost:8080/MyserviceTestyuanchuang/MyserverletTestyuanchuang";
                HttpClientBuilder builder=HttpClientBuilder.create();
                builder.setConnectionTimeToLive(3000, TimeUnit.MILLISECONDS);
                HttpClient client=builder.build();
                HttpPost post=new HttpPost(urlstring);

                String type="query";
                String username="";
                String password="";

                Jsonobj jsonobj=new Jsonobj();
                String jsonstring=jsonobj.json(type, username, password);


                NameValuePair pair=new BasicNameValuePair("json", jsonstring);
                ArrayList<NameValuePair> param=new ArrayList<>();
                param.add(pair);
                 try {
                    post.setEntity(new UrlEncodedFormEntity(param,"UTF-8"));
                    post.setHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
                    HttpResponse response=client.execute(post);

                    int code=response.getStatusLine().getStatusCode();
                    if(code==HttpURLConnection.HTTP_OK){
                        HttpEntity entity=response.getEntity();
                        InputStream is=entity.getContent();
                        BufferedReader br=new BufferedReader(new InputStreamReader(is));
                        String line=br.readLine();
                        while(line!=null){
                            System.out.println(line);
                            line=br.readLine();
                        }

                    }
                } catch (UnsupportedEncodingException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                } catch (ClientProtocolException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                } catch (IOException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                }

            }
        });
        button_2.setBounds(284, 182, 93, 23);
        contentPane.add(button_2);

客户端JSON串：

package com.augtwleve;

import net.sf.json.JSONObject;

public class Jsonobj
    private String jsonstring;
    public Jsonobj(){
    }
    public String json(String type,String username,String password){
        JSONObject obj=new JSONObject();
        obj.put("Type", type);
        obj.put("username", username);
        obj.put("password", password);      
        String jsonstring= obj.toString();
        return

服务器代码：

package com.augtwleve;

import java.io.IOException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import net.sf.json.JSONObject;


/**
 * Servlet implementation class MyserverletTestyuanchuang
 */
@WebServlet("/MyserverletTestyuanchuang")
public class MyserverletTestyuanchuang extends HttpServlet
    private static final long serialVersionUID = 1L;

    /**
     * @see
    public MyserverletTestyuanchuang() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
//      String username=request.getParameter("username");
//      String password=request.getParameter("password");
//      username=Encoding.encoding(username);//编码转换

        System.out.println("接收到的数据"+request.getParameter("json"));
        JSONObject obj=JSONObject.fromObject(request.getParameter("json"));

        String type=obj.getString("Type");
        String username=obj.getString("username");
        String password=obj.getString("password");
        Mysqlmanager manager=new Mysqlmanager();
        String s=manager.judgement(type, username, password);

        response.setHeader("Content-type","text/html;charset=UTF-8");
        System.out.println(s);  
        response.getWriter().append(s);


    }

    /**
     * @see
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub

数据库操作

package com.augtwleve;

import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import com.sun.swing.internal.plaf.synth.resources.synth_zh_CN;

import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
/**
 * 在此方法中判断是哪一种类型： 注册（register）  登录（login） 查询（query）
 * */
public class Mysqlmanager {
    private Connection connection;//私有化
    //get connection方法
    public Connection getConnection() {
        return connection;
    }
    //单例设计
    private static Mysqlmanager manager;
    public static synchronized Mysqlmanager newInstance(){
        if(manager==null){
            manager=new Mysqlmanager();
        }
        return manager;
    }
    //在构造器中进行初始化
    public Mysqlmanager(){
        //注意这是要记得导入mysql的jar包
        String driver="com.mysql.jdbc.Driver";
        String url="jdbc:mysql://localhost:3306/clazz";
        String user="root";
        String password="123456";
        try {
            Class.forName(driver);
            connection=DriverManager.getConnection(url, user, password);

        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }


    }
    public String judgement(String type,String username,String password){
        String s="";
     if(type.equals("register")){
          s= this.register(username, password); 
     }
     if(type.equals("login")){
          s=this.login(username, password);
    }
    if(type.equals("query")){
         s="";
        s=this.query(username, password);
    }
    return s;
}

    public String register(String username,String password){
         String s="";
         Pattern p = Pattern.compile("^\\w{0,16}$");
         Matcher m = p.matcher(username);
         boolean b = m.matches();
         //正则判断
         if(b==false){
             s="用户名不符合规则请重新命名";
         }else{
             //重名判断
             connection=Mysqlmanager.newInstance().getConnection();//注意导包
             String sql="select * from user where user_name=? ";
             System.out.println("!!!");
             PreparedStatement prestate;
            try {
                 prestate = connection.prepareStatement(sql);
                 prestate.setString(1, username);
            //   prestate.setString(2, password);       
                 ResultSet set=prestate.executeQuery();
                 set.last();
                 int num=set.getRow();
                 System.out.println(num);
                 if(num>0){
                     s="该用户已存在，请重新输入";
                 }else{
                      String insert="insert into user(user_name,passerword)values('"+username+"','"+password+"')";
                      Statement statement=connection.createStatement();
                      statement.execute(insert);
                      s="注册成功";
                 }

            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }


         }
         return s;
    }
    public String login(String username,String password){
        String s="";
        connection=Mysqlmanager.newInstance().getConnection();//注意导包
         String sql="select * from user where user_name=? and passerword=?";
         PreparedStatement prestate;
        try {
             prestate = connection.prepareStatement(sql);
             prestate.setString(1, username);
             prestate.setString(2, password);       
             ResultSet set=prestate.executeQuery();
             set.last();
             int num=set.getRow();
             if(num>0){
                 s="登录成功";
             }else{
                 s="用户名或密码错误，登录失败";
             }

        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return s;
    }
    public String query(String username,String password){
        String s="";
        JSONObject obj = null;
        String sql="select * from user";
        connection=Mysqlmanager.newInstance().getConnection();
        try {
            Statement state=connection.createStatement();
            ResultSet set=state.executeQuery(sql);
            set.first();    
            //注意jsonarray的用法和使用的位置，如果放在while循环内将会出错
            JSONArray json=json=new JSONArray();
            while(!set.isAfterLast()){  
                JSONObject item=new JSONObject();
                item.put("username", set.getString("user_name"));
                item.put("password", set.getString("passerword"));
                json.add(item);                     
                set.next();
            }
              obj=new JSONObject(); 
              obj.put("data", json);


        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            return "error";
        }
         s="获得的用户名与密码："+obj.toString(); 
         return

二、修改后

将客户端中的注册（register）登录（login）查询（query）的方法提出。

客户端：

package com.augtwleve;

import java.awt.BorderLayout;
import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.message.BasicNameValuePair;

import net.sf.json.JSONObject;

import javax.swing.JTextField;
import javax.swing.JLabel;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.util.ArrayList;
import java.util.concurrent.TimeUnit;
import java.awt.event.ActionEvent;

public class Httpclientpost extends JFrame {

    private JPanel contentPane;
    private JTextField textField;
    private JTextField textField_1;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    Httpclientpost frame = new Httpclientpost();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public Httpclientpost() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 450, 300);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(null);

        textField = new JTextField();
        textField.setBounds(139, 45, 66, 21);
        contentPane.add(textField);
        textField.setColumns(10);

        textField_1 = new JTextField();
        textField_1.setBounds(139, 104, 66, 21);
        contentPane.add(textField_1);
        textField_1.setColumns(10);

        JLabel label = new JLabel("用户名");
        label.setBounds(22, 48, 54, 15);
        contentPane.add(label);

        JLabel label_1 = new JLabel("密码");
        label_1.setBounds(22, 107, 54, 15);
        contentPane.add(label_1);

        JButton button = new JButton("登录");
        button.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {

                String username=textField.getText();
                String password=textField_1.getText();
                ClientMethod.newInstance().login(username, password);


            }
        });
        button.setBounds(139, 182, 93, 23);
        contentPane.add(button);

        JButton button_1 = new JButton("注册");
        button_1.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                String username=textField.getText();
                String password=textField_1.getText();
                ClientMethod.newInstance().register(username, password);
            }
        });
        button_1.setBounds(29, 182, 93, 23);
        contentPane.add(button_1);

        JButton button_2 = new JButton("查询");
        button_2.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                String username=textField.getText();
                String password=textField_1.getText();
                ClientMethod.newInstance().query(username, password);
            }
        });
        button_2.setBounds(284, 182, 93, 23);
        contentPane.add(button_2);

客户端操作

package com.augtwleve;

import java.awt.event.ActionEvent;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.util.ArrayList;
import java.util.concurrent.TimeUnit;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.message.BasicNameValuePair;

import net.sf.json.JSONObject;

public class ClientMethod {
    private static ClientMethod method;
    public static synchronized ClientMethod newInstance(){
        if(method==null){
            method=new ClientMethod();
        }
        return method;
    }
    public ClientMethod(){

    }
    public void login(String username,String password){

        String urlstring="http://localhost:8080/MyserviceTestyuanchuang/MyserverletTestyuanchuang";
        HttpClientBuilder builder=HttpClientBuilder.create();
        builder.setConnectionTimeToLive(3000, TimeUnit.MILLISECONDS);
        HttpClient client=builder.build();
        HttpPost post=new HttpPost(urlstring);

        JSONObject obj=new JSONObject();
        obj.put("Type", "login");
        obj.put("username", username);
        obj.put("password", password);      
        String jsonstring= obj.toString();  

        NameValuePair pair=new BasicNameValuePair("json", jsonstring);
        ArrayList<NameValuePair> param=new ArrayList<>();
        param.add(pair);
         try {
            post.setEntity(new UrlEncodedFormEntity(param,"UTF-8"));
            post.setHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
            HttpResponse response=client.execute(post);

            int code=response.getStatusLine().getStatusCode();
            if(code==HttpURLConnection.HTTP_OK){
                HttpEntity entity=response.getEntity();
                InputStream is=entity.getContent();
                BufferedReader br=new BufferedReader(new InputStreamReader(is));
                String line=br.readLine();
                while(line!=null){
                    System.out.println(line);
                    line=br.readLine();
                }

            }
        } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }   

    }
     public void register(String username,String password){

                String urlstring="http://localhost:8080/MyserviceTestyuanchuang/MyserverletTestyuanchuang";
                HttpClientBuilder builder=HttpClientBuilder.create();
                builder.setConnectionTimeToLive(3000, TimeUnit.MILLISECONDS);
                HttpClient client=builder.build();
                HttpPost post=new HttpPost(urlstring);

                JSONObject obj=new JSONObject();
                obj.put("Type", "register");
                obj.put("username", username);
                obj.put("password", password);      
                String jsonstring= obj.toString();  

                NameValuePair pair=new BasicNameValuePair("json", jsonstring);
                ArrayList<NameValuePair> param=new ArrayList<>();
                param.add(pair);
                 try {
                    post.setEntity(new UrlEncodedFormEntity(param,"UTF-8"));
                    post.setHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
                    HttpResponse response=client.execute(post);

                    int code=response.getStatusLine().getStatusCode();
                    if(code==HttpURLConnection.HTTP_OK){
                        HttpEntity entity=response.getEntity();
                        InputStream is=entity.getContent();
                        BufferedReader br=new BufferedReader(new InputStreamReader(is));
                        String line=br.readLine();
                        while(line!=null){
                            System.out.println(line);
                            line=br.readLine();
                        }

                    }
                } catch (UnsupportedEncodingException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (ClientProtocolException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }

     }
     public void query(String username,String password){

            String urlstring="http://localhost:8080/MyserviceTestyuanchuang/MyserverletTestyuanchuang";
            HttpClientBuilder builder=HttpClientBuilder.create();
            builder.setConnectionTimeToLive(3000, TimeUnit.MILLISECONDS);
            HttpClient client=builder.build();
            HttpPost post=new HttpPost(urlstring);

            JSONObject obj=new JSONObject();
            obj.put("Type", "query");
            obj.put("username", username);
            obj.put("password", password);      
            String jsonstring= obj.toString();  

            NameValuePair pair=new BasicNameValuePair("json", jsonstring);
            ArrayList<NameValuePair> param=new ArrayList<>();
            param.add(pair);
             try {
                post.setEntity(new UrlEncodedFormEntity(param,"UTF-8"));
                post.setHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
                HttpResponse response=client.execute(post);

                int code=response.getStatusLine().getStatusCode();
                if(code==HttpURLConnection.HTTP_OK){
                    HttpEntity entity=response.getEntity();
                    InputStream is=entity.getContent();
                    BufferedReader br=new BufferedReader(new InputStreamReader(is));
                    String line=br.readLine();
                    while(line!=null){
                        System.out.println(line);
                        line=br.readLine();
                    }

                }
            } catch (UnsupportedEncodingException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            } catch (ClientProtocolException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            } catch (IOException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();

服务器

package com.augtwleve;

import java.io.IOException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import net.sf.json.JSONObject;


/**
 * Servlet implementation class MyserverletTestyuanchuang
 */
@WebServlet("/MyserverletTestyuanchuang")
public class MyserverletTestyuanchuang extends HttpServlet
    private static final long serialVersionUID = 1L;

    /**
     * @see
    public MyserverletTestyuanchuang() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
//      String username=request.getParameter("username");
//      String password=request.getParameter("password");
//      username=Encoding.encoding(username);//编码转换

        String s="";
        System.out.println("接收到的数据"+request.getParameter("json"));
        JSONObject obj=JSONObject.fromObject(request.getParameter("json"));

        String type=obj.getString("Type");
        String username=obj.getString("username");
        String password=obj.getString("password");

        if(type.equals("register")){
            s=Mysqlmanager.newInstance().register(username, password);
        }
        if(type.equals("login")){
            s=Mysqlmanager.newInstance().login(username, password);


        }
        if(type.equals("query")){
            s=Mysqlmanager.newInstance().query(username, password);

        }
//        Mysqlmanager manager=new Mysqlmanager();
//        String s=manager.judgement(type, username, password);

        response.setHeader("Content-type","text/html;charset=UTF-8");
        System.out.println(s);  
        response.getWriter().append(s);


    }

    /**
     * @see
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub

服务器操作

package com.augtwleve;

import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import com.sun.swing.internal.plaf.synth.resources.synth_zh_CN;

import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
/**
 * 在此方法中判断是哪一种类型： 注册（register）  登录（login） 查询（query）
 * */
public class Mysqlmanager {
    private Connection connection;//私有化
    //get connection方法
    public Connection getConnection() {
        return connection;
    }
    //单例设计
    private static Mysqlmanager manager;
    public static synchronized Mysqlmanager newInstance(){
        if(manager==null){
            manager=new Mysqlmanager();
        }
        return manager;
    }
    //在构造器中进行初始化
    public Mysqlmanager(){
        //注意这是要记得导入mysql的jar包
        String driver="com.mysql.jdbc.Driver";
        String url="jdbc:mysql://localhost:3306/clazz";
        String user="root";
        String password="123456";
        try {
            Class.forName(driver);
            connection=DriverManager.getConnection(url, user, password);

        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }


    }
    public String judgement(String type,String username,String password){
        String s="";
     if(type.equals("register")){
          s= this.register(username, password); 
     }
     if(type.equals("login")){
          s=this.login(username, password);
    }
    if(type.equals("query")){
         s="";
        s=this.query(username, password);
    }
    return s;
}

    public String register(String username,String password){
         String s="";
         Pattern p = Pattern.compile("^\\w{0,16}$");
         Matcher m = p.matcher(username);
         boolean b = m.matches();
         //正则判断
         if(b==false){
             s="用户名不符合规则请重新命名";
         }else{
             //重名判断
             connection=Mysqlmanager.newInstance().getConnection();//注意导包
             String sql="select * from user where user_name=? ";
             System.out.println("!!!");
             PreparedStatement prestate;
            try {
                 prestate = connection.prepareStatement(sql);
                 prestate.setString(1, username);
            //   prestate.setString(2, password);       
                 ResultSet set=prestate.executeQuery();
                 set.last();
                 int num=set.getRow();
                 System.out.println(num);
                 if(num>0){
                     s="该用户已存在，请重新输入";
                 }else{
                      String insert="insert into user(user_name,passerword)values('"+username+"','"+password+"')";
                      Statement statement=connection.createStatement();
                      statement.execute(insert);
                      s="注册成功";
                 }

            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }


         }
         return s;
    }
    public String login(String username,String password){
        String s="";
        connection=Mysqlmanager.newInstance().getConnection();//注意导包
         String sql="select * from user where user_name=? and passerword=?";
         PreparedStatement prestate;
        try {
             prestate = connection.prepareStatement(sql);
             prestate.setString(1, username);
             prestate.setString(2, password);       
             ResultSet set=prestate.executeQuery();
             set.last();
             int num=set.getRow();
             if(num>0){
                 s="登录成功";
             }else{
                 s="用户名或密码错误，登录失败";
             }

        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return s;
    }
    public String query(String username,String password){
        String s="";
        JSONObject obj = null;
        String sql="select * from user";
        connection=Mysqlmanager.newInstance().getConnection();
        try {
            Statement state=connection.createStatement();
            ResultSet set=state.executeQuery(sql);
            set.first();    

            System.out.println("1111111");
            JSONArray json=json=new JSONArray();;
            while(!set.isAfterLast()){  
                JSONObject item=new JSONObject();
                item.put("username", set.getString("user_name"));
                item.put("password", set.getString("passerword"));
                json.add(item);                     
                set.next();
            }
              obj=new JSONObject(); 
              obj.put("data", json);


        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            return "error";
        }
         s="获得的用户名与密码："+obj.toString(); 
         return