HTTPdoGet与HTTPdoPost

一、未添加数据库的GET和POST方法
1、serverlet服务器的搭建在前面的博客中已经想写描述，此处不再赘述。

2、serverlet代码：

package com.augtwleve;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * Servlet implementation class MyserverletTestyuanchuang */@WebServlet("/MyserverletTestyuanchuang")public class MyserverletTestyuanchuang extends HttpServlet {    private static final long serialVersionUID = 1L;    /**     * @see HttpServlet#HttpServlet()     */    public MyserverletTestyuanchuang() {        super();        // TODO Auto-generated constructor stub    }    /**     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)     */    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="获得的用户名为："+username+":"+password+"";        System.out.println(s);          response.getWriter().append(s);    }    /**     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)     */    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        // TODO Auto-generated method stub        doGet(request, response);    }}

3、HttpdoGet方法
首先是建立连接即 new url
再转换成 HttpURLConnection，此处注意导包问题，可能出错
然后设置连接超时与读超时，设置request方法为“GET”
再获得回应，答复
判断http状态来回复先读入，再在屏幕输出

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 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.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.URL;import java.awt.event.ActionEvent;public class Httpdoget extends JFrame {    private JPanel contentPane;    /**     * Launch the application.     */    public static void main(String[] args) {        EventQueue.invokeLater(new Runnable() {            public void run() {                try {                    Httpdoget frame = new Httpdoget();                    frame.setVisible(true);                } catch (Exception e) {                    e.printStackTrace();                }            }        });    }    /**     * Create the frame.     */    public Httpdoget() {        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);        JButton btnNewButton = new JButton("提交");        btnNewButton.addActionListener(new ActionListener() {            public void actionPerformed(ActionEvent arg0) {            String urlString="http://localhost:8080/MyserviceTestyuanchuang/MyserverletTestyuanchuang?username=zhangsan&password=123456";            try {                URL url=new URL(urlString);                HttpURLConnection connection=(HttpURLConnection) url.openConnection();                connection.setConnectTimeout(30000);                connection.setReadTimeout(30000);                connection.setRequestMethod("GET");                int code=connection.getResponseCode();                if(code==connection.HTTP_OK){                    InputStream is=connection.getInputStream();                    BufferedReader br=new BufferedReader(new InputStreamReader(is));                    String line=br.readLine();                    while(line!=null){                        System.out.println(line);                        line=br.readLine();                    }                }            } catch (MalformedURLException e) {                // TODO Auto-generated catch block                e.printStackTrace();            } catch (IOException e) {                // TODO Auto-generated catch block                e.printStackTrace();            }            }        });        btnNewButton.setBounds(146, 101, 93, 23);        contentPane.add(btnNewButton);    }}

4、HttpdoPost方法
首先是建立连接即 new url
再转换成 HttpURLConnection，此处注意导包问题，可能出错
然后设置连接超时与读超时，设置编码转换，
设置url输出为true，设置不适用缓冲（catche）
设置request方法为“POST”
执行输出语句，注意，此处必须先输出，将s字符串发给服务器，才能获得服务器的回应
再获得回应，答复
判断http状态来回复先读入，再在屏幕输出

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 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.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.URL;import java.awt.event.ActionEvent;public class Httpdopost extends JFrame {    private JPanel contentPane;    /**     * Launch the application.     */    public static void main(String[] args) {        EventQueue.invokeLater(new Runnable() {            public void run() {                try {                    Httpdopost frame = new Httpdopost();                    frame.setVisible(true);                } catch (Exception e) {                    e.printStackTrace();                }            }        });    }    /**     * Create the frame.     */    public Httpdopost() {        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);        JButton btnNewButton = new JButton("提交");        btnNewButton.addActionListener(new ActionListener() {            public void actionPerformed(ActionEvent arg0) {                String urlString="http://localhost:8080/MyserviceTestyuanchuang/MyserverletTestyuanchuang";                URL url;                try {                    url = new URL(urlString);                               HttpURLConnection connection=(HttpURLConnection) url.openConnection();                    connection.setConnectTimeout(30000);                    connection.setReadTimeout(30000);                    //为防止乱码进行编码转换                    connection.setRequestProperty("Accept-Charset", "utf-8");                    // 设置可以接受序列化的java对象                    connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");                    //URL连接可用于输入和/或输出。如果打算使用 URL 连接进行输出，则将 DoOutput 标志设置为 true；如果不打算使用，则设置为 false。默认值为 false。                               connection.setDoOutput(true);                    connection.setUseCaches(false);                    String s="username=zhangsan&password=123456";                    connection.setRequestMethod("POST");                    connection.getOutputStream().write(s.getBytes());//将字符串s发给服务器，有服务器的request接收                    int code=connection.getResponseCode();//注意不是hashcode()                    //注意是connection.HTTP_OK                    if(code==connection.HTTP_OK){                        InputStream is=connection.getInputStream();                        BufferedReader br=new BufferedReader(new InputStreamReader(is));                        String line=br.readLine();                        while(line!=null){                            System.out.println(line);                            line=br.readLine();                        }                    }                } catch (MalformedURLException e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                } catch (IOException e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                }            }        });        btnNewButton.setBounds(114, 79, 93, 23);        contentPane.add(btnNewButton);    }}

5、编码转换

package com.augtwleve;import java.io.UnsupportedEncodingException;public class Encoding {    public static String encoding(String s){        if(s==null){            return null;        }        try {            byte[] by=s.getBytes("ISO-8859-1");            s=new String(by,"UTF-8");        } catch (UnsupportedEncodingException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }        return s;    }}

二、加载数据库
1、serverlet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;/** * Servlet implementation class MyserverletTestyuanchuang */@WebServlet("/MyserverletTestyuanchuang")public class MyserverletTestyuanchuang extends HttpServlet {    private static final long serialVersionUID = 1L;    /**     * @see HttpServlet#HttpServlet()     */    public MyserverletTestyuanchuang() {        super();        // TODO Auto-generated constructor stub    }    /**     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)     */    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        Connection connection=Mysqlmanager.newInstance().getConnection();//注意导包        String sql="selection * from user where user_name=? and passerword=?";        String s1="";        try {            PreparedStatement prestate=connection.prepareStatement(sql);//注意导包            prestate.setString(1, username);            prestate.setString(2, password);                    ResultSet set=prestate.executeQuery();            set.last();            int num=set.getRow();            if(num==1){                System.out.println("登录成功");                s1="登录成功";            }else{                System.out.println("登录失败");                s1="登录失败";            }        } catch (SQLException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }        String s="获得的用户名为："+username+":"+password+"";        response.setHeader("Content-type","text/html;charset=UTF-8");        System.out.println(s);          response.getWriter().append(s);        response.getWriter().append(s1);    }    /**     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)     */    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        // TODO Auto-generated method stub        doGet(request, response);    }}

2、数据库代码

package com.augtwleve;import java.sql.Connection;import java.sql.DriverManager;import java.sql.SQLException;import com.sun.swing.internal.plaf.synth.resources.synth_zh_CN;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();        }    }}

3、注意加载数据库jar包时，jar包的位置