Android入门：发送HTTP的GET和POST请求

HTTP的请求详解在我的博客中已经讲解过：

http://blog.csdn.net/xiazdong/article/details/7215296

我在http://blog.csdn.net/xiazdong/article/details/7725867 中已经封装了一个HTTP请求的辅助类，因此可以很简单的发送GET、POST请求；

如HttpRequestUtil.sendGetRequest();是发送GET请求；

一、核心代码

HTTP GET 核心代码：

(1)String value = URLEncoder.encode(String value,"UTF-8");

(2)String path = "http://../path?key="+value;

(3)URL url = new URL(path);//此处的URL需要进行URL编码；

(4)HttpURLConnection con = (HttpURLConnection)url.openConnection();

(5)con.setRequestMethod("GET");

(6)con.setDoOutput(true);

(7)OutputStream out = con.getOutputStream();

(8)out.write(byte[]buf);

(9)int code = con.getResponseCode();

HTTP POST 核心代码：

(1)String value = URLEncoder.encode(String value,"UTF-8");

(2)byte[]buf = ("key="+value).getBytes("UTF-8");

(3)String path = "http://../path";

(4)URL url = new URL(path);//此处的URL需要进行URL编码；

(5)HttpURLConnection con = (HttpURLConnection)url.openConnection();

(6)con.setRequestMethod("POST");

(7)con.setDoOutput(true);

(8)OutputStream out = con.getOutputStream();

(9)out.write(byte[]buf);

(10)int code = con.getResponseCode();

二、GET和POST乱码解决方式

GET：

在doGet中加入：

String name = new String(request.getParameter("name").getBytes("ISO-8859-1"),"UTF-8");

POST：

在doPost中加入：

request.setCharacterEncoding("UTF-8");

详情请看我的博文：

http://blog.csdn.net/xiazdong/article/details/7217022

三、服务器端代码

package org.xiazdong.servlet;

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;

@WebServlet("/PrintServlet")
public class PrintServlet extends HttpServlet {

	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		String name = new String(request.getParameter("name").getBytes("ISO-8859-1"),"UTF-8");
		String age = new String(request.getParameter("age").getBytes("ISO-8859-1"),"UTF-8");
		System.out.println("姓名:"+name+"\n年龄："+age);
	}

	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		request.setCharacterEncoding("UTF-8");
		System.out.println("姓名:"+request.getParameter("name")+"\n年龄："+request.getParameter("age"));
	}
}

四、Android端代码

在AndroidManifest.xml加入：

<uses-permission android:name="android.permission.INTERNET"/>

MainActivity.java

package org.xiazdong.network.submit;

import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {
	private EditText name, age;
	private Button getbutton, postbutton;
	private OnClickListener listener = new OnClickListener() {
		@Override
		public void onClick(View v) {
			try{
				if (getbutton == v) {
					/*
					 * 因为是GET请求，所以需要将请求参数添加到URL后，并且还需要进行URL编码
					 * URL = http://192.168.0.103:8080/Server/PrintServlet?name=%E6%88%91&age=20
					 * 此处需要进行URL编码因为浏览器提交时自动进行URL编码
					 * */
					StringBuilder buf = new StringBuilder("http://192.168.0.103:8080/Server/PrintServlet");
					buf.append("?");
					buf.append("name="+URLEncoder.encode(name.getText().toString(),"UTF-8")+"&");
					buf.append("age="+URLEncoder.encode(age.getText().toString(),"UTF-8"));
					URL url = new URL(buf.toString());
					HttpURLConnection conn = (HttpURLConnection)url.openConnection();
					conn.setRequestMethod("GET");
					if(conn.getResponseCode()==200){
						Toast.makeText(MainActivity.this, "GET提交成功", Toast.LENGTH_SHORT).show();
					}
					else Toast.makeText(MainActivity.this, "GET提交失败", Toast.LENGTH_SHORT).show();
				}
				if (postbutton == v) {
					/*
					 * 如果是POST请求，则请求参数放在请求体中，
					 * name=%E6%88%91&age=12
					 * 
					 * */
					StringBuilder buf = new StringBuilder();
					buf.append("name="+URLEncoder.encode(name.getText().toString(),"UTF-8")+"&");
					buf.append("age="+URLEncoder.encode(age.getText().toString(),"UTF-8"));
					byte[]data = buf.toString().getBytes("UTF-8");
					URL url = new URL("http://192.168.0.103:8080/Server/PrintServlet");
					HttpURLConnection conn = (HttpURLConnection)url.openConnection();
					conn.setRequestMethod("POST");
					conn.setDoOutput(true);	//如果要输出，则必须加上此句
					OutputStream out = conn.getOutputStream();
					out.write(data);
					if(conn.getResponseCode()==200){
						Toast.makeText(MainActivity.this, "GET提交成功", Toast.LENGTH_SHORT).show();
					}
					else Toast.makeText(MainActivity.this, "GET提交失败", Toast.LENGTH_SHORT).show();
				}
			}
			catch(Exception e){
				
			}
		}
	};

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		name = (EditText) this.findViewById(R.id.name);
		age = (EditText) this.findViewById(R.id.age);
		getbutton = (Button) this.findViewById(R.id.getbutton);
		postbutton = (Button) this.findViewById(R.id.postbutton);
		getbutton.setOnClickListener(listener);
		postbutton.setOnClickListener(listener);
	}
}