网络通信(POST方式)

 

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

//以post方式上传参数
public class Activity04  extends Activity
{
 private final String DEBUG_TAG = "Activity04";
 /** Called when the activity is first created. */
 @Override
 public void onCreate(Bundle savedInstanceState)
 {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.http);
  
  TextView mTextView = (TextView)this.findViewById(R.id.TextView_HTTP);
  //http地址"?par=abcdefg"是我们上传的参数
  String httpUrl = "http://192.168.1.110:8080/httpget.jsp";
  //获得的数据
  String resultData = "";
  URL url = null;
  try
  {
   //构造一个URL对象
   url = new URL(httpUrl);
  }
  catch (MalformedURLException e)
  {
   Log.e(DEBUG_TAG, "MalformedURLException");
  }
  if (url != null)
  {
   try
   {
    // 使用HttpURLConnection打开连接
    HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();
    //因为这个是post请求,设立需要设置为true
    urlConn.setDoOutput(true);//使用用POST必须设置允许输出为TRUE
    urlConn.setDoInput(true);
          // 设置以POST方式
    urlConn.setRequestMethod("POST");

    urlConn.setConnectTimeout(6*1000);
          // Post 请求不能使用缓存
    urlConn.setUseCaches(false);
    urlConn.setInstanceFollowRedirects(true);

 

    urlConn.setRequestProperty("Connection","Keep-Alive");//维持长连接

    urlConn.setRequestProperty("charset","UTF-8");

          // 配置本次连接的Content-type，配置为application/x-www-form-urlencoded的
    urlConn.setRequestProperty("Content-Type","application/x-www-form-urlencoded");

          // 连接，从postUrl.openConnection()至此的配置必须要在connect之前完成，
          // 要注意的是connection.getOutputStream会隐含的进行connect。
    urlConn.connect();
    //DataOutputStream流
          DataOutputStream out = new DataOutputStream(urlConn.getOutputStream());
          //要上传的参数
          String content = "par=" + URLEncoder.encode("ABCDEFG", "gb2312");
          //将要上传的内容写入流中
          out.writeBytes(content);
          //刷新、关闭
          out.flush();
          out.close();
          //获取数据
          BufferedReader reader = new BufferedReader(new InputStreamReader(urlConn.getInputStream()));
    String inputLine = null;
    //使用循环来读取获得的数据
    while (((inputLine = reader.readLine()) != null))
    {
     //我们在每一行后面加上一个"/n"来换行
     resultData += inputLine + "/n";
    }   
    reader.close();
    //关闭http连接
    urlConn.disconnect();
    //设置显示取得的内容
    if ( resultData != null )
    {
     mTextView.setText(resultData);
    }
    else
    {
     mTextView.setText("读取的内容为NULL");
    }
   }
   catch (IOException e)
   {
    Log.e(DEBUG_TAG, "IOException");
   }
  }
  else
  {
   Log.e(DEBUG_TAG, "Url NULL");
  }
  
  Button button_Back = (Button) findViewById(R.id.Button_Back);
  /* 监听button的事件信息 */
  button_Back.setOnClickListener(new Button.OnClickListener()
  {
   public void onClick(View v)
   {
    /* 新建一个Intent对象 */
    Intent intent = new Intent();
    /* 指定intent要启动的类 */
    intent.setClass(Activity04.this, Activity01.class);
    /* 启动一个新的Activity */
    startActivity(intent);
    /* 关闭当前的Activity */
    Activity04.this.finish();
   }
  });
 }
}