Android开发之HttpURLConnection

前面说到的网络通信是用以socket的方式，是标准的java接口，但是操作还是比较繁琐，这里介绍用HttpURLConnection通信的方法，这里添加两个实例：

1.加载网络页面

package com.linxiaosheng.http;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.URL;import org.apache.http.HttpConnection;import android.app.Activity;import android.os.Bundle;import android.os.Handler;import android.webkit.WebView;import com.linxiaosheng.R;public class MyHttp extends Activity {private WebView webView;@Overrideprotected void onCreate(Bundle savedInstanceState) {// TODO Auto-generated method stubsuper.onCreate(savedInstanceState);setContentView(R.layout.myhttp);String url="http://www.baidu.com";Handler handler=new Handler();webView=(WebView)findViewById(R.id.webView1);//启动线程new HttpThread(url, webView, handler).start();}}//由于网络通信是比较耗时的操作，需要把把单独放在一个线程里面class HttpThread extends Thread{private String path;private WebView webView;private Handler handler;public HttpThread(String path,WebView webView,Handler handler){this.path=path;this.webView=webView;this.handler=handler;}@Overridepublic void run() {// TODO Auto-generated method stubURL httpUrl;try {httpUrl = new URL(path);try {HttpURLConnection connection=(HttpURLConnection) httpUrl.openConnection();//这里请求方法需要大写connection.setRequestMethod("GET");//设置网络连接超时时间connection.setConnectTimeout(5000);final StringBuffer sb=new StringBuffer();BufferedReader br=new BufferedReader(new InputStreamReader(connection.getInputStream()));String str="";while((str=br.readLine())!=null){sb.append(str);}System.out.println(sb.toString());handler.post(new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stub//加载图片资源webView.loadData(sb.toString(), "text/html;charset=utf-8",null);}});} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}} catch (MalformedURLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical" >    <WebView        android:id="@+id/webView1"        android:layout_width="match_parent"        android:layout_height="match_parent" /></LinearLayout>

这里因为要访问网络通信，需要添加权限

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

2.加载网络图片

package com.linxiaosheng.http;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.io.OutputStream;import java.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.URL;import android.app.Activity;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.os.Environment;import android.os.Handler;import android.util.Log;import android.widget.ImageView;import com.linxiaosheng.R;public class MyHttp2 extends Activity {protected void onCreate(android.os.Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.myhttp2);String path="http://d.hiphotos.baidu.com/image/pic/item/902397dda144ad347a82f507d3a20cf431ad8574.jpg";Handler handler=new Handler();ImageView imageView=(ImageView)findViewById(R.id.imageView1);new HttpThread2(path,imageView,handler).start();};}class HttpThread2 extends Thread{private ImageView imageView;private Handler handler;private String path;public HttpThread2(String path,ImageView imageView,Handler handler){this.imageView=imageView;this.handler=handler;this.path=path;}public void run(){URL url;try {url = new URL(path);HttpURLConnection connection=(HttpURLConnection) url.openConnection();connection.setReadTimeout(5000);connection.setRequestMethod("GET");connection.setDoInput(true);File file=null;FileOutputStream os=null;if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){File basepath=Environment.getExternalStorageDirectory();Log.i("sysout", basepath.getAbsolutePath());String filename=Long.toString(System.currentTimeMillis());file=new File(basepath,filename);/*if(!file.exists()){file.createNewFile();}*/Log.i("sysout", file.getAbsolutePath());os=new FileOutputStream(file);}//Log.i("sysout", file.getAbsolutePath());if(os!=null){byte[] b=new byte[1024*4];int len=0;while((len=connection.getInputStream().read(b))!=-1){os.write(b,0,len);}final Bitmap bitmap=BitmapFactory.decodeFile(file.getAbsolutePath());handler.post(new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stubimageView.setImageBitmap(bitmap);}});}} catch (MalformedURLException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical" >    <ImageView        android:id="@+id/imageView1"        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:src="@drawable/abc_ab_bottom_solid_dark_holo" /></LinearLayout>

这里要读写SD卡，需要加入以下权限

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