Android Http访问网络 学习（慕课网学习）

一：通过Http 下载百度源码加载到 WebView显示

1：需要访问网络必须先要获取网络权限：

<span style="font-family: Arial, Helvetica, sans-serif;">   <uses-permission android:name="android.permission.INTERNET" ></span>

    </uses-permission>

2：在xml文件 定义Webview。

3：因为网络数据加载延迟问题，所以必须要用线程类来显示网页：

package testHttp;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.R.string;import android.os.Handler;import android.webkit.WebView;public class HttpThread extends Thread{private String url;private WebView webView;private Handler handler;HttpThread(String url,WebView webView,Handler handler){this.url=url;this.webView=webView;this.handler=handler;}@Overridepublic void run() {try {URL httpUrl=new URL(url); try {HttpURLConnection httpConnection=(HttpURLConnection) httpUrl.openConnection();//建立http连接httpConnection.setReadTimeout(5000);//设置超时时间httpConnection.setRequestMethod("GET");//设置请求为GET方法final StringBuffer bufferString=new StringBuffer();//用Stringbuffer来存储读到的代码BufferedReader reader=new BufferedReader(new InputStreamReader(httpConnection.getInputStream()));String str;while((str=reader.readLine())!=null){bufferString.append(str);}handler.post(new Runnable() {@Overridepublic void run() {

webView.loadData(bufferString.toString(), 

"text/html;charset=utf-8", null);//将webView显示到网页上，还是要想 Web一样设置其编码}});} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}} catch (MalformedURLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}

4：在MainActivity中建立线程，并传参数到Thread：

package testHttp;import com.example.androidtest.R;import android.app.Activity;import android.os.Bundle;import android.os.Handler;import android.webkit.WebView;public class TestHttpActivity extends Activity{private WebView webView;private String urlString="http://www.baidu.com";Handler handler=new Handler();@Overrideprotected void onCreate(Bundle savedInstanceState) {// TODO Auto-generated method stubsuper.onCreate(savedInstanceState);setContentView(R.layout.http_main_activity);webView=(WebView) findViewById(R.id.httpWebView);new HttpThread(urlString, webView, handler).start();}}

二：使用http协议在app中加载图片：

1：手写也是网络权限；

2：在xml文件 定义ImageView。

3：使用http获取网络图片，但是不同的是现在要通过二进制流来获取图片了。

先用二进制流获取到图片到本地之后，再用本地地址打开图片到ImageView：

package testHttp;import java.io.BufferedReader;import java.io.File;import java.io.FileOutputStream;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 org.apache.http.HttpConnection;import android.R.string;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.os.Environment;import android.os.Handler;import android.webkit.WebView;import android.widget.ImageView;public class HttpThread extends Thread{private String url;private ImageView imageView;private Handler handler;HttpThread(String url,ImageView imageView,Handler handler){this.url=url;this.imageView=imageView;this.handler=handler;}@Overridepublic void run() {try {URL httpUrl=new URL(url);try {HttpURLConnection httpConnection=(HttpURLConnection) httpUrl.openConnection();httpConnection.setReadTimeout(5000);httpConnection.setRequestMethod("GET");httpConnection.setDoInput(true); //允许写InputStream inputStream=httpConnection.getInputStream();FileOutputStream fileOutputStream=null;File downFile=null;String fileNameString=String.valueOf(System.currentTimeMillis());if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){File parentFile=Environment.getExternalStorageDirectory();//获取本地路径downFile=new File(parentFile, fileNameString);fileOutputStream = new FileOutputStream(downFile);}byte[] bt=new byte[2*1024];int len;if(fileOutputStream!=null){while((len=inputStream.read(bt))!=-1){fileOutputStream.write(bt, 0, len);}}final Bitmap bitmap=BitmapFactory.decodeFile(downFile.getAbsolutePath());handler.post(new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stubimageView.setImageBitmap(bitmap);}});} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}} catch (MalformedURLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}