android利用http协议下载网页内容到指定位置的方法

源码如下：

public class LoadTestActivity extends Activity {private TextView tv;private URL url;    /** Called when the activity is first created. */    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        init();        String urlStr="http://www.eoeandroid.com/thread-108676-1-1.html";        tv.setText(getWebText(urlStr));        //loadToSdcard(urlStr,"/TTTTT","Ada的文件.txt");        loadToLocation(urlStr,"Abc.txt");    }    //初始化组件    public void init(){    tv=(TextView)findViewById(R.id.tv);    }    //获取文件流    private InputStream getInputStream(String urlStr){    InputStream is = null;    try {url=new URL(urlStr);HttpURLConnection conn=(HttpURLConnection)url.openConnection();conn.setRequestMethod("POST");conn.setConnectTimeout(5000);conn.connect();is=conn.getInputStream();} catch (MalformedURLException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (ProtocolException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}return is;    }        //获取网页文本内容    private String getWebText(String urlStr){    InputStream is=getInputStream(urlStr);    StringBuffer sb=new StringBuffer();    BufferedReader br=new BufferedReader(new InputStreamReader(is));    String s="";    try {while((s=br.readLine())!=null){sb.append(s);}} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();Log.e("TAG", "流文件读写错误");}    finally{    try {br.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}    }    return sb.toString();    }        //下载文件    private void downloader(InputStream is,String path,String filename){    String filepath=null;    if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){    filepath=Environment.getExternalStorageDirectory()+path;        }    else{    Toast.makeText(LoadTestActivity.this, "SDCard异常，请检查SDCard是否安装正确！", Toast.LENGTH_LONG).show();    }    if(!filepathExist(filepath)){    createFilepath(filepath);    }    if(!fileExist(filepath+"/"+filename)){    createFile(is,filepath,filename);    }    }        //判断文件路径是否存在    private boolean filepathExist(String filepath){    File file=new File(filepath);    return file.exists();    }    //创建文件路径    private void createFilepath(String filepath){    File file=new File(filepath);    file.mkdirs();    }        //判断文件是否存在    private boolean fileExist(String filename){    return filepathExist(filename);    }    //创建文件    private void createFile(InputStream is,String filepath,String filename){    File file=new File(filepath+"/"+filename);    OutputStream os=null;    try {os=new FileOutputStream(file);int len=0;byte[] buffer=new byte[1024];while((len=is.read(buffer))!=-1){os.write(buffer, 0, len);}} catch (FileNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}       }        //下载文件到SDCard    private void loadToSdcard(String url,String filepath,String filename){    InputStream is=getInputStream(url);    downloader(is,filepath,filename);    }        //下载文件到应用所在的本地目录    private void loadToLocation(String urlStr,String filename){    InputStream is=getInputStream(urlStr);    OutputStream os=null;    try {os=this.openFileOutput(filename, Context.MODE_WORLD_READABLE|Context.MODE_WORLD_WRITEABLE);byte[] buffer=new byte[1024];int len=0;while((len=is.read(buffer))!=-1){os.write(buffer, 0, len);}} catch (FileNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}        }    }

不要忘记了在AndroidManifest.xml中添加权限：

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

注意：

一、loadToLocation(String urlStr,String filename)这个方法是把下载的内容放到以filename命名的文件当中，这个以filename命名的文件被放在应用所在的本地目录，可以通过以下方法来找到并查看它当中的内容：

在Eclipse中按以下路径进行查找：Window---Open perspective---Hierarchy  View---File  Explorer---data---data---<package  name,该程序所在包的包名>---files

通过上面的步骤就可以找到该文件了。

二、loadToSdcard(String url,String filepath,String filename)这个方法是把下载的内容放到sdcard中的以filepath命名的文件夹中的那个以filename命名的文件当中。可以打开android手机当中的“文件管理器”---sdcard---以filepath命名的文件夹，找到以filename命名的文件来查看所下载的内容。