Android开发 --- 文件下载

1.Android 提供 URL、HttpURLConnection类

URL url = new URL(urlStr);  //根据url地址创建URL对象

HttpURLConnection  httpConn =(HttpURLConnection)url.openConnection();  //获取HttpURLConnection实体

inputStream = httpConn.getInputStream();   // 获取流管道

 

2. 字符文件

buffer = new BufferedReader(new InputStreamReader(urlConn.getInputStream()));

while( (line=buffer.readLine()) != null ){

sb.append(line);

}

3.二进制文件

OutputStream outStream = new FileOutputStream(file);

byte[] buffer = new byte[ 4 * 1024];

while((input.read(buffer)) != -1) {   //input 为urlConn.getInputStream() 获取的inputstream对象

outStream.write(buffer);

}

outStream.flush();

 

4. 配置 权限

在 AndroidManifest.xml根节点中加入如下语句

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

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