Android下载文件到SD卡

 1 //创建一个URL对象
 2 URL url = new URL(urlString);
 3  
 4 //创建一个HttpURLConnection
 5 HttpURLConnetion urlConn = (HttpURLConnection)url.openConnecton();
 6  
 7 //读取数据
 8 BufferReader buffer = new BufferReader(new InputStreamReader(urlConn.getInputStream()));
 9 StringBuffer sb = null;
10 String line = null;
11 while((line = buffer.readline()) != null){
12     sb.append(line);
13 }

//创建一个URL对象
URL url = new URL(urlString);
 
//创建一个HttpURLConnection
HttpURLConnection urlConn ＝(HttpURLConnection)url.openConnection();
 
//获取一个InputStream
InputStream inputStream = urlConn.getInputStream();
 
//获取SD卡的路径
String SDPath = Environment.getExternalStorageDirectory() + "/";

//创建要使用的文件夹
File dir = new File(SDPath + dirName);
dir.mkdirs();

//创建输出文件
File file = new File(SDPath + dirName + fileName);
file.createNewFile();

//创建一个文件输出流
OutputStream output = new FileOutputStream(file);
 
//建立缓冲
byte[] buffer = new byte[1*1024];

//Stream读取索引
int downloadNum = 0;
 
//将输入流写到文件当中
while((downloadNum = inputStream.read(buffer)) != -1){
   output.write(buffer, 0, downloadNum);
}
output.flush();