从 URLConnection 读取二进制文件

我正在尝试从 URLConnection 读取二进制文件。当我用文本文件测试它时，它似乎工作正常，但对于二进制文件则不然。发送文件时，我在服务器上使用以下 mime 类型：

application/octet-stream

但到目前为止似乎没有任何效果。这是我用来接收文件的代码：

file = File.createTempFile( "tempfile", ".bin");
file.deleteOnExit();

URL url = new URL( "http://somedomain.com/image.gif" );

URLConnection connection = url.openConnection();

BufferedReader input = new BufferedReader( new InputStreamReader( connection.getInputStream() ) );

Writer writer = new OutputStreamWriter( new FileOutputStream( file ) );

int c;

while( ( c = input.read() ) != -1 ) {

   writer.write( (char)c );
}

writer.close();

input.close();

我就是这样做的

input = connection.getInputStream();
byte[] buffer = new byte[4096];
int n;

OutputStream output = new FileOutputStream( file );
while ((n = input.read(buffer)) != -1) 
{
    output.write(buffer, 0, n);
}
output.close();