简单的下载代码

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class RbdTest {
	private static String musicURL = "http://droidreader.googlecode.com/files/droidreader-0.4.apk";
	private static String filename = "sb.apk";

	public static void main(String[] args) {
		download();
	}

	private static void download() {
		try {
			// 读取链接地址歌曲文件流
			URL url = new URL(musicURL);
			HttpURLConnection conn = (HttpURLConnection) url.openConnection();
			conn.setDoInput(true);
			conn.connect();
			InputStream is = conn.getInputStream();

			// 创建本地保存流的文件
			File musicFile = new File("c:/", filename);

			FileOutputStream fos = new FileOutputStream(musicFile);

			byte[] bt = new byte[1024];
			int i = 0;

			while ((i = is.read(bt)) > 0) {
				fos.write(bt, 0, i);
			}

			fos.close();
			is.close();

		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}