java一个简单的下载功能分享

最近闲来无事，所以写了一个java的下载模块，稍微修改了一下弄成了无限下载。

首先是线程类：

package com.gzh.test;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.net.HttpURLConnection;
import java.net.URL;

public class DownloadThread extends Thread {
	private String url = null;
	private String file = null;
	private long offset = 0;
	private long length = 0;

	public DownloadThread(String url, String file, long offset, long length) {
		this.url = url;
		this.file = file;
		this.offset = offset;
		this.length = length;
	}

	@Override
	public void run() {
		try {
			HttpURLConnection conn = (HttpURLConnection) new URL(url)
					.openConnection();
			conn.setRequestMethod("GET");
			conn.setRequestProperty("RANGE", "bytes=" + this.offset + "-"
					+ (this.offset + this.length - 1));
			BufferedInputStream bis = new BufferedInputStream(
					conn.getInputStream());
			byte[] buf = new byte[1024];
			int bytesRead;
			while ((bytesRead = bis.read(buf, 0, buf.length)) != -1) {
				this.writeFile(file, offset, buf, bytesRead);
				this.offset += bytesRead;
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	public void writeFile(String fileName, long offset, byte[] bytes,
			int realLength) throws IOException {
		File file = new File(fileName);
		RandomAccessFile raf = new RandomAccessFile(file, "rw");
		raf.seek(offset);
		raf.write(bytes, 0, realLength);
		raf.close();
	}
}

 然后随便写一个类实现main():

while循环是个死循环，每隔10秒运行一次线程。

 

package com.gzh.test;

import java.io.File;

public class Main {

	public static void main(String[] args) {
		String url = "http://d2.eoemarket.com/upload/apps/2013/0607/148237/apks/07c73b70-9cbf-4a7f-eeb7-1f8b35e24cd1.apk";
		int a = 0;
		while (true) {
			String file = "D:\\javaTest\\" + System.currentTimeMillis()
					+ ".apk";
			long offset = 0;
			long length = 0;
			new DownloadThread(url, file, offset, length).start();
			try {
				Thread.sleep(15000);
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
			System.out.println(a++);
		}
	}
}

 灰常无聊啊，只是希望初学者能够掌握简单的java单线程下载。最后推荐一款IT学习软件“IT视频排行榜”，绿色健康小清新呦，地址→http://www.eoemarket.com/soft/148237.html