多线程下载时HTTP response code: 416 解决方案

今天用java写的多线程下载报错，找了很久，发现是第一次请求服务器时响应码正常，开启多线程部分的响应码为416，响应码对应的意思可以去这里看看点击打开链接。主要意思就是public void
setRequestProperty (String field,

String newValue)出现了错误，设置的下载字节范围和访问文件大小有出入，要么就是上面确认各个线程的下载范围出现问题，要么就是该语句没用对。将之前的每个线程下载字节范围都打印出来发现没问题。后来查看setRequestProperty相关资料发现是setRequestProperty("Range", "bytes：" + threadStart + "-" + threadEnd)这里出错了，bytes后面应该是=号而不是：

附上没有完成断点下载的多线程下载代码.

（我用的是某马的74期的视频学习的，而他的代码用的是：却可以运行，有点郁闷，，还有他的getFileName（）方法中获取/的索引后没有+1就截取文件名得到的是/feiq.exe, 那也是错误的,后面运行时会报错拒绝访问)

package com.lyle.study;

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

public class UpDownload1 {

public static String path = "http://192.168.56.1:8080/itheima74/feiq.exe";
public static int threadCount = 3;

public static void main(String[] args) {

try {

URL url = new URL(path);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.setConnectTimeout(1000 * 10);

if (connection.getResponseCode() == 200) {
long length = connection.getContentLength();

RandomAccessFile randomAccessFile = new RandomAccessFile(new File(getFileName()),
"rw");
randomAccessFile.setLength(length);
randomAccessFile.close();

long threadSize = length / threadCount;

for (int i = 0; i < threadCount; i++) {
int threadId = i;
long threadStart = threadId * threadSize;
long threadEnd = (threadId == threadCount - 1 ? length - 1 : (threadId + 1)
* threadSize - 1);

new DoThreadOpen(threadStart, threadEnd).start();

}

}
} catch (Exception e) {

e.printStackTrace();
}

}

public static class DoThreadOpen extends Thread {

private long threadStart;
private long threadEnd;

public DoThreadOpen(long threadStart, long threadEnd) {
this.threadEnd = threadEnd;
this.threadStart = threadStart;
}

@Override
public void run() {

try {

URL url = new URL(path);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.setConnectTimeout(1000 * 10);

connection.setRequestProperty("Range", "bytes=" + threadStart + "-" + threadEnd);

int code = connection.getResponseCode();

if (code == 206) {
InputStream inputStream = connection.getInputStream();
RandomAccessFile randomAccessFile = new RandomAccessFile(
new File(getFileName()), "rw");
randomAccessFile.seek(threadStart);

byte[] buffer = new byte[1024];
int len;
while ((len = inputStream.read(buffer)) != -1) {
randomAccessFile.write(buffer, 0, len);

}

inputStream.close();
randomAccessFile.close();

}

} catch (Exception e) {

e.printStackTrace();
}

}

}

private static String getFileName() {

return path.substring(path.lastIndexOf("/") + 1);
}

}