标签：线程 adc 服务 [] for size nec new 一个
package downLoad; import java.io.InputStream; import java.io.RandomAccessFile; import java.net.HttpURLConnection; import java.net.URL; public class ThreadDownLoader extends Thread { private String path; private int startIndex; private int endIndex; private int threadId; private int threadCount; // 正在运行的线程个数 private static int runningThreadCount = 3; ThreadDownLoader(String path, int startIndex, int endIndex, int threadId, int threadCount) { this.path = path; this.startIndex = startIndex; this.endIndex = endIndex; this.threadId = threadId; this.threadCount = threadCount; } @Override public void run() { downLoad(path, startIndex, endIndex, threadId, threadCount); } public void downLoad(String path, int startIndex, int endIndex, int threadId, int threadCount) { try { URL url = new URL(path); HttpURLConnection conn = (HttpURLConnection) url.openConnection(); conn.setRequestMethod("GET"); conn.setConnectTimeout(3000); // 设置子线程请求数据的范围 conn.setRequestProperty("Range", "bytes=" + startIndex + "-" + endIndex); int code = conn.getResponseCode(); if (code == 206) {// 请求部分数据 InputStream is = conn.getInputStream(); RandomAccessFile file = new RandomAccessFile("temp.exe", "rw"); // 指定从哪个位置开始写数据 file.seek(startIndex); byte[] buffer = new byte[1024]; int len = -1; while ((len = is.read(buffer)) != -1) { file.write(buffer, 0, len); } file.close(); System.out.println("线程" + threadId + "下载完成..............."); synchronized (ThreadDownLoader.this) { runningThreadCount--; if (runningThreadCount == 0) { System.out.println("文件下载完成..............."); } } } } catch (Exception e) { System.out.println("线程" + threadId + "下载失败..............."); e.printStackTrace(); } } }
package downLoad;
import java.io.RandomAccessFile;
import java.net.HttpURLConnection;
import java.net.URL;
public class MultiThreadDownLoader {
// 2、使用的子线程的个数
private static int threadCount = 3;
/**
* @param args
*/
public static void main(String[] args) {
try {
String path = "https://download.jetbrains.8686c.com/idea/ideaIU-2018.3.1.exe";//文件路径
URL url = new URL(path);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.setConnectTimeout(3000);
int code = conn.getResponseCode();
if (code == 200) {
int length = conn.getContentLength();
// 1、在客户端创建一个与服务端文件一样大小的文件
RandomAccessFile file = new RandomAccessFile("temp.exe", "rw");
file.setLength(length);
// 3、每个子线程下载数据块 ,下载的起始位置和结束位置
int blockSize = length / threadCount;
// threadId * blockSize ---- （threadId+1）* blockSize -1
for (int threadId = 0; threadId < threadCount; threadId++) {
// 下载的起始位置和结束位置
int startIndex = threadId * blockSize;
int endIndex = 0;
if (threadId != (threadCount - 1)) {
endIndex = (threadId + 1) * blockSize - 1;
} else {
endIndex = length - 1;
}
// 开启子线程下载数据
new ThreadDownLoader(path, startIndex, endIndex, threadId, threadCount).start();
}
} else {
// 抛出异常
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
标签：线程 adc 服务 [] for size nec new 一个
原文地址：https://www.cnblogs.com/ch94/p/10102920.html
