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package com.janetfilter.core.utils;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.management.ManagementFactory;
import java.util.ArrayList;
import java.util.List;
public class ProcessUtils {
private static String processId;
public synchronized static String currentId() {
if (null == processId) {
String name = ManagementFactory.getRuntimeMXBean().getName() + "@";
processId = name.split("@", 2)[0];
}
return processId;
}
public static int start(ProcessBuilder pb) throws Exception {
return start(pb, System.out, System.err);
}
public static int start(ProcessBuilder pb, OutputStream out) throws Exception {
return start(pb, out, null);
}
public static int start(ProcessBuilder pb, OutputStream out, OutputStream err) throws Exception {
Process p = pb.start();
List threads = new ArrayList<>();
if (null != out) {
threads.add(new Thread(new RedirectOutput(p.getInputStream(), out)));
}
if (null != err) {
threads.add(new Thread(new RedirectOutput(p.getErrorStream(), err)));
}
for (Thread thread : threads) {
thread.start();
}
for (Thread thread : threads) {
thread.join();
}
return p.waitFor();
}
static class RedirectOutput implements Runnable {
private static final int BUFF_SIZE = 1024;
private final InputStream origin;
private final OutputStream dest;
RedirectOutput(InputStream origin, OutputStream dest) {
this.origin = origin;
this.dest = dest;
}
public void run() {
int length;
byte[] buffer = new byte[BUFF_SIZE];
try {
while ((length = origin.read(buffer)) != -1) {
dest.write(buffer, 0, length);
}
} catch (IOException e) {
throw new RuntimeException("ERROR: Redirect output failed.", e);
}
}
}
}