Java ProcessBuilder 守护进程在退出 jvm 后将 output 重定向到文件而不终止进程

Question

I want to recreate java -jar [jar] &>logfile & in java via the ProcessBuilder.

Here's my current code:

File outFile = new File(".."); // logfile
ProcessBuilder builder = new ProcessBuilder(args);  // args = ["java", "-jar", "[jar]"]
builder.redirectError(outFile);
builder.redirectOutput(outFile);
Process process = builder.start();

The said jar is a web server and is supposed to run forever. But when I exit the java process that spawned the server it is also terminated.

My question now is: How do I tell the ProcessBuilder to execute the command in a background thread that doesn't terminate when the caller exits?

Prepending the args with nohup has not changed this behavior, using:

args = ["nohup", "java", "-jar", "[jar]"]

I've also tried

args = ["nohup", "java", "-jar", "[jar]", "&"]

Both of these do not work, neither on windows or linux

Answer 1

According to https://pubs.opengroup.org/onlinepubs/9699919799/functions/exec.html#tag_16_111_03 if parent processes ignore signals, their children will too.

So the easy fix here is to start my parent java process with nohup or append a &

Answer 2

before start this process, redirect input,output and erorr string to other file, then start the process, this process will not be closed after main process exit.