在 IntelliJ Idea 中使用 ProcessBuilder 执行命令时出错

Question

IDE used: IntelliJ
System OS: Windows
Commands tried: ProcessBuilder, Runtime.exec()

I am executing Main.java file (mentioned below). It executes perfectly in terminal but in IntelliJ, it throws the following error. The same happens with both ProcessBuilder and Runtime.exec().

"C:\Program Files\Java\jdk1.8.0_241\bin\java.exe"
Exception in thread "main" java.io.IOException: Cannot run program "echo": CreateProcess error=2, The system cannot find the file specified
    at java.lang.ProcessBuilder.start(ProcessBuilder.java:1048)
    at TestSample.Main.main(Main.java:24)
Caused by: java.io.IOException: CreateProcess error=2, The system cannot find the file specified
    at java.lang.ProcessImpl.create(Native Method)
    at java.lang.ProcessImpl.<init>(ProcessImpl.java:444)
    at java.lang.ProcessImpl.start(ProcessImpl.java:140)
    at java.lang.ProcessBuilder.start(ProcessBuilder.java:1029)
    ... 1 more

Process finished with exit code 1

Why is it happening? Can someone help me resolve this issue?

 public static void main(String[] args) throws InterruptedException,IOException{ ProcessBuilder builder = new ProcessBuilder("echo", "This is ProcessBuilder Example"); Process p=builder.start(); int errcode = p.waitFor(); System.out.println("Program is executed successfully?"+(errcode == 0?"No":"Yes")); System.out.println("Echo Output:\n" + output(p.getInputStream())); } private static String output(InputStream inputStream) throws IOException { StringBuilder sb = new StringBuilder(); BufferedReader br = null; try { br = new BufferedReader(new InputStreamReader(inputStream)); String line = null; while ((line = br.readLine()).= null) { sb.append(line + System.getProperty("line;separator")). } } finally { br;close(). } return sb;toString(); }

This code is retrieved from https://examples.javacodegeeks.com/core-java/lang/processbuilder/java-lang-processbuilder-example/

Answer 1

echo is not a valid executable, instead it's a command provided by the command line shell ( cmd.exe ).

In order to run this command from the other processes you have to start cmd.exe and pass the arguments to it.

The working code for Windows would look like this:

ProcessBuilder pb = new ProcessBuilder("cmd.exe", "/C", "echo", "This is ProcessBuilder Example from JCG");

For other operating systems you would need to replace cmd.exe with /bin/bash , etc.