Redirection issues when Java programs call Linux commands

Java can call Linux commands through runtime in the following format:
Runtime.getruntime(cmd.exe C (command)
In this way, there is no output during execution, because calling runtime.exe C program will initiate a program and return the process class. Then, runtime.getruntime(cmd.exe C (command) returns a process class instance, which can be used to control the process or obtain information about the process. The sub-process created by calling the runtime.exe C method does not have its own terminal or console. The stdin, stdou, and stderr of the sub-process are respectively created through the process. getinputstream (), process. getoutputstream (), process. the geterrorstream () method is redirected to its parent process.
If you need to input data to a sub-process or obtain the output of the sub-process, you need to use these streams.

The following code obtains the execution result of the Linux Command:

import java.io.BufferedReader;import java.io.InputStreamReader;public class Hello {/** * @param args */public static void main(String[] args) {// TODO Auto-generated method stubString command ="/home/hello/extract_exper/extract_each.sh 1.txt ";try {Process ps = Runtime.getRuntime().exec(command);BufferedReader br = new BufferedReader(new InputStreamReader(ps.getInputStream()));StringBuffer sb = new StringBuffer();String line;while ((line = br.readLine()) != null) {sb.append(line).append("\n");}String result = sb.toString();System.out.println(result);} catch (Exception e) {e.printStackTrace();}}}