Java笔记-使用processBuilder调用shell（Linux）

背景

环境是这样的，前端发起一个post请求，里面的信息带有要启动的进程，java后端接收到这个进程名后，使用linux的shell调用指定的程序。

代码

相关代码如下：

package xx.xx.xx.service;
 
import org.springframework.stereotype.Service;
 
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.concurrent.Semaphore;
 
@Service
public class ProcessService {
 
    static Boolean isSomeProcessRun = false;
    Semaphore semaphore = new Semaphore(1);
 
    public String runProcess(String processName){
 
        System.out.println(isSomeProcessRun);
        if(isSomeProcessRun){
 
            return "有程序正在计算，" + processName + " 无法启动";
        }
 
        try {
 
            isSomeProcessRun = true;
            semaphore.acquire();
            run(processName);
        }
        catch (InterruptedException e) {
 
            e.printStackTrace();
        }
 
        return processName + "后台已调用";
    }
 
    protected void run(String processName){
 
        Thread thread = new Thread(){
 
            @Override
            public void run() {
 
                ProcessBuilder processBuilder = new ProcessBuilder();
                processBuilder.command("/root/program/" + processName);
                processBuilder.redirectErrorStream(true);
                try {
 
                    Process start = processBuilder.start();
                    InputStream inputStream = start.getInputStream();
                    InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "gbk");
 
                    char[] chs = new char[1024];
                    int len = -1;
                    while ((len = inputStreamReader.read(chs)) != -1){
 
                        String str = new String(chs, 0, len);
                        System.out.println(str);
                    }
 
                    inputStreamReader.close();
                    inputStream.close();
                }
                catch (IOException e) {
 
                    e.printStackTrace();
                }
 
                semaphore.release();
                isSomeProcessRun = false;
            }
        };
        thread.start();
    }
}

这里有几点要注意的：

调用shell的关键代码：

Thread thread = new Thread(){
 
    @Override
    public void run() {
 
        ProcessBuilder processBuilder = new ProcessBuilder();
        processBuilder.command("/root/program/" + processName);
        processBuilder.redirectErrorStream(true);
        try {
 
            Process start = processBuilder.start();
            InputStream inputStream = start.getInputStream();
            InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "gbk");
 
            char[] chs = new char[1024];
            int len = -1;
            while ((len = inputStreamReader.read(chs)) != -1){
 
                String str = new String(chs, 0, len);
                System.out.println(str);
            }
 
            inputStreamReader.close();
            inputStream.close();
        }
        catch (IOException e) {
 
            e.printStackTrace();
        }
 
        semaphore.release();
        isSomeProcessRun = false;
    }
};

启动一个进程，让这个进程调用shell，用这种方式来做，比较合理。