Question

我希望在Runtime.getRuntime（）。exec（...）的帮助下，从另一个内部运行NetBeans + Java 8中的程序。它正确运行javac和javah但不运行java。非常感谢您的帮助。

这是我想要运行的程序

package Programs;


public class AddTwoIntegers {

    private static Integer addTwoIntegers(Integer a, Integer b)
    {
        return a + b;
    }


    public static void main(String[] args)
    {
        Integer a = 5;
        Integer b = 8;
        Integer result = addTwoIntegers(a, b);
        System.out.println(a.toString()
                .concat(  " + ")
                .concat(  b.toString() )
                .concat( " = " )
                .concat(  result.toString()));
    }

}

这是假装运行上一课程的程序：

/*

This program is intended to run a java program from another java program
It runs javac and javah but not java.

 */
package Programs;

import java.io.*;

import java.util.Arrays;

//import java.util.concurrent.TimeUnit;
// java.util.concurrent.TimeUnit;

public class JavacTest {

    private static void printLines(String name, InputStream ins) throws Exception {
        String line;
        BufferedReader in = new BufferedReader(new InputStreamReader(ins));
        while ((line = in.readLine()) != null) {
            System.out.println(name + " " + line);
        }
    }

    private static void runProcess(String command) throws Exception {
        Process pro = Runtime.getRuntime().exec(command);
        printLines(command + " stdin:", pro.getInputStream());
        printLines(command + " stdout:", pro.getInputStream());
        printLines(command + " stderr:", pro.getErrorStream());
        //Take your time
        pro.waitFor();
        System.out.println(command + " exitValue() " + pro.exitValue());
    }

    private static void runProcess2(String [] command) throws Exception {
        Process pro = Runtime.getRuntime().exec(command);
        printLines(Arrays.toString(command) + " stdin:", pro.getInputStream());
        printLines(Arrays.toString(command) + " stdout:", pro.getInputStream());
        printLines(Arrays.toString(command) + " stderr:", pro.getErrorStream());
        //Take your time
        pro.waitFor();
        System.out.println(Arrays.toString(command) + " exitValue() " + pro.exitValue());
    } 




    public static void main(String[] args) {
        try {
            System.out.println("\nCompiling with javac: .java -> .class");
            runProcess("/home/jose/jdk1.8.0_111/bin/javac    
/home/jose/NetBeansProjects/eJVolu17P/src/Programs/AddTwoIntegers.java");
            //take your time
            //TimeUnit.SECONDS.sleep(1);
            System.out.println("\n\nShowing the bytecode content of the .class file with javap");
            runProcess("/home/jose/jdk1.8.0_111/bin/javap  -c 
/home/jose/NetBeansProjects/eJVolu17P/src/Programs/AddTwoIntegers.class");
            System.out.println("\n\nWorking Directory = " +
              System.getProperty("user.dir"));
            //TimeUnit.SECONDS.sleep(1);
            System.out.println("\n\nRunning the .class file with java");

            //runProcess("/home/jose/jdk1.8.0_111/bin/java   -cp    
/home/jose/NetBeansProjects/eJVolu17P/build/classes/Programs/AddTwoIntegers");
            //runProcess("/home/jose/jdk1.8.0_111/bin/java   -cp     /build/classes/Programs/AddTwoIntegers");
            String[] Commands  = new String[3];
            Commands[0] = "/home/jose/jdk1.8.0_111/bin/java";
            Commands[1] = "-classpath";
                    Commands[2] = "/home/jose/NetBeansProjects/eJVolu17P/build/classes/Programs/AddTwoIntegers";
            runProcess2(Commands );
        } catch (Exception e) {
        }
    }
}

Answer 1

您应该通过类似的方式运行程序 /home/jose/jdk1.8.0_111/bin/java -cp / home / jose / NetBeansProjects / eJVolu17P / build / classes / Programs.AddTwoIntegers 试一试，看看是否有效。

类路径应指向package.Java类名的父文件夹。检查一下是否有效。

Answer 2

我有一个误解：.exec（java ...）的参数有3个令牌，但在考虑了Ayusman提出的解决方案之后，很明显它由4个令牌组成，例如它在以下最终解决方案：

plt.margins(x=0.04)

Runtime.getRuntime（）。exec（...）在Java 8 + NetBeans下运行javac，javah但不运行java：

2 个答案: