Java 通过传递参数从另一个 jar 运行 jar

Question

我已经生成了 run1.jar:

   package runner;

    import java.io.IOException;
    import java.io.PrintWriter;

    public class Run1 {
        public static void main(String[] args) {

            int i = Integer.parseInt(args[0]);
            System.out.println(i);

            try {
                PrintWriter writer = new PrintWriter("1.txt", "UTF-8");
                writer.println(i);
                writer.println(i);
                writer.close();
            } catch (IOException e) {
                // do something
            }

        }
    }

我还生成了 run2.jar:

package runner;

import java.io.File;
import java.io.IOException;

public class Run2 {

    public static void main(String[] args) throws IOException, InterruptedException {

        ProcessBuilder pb = new ProcessBuilder("java", "-jar", "C:\\test2\\run1.jar", "1");
        pb.directory(new File("C:\\"));
        try {
            Process p = pb.start();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

}

我已经使用此命令 java -jar run2.jar 1 运行并运行它。使用此命令运行预期结果:java -jar run2.jar 不起作用。

如何从 run2.jar 的 main 方法内部传递参数来运行 run2.jar？

错误是:

C:\test2>java -jar run2.jar
Exception in thread "main" java.lang.reflect.InvocationTargetException
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader.main(JarRsrcLoa
der.java:58)
Caused by: java.lang.ArrayIndexOutOfBoundsException: 0
        at runner.Run1.main(Run1.java:9)

Answer 1

我们在这里，下面是两个不同的例子来回答你的问题

Process proc = Runtime.getRuntime().exec("java -jar C:\\...\\Run1.jar 1");
        proc.waitFor();

        //2 inputstream for the result and for the errors in subprogram     
        InputStream in = proc.getInputStream();
        InputStream err = proc.getErrorStream();

        byte b[]=new byte[in.available()];
        in.read(b,0,b.length);
        System.out.println(new String(b));

        byte c[]=new byte[err.available()];
        err.read(c,0,c.length);
        System.out.println(new String(c));

        ProcessBuilder pb = new ProcessBuilder("java", "-jar", "C:\\...\\Run1.jar", "1");
        Process proc2 = pb.start();
        proc2.waitFor();

        InputStream in2 = proc2.getInputStream();
        InputStream err2 = proc2.getErrorStream();

        byte b2[]=new byte[in.available()];
        in.read(b,0,b.length);
        System.out.println(new String(b));

        byte c2[]=new byte[err.available()];
        err.read(c,0,c.length);
        System.out.println(new String(c));

IDE (Eclipse) 的输出

命令行输出:

注意:“ok”是我放入 Run1.jar 中的 System.out.println(我用大写字母保存了文件 jar，但你可以使用你自己的名字)