processclassinst.java

来自「kaffe Java 解释器语言,源码,Java的子集系统,开放源代码」· Java 代码 · 共 110 行

/**
 * ???
 *
 * @author Godmar Back <[e-mail]>
 */
import java.util.Vector;
import java.lang.reflect.*;

class Base {
    static boolean useme;

    static {
	Base b = new Base();
	ProcessClassInst.v.addElement(b);
	useme = true;

	try {
	    Thread.sleep(2000);
	} catch (InterruptedException e) { }
	((Object)null).toString();
    }
    public String toString() { return "a base"; }
}

public class ProcessClassInst
{
    static Vector v = new Vector();

    public static void main(String av[]) throws Exception {
	// a watchdog thread that kills us off after 9 sec
	Thread wd = new Thread() {
	    public void run() {
		try {
		    Thread.sleep(9000);
		    System.out.println("sorry, you timed out");
		    System.exit(-1);
		} catch (Exception e) {
		    System.out.println(e);
		}
	    }
	};
	wd.setDaemon(true);
	wd.start();

	// a thread that will load Base
	Thread t = new Thread() {
	    public void run() {
		try {
		    Class.forName("Base");
		} catch (Throwable tx) {
		    // System.out.println(tx);
		}
	    }
	};
	t.start();
	Thread.sleep(1000);

	// nobody knows yet whether that should succeed...
	Thread t0 = new Thread() {
	    public void run() {
		try {
		    System.out.println("tan " + new Base());
		} catch (Throwable tt) {
		    System.out.println("tan " + tt);
		}
	    }
	};
	t0.start();
	t0.join();

	Class cc = v.elementAt(0).getClass();
	final Object ni = cc.newInstance();

/***
	Thread other = new Thread() {
	    public void run() {
		System.out.println(ni);
	    }
	};
	other.start();
	other.join();
***/

	System.out.println("m2 " + ni);

	Thread t2 = new Thread() {
	    public void run() {
		try {
		    System.out.println("t2 " + 
			v.elementAt(0).getClass().newInstance());
		} catch (Throwable ty) {
		    System.out.println(ty);
		}
	    }
	};
	t2.start();
	t2.join();
	System.exit(0);
    }
}

/* Expected Output:
tan java.lang.NoClassDefFoundError: Base
java.lang.NoClassDefFoundError: Base
   at java.lang.Class.getConstructor0 (Class.java)
   at java.lang.Class.getDeclaredConstructor (Class.java:174)
   at java.lang.Class.newInstance (Class.java:422)
   at ProcessClassInst.main (ProcessClassInst.java:72)
*/