deet.java

it contains the practical programs in our college

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
import java.util.Locale;
import static java.lang.System.out;
import static java.lang.System.err;

public class Deet<T> {
    private boolean testDeet(Locale l) {
	// getISO3Language() may throw a MissingResourceException
	out.format("Locale = %s, ISO Language Code = %s%n", l.getDisplayName(), l.getISO3Language());
	return true;
    }

    private int testFoo(Locale l) { return 0; }
    private boolean testBar() { return true; }

    public static void main(String... args) {
	if (args.length != 4) {
	    err.format("Usage: java Deet <classname> <langauge> <country> <variant>%n");
	    return;
	}

	try {
	    Class<?> c = Class.forName(args[0]);
	    Object t = c.newInstance();

	    Method[] allMethods = c.getDeclaredMethods();
	    for (Method m : allMethods) {
		String mname = m.getName();
		if (!mname.startsWith("test")
		    || (m.getGenericReturnType() != boolean.class)) {
		    continue;
		}
 		Type[] pType = m.getGenericParameterTypes();
 		if ((pType.length != 1)
		    || Locale.class.isAssignableFrom(pType[0].getClass())) {
 		    continue;
 		}

		out.format("invoking %s()%n", mname);
		try {
		    m.setAccessible(true);
		    Object o = m.invoke(t, new Locale(args[1], args[2], args[3]));
		    out.format("%s() returned %b%n", mname, (Boolean) o);

		// Handle any exceptions thrown by method to be invoked.
		} catch (InvocationTargetException x) {
		    Throwable cause = x.getCause();
		    err.format("invocation of %s failed: %s%n",
			       mname, cause.getMessage());
		}
	    }

        // production code should handle these exceptions more gracefully
	} catch (ClassNotFoundException x) {
	    x.printStackTrace();
	} catch (InstantiationException x) {
	    x.printStackTrace();
	} catch (IllegalAccessException x) {
	    x.printStackTrace();
	}
    }
}