得到一个方法的异常信息

import java.lang.reflect.Method;
import java.lang.reflect.Type;
import static java.lang.System.out;

public class MethodSpy {
    private static final String fmt = "%24s: %s%n";

    // for the morbidly curious
    <E extends RuntimeException> void genericThrow() throws E {
    }

    public static void main(String... args) {
        try {
            Class<?> c = Class.forName(args[0]);
            Method[] allMethods = c.getDeclaredMethods();
            for (Method m : allMethods) {
                if (!m.getName().equals(args[1])) {
                    continue;
                }
                out.format("%s%n", m.toGenericString());

                out.format(fmt, "ReturnType", m.getReturnType());
                out.format(fmt, "GenericReturnType",
                        m.getGenericReturnType());

                Class<?>[] pType = m.getParameterTypes();
                Type[] gpType = m.getGenericParameterTypes();
                for (int i = 0; i < pType.length; i++) {
                    out.format(fmt, "ParameterType", pType[i]);
                    out.format(fmt, "GenericParameterType", gpType[i]);
                }

                Class<?>[] xType = m.getExceptionTypes();
                Type[] gxType = m.getGenericExceptionTypes();
                for (int i = 0; i < xType.length; i++) {
                    out.format(fmt, "ExceptionType", xType[i]);
                    out.format(fmt, "GenericExceptionType", gxType[i]);
                }
            }

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