methodutils.java

APACHE 公司出的java bean 工具包

    }


    /**
     * <p>Invoke a method whose parameter types match exactly the parameter
     * types given.</p>
     *
     * <p>This uses reflection to invoke the method obtained from a call to
     * <code>getAccessibleMethod()</code>.</p>
     *
     * @param object invoke method on this object
     * @param methodName get method with this name
     * @param args use these arguments - treat null as empty array
     * @param parameterTypes match these parameters - treat null as empty array
     * @return The value returned by the invoked method
     *
     * @throws NoSuchMethodException if there is no such accessible method
     * @throws InvocationTargetException wraps an exception thrown by the
     *  method invoked
     * @throws IllegalAccessException if the requested method is not accessible
     *  via reflection
     */
    public static Object invokeExactMethod(
            Object object,
            String methodName,
            Object[] args,
            Class[] parameterTypes)
            throws
            NoSuchMethodException,
            IllegalAccessException,
            InvocationTargetException {
        
        if (args == null) {
            args = EMPTY_OBJECT_ARRAY;
        }  
                
        if (parameterTypes == null) {
            parameterTypes = EMPTY_CLASS_PARAMETERS;
        }

        Method method = getAccessibleMethod(
                object.getClass(),
                methodName,
                parameterTypes);
        if (method == null) {
            throw new NoSuchMethodException("No such accessible method: " +
                    methodName + "() on object: " + object.getClass().getName());
        }
        return method.invoke(object, args);

    }

    /**
     * <p>Invoke a static method whose parameter types match exactly the parameter
     * types given.</p>
     *
     * <p>This uses reflection to invoke the method obtained from a call to
     * {@link #getAccessibleMethod(Class, String, Class[])}.</p>
     *
     * @param objectClass invoke static method on this class
     * @param methodName get method with this name
     * @param args use these arguments - treat null as empty array
     * @param parameterTypes match these parameters - treat null as empty array
     * @return The value returned by the invoked method
     *
     * @throws NoSuchMethodException if there is no such accessible method
     * @throws InvocationTargetException wraps an exception thrown by the
     *  method invoked
     * @throws IllegalAccessException if the requested method is not accessible
     *  via reflection
     */
    public static Object invokeExactStaticMethod(
            Class objectClass,
            String methodName,
            Object[] args,
            Class[] parameterTypes)
            throws
            NoSuchMethodException,
            IllegalAccessException,
            InvocationTargetException {
        
        if (args == null) {
            args = EMPTY_OBJECT_ARRAY;
        }  
                
        if (parameterTypes == null) {
            parameterTypes = EMPTY_CLASS_PARAMETERS;
        }

        Method method = getAccessibleMethod(
                objectClass,
                methodName,
                parameterTypes);
        if (method == null) {
            throw new NoSuchMethodException("No such accessible method: " +
                    methodName + "() on class: " + objectClass.getName());
        }
        return method.invoke(null, args);

    }

    /**
     * <p>Invoke a named static method whose parameter type matches the object type.</p>
     *
     * <p>The behaviour of this method is less deterministic 
     * than {@link #invokeExactMethod(Object, String, Object[], Class[])}. 
     * It loops through all methods with names that match
     * and then executes the first it finds with compatable parameters.</p>
     *
     * <p>This method supports calls to methods taking primitive parameters 
     * via passing in wrapping classes. So, for example, a <code>Boolean</code> class
     * would match a <code>boolean</code> primitive.</p>
     *
     * <p> This is a convenient wrapper for
     * {@link #invokeStaticMethod(Class objectClass,String methodName,Object [] args)}.
     * </p>
     *
     * @param objectClass invoke static method on this class
     * @param methodName get method with this name
     * @param arg use this argument
     * @return The value returned by the invoked method
     *
     * @throws NoSuchMethodException if there is no such accessible method
     * @throws InvocationTargetException wraps an exception thrown by the
     *  method invoked
     * @throws IllegalAccessException if the requested method is not accessible
     *  via reflection
     */
    public static Object invokeStaticMethod(
            Class objectClass,
            String methodName,
            Object arg)
            throws
            NoSuchMethodException,
            IllegalAccessException,
            InvocationTargetException {

        Object[] args = {arg};
        return invokeStaticMethod (objectClass, methodName, args);

    }


    /**
     * <p>Invoke a named static method whose parameter type matches the object type.</p>
     *
     * <p>The behaviour of this method is less deterministic 
     * than {@link #invokeExactMethod(Object object,String methodName,Object [] args)}. 
     * It loops through all methods with names that match
     * and then executes the first it finds with compatable parameters.</p>
     *
     * <p>This method supports calls to methods taking primitive parameters 
     * via passing in wrapping classes. So, for example, a <code>Boolean</code> class
     * would match a <code>boolean</code> primitive.</p>
     *
     * <p> This is a convenient wrapper for
     * {@link #invokeStaticMethod(Class objectClass,String methodName,Object [] args,Class[] parameterTypes)}.
     * </p>
     *
     * @param objectClass invoke static method on this class
     * @param methodName get method with this name
     * @param args use these arguments - treat null as empty array
     * @return The value returned by the invoked method
     *
     * @throws NoSuchMethodException if there is no such accessible method
     * @throws InvocationTargetException wraps an exception thrown by the
     *  method invoked
     * @throws IllegalAccessException if the requested method is not accessible
     *  via reflection
     */
    public static Object invokeStaticMethod(
            Class objectClass,
            String methodName,
            Object[] args)
            throws
            NoSuchMethodException,
            IllegalAccessException,
            InvocationTargetException {
        
        if (args == null) {
            args = EMPTY_OBJECT_ARRAY;
        }  
        int arguments = args.length;
        Class[] parameterTypes = new Class[arguments];
        for (int i = 0; i < arguments; i++) {
            parameterTypes[i] = args[i].getClass();
        }
        return invokeStaticMethod (objectClass, methodName, args, parameterTypes);

    }


    /**
     * <p>Invoke a named static method whose parameter type matches the object type.</p>
     *
     * <p>The behaviour of this method is less deterministic 
     * than {@link 
     * #invokeExactStaticMethod(Class objectClass,String methodName,Object [] args,Class[] parameterTypes)}. 
     * It loops through all methods with names that match
     * and then executes the first it finds with compatable parameters.</p>
     *
     * <p>This method supports calls to methods taking primitive parameters 
     * via passing in wrapping classes. So, for example, a <code>Boolean</code> class
     * would match a <code>boolean</code> primitive.</p>
     *
     *
     * @param objectClass invoke static method on this class
     * @param methodName get method with this name
     * @param args use these arguments - treat null as empty array
     * @param parameterTypes match these parameters - treat null as empty array
     * @return The value returned by the invoked method
     *
     * @throws NoSuchMethodException if there is no such accessible method
     * @throws InvocationTargetException wraps an exception thrown by the
     *  method invoked
     * @throws IllegalAccessException if the requested method is not accessible
     *  via reflection
     */
    public static Object invokeStaticMethod(
            Class objectClass,
            String methodName,
            Object[] args,
            Class[] parameterTypes)
                throws
                    NoSuchMethodException,
                    IllegalAccessException,
                    InvocationTargetException {
                    
        if (parameterTypes == null) {
            parameterTypes = EMPTY_CLASS_PARAMETERS;
        }        
        if (args == null) {
            args = EMPTY_OBJECT_ARRAY;
        }  

        Method method = getMatchingAccessibleMethod(
                objectClass,
                methodName,
                parameterTypes);
        if (method == null) {
            throw new NoSuchMethodException("No such accessible method: " +
                    methodName + "() on class: " + objectClass.getName());
        }
        return method.invoke(null, args);
    }


    /**
     * <p>Invoke a static method whose parameter type matches exactly the object
     * type.</p>
     *
     * <p> This is a convenient wrapper for
     * {@link #invokeExactStaticMethod(Class objectClass,String methodName,Object [] args)}.
     * </p>
     *
     * @param objectClass invoke static method on this class
     * @param methodName get method with this name
     * @param arg use this argument
     * @return The value returned by the invoked method
     *
     * @throws NoSuchMethodException if there is no such accessible method
     * @throws InvocationTargetException wraps an exception thrown by the
     *  method invoked
     * @throws IllegalAccessException if the requested method is not accessible
     *  via reflection
     */
    public static Object invokeExactStaticMethod(
            Class objectClass,
            String methodName,
            Object arg)
            throws
            NoSuchMethodException,
            IllegalAccessException,
            InvocationTargetException {

        Object[] args = {arg};
        return invokeExactStaticMethod (objectClass, methodName, args);

    }


    /**
     * <p>Invoke a static method whose parameter types match exactly the object
     * types.</p>
     *
     * <p> This uses reflection to invoke the method obtained from a call to
     * {@link #getAccessibleMethod(Class, String, Class[])}.</p>
     *
     * @param objectClass invoke static method on this class
     * @param methodName get method with this name
     * @param args use these arguments - treat null as empty array
     * @return The value returned by the invoked method
     *
     * @throws NoSuchMethodException if there is no such accessible method
     * @throws InvocationTargetException wraps an exception thrown by the
     *  method invoked
     * @throws IllegalAccessException if the requested method is not accessible
     *  via reflection
     */
    public static Object invokeExactStaticMethod(
            Class objectClass,
            String methodName,
            Object[] args)
            throws
            NoSuchMethodException,
            IllegalAccessException,
            InvocationTargetException {
        if (args == null) {
            args = EMPTY_OBJECT_ARRAY;
        }  
        int arguments = args.length;
        Class[] parameterTypes = new Class[arguments];
        for (int i = 0; i < arguments; i++) {
            parameterTypes[i] = args[i].getClass();
        }
        return invokeExactStaticMethod(objectClass, methodName, args, parameterTypes);