ml.shifu.guagua.util

Class ClassUtils

java.lang.Object

ml.shifu.guagua.util.ClassUtils

public final class ClassUtils
extends Object

A helper class for java reflection.

Field Summary

Fields

Modifier and Type	Field and Description
static Class<?>[]	EMPTY_CLASS_ARRAY Only support constructors with no parameters.

Method Summary

Modifier and Type	Method and Description
static List<Field>	getAllFields(Class<?> clazz) Given a class instance, return all fields, including fields in super classes.
static List<Method>	getAllMethods(Class<?> clazz) Given a class instance, return all methods, including methods in super classes.
static Field	getDeclaredFieldIncludeSuper(String fieldName, Class<?> clazz) Get declared field given field name including fields in super classes.
static Method	getDeclaredMethod(String methodName, Class<?> clazz) Return declared method with empty parameter.
static Object	getFieldValue(String fieldName, Class<?> clazz, Object instance) Return field value according to field name, class, instance.All exceptions are wrapped as RuntimeException.
static Method	getFirstMethodWithName(String name, Class<?> clazz) Iterate all methods including methods in super class, return the first one; if no method with such name, return null.
static Object	invokeMethod(Method method, Object instance, Object... parameters) Call method through java reflection.
static Object	invokeMethod(String name, Class<?> clazz, Object instance, Object... parameters) Call method through java reflection.
static <T> T	newInstance(Class<T> clazz) Create an object for the given class.
static <T> T	newInstance(Class<T> clazz, Class<?>[] parameterClasses, Object[] parameters) Create an object for the given class.
static void	setFieldValue(String fieldName, Class<?> clazz, Object instance, Object value) Set filed value according to field name, class instance, object instance and field value.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

EMPTY_CLASS_ARRAY

public static final Class<?>[] EMPTY_CLASS_ARRAY

Only support constructors with no parameters.

Method Detail

getAllFields

public static List<Field> getAllFields(Class<?> clazz)

Given a class instance, return all fields, including fields in super classes.

getAllMethods

public static List<Method> getAllMethods(Class<?> clazz)

Given a class instance, return all methods, including methods in super classes.

newInstance

public static <T> T newInstance(Class<T> clazz)

Create an object for the given class. The class should have constructor without any parameters.

Parameters:

clazz - class of which an object is created

Returns:

a new object

Throws:

RuntimeException - In case any exception for reflection.

newInstance

public static <T> T newInstance(Class<T> clazz,
                                Class<?>[] parameterClasses,
                                Object[] parameters)

Create an object for the given class. The class should have constructor without any parameters.

Parameters:

clazz - class of which an object is created

parameterClasses - the parameter classes used for constructor

parameters - the parameters used for new instance

Returns:

a new object

Throws:

RuntimeException - In case any exception for reflection.

getDeclaredFieldIncludeSuper

public static Field getDeclaredFieldIncludeSuper(String fieldName,
                                                 Class<?> clazz)

Get declared field given field name including fields in super classes. If no field get, return null.

getDeclaredMethod

public static Method getDeclaredMethod(String methodName,
                                       Class<?> clazz)
                                throws NoSuchMethodException

Return declared method with empty parameter.

Throws:

NoSuchMethodException

getFirstMethodWithName

public static Method getFirstMethodWithName(String name,
                                            Class<?> clazz)

Iterate all methods including methods in super class, return the first one; if no method with such name, return null.

setFieldValue

public static void setFieldValue(String fieldName,
                                 Class<?> clazz,
                                 Object instance,
                                 Object value)

Set filed value according to field name, class instance, object instance and field value. All exceptions are wrapped as RuntimeException.

Throws:

RuntimeException - wraps any exception as root cause.

getFieldValue

public static Object getFieldValue(String fieldName,
                                   Class<?> clazz,
                                   Object instance)

Return field value according to field name, class, instance.All exceptions are wrapped as RuntimeException.

Throws:

RuntimeException - wraps any exception as root cause.

invokeMethod

public static Object invokeMethod(Method method,
                                  Object instance,
                                  Object... parameters)

Call method through java reflection.

Throws:

RuntimeException - wraps any exception as root cause.

invokeMethod

public static Object invokeMethod(String name,
                                  Class<?> clazz,
                                  Object instance,
                                  Object... parameters)

Call method through java reflection. TODO getFirstMethodWithName should be changed by finding method with method name and parameter types.

Throws:

RuntimeException - wraps any exception as root cause.