Java reflect 你会了吗？
package util;
import java.lang.reflect.Method;
public class ClassUtil {
public static void main(String[] args) {
ClassUtil.printClassMessage(Object.class.getName());
}
public static void printClassMessage(Object obj)
{
//要获取类的信息 首先要获取类的类型
Class c=obj.getClass();
//获取类的名称
System.out.println("类的名称:"+c.getName());
/**
* Method的类 方法对象
* 一个成员方法就是一个Method对象
* getMethod()方法获取所有类的public的函数 包括父类继承而来
* getDeclaredMethods()获取的是所有字节
*/
Method[] ms=c.getMethods();
for (int i = 0; i < ms.length; i++) {
//得到方法返回值的类型
Class returnType=ms[i].getReturnType();
System.out.println(returnType.getName()+" ");
//获取方法的名称
System.out.println(ms[i].getName());
//获取参数类型
Class[] paramsType=ms[i].getParameterTypes();
}
//c.getDeclaredMethods();
}
}
结果:
反射的工具类
import java.lang.reflect.Array;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
/**
*
* @className: ReflectionUtils
* @description: 反射工具类
* @author: kandamin
* @date: 2017年3月4日 下午10:51:49
*/
public class ReflectionUtils
{
/**
*
* @title: setField
* @description: 设置某个成员遍历的值
* @param owner
* @param fieldName
* @param value
* @throws Exception
* @return: void
*/
public static void setField(Object owner, String fieldName, Object value) throws Exception {
Class ownerClass = owner.getClass();
Field field = ownerClass.getDeclaredField(fieldName);
field.setAccessible(true);
field.set(owner, value);
}
/**
*
* @title: setFieldAll
* @description: 可以设置父类的field的值
* @param owner
* @param fieldName
* @param value
* @throws Exception
* @return: void
*/
public static void setFieldAll(Object owner, String fieldName, Object value) throws Exception {
Class ownerClass = owner.getClass();
Field field = null;
for (Class clazz = ownerClass; clazz != Object.class; clazz = clazz.getSuperclass()) {
try {
field = clazz.getDeclaredField(fieldName);
LogUtil.d(field + " find : in " + clazz.getName());
break;
}
catch (Exception e) {
LogUtil.d(fieldName + " not find in " + clazz.getName());
}
}
field.setAccessible(true);
field.set(owner, value);
}
/**
* 得到某个对象的公共属性
*
* @param owner
* , fieldName
* @return 该属性对象
* @throws Exception
*
*/
public static Object getField(Object owner, String fieldName) throws Exception {
Class ownerClass = owner.getClass();
Field field = ownerClass.getField(fieldName);
Object property = field.get(owner);
return property;
}
/**
* 得到某类的静态公共属性
*
* @param className
* 类名
* @param fieldName
* 属性名
* @return 该属性对象
* @throws Exception
*/
public static Object getStaticField(String className, String fieldName) throws Exception {
Class ownerClass = Class.forName(className);
Field field = ownerClass.getField(fieldName);
Object property = field.get(ownerClass);
return property;
}
/**
* 执行某对象方法
*
* @param owner
* 对象
* @param methodName
* 方法名
* @param args
* 参数
* @return 方法返回值
* @throws Exception
*/
public static Object invokeMethod(Object owner, String methodName, Object... args) throws Exception {
Class ownerClass = owner.getClass();
Class[] argsClass = new Class[args.length];
for (int i = 0, j = args.length; i < j; i++) {
if (args[i].getClass() == Integer.class) { //一般的函数都是 int 而不是Integer
argsClass[i] = int.class;
}
else if (args[i].getClass() == Float.class) { //一般的函数都是 int 而不是Integer
argsClass[i] = float.class;
}
else if (args[i].getClass() == Double.class) { //一般的函数都是 int 而不是Integer
argsClass[i] = double.class;
}
else {
argsClass[i] = args[i].getClass();
}
}
Method method = ownerClass.getDeclaredMethod(methodName, argsClass);
method.setAccessible(true);
return method.invoke(owner, args);
}
/**
*
* @title: invokeMethodAll
* @description: 调用所有的函数, 包括父类的所有函数
* @param owner
* @param methodName
* @param args
* @return
* @throws Exception
* @return: Object
*/
public static Object invokeMethodAll(Object owner, String methodName, Object... args) throws Exception {
Class ownerClass = owner.getClass();
Class[] argsClass = new Class[args.length];
for (int i = 0, j = args.length; i < j; i++) {
if (args[i].getClass() == Integer.class) { //一般的函数都是 int 而不是Integer
argsClass[i] = int.class;
}
else if (args[i].getClass() == Float.class) { //一般的函数都是 int 而不是Integer
argsClass[i] = float.class;
}
else if (args[i].getClass() == Double.class) { //一般的函数都是 int 而不是Integer
argsClass[i] = double.class;
}
else {
argsClass[i] = args[i].getClass();
}
}
Method method = null;
for (Class clazz = ownerClass; clazz != Object.class; clazz = clazz.getSuperclass()) {
try {
method = clazz.getDeclaredMethod(methodName, argsClass);
LogUtil.d(method + " find : in " + clazz.getName());
return method;
}
catch (Exception e) {
//e.printStackTrace();
LogUtil.d(methodName + " not find in " + clazz.getName());
}
}
method.setAccessible(true);
return method.invoke(owner, args);
}
/**
* 执行某类的静态方法
*
* @param className
* 类名
* @param methodName
* 方法名
* @param args
* 参数数组
* @return 执行方法返回的结果
* @throws Exception
*/
public static Object invokeStaticMethod(String className, String methodName, Object... args) throws Exception {
Class ownerClass = Class.forName(className);
Class[] argsClass = new Class[args.length];
for (int i = 0, j = args.length; i < j; i++) {
argsClass[i] = args[i].getClass();
}
Method method = ownerClass.getMethod(methodName, argsClass);
method.setAccessible(true);
return method.invoke(null, args);
}
/**
* 新建实例
*
* @param className
* 类名
* @param args
* 构造函数的参数 如果无构造参数，args 填写为 null
* @return 新建的实例
* @throws Exception
*/
public static Object newInstance(String className, Object[] args) throws NoSuchMethodException, SecurityException, ClassNotFoundException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
return newInstance(className, args, null);
}
/**
* 新建实例
*
* @param className
* 类名
* @param args
* 构造函数的参数 如果无构造参数，args 填写为 null
* @return 新建的实例
* @throws Exception
*/
public static Object newInstance(String className, Object[] args, Class[] argsType) throws NoSuchMethodException, SecurityException, ClassNotFoundException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
Class newoneClass = Class.forName(className);
if (args == null) {
return newoneClass.newInstance();
}
else {
Constructor cons;
if (argsType == null) {
Class[] argsClass = new Class[args.length];
for (int i = 0, j = args.length; i < j; i++) {
argsClass[i] = args[i].getClass();
}
cons = newoneClass.getConstructor(argsClass);
}
else {
cons = newoneClass.getConstructor(argsType);
}
return cons.newInstance(args);
}
}
/**
* 是不是某个类的实例
*
* @param obj
* 实例
* @param cls
* 类
* @return 如果 obj 是此类的实例，则返回 true
*/
public static boolean isInstance(Object obj, Class cls) {
return cls.isInstance(obj);
}
/**
* 得到数组中的某个元素
*
* @param array
* 数组
* @param index
* 索引
* @return 返回指定数组对象中索引组件的值
*/
public static Object getItemInArray(Object array, int index) {
return Array.get(array, index);
}
/**
*
* @title: GetClassListByPackage
* @description: 获取包下的所有Class
* @param pPackage
* @return
* @return: Class
*/
public static Class getClassListByPackage(String pPackage) {
Package _Package = Package.getPackage(pPackage);
Class _List = _Package.getClass();
return _List;
}
}