java 反射List

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package com.enhance.reflect;

import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Array;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.ParameterizedType;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;

import org.apache.commons.lang.ArrayUtils;

public class ReflectTest {
	public static void main(String[] args) throws Exception{
        //反射List 集合
		reflectCollection();
       } 



/**
	 * 反射获取集合属性 和 集合中的 泛型 
	 * @throws Exception 
	 */
	public static void reflectCollection() throws Exception{
		List nums=new ArrayList();
		nums.add(1);
		
		Person p =new Person();
		p.setAge(18);
		p.setName("luck");
		
		List list=new LinkedList();
		list.add(p);
		
		List
 address = new ArrayList
();
		Address addr=new Address();
		addr.setAddName("上海人民广场");
		addr.setAddNo("add001");
		address.add(addr);
		
		p.setAddress(address);
		
		TestA a=new TestA();
		a.setNums(nums);
		a.setP(p);
		a.setAge(16);
		a.setBig(55);
		a.setData(list);
		
		TestB b=new TestB();
		copyProperties(a,b);
		//BeanUtils.copyProperties(b,a); //只能copy 类型相同的,
		System.out.println("基本类型:"+b.getBig());
		System.out.println("包装类型:"+b.getAge());
		System.out.println("自定义类"+b.getP().getAge());
		System.out.println("List<包装类型>:"+b.getNums().get(0));
		System.out.println("List<自定义类>:"+b.getData().get(0).getAge());
		System.out.println("List<自定义类.List>:"+b.getData().get(0).getAddress().get(0).getAddName());
		
	}

/**
     * 能 复制 相同类型的属性
     * 也能复制 "属性名相同,类型不同" 的属性
     * @param src 原对象
     * @param dest 目标对象
     * @throws Exception
     * Person ==> People
     * 注意:本程序省略 NoSuchMethodException 的判断
     *    每获取 Method 都需要判断  NoSuchMethodException 后在 invoke
     */
    public static void copyProperties(Object src,Object dest) {
        Class sclazz =src.getClass();
        Class dclazz =dest.getClass();

        //Object.class 为 stopClass  不反射的 Class
        PropertyDescriptor[] ps= new PropertyDescriptor[0];
        try {
            ps = Introspector.getBeanInfo(dclazz,Object.class).getPropertyDescriptors();
            for (PropertyDescriptor prop : ps) {
                Object srcVal=null;
                try {

                    if(prop.getPropertyType() == Class.class){ //Class 不反射
                        continue;
                    }else if(prop.getPropertyType().isPrimitive()){ //基本数据类型
                        srcVal=getValue(src,sclazz,prop.getReadMethod().getName());
                        if(srcVal !=null){
                            prop.getWriteMethod().invoke(dest,srcVal);
                        }
                    }else if(isWrapType(prop.getPropertyType().getName())){ //包装类型
                        srcVal=getValue(src,sclazz,prop.getReadMethod().getName());
                        if(srcVal !=null){
                            if(prop.getPropertyType().getName().equals("java.lang.Double")){ //Double
                                BigDecimal newVal=new BigDecimal(srcVal.toString());
                                NumberUtil.setScale(newVal,2);
                                prop.getWriteMethod().invoke(dest,  NumberUtil.setScale(newVal,2));
                            }else {
                                prop.getWriteMethod().invoke(dest, srcVal);
                            }
                        }
                    }else if(prop.getPropertyType().getInterfaces() !=null && prop.getPropertyType().getInterfaces().length > 0
                            && prop.getPropertyType().getInterfaces()[0] == Collection.class){ //集合类型
                        Object obj=getValue(src,sclazz,prop.getReadMethod().getName());
                        if(obj !=null && obj instanceof Collection){
                            Collection srcList=(Collection)obj;
                            Class collClazz=obj.getClass();
                            ParameterizedType pt= (ParameterizedType)prop.getReadMethod().getGenericReturnType();
                            Class type = (Class)pt.getActualTypeArguments()[0];
                            Object destList=collClazz.newInstance();
                            Method addMethod=collClazz.getMethod("add",Object.class);
                            if(addMethod !=null) {
                                for (Object object : srcList) {
                                    Object item = null;
                                    if (isWrapType(type.getName())) {
                                        Class parmClazz=String.class;
                                        try{
                                            parmClazz = (Class)object.getClass().getField("TYPE").get(object);
                                        }catch (Exception e) {
                                        }
                                        item = type.getConstructor(parmClazz).newInstance(object);
                                    } else {
                                        item = type.newInstance();
                                        copyProperties(object, item);
                                    }
                                    addMethod.invoke(destList, item);
                                }
                            }
                            prop.getWriteMethod().invoke(dest, destList);
                        }
                    }else{//自定义类型  Class
                        Object d=prop.getPropertyType().newInstance();
                        copyProperties(getValue(src,sclazz,prop.getReadMethod().getName()),d);
                        prop.getWriteMethod().invoke(dest, d);
                    }
                } catch (Exception e) {
                    log.info("copyProperties ERROR:"+ ThrowableUtil.getStackTrace(e));
                }
            }
        } catch (Exception e) {
            log.info("copyProperties ERROR:"+ ThrowableUtil.getStackTrace(e));
        }
    }

    /**
     * 获取属性值
     * @param obj
     * @param clazz
     * @param methodName
     * @return
     */
    public static Object getValue(Object obj,Class clazz,String methodName){
        Object value=null;
        try {
            Method method=clazz.getMethod(methodName);
            if(method !=null){
                value=method.invoke(obj);
            }
        } catch (Exception e) {
            log.info("copyProperties.getValue method: "+methodName+",ERROR"+ ThrowableUtil.getStackTrace(e));
        }
        return value;
    }
	
	/**
	 * 是否是包装类型
	 * @param typeName
	 * @return
	 */
	public static boolean isWarpType(String typeName){
		 String[] types = {"java.lang.Integer",  
			        "java.lang.Double",  
			        "java.lang.Float",  
			        "java.lang.Long",  
			        "java.lang.Short",  
			        "java.lang.Byte",  
			        "java.lang.Boolean",  
			        "java.lang.Character",  
			        "java.lang.String"};  
		return ArrayUtils.contains(types, typeName);
	}

}

public class TestA {
	private List nums;
	private Person p;
	private Integer age;
	private int big;
	
	private List data;
}

public class TestB {
	private List nums;

	private Integer age;
	private People p;
	private int big;
	
	private List data;
}

public class People {
	private String name;
	private int age;
	
	List
 address;
}

public class Person {

	private String name;
	private int age;
	
	List
 address;
}

public class Address {

	private String addNo;
	private String addName;
}

运行结果

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• 大小: 26.7 KB

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