java 类反射 练习

package cn.hncu.reflect.ex;

public class User {
	private String id;
	private String name;//setName
	private int age;//setAge
	public User(String id, String name, int age) {
		this.id = id;
		this.name = name;
		this.age = age;
	}
	public User() {
	}
	public String getId() {
		return id;
	}
	public void setId(String id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	
	public void setAge(int age) {
		this.age = age;
	}
	
	@Override
	public String toString() {
		return id + ", " + name + ", " + age;
	}
	
}

import java.io.Serializable;

public class BookModel implements Serializable{
	private String uuid;
	private String name;
	private double inPrice;
	private double salePrice;
	
	public BookModel() {
	}

	public String getUuid() {
		return uuid;
	}

	public void setUuid(String uuid) {
		this.uuid = uuid;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public double getInPrice() {
		return inPrice;
	}

	public void setInPrice(double inPrice) {
		this.inPrice = inPrice;
	}

	public double getSalePrice() {
		return salePrice;
	}

	public void setSalePrice(double salePrice) {
		this.salePrice = salePrice;
	}

	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + ((uuid == null) ? 0 : uuid.hashCode());
		return result;
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		BookModel other = (BookModel) obj;
		if (uuid == null) {
			if (other.uuid != null)
				return false;
		} else if (!uuid.equals(other.uuid))
			return false;
		return true;
	}

	@Override
	public String toString() {
		return uuid + ",《" + name + "》,进价:"
				+ inPrice + ",售价:" + salePrice + "元";
	}
	
}

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.Map;

public class MyBeanUtils {
	
	public static<T> T populate(Class<T> c, Map<String,Object> map) throws Exception{
		//1通过类模板c创建一个空对象obj
		T obj = c.newInstance();
		
		/*2 遍历类模板c中的所有属性,分别把这些属性当作key到map中
		 * 去取value,若有值则调用对应的setter方法进行封装
		 */
		Field flds[] = c.getDeclaredFields();
		if(flds==null){
			return obj;
		}
		for(Field fld: flds){
			Object value = map.get( fld.getName() );
			if(value==null){
				System.out.println("属性"+fld.getName()+"的数据为空，没有封装上");
				continue;
			}
			
			//value不为空时
			//生成对应属性的setter方法名="set"+首字母大写+name.subString(1)
			String methodName = "set" + fld.getName().substring(0, 1).toUpperCase() + fld.getName().substring(1);
			Method m = c.getMethod( methodName, fld.getType() );
			m.invoke(obj,value);
		}
		
		//3 把封装完成的对象obj返回
		
		return obj;
	}
	
}

import java.util.HashMap;
import java.util.Map;

import org.junit.Test;

public class BeanUtilsTest {
	@Test
	public void t1() throws Exception{
		Map<String,Object> map = new HashMap<String,Object>();
		//map.put("id","A001");
		map.put("name","Jack");
		map.put("price",12.45);
		map.put("age",23);
		User u = MyBeanUtils.populate(User.class, map);
		System.out.println(u);
	}
	@Test
	public void t2() throws Exception{
		Map<String,Object> map = new HashMap<String,Object>();
		map.put("id","A001");
		map.put("name","三国演义");
		map.put("inPrice",12.45);
		map.put("age",23);
		BookModel u = MyBeanUtils.populate(BookModel.class, map);
		System.out.println(u);
	}
}