通过反射把JavaBean映射到map

通过反射吧一个JavaBean中的属性和属性值拷贝到Map集合中

遍历所有get方法，得到方法名，有此方法名进行截取，得到name作为map的key。执行此方法，得到返回值作为map的value。

package reflectmap;

public class Product {
    private int id;
    private String name;
    private String kind;
    private double price;
    public Product() {
    }
    public Product(int id, String name, String kind, double price) {
        this.id = id;
        this.name = name;
        this.kind = kind;
        this.price = price;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getKind() {
        return kind;
    }
    public void setKind(String kind) {
        this.kind = kind;
    }
    public double getPrice() {
        return price;
    }
    public void setPrice(double price) {
        this.price = price;
    }
    

}

package reflectmap;

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

public class CopyToMap {
    public static void copy(Object obj,Map<String,Object>map) throws Exception{
        //实现从obj复制数据到map中
        Class<?> cls = obj.getClass();
        //查找该类中的get方法
        Method[] methods = cls.getDeclaredMethods();
        //判断是否为get方法
        for (Method m : methods) {
            // getName get Name
            String name = m.getName();
            if(name.startsWith("get")){
                //截取name得到key
                System.out.println("origin :"+name);
                name=name.substring(3);
                System.out.println("withoutget :"+name);
                String first=name.substring(0, 1).toLowerCase();
                System.out.println("first :"+first);
                String last=name.substring(1);
                System.out.println("last :"+last);
                String key=first+last;
                //执行方法得到value
                Object value = m.invoke(obj);
                map.put(key, value);
                System.out.println();
            }
        }
        
    }
    public static void main(String[] args)throws Exception {
        Product p=new Product(1,"九口南红","南红",1.1);
        Map<String,Object> map=new HashMap<>();
        copy(p, map);
        System.out.println(map);
    }
}

运行结果

origin :getName
withoutget :Name
first :n
last :ame

origin :getId
withoutget :Id
first :i
last :d

origin :getPrice
withoutget :Price
first :p
last :rice

origin :getKind
withoutget :Kind
first :k
last :ind

{id=1, price=1.1, name=九口南红, kind=南红}

去掉日志后

package reflectmap;

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

public class CopyToMap {
    public static void copy(Object obj,Map<String,Object>map) throws Exception{
        //实现从obj复制数据到map中
        Class<?> cls = obj.getClass();
        //查找该类中的get方法
        Method[] methods = cls.getDeclaredMethods();
        //判断是否为get方法
        for (Method m : methods) {
            // getName get Name
            String name = m.getName();
            if(name.startsWith("get")){
                //截取name得到key
                name=name.substring(3);
                String first=name.substring(0, 1).toLowerCase();
                String last=name.substring(1);
                String key=first+last;
                //执行方法得到value
                Object value = m.invoke(obj);
                map.put(key, value);
            }
        }
        
    }
    public static void main(String[] args)throws Exception {
        Product p=new Product(1,"九口南红","南红",1.1);
        Map<String,Object> map=new HashMap<>();
        copy(p, map);
        System.out.println(map);
    }
}