Java实体类转Map、Map转实体类-蒲公英云

Java实体类转Map、Map转实体类

1、创建entity（User.java）

package com.jeff.entity;
public class User { 
    private String userName;
    private String password;
    private Integer age;
    public User() { 
        super();
    }
    public User(String userName, String password, Integer age) { 
        super();
        this.userName = userName;
        this.password = password;
        this.age = age;
    }
    public String getUserName() { 
        return userName;
    }
    public void setUserName(String userName) { 
        this.userName = userName;
    }
    public String getPassword() { 
        return password;
    }
    public void setPassword(String password) { 
        this.password = password;
    }
    public Integer getAge() { 
        return age;
    }
    public void setAge(Integer age) { 
        this.age = age;
    }
    @Override
    public String toString() { 
        return "User [userName=" + userName + ", password=" + password + ", age=" + age + "]";
    }
}

2、创建utils（EntityUtils.java）

package com.jeff.utils;
import java.lang.reflect.Field;
import java.util.HashMap;
import java.util.Map;
public class EntityUtils { 
    /** * * @description: 实体类转Map * @author: Jeff * @date: 2019年10月29日 * @param object * @return */
    public static Map<String, Object> entityToMap(Object object) { 
        Map<String, Object> map = new HashMap<>();
        for (Field field : object.getClass().getDeclaredFields()) { 
            try { 
                boolean flag = field.isAccessible();
                field.setAccessible(true);
                Object o = field.get(object);
                map.put(field.getName(), o);
                field.setAccessible(flag);
            } catch (Exception e) { 
                e.printStackTrace();
            }
        }
        return map;
    }
    /** * * @description: Map转实体类 * @author: Jeff * @date: 2019年10月29日 * @param <T> * @param map 需要初始化的数据，key字段必须与实体类的成员名字一样，否则赋值为空 * @param entity 需要转化成的实体类 * @return */
    public static <T> T mapToEntity(Map<String, Object> map, Class<T> entity) { 
        T t = null;
        try { 
            t = entity.newInstance();
            for (Field field : entity.getDeclaredFields()) { 
                if (map.containsKey(field.getName())) { 
                    boolean flag = field.isAccessible();
                    field.setAccessible(true);
                    Object object = map.get(field.getName());
                    if (object != null && field.getType().isAssignableFrom(object.getClass())) { 
                        field.set(t, object);
                    }
                    field.setAccessible(flag);
                }
            }
            return t;
        } catch (InstantiationException e) { 
            e.printStackTrace();
        } catch (IllegalAccessException e) { 
            e.printStackTrace();
        }
        return t;
    }
}

3、创建Map转实体类（TestCopyObj3.java）

package com.jeff;
import java.util.HashMap;
import java.util.Map;
import com.jeff.entity.User;
import com.jeff.utils.EntityUtils;
public class TestCopyObj3 { 
    public static void main(String[] args) throws Exception { 
        Map<String, Object> map = new HashMap<String, Object>();
        map.put("userName", "Jeff");
        map.put("password", "123456");
        map.put("age", 18);
        System.out.println("Map对象：" + map);
        User user = EntityUtils.mapToEntity(map, User.class);
        System.out.println("User对象：" + user);
    }
}

4、控制台输出结果
在这里插入图片描述
5、创建实体类转Map（TestCopyObj4.java）

package com.jeff;
import java.util.Map;
import com.jeff.entity.User;
import com.jeff.utils.EntityUtils;
public class TestCopyObj4 { 
    public static void main(String[] args) throws Exception { 
        User user = new User("Jeff", "123456", 18);
        System.out.println("User对象：" + user);
        Map<String, Object> map = EntityUtils.entityToMap(user);
        System.out.println("Map对象：" + map);
    }
}