Java实体类转Map、Map转实体类

古城微笑少年丶 2023-06-11 07:28 21阅读 0赞

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][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTczOTcyMA_size_16_color_FFFFFF_t_70]  
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);
    	}
    
    }

6、控制台输出结果  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTczOTcyMA_size_16_color_FFFFFF_t_70 1]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTczOTcyMA_size_16_color_FFFFFF_t_70]: /images/20230531/7aa2fb8db640435f970db456b5b3eca9.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTczOTcyMA_size_16_color_FFFFFF_t_70 1]: /images/20230531/cb33a711cf6d444ea25a58b8c3d2c914.png