java动态给类添加属性

maven依赖

<dependency>
    <groupId>cglib</groupId>
    <artifactId>cglib</artifactId>
    <version>3.1</version>
</dependency>
<dependency>
    <groupId>com.google.collections</groupId>
    <artifactId>google-collections</artifactId>
    <version>1.0</version>
</dependency>

动态Bean类

package com.wl.putrecord;


import net.sf.cglib.beans.BeanGenerator;
import net.sf.cglib.beans.BeanMap;

import java.util.Map;

public class DynamicBean {

    private Object target;
    private BeanMap beanMap;

    public DynamicBean(Class superclass, Map<String, Class> propertyMap) {
        this.target = generateBean(superclass, propertyMap);
        this.beanMap = BeanMap.create(this.target);
    }

    public void setValue(String property, Object value) {
        beanMap.put(property, value);
    }

    public Object getValue(String property) {
        return beanMap.get(property);
    }

    public Object getTarget() {
        return this.target;
    }

    /**
     * 根据属性生成对象
     */
    private Object generateBean(Class superclass, Map<String, Class> propertyMap) {
        BeanGenerator generator = new BeanGenerator();
        if (null != superclass) {
            generator.setSuperclass(superclass);
        }
        BeanGenerator.addProperties(generator, propertyMap);
        return generator.create();
    }
}

工具类

package com.wl.putrecord;


import avro.shaded.com.google.common.collect.Maps;
import org.apache.commons.beanutils.PropertyUtilsBean;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.beans.PropertyDescriptor;
import java.util.Date;
import java.util.Map;

public class ReflectUtil {
	private static Logger logger = LoggerFactory.getLogger(ReflectUtil.class);

	public static Object getObject(Object dest, Map<String, Object> addProperties) {
	    PropertyUtilsBean propertyUtilsBean = new PropertyUtilsBean();
	    PropertyDescriptor[] descriptors = propertyUtilsBean.getPropertyDescriptors(dest);
	    Map<String, Class> propertyMap = Maps.newHashMap();
	    for (PropertyDescriptor d : descriptors) {
	        if (!"class".equalsIgnoreCase(d.getName())) {
	            propertyMap.put(d.getName(), d.getPropertyType());
	        }
	    }
	    addProperties.forEach((k, v) -> {
	    	String sclass = v.getClass().toString();
	    	if(sclass.equals("class java.util.Date")) {//对日期进行处理
	    		propertyMap.put(k, Long.class);
	    	}else {
	    		propertyMap.put(k, v.getClass());
	    	}

	    });
	    DynamicBean dynamicBean = new DynamicBean(dest.getClass(), propertyMap);
	    propertyMap.forEach((k, v) -> {
	        try {
	            if (!addProperties.containsKey(k)) {
	                dynamicBean.setValue(k, propertyUtilsBean.getNestedProperty(dest, k));
	            }
	        } catch (Exception e) {
	            logger.error("动态添加字段出错", e);
	        }
	    });
	    addProperties.forEach((k, v) -> {
	        try {
	        	String sclass = v.getClass().toString();
		    	if(sclass.equals("class java.util.Date")) {//动态添加的字段为date类型需要进行处理
		    		Date date = (Date) v;
		    		dynamicBean.setValue(k, date.getTime());
		    	}else {
		    		dynamicBean.setValue(k, v);
		    	}
	        } catch (Exception e) {
	        	logger.error("动态添加字段值出错", e);
	        }
	    });
	    Object obj = dynamicBean.getTarget();
	    return obj;
	}
}

测试类

package com.wl.putrecord;

import java.lang.reflect.Field;

/**
 * @author 没有梦想的java菜鸟
 * @Date 创建时间：2022/4/27 上午10:38
 * @qq 2315290571
 * @Description a
 */
public class Test {
    public static void main(String[] args) throws Exception {
            User user = new User();
        user.setId(1004);
        user.setUsername("小张");
        HashMap<String, Object> propertiesMap = new HashMap<>();
        propertiesMap.put("password","123456");
        User object = (User) ReflectUtil.getObject(user, propertiesMap);
        System.out.println(JSON.toJSONString(object));
    }
}