可以给已有实体类动态的添加字段并返回新的实体对象，不影响原来的实体对象结构。
添加依赖
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< dependency > < groupId >cglib</ groupId > < artifactId >cglib</ artifactId > < version >2.2.2</ version > </ dependency >
< dependency > < groupId >commons-beanutils</ groupId > < artifactId >commons-beanutils</ artifactId > < version >1.9.4</ version > </ dependency > |
代码
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import com.google测试数据mon.collect.Maps; import net.sf.cglib.beans.BeanGenerator; import net.sf.cglib.beans.BeanMap; import org.apache测试数据mons.beanutils.PropertyUtilsBean; import org.slf4j.Logger; import org.slf4j.LoggerFactory;
import java.beans.PropertyDescriptor; import java.util.Map;
/** * 动态为bean添加字段 * @Author gongl * @Create 2022-01-11 */ public class DynamicBeanUtils {
private static final Logger logger = LoggerFactory.getLogger(DynamicBeanUtils. class );
public static Object getTarget(Object dest, Map<String, Object> addProperties) { PropertyUtilsBean propertyUtilsBean = new PropertyUtilsBean(); //得到原对象的属性 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) -> propertyMap.put(k, v.getClass())); //构建新的对象 DynamicBean dynamicBean = new DynamicBean(dest.getClass(), propertyMap); for (Map.Entry<String, Class<?>> entry : propertyMap.entrySet()) { try { if (!addProperties.containsKey(entry.getKey())) { //原来的值 dynamicBean.setValue(entry.getKey(), propertyUtilsBean.getNestedProperty(dest, entry.getKey())); } else { //新增的值 dynamicBean.setValue(entry.getKey(), addProperties.get(entry.getKey())); } } catch (Exception e) { logger.error(e.getMessage(), e); } } return dynamicBean.getTarget(); }
private static class DynamicBean { /** * 目标对象 */ private Object target;
/** * 属性集合 */ private BeanMap beanMap;
public DynamicBean(Class<?> superclass, Map<String, Class<?>> propertyMap) { this .target = generateBean(superclass, propertyMap); this .beanMap = BeanMap.create( this .target); }
/** * bean 添加属性和值 * * @param property * @param value */ public void setValue(String property, Object value) { beanMap.put(property, value); }
/** * 获取属性值 * * @param property * @return */ public Object getValue(String property) { return beanMap.get(property); }
/** * 获取对象 * * @return */ public Object getTarget() { return this .target; }
/** * 根据属性生成对象 * * @param superclass * @param propertyMap * @return */ 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(); } } } |
测试
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public static class TestBean{ private String name;
public String getName() { return name; }
public void setName(String name) { this .name = name; } } public static void main(String[] args) throws InvocationTargetException, IllegalAccessException { TestBean bean = new TestBean(); bean.setName( "张三" ); Map<String, Object> map = new HashMap<>(); map.put( "age" , 29 ); //添加参数age--->29 Object obj = DynamicBeanUtils.getTarget(bean, map); //打印结果 Method[] declaredMethods = obj.getClass().getDeclaredMethods(); for (Method method:declaredMethods){ if (method.getName().startsWith( "get" )){ Object o=method.invoke(obj); System.out.println( "属性值get方法->" +o); } } } |
结果打印出name和age的值
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原文链接：https://blog.csdn.net/weixin_47914635/article/details/123550354
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