Java-动态给字节码添加新属性(字段)

工具一

/**
 * @author BNTang
 * @version 1.0
 * @date Created in 2022/3/10 010 15:07
 * @description
 **/
@Slf4j
@UtilityClass
public class ReflectUtil {

    public Object getTarget(Object dest, Map<String, Object> addProperties) {
        // get property map
        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());
            }
        }
        // add extra properties
        addProperties.forEach((k, v) -> propertyMap.put(k, v.getClass()));
        // new dynamic bean
        DynamicBean dynamicBean = new DynamicBean(dest.getClass(), propertyMap);
        // add old value
        propertyMap.forEach((k, v) -> {
            try {
                // filter extra properties
                if (!addProperties.containsKey(k)) {
                    dynamicBean.setValue(k, propertyUtilsBean.getNestedProperty(dest, k));
                }
            } catch (Exception e) {
                log.error(e.getMessage(), e);
            }
        });
        // add extra value
        addProperties.forEach((k, v) -> {
            try {
                dynamicBean.setValue(k, v);
            } catch (Exception e) {
                log.error(e.getMessage(), e);
            }
        });
        return dynamicBean.getTarget();
    }

    public static class DynamicBean {
        /**
         * 目标对象
         */
        private final Object target;

        /**
         * 属性集合
         */
        private final 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 财产
         * @param value    价值
         */
        public void setValue(String property, Object value) {
            beanMap.put(property, value);
        }

        /**
         * 获取属性值
         *
         * @param property 财产
         * @return {@link Object}
         */
        public Object getValue(String property) {
            return beanMap.get(property);
        }

        /**
         * 得到目标对象
         *
         * @return {@link Object}
         */
        public Object getTarget() {
            return this.target;
        }

        /**
         * 根据属性生成对象
         *
         * @param superclass  超类
         * @param propertyMap 属性映射
         * @return {@link Object}
         */
        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();
        }
    }
}