两个实体类 复制 copy 工具类

 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.util.Date;

 public class CopyBean{

     /**
      * 复制sour里属性不为空的值到obje为空的属性
      *
      * @param obje
      *            目标实体类
      * @param sour
      *            源实体类
      * @param isCover
      *            是否保留obje类里不为null的属性值(保留源值，属性为null则赋值)
      * @return obje
      */
     public static Object Copy(Object obje, Object sour, boolean isCover) {
         Field[] fields = sour.getClass().getDeclaredFields();
         for (int i = 0, j = fields.length; i < j; i++) {
             String propertyName = fields[i].getName();
             Object propertyValue = getProperty(sour, propertyName);
             if (isCover) {
                 if (getProperty(obje, propertyName) == null
                         && propertyValue != null) {
                     Object setProperty = setProperty(obje, propertyName,
                             propertyValue);
                 }
             } else {
                 Object setProperty = setProperty(obje, propertyName,
                         propertyValue);
             }

         }
         return obje;
     }

     /**
      * 得到值
      *
      * @param bean
      * @param propertyName
      * @return
      */
     private static Object getProperty(Object bean, String propertyName) {
         Class clazz = bean.getClass();
         try {
             Field field = clazz.getDeclaredField(propertyName);
             Method method = clazz.getDeclaredMethod(
                     getGetterName(field.getName()), new Class[] {});
             return method.invoke(bean, new Object[] {});
         } catch (Exception e) {
         }
         return null;
     }

     /**
      * 给bean赋值
      *
      * @param bean
      * @param propertyName
      * @param value
      * @return
      */
     private static Object setProperty(Object bean, String propertyName,
             Object value) {
         Class clazz = bean.getClass();
         try {
             Field field = clazz.getDeclaredField(propertyName);
             Method method = clazz.getDeclaredMethod(
                     getSetterName(field.getName()),
                     new Class[] { field.getType() });
             return method.invoke(bean, new Object[] { value });
         } catch (Exception e) {
         }
         return null;
     }

     /**
      * 根据变量名得到get方法
      *
      * @param propertyName
      * @return
      */
     private static String getGetterName(String propertyName) {
         String method = "get" + propertyName.substring(0, 1).toUpperCase()
                 + propertyName.substring(1);
         return method;
     }

     /**
      * 得到setter方法
      *
      * @param propertyName
      *            变量名
      * @return
      */
     private static String getSetterName(String propertyName) {
         String method = "set" + propertyName.substring(0, 1).toUpperCase()
                 + propertyName.substring(1);
         return method;
     }

 //    public static void main(String[] args) {
 //        User u = new User();
 //        u.setId(1l);
 //        u.setAge(30);
 //        User u1 = new User();
 //        u1.setAge(10);
 //        u1.setBirthday(new Date());
 //        u1.setFirtsName("aaaa");
 //        u1.setName("adf");
 //        u1.setSchool("aaaa");
 //        Field[] fields = u1.getClass().getDeclaredFields();
 //        u.setSchool("bbbbbbbbb");
 //        System.out.println("u1--------->  " + u1);
 //        System.out.println("u---------->  " + u);
 //        System.out.println(Copy(u, u1, false));
 //    }

 }