1、记录某个实体类（表）的变化

 

②、

1 package gwm.xtkf.tool;  2   3 import java.lang.reflect.Field;  4 import java.lang.reflect.Method;  5 import java.text.SimpleDateFormat;  6 import java.util.Date;  7 import java.util.HashMap;  8 import java.util.Locale;  9 import java.util.Map; 10  11 import xs.jszx.systemmanage.domain.Purpose; 12  13 public class CompareClass { 14      15     public static String compareClass(Object from, Object target, Map
      
        describe) throws Exception{ 16          17         if (from.getClass() == target.getClass()){ 18             Class
        c = target.getClass(); 19             Field field[] = c.getDeclaredFields(); 20              21             StringBuilder str = new StringBuilder(); 22             for (Field f: field){ 23                 String type = f.getGenericType().toString();    //获取属性的类型 24                 25                 if (describe.get(f.getName())!=null){ 26                     Object fv = invokeMethod(from, f.getName(), type); 27                     Object tv = invokeMethod(target, f.getName(), type); 28                      29                     if (fv!=null && tv!=null){ 30                         if (!fv.equals(tv)){ 31                             str.append(describe.get(f.getName()) + ":" + tv + "->" + fv + ";"); 32                         } 33                     } 34                     else if(fv==null && tv==null){} 35                     else{ 36                          37                         if (fv!=null && fv.toString().trim().length()>0){ 38                             str.append(describe.get(f.getName()) + ":" + tv + "->" + fv + ";"); 39                         } 40                         if (tv!=null && tv.toString().trim().length()>0){ 41                             str.append(describe.get(f.getName()) + ":" + tv + "->" + fv + ";"); 42                         } 43                          44                     }     45                 } 46                        47             } 48              49             return str.toString(); 50         } 51         else{ 52             return null; 53         } 54     } 55      56     @SuppressWarnings("unchecked") 57     private static Object invokeMethod(Object owner, String methodName, String type) throws Exception { 58         @SuppressWarnings("rawtypes") 59         Class ownerClass = owner.getClass();   60         methodName = methodName.substring(0, 1).toUpperCase()   61                 + methodName.substring(1);   62         Method method = null;   63          64         try {   65             method = ownerClass.getMethod("get" + methodName);   66         } catch (SecurityException e) {   67         } catch (NoSuchMethodException e) {   68             return null;   69         }   70         //如果type是类类型，则前面包含"class "，后面跟类名   71         //对日期类型进行转换 72         if(type.equals("class java.util.Date")){    73             Date date = (Date) method.invoke(owner); 74             if(date != null){ 75                 SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd",Locale.US);   76                 return sdf.format(date);  77             }             78         }   79         return method.invoke(owner); 80     } 81      82     public static void main(String[] args){ 83          84         Purpose purpose1 = new Purpose(); 85         Purpose purpose2 = new Purpose(); 86          87          88         purpose1.setName("住宅"); 89         purpose2.setName("别墅"); 90          91         Map
       
         map = new HashMap
        
         (); 92         map.put("name", "名称"); 93          94         try { 95             System.out.println(compareClass(purpose1, purpose2, map)); 96         } catch (Exception e) { 97             // TODO Auto-generated catch block 98             e.printStackTrace(); 99         }100     }101 }