时间:2023-03-11 10:59:58 | 栏目:JAVA代码 | 点击:次
例如下述Java类:
import java.io.Serializable; import java.util.List; public class Bean_Topology implements Serializable { private static final long serialVersionUID = 1L; public static long getSerialversionuid() { return serialVersionUID; } private Long topology_pk; private String topology_id; public String getTopology_id() { return topology_id; } public void setTopology_id(String topology_id) { this.topology_id = topology_id; } public Long getTopology_pk() { return topology_pk; } public void setTopology_pk(Long topology_pk) { this.topology_pk = topology_pk; } @Override public String toString() { return "当前拓扑的PK为:" + topology_pk + ",ID为:" + topology_id; } }
如下想判断下面两个对象中全部属性值是否一致时,有哪些办法呢?
Bean_Topology topology1 = new Bean_Topology(); topology1.setTopology_id("1"); Bean_Topology topology2 = new Bean_Topology(); topology2.setTopology_pk(1L); topology2.setTopology_id("1");
@Override public boolean equals(Object obj) { if (this == obj) { return true; } if (obj == null || getClass() != obj.getClass()) { return false; } Bean_Topology topology = (Bean_Topology) obj; if (topology_pk == null) { if (topology.topology_pk != null) { return false; } }else if (!topology_pk.equals(topology.topology_pk)) { return false; } if (topology_id == null) { if (topology.topology_id != null) { return false; } }else if (!topology_id.equals(topology.topology_id)) { return false; } return true; } @Override public int hashCode() { return topology_pk.hashCode()+topology_id.hashCode(); }
测试代码如下:
if(topology1.equals(topology2)) { System.out.println("对象1与对象2的属性值无差异。"); }else { System.out.println("对象1与对象2的属性值有差异。"); }
输出结果为:
对象1与对象2的属性值有差异。
Map<String, Map<String,Object>> resultMap=compareFields(topology1,topology2); int size=resultMap.size(); if(size>0) { System.out.println("对象1与对象2的属性值有差异,差异结果如下:"); Iterator<String> it = resultMap.keySet().iterator(); while(it.hasNext()) { String key=it.next(); System.out.println(" "+key+"(oldValue:"+resultMap.get(key).get("oldValue")+",newValue:"+resultMap.get(key).get("newValue")+")"); } }else { System.out.println("对象1与对象2的属性值无差异!"); }
输出结果为:
对象1与对象2的属性值有差异,差异结果如下:
topology_pk(oldValue:null,newValue:1)
工具类如下:
package com.sitech.modual.util.compare; import java.beans.Introspector; import java.beans.PropertyDescriptor; import java.lang.reflect.Method; import java.sql.Timestamp; import java.util.ArrayList; import java.util.Date; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import com.sitech.modual.bean.Bean_Link; import com.sitech.modual.bean.Bean_Topology; public class ClassCompareUtil { /** * 比较两个实体属性值,返回一个boolean,true则表时两个对象中的属性值无差异 * @param oldObject 进行属性比较的对象1 * @param newObject 进行属性比较的对象2 * @return 属性差异比较结果boolean */ public static boolean compareObject(Object oldObject, Object newObject) { Map<String, Map<String,Object>> resultMap=compareFields(oldObject,newObject); if(resultMap.size()>0) { return false; }else { return true; } } /** * 比较两个实体属性值,返回一个map以有差异的属性名为key,value为一个Map分别存oldObject,newObject此属性名的值 * @param oldObject 进行属性比较的对象1 * @param newObject 进行属性比较的对象2 * @return 属性差异比较结果map */ @SuppressWarnings("rawtypes") public static Map<String, Map<String,Object>> compareFields(Object oldObject, Object newObject) { Map<String, Map<String, Object>> map = null; try{ /** * 只有两个对象都是同一类型的才有可比性 */ if (oldObject.getClass() == newObject.getClass()) { map = new HashMap<String, Map<String,Object>>(); Class clazz = oldObject.getClass(); //获取object的所有属性 PropertyDescriptor[] pds = Introspector.getBeanInfo(clazz,Object.class).getPropertyDescriptors(); for (PropertyDescriptor pd : pds) { //遍历获取属性名 String name = pd.getName(); //获取属性的get方法 Method readMethod = pd.getReadMethod(); // 在oldObject上调用get方法等同于获得oldObject的属性值 Object oldValue = readMethod.invoke(oldObject); // 在newObject上调用get方法等同于获得newObject的属性值 Object newValue = readMethod.invoke(newObject); if(oldValue instanceof List){ continue; } if(newValue instanceof List){ continue; } if(oldValue instanceof Timestamp){ oldValue = new Date(((Timestamp) oldValue).getTime()); } if(newValue instanceof Timestamp){ newValue = new Date(((Timestamp) newValue).getTime()); } if(oldValue == null && newValue == null){ continue; }else if(oldValue == null && newValue != null){ Map<String,Object> valueMap = new HashMap<String,Object>(); valueMap.put("oldValue",oldValue); valueMap.put("newValue",newValue); map.put(name, valueMap); continue; } if (!oldValue.equals(newValue)) {// 比较这两个值是否相等,不等就可以放入map了 Map<String,Object> valueMap = new HashMap<String,Object>(); valueMap.put("oldValue",oldValue); valueMap.put("newValue",newValue); map.put(name, valueMap); } } } }catch(Exception e){ e.printStackTrace(); } return map; } }
注意:本工具类不适用于比较包含List,Map等类的Class。