1、定義一個實體類：
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package reflect; public class User { private String name; private int age; public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; }} |
2、Map轉Object轉換如下：
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package reflect; import java.beans.BeanInfo;import java.beans.Introspector;import java.beans.PropertyDescriptor;import java.lang.reflect.Method;import java.util.HashMap;import java.util.Map; public class testMapToObject { public static void main(String[] args){ //假設有一個Map存放了一個對象的姓名和年齡 Map<string,object> map = new HashMap<string,object>(); map.put("name", "Kobi"); map.put("age", 39); User user = transferMapToUser(map,User.class); System.out.println(user.getName()); System.out.println(user.getAge()); } public static <t> T transferMapToUser(Map<string,object> map,Class<t> classT){ try { return transfer(map,classT.newInstance()); } catch (InstantiationException ex) { System.out.println("what the fuck?"); } catch (IllegalAccessException ex) { System.out.println("what the fuck?"); } return null; } public static <t> T transfer(Map<string,object> map,Object obj){ try { BeanInfo beanInfo = Introspector.getBeanInfo(obj.getClass()); PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors(); for (PropertyDescriptor property : propertyDescriptors) { String key = property.getName(); if (map.containsKey(key)) { Object value = map.get(key); // 得到property對應的setter方法 Method setter = property.getWriteMethod(); try { setter.invoke(obj, value); } catch (IllegalArgumentException ex) { System.out.println("what the fuck?"); } } } } catch (Exception ex) { System.out.println("what the fuck?"); } return (T) obj; } } |
運行結果：
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run:Kobi39成功構建 (總時間: 0 秒) |
3、Object轉Map：
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package reflect; import java.beans.BeanInfo;import java.beans.Introspector;import java.beans.PropertyDescriptor;import java.lang.reflect.Method;import java.util.Map;import java.util.TreeMap; public class testObjectToMap { public static void main(String[] args){ User user = new User(); user.setName("Kobi"); user.setAge(39); Map<string, object=""> map = transBean2Map(user); System.out.println(map); } public static Map<string, object=""> transBean2Map(Object obj) { if (obj == null) { return null; } TreeMap<string, object=""> map = new TreeMap<>(); try { BeanInfo beanInfo = Introspector.getBeanInfo(obj.getClass()); PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors(); for (PropertyDescriptor property : propertyDescriptors) { String key = property.getName(); // 過濾class屬性 if (key.equals("class")) { continue; } // 得到property對應的getter方法 Method getter = property.getReadMethod(); Object value = getter.invoke(obj); map.put(key, value); } } catch (Exception e) { System.out.println("transBean2Map Error " + e); } return map; }} |
運行結果：
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run:{age=39, name=Kobi}成功構建 (總時間: 0 秒) |
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原文鏈接：http://www.2cto.com/kf/201701/584920.html
