java对象与map对象相互转换

  1 /**
  2  * 使用org.apache.commons.beanutils进行转换
  3  */
  4 class A {
  5
  6     public static Object mapToObject(Map<String, Object> map, Class<?> beanClass) throws Exception {
  7         if (map == null)
  8             return null;
  9
 10         Object obj = beanClass.newInstance();
 11
 12         org.apache.commons.beanutils.BeanUtils.populate(obj, map);
 13
 14         return obj;
 15     }
 16
 17     public static Map<?, ?> objectToMap(Object obj) {
 18         if(obj == null)
 19             return null;
 20
 21         return new org.apache.commons.beanutils.BeanMap(obj);
 22     }
 23
 24 }
 25
 26 /**
 27  * 使用Introspector进行转换
 28  */
 29 class B {
 30
 31     public static Object mapToObject(Map<String, Object> map, Class<?> beanClass) throws Exception {
 32         if (map == null)
 33             return null;
 34
 35         Object obj = beanClass.newInstance();
 36
 37         BeanInfo beanInfo = Introspector.getBeanInfo(obj.getClass());
 38         PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
 39         for (PropertyDescriptor property : propertyDescriptors) {
 40             Method setter = property.getWriteMethod();
 41             if (setter != null) {
 42                 setter.invoke(obj, map.get(property.getName()));
 43             }
 44         }
 45
 46         return obj;
 47     }
 48
 49     public static Map<String, Object> objectToMap(Object obj) throws Exception {
 50         if(obj == null)
 51             return null;
 52
 53         Map<String, Object> map = new HashMap<String, Object>();
 54
 55         BeanInfo beanInfo = Introspector.getBeanInfo(obj.getClass());
 56         PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
 57         for (PropertyDescriptor property : propertyDescriptors) {
 58             String key = property.getName();
 59             if (key.compareToIgnoreCase("class") == 0) {
 60                 continue;
 61             }
 62             Method getter = property.getReadMethod();
 63             Object value = getter!=null ? getter.invoke(obj) : null;
 64             map.put(key, value);
 65         }
 66
 67         return map;
 68     }
 69
 70 }
 71
 72 /**
 73  * 使用reflect进行转换
 74  */
 75 class C {
 76
 77     public static Object mapToObject(Map<String, Object> map, Class<?> beanClass) throws Exception {
 78         if (map == null)
 79             return null;
 80
 81         Object obj = beanClass.newInstance();
 82
 83         Field[] fields = obj.getClass().getDeclaredFields();
 84         for (Field field : fields) {
 85             int mod = field.getModifiers();
 86             if(Modifier.isStatic(mod) || Modifier.isFinal(mod)){
 87                 continue;
 88             }
 89
 90             field.setAccessible(true);
 91             field.set(obj, map.get(field.getName()));
 92         }
 93
 94         return obj;
 95     }
 96
 97     public static Map<String, Object> objectToMap(Object obj) throws Exception {
 98         if(obj == null){
 99             return null;
100         }
101
102         Map<String, Object> map = new HashMap<String, Object>();
103
104         Field[] declaredFields = obj.getClass().getDeclaredFields();
105         for (Field field : declaredFields) {
106             field.setAccessible(true);
107             map.put(field.getName(), field.get(obj));
108         }
109
110         return map;
111     }
112 }