是否有一个版本的
BeanUtils.describe(customer)递归调用describe()方法对’客户’的复杂属性.
class Customer { String id; Address address; }
在这里,我想使用describe方法来检索address属性的内容.
目前,我可以看到类的名称如下:
{id=123,address=com.test.entities.Address@2a340e}
解决方法
有趣的是,我想使用describe方法来检索嵌套属性的内容,我不明白为什么不这样做.我继续前进,滚过我自己.在这里,你可以打电话:
Map<String,String> beanMap = BeanUtils.recursiveDescribe(customer);
一些警告.
>我不知道如何在集合中如何使用BeanUtils格式的属性,所以我用“attribute [index]”去了.
>我不知道如何在地图中格式化属性,所以我用“属性[key]”.
>对于名称冲突,优先级是这样的:第一个属性从超级类的字段,然后是类,然后从getter方法加载.
>我没有分析这种方法的性能.如果对象中包含大量集合的对象也包含集合,那么可能会有一些问题.
>这是阿尔法的代码,并不是无法免费的.
>我假设你有最新版本的commons beanutils
此外,fyi,这大概取自于我一直在工作的一个项目,亲切地,java in jails,所以你可以下载它,然后运行:
Map<String,String[]> beanMap = new SimpleMapper().toMap(customer);
虽然,你会注意到它返回一个String [],而不是String,这可能无法满足你的需要.无论如何,下面的代码应该工作,所以有它!
public class BeanUtils { public static Map<String,String> recursiveDescribe(Object object) { Set cache = new HashSet(); return recursiveDescribe(object,null,cache); } private static Map<String,String> recursiveDescribe(Object object,String prefix,Set cache) { if (object == null || cache.contains(object)) return Collections.EMPTY_MAP; cache.add(object); prefix = (prefix != null) ? prefix + "." : ""; Map<String,String> beanMap = new TreeMap<String,String>(); Map<String,Object> properties = getProperties(object); for (String property : properties.keySet()) { Object value = properties.get(property); try { if (value == null) { //ignore nulls } else if (Collection.class.isAssignableFrom(value.getClass())) { beanMap.putAll(convertAll((Collection) value,prefix + property,cache)); } else if (value.getClass().isArray()) { beanMap.putAll(convertAll(Arrays.asList((Object[]) value),cache)); } else if (Map.class.isAssignableFrom(value.getClass())) { beanMap.putAll(convertMap((Map) value,cache)); } else { beanMap.putAll(convertObject(value,cache)); } } catch (Exception e) { e.printStackTrace(); } } return beanMap; } private static Map<String,Object> getProperties(Object object) { Map<String,Object> propertyMap = getFields(object); //getters take precedence in case of any name collisions propertyMap.putAll(getGetterMethods(object)); return propertyMap; } private static Map<String,Object> getGetterMethods(Object object) { Map<String,Object> result = new HashMap<String,Object>(); BeanInfo info; try { info = Introspector.getBeanInfo(object.getClass()); for (PropertyDescriptor pd : info.getPropertyDescriptors()) { Method reader = pd.getReadMethod(); if (reader != null) { String name = pd.getName(); if (!"class".equals(name)) { try { Object value = reader.invoke(object); result.put(name,value); } catch (Exception e) { //you can choose to do something here } } } } } catch (IntrospectionException e) { //you can choose to do something here } finally { return result; } } private static Map<String,Object> getFields(Object object) { return getFields(object,object.getClass()); } private static Map<String,Object> getFields(Object object,Class<?> classType) { Map<String,Object>(); Class superClass = classType.getSuperclass(); if (superClass != null) result.putAll(getFields(object,superClass)); //get public fields only Field[] fields = classType.getFields(); for (Field field : fields) { try { result.put(field.getName(),field.get(object)); } catch (IllegalAccessException e) { //you can choose to do something here } } return result; } private static Map<String,String> convertAll(Collection<Object> values,String key,Set cache) { Map<String,String> valuesMap = new HashMap<String,String>(); Object[] valArray = values.toArray(); for (int i = 0; i < valArray.length; i++) { Object value = valArray[i]; if (value != null) valuesMap.putAll(convertObject(value,key + "[" + i + "]",cache)); } return valuesMap; } private static Map<String,String> convertMap(Map<Object,Object> values,String>(); for (Object thisKey : values.keySet()) { Object value = values.get(thisKey); if (value != null) valuesMap.putAll(convertObject(value,key + "[" + thisKey + "]",cache)); } return valuesMap; } private static ConvertUtilsBean converter = BeanUtilsBean.getInstance().getConvertUtils(); private static Map<String,String> convertObject(Object value,Set cache) { //if this type has a registered converted,then get the string and return if (converter.lookup(value.getClass()) != null) { String stringValue = converter.convert(value); Map<String,String> valueMap = new HashMap<String,String>(); valueMap.put(key,stringValue); return valueMap; } else { //otherwise,treat it as a nested bean that needs to be described itself return recursiveDescribe(value,key,cache); } } }