Java Field.getGenericType方法代碼示例

import java.lang.reflect.Field; //導入方法依賴的package包/類
@SuppressWarnings("rawtypes")
public static Class getFieldGenricType(final Field field, final int index) {
   	Assert.notNull(field, "Parameter 'field' must be not null!");
   	Assert.state(index > -1, "Parameter 'index' must be > -1!");
   	Type type = field.getGenericType();
   	if(type instanceof ParameterizedType){
		ParameterizedType ptype = (ParameterizedType)type;
		type = ptype.getActualTypeArguments()[index];
		if(type instanceof ParameterizedType){
			return (Class)((ParameterizedType) type).getRawType();
		}else{
			return (Class) type;
		}
	}else{
		return (Class) type;
	}
   }
 

import java.lang.reflect.Field; //導入方法依賴的package包/類
public static boolean isFieldPrintable(Field field)
{
    boolean isPrintable = false;
    Type fieldType = field.getGenericType();
    if (fieldType instanceof ParameterizedType)
    {
        Type[] declaredGenericTypes = ((ParameterizedType) fieldType).getActualTypeArguments();
        for (Type type : declaredGenericTypes)
        {
            isPrintable = ClassTypeHelper.isPrintableClass((Class<?>) type);
            if (!isPrintable)
            {
                break;
            }
        }
    }
    return isPrintable;
}
 

import java.lang.reflect.Field; //導入方法依賴的package包/類
public CollectionProperty(EntityMetadata metadata, Field field) {
	super(metadata, field);
	Collection collection = field.getAnnotation(Collection.class);
	if(!java.util.Collection.class.isAssignableFrom(field.getType())){
		throw new HibatisException("Collection屬性必須為集合類型");
	}
	this.isLazy = collection.lazy();
	this.isIn = collection.in();
	this.cacheable = collection.cacheable();
	ParameterizedType type = (ParameterizedType) field.getGenericType();
	this.referenceType = (Class<?>) type.getActualTypeArguments()[0];
	this.rawType = field.getType();
	if(this.rawType != List.class){
		throw new HibatisException("@Collection隻支持java.util.List類型");
	}
	this.setProperties(collection.property());
	this.setReferences(collection.reference());
	String[] orderBy = collection.orderBy();
	if(orderBy != null){
		sorts = new Sort[orderBy.length];
		for (int i = 0; i < sorts.length; i++) {
			String order = orderBy[i];
			sorts[i] = Sort.parse(order);
		}
	}
}
 

import java.lang.reflect.Field; //導入方法依賴的package包/類
@Override
public final boolean check(Field field) {
    if (field == null)
        return false;

    Type type = field.getGenericType();

    if (type instanceof ParameterizedType) {
        ParameterizedType parameterizedType = (ParameterizedType) type;
        Type rawType = parameterizedType.getRawType();

        if (rawType.equals(collectionType)) {
            return checkGenericType(parameterizedType);
        } else
            return false;
    }
    return false;
}
 

import java.lang.reflect.Field; //導入方法依賴的package包/類
/**
 * 給List中的泛型取別名
 * 
 * @param xStream
 * @param obj
 */
private static void toListGenericsAlias(XStream xStream, Object obj) {
	/** 得到所有的fields **/
	Field[] fs = obj.getClass().getDeclaredFields();
	for (Field f : fs) {
		/** 得到field的class及類型全路徑 **/
		Class<?> fieldClazz = f.getType();
		/** 如果是List類型，得到其類的類型 **/
		if (fieldClazz.isAssignableFrom(List.class)) {
			/** 獲取類的類型 **/
			Type fc = f.getGenericType();
			if (fc == null)
				continue;
			/** 是否是參數化泛型類型 **/
			if (fc instanceof ParameterizedType) {
				/** 得到泛型裏的class類型對象 **/
				ParameterizedType pt = (ParameterizedType) fc;
				Class<?> genericClazz = (Class<?>) pt.getActualTypeArguments()[0];
				xStream.alias(genericClazz.getSimpleName(), genericClazz);
			}
		}
	}
}
 

import java.lang.reflect.Field; //導入方法依賴的package包/類
/**
 * Get the generic type class of List or Set. If there's no generic type of
 * List or Set return null.
 *
 * @param field
 *            A generic type field.
 * @return The generic type of List or Set.
 */
protected Class<?> getGenericTypeClass(Field field) {
    Type genericType = field.getGenericType();
    if (genericType != null) {
        if (genericType instanceof ParameterizedType) {
            ParameterizedType parameterizedType = (ParameterizedType) genericType;
            return (Class<?>) parameterizedType.getActualTypeArguments()[0];
        }
    }
    return null;
}
 

import java.lang.reflect.Field; //導入方法依賴的package包/類
private static Object convertCollectionFromProtobufs(Field field,
    Collection<?> collectionOfProtobufs)
    throws JException, InstantiationException, IllegalAccessException {
  if (collectionOfProtobufs.isEmpty()) {
    return collectionOfProtobufs;
  }
  final ParameterizedType listType = (ParameterizedType) field.getGenericType();
  final Class<?> collectionClazzType = (Class<?>) listType.getActualTypeArguments()[0];
  final ProtobufEntity protoBufEntityAnno =
      ProtobufSerializerUtils.getProtobufEntity(collectionClazzType);
  final Object first = collectionOfProtobufs.toArray()[0];
  if (!(first instanceof Message) && protoBufEntityAnno == null) {
    return collectionOfProtobufs;
  }
  final Collection<Object> newCollectionOfValues = new ArrayList<>();
  for (Object protobufValue : collectionOfProtobufs) {
    if (!(protobufValue instanceof Message)) {
      throw new ProtobufException(
          "Collection contains an object of type " + protobufValue.getClass()
              + " which is not an instanceof GeneratedMessage, can not (de)serialize this");
    }
    newCollectionOfValues
        .add(serializeFromProtobufEntity((Message) protobufValue, collectionClazzType));
  }

  return newCollectionOfValues;
}
 

import java.lang.reflect.Field; //導入方法依賴的package包/類
private Class<?> getConvertedType(String fieldName) {
    try {
        Field field = clazz.getField(fieldName);

        if (field.getType().equals(Optional.class)) {
            ParameterizedType type = (ParameterizedType) field.getGenericType();
            return converters.getConvertedType((Class<?>) type.getActualTypeArguments()[0]);
        } else {
            return converters.getConvertedType(field.getType());
        }
    } catch (NoSuchFieldException e) {
        throw new FieldAccessException(fieldName, clazz.getName());
    }

}
 

import java.lang.reflect.Field; //導入方法依賴的package包/類
public static Class<?>[] getFieldGenericType(Field field) {
	Type genericFieldType = field.getGenericType();

	if (genericFieldType instanceof ParameterizedType) {
		ParameterizedType aType = (ParameterizedType) genericFieldType;
		Type[] fieldArgTypes = aType.getActualTypeArguments();
		return (Class<?>[]) fieldArgTypes;
	}
	return null;
}
 

import java.lang.reflect.Field; //導入方法依賴的package包/類
public static void main(String[] args) throws NoSuchMethodException, SecurityException, NoSuchFieldException {
  for (TypeVariable<Class<Generic>> var : Generic.class.getTypeParameters()) {
    System.out.println(var.getName());
    Type bound = var.getBounds()[0];
    System.out.println(((Class<?>) bound).getName().equals(AA.class.getName()));
  }

  Field f = Generic.class.getField("f");
  ParameterizedType fieldType = (java.lang.reflect.ParameterizedType)f.getGenericType();
  checkOneParameterType(fieldType, Generic.class, AA.class);

  ParameterizedType methodReturnType =
      (ParameterizedType) Generic.class.getMethod("get").getGenericReturnType();
  checkOneParameterType(methodReturnType, Generic.class, AA.class);
}
 

import java.lang.reflect.Field; //導入方法依賴的package包/類
/**
 * Reflection to get the type of a given field, even nested or in a superclass.
 * @param rootClass
 * @param attributePath field name like "surname" or even a path like "friend.name"
 * @return
 * @throws NoSuchFieldException if the field is not found in the class hierarchy
 * @throws SecurityException
 */
public Class getType(Class rootClass, String attributePath) throws NoSuchFieldException, SecurityException {
	if (StringUtils.isBlank(attributePath)) {
		return rootClass;
	}
	String attributeName = StringUtils.substringBefore(attributePath, ".");
	Field field = null;
	NoSuchFieldException exception = null;
	while (field==null && rootClass!=null) {
		try {
			field = rootClass.getDeclaredField(attributeName);
		} catch (NoSuchFieldException e) {
			if (exception==null) {
				exception=e;
			}
			rootClass = rootClass.getSuperclass();
		}
	}
	if (field==null) {
		if (exception!=null) {
			throw exception;
		} else {
			throw new NoSuchFieldException("No field " + attributeName + " found in hierarchy");
		}
	}
	Class attributeType = field.getType();
	// If it's a list, look for the list type
	if (attributeType == java.util.List.class) {
		// TODO check if the attributeType is an instance of java.util.Collection
		ParameterizedType parameterizedType = (ParameterizedType)field.getGenericType();
		if (parameterizedType!=null) {
			Type[] types = parameterizedType.getActualTypeArguments();
			if (types.length==1) {
				attributeType = (Class<?>) types[0];
			}
		}
	}
	return getType(attributeType, StringUtils.substringAfter(attributePath, "."));
}
 

import java.lang.reflect.Field; //導入方法依賴的package包/類
/**
 * 獲取域的泛型類型，如果不帶泛型返回null
 *
 * @param f
 * @return
 */
public static Class<?> getGenericType(Field f) {
    Type type = f.getGenericType();
    if (type instanceof ParameterizedType) {
        type = ((ParameterizedType) type).getActualTypeArguments()[0];
        if (type instanceof Class<?>) return (Class<?>) type;
    } else if (type instanceof Class<?>) return (Class<?>) type;
    return null;
}
 

import java.lang.reflect.Field; //導入方法依賴的package包/類
public static Type getFieldType(Class<?> clazz, String fieldName) {
    try {
        Field field = clazz.getField(fieldName);

        return field.getGenericType();
    } catch (Exception ex) {
        return null;
    }
}
 

import java.lang.reflect.Field; //導入方法依賴的package包/類
public boolean load() {
    if (!this.configFile.exists()) return false;
    Config cfg = new Config(configFile, Config.YAML);
    for (Field field : this.getClass().getDeclaredFields()) {
        if (field.getName().equals("configFile")) continue;
        if (skipSave(field)) continue;
        String path = getPath(field);
        if (path == null) continue;
        if (path.isEmpty()) continue;
        field.setAccessible(true);
        try {
            if (field.getType() == int.class || field.getType() == Integer.class)
                field.set(this, cfg.getInt(path, field.getInt(this)));
            else if (field.getType() == boolean.class || field.getType() == Boolean.class)
                field.set(this, cfg.getBoolean(path, field.getBoolean(this)));
            else if (field.getType() == long.class || field.getType() == Long.class)
                field.set(this, cfg.getLong(path, field.getLong(this)));
            else if (field.getType() == double.class || field.getType() == Double.class)
                field.set(this, cfg.getDouble(path, field.getDouble(this)));
            else if (field.getType() == String.class)
                field.set(this, cfg.getString(path, (String) field.get(this)));
            else if (field.getType() == ConfigSection.class)
                field.set(this, cfg.getSection(path));
            else if (field.getType() == List.class) {
                Type genericFieldType = field.getGenericType();
                if (genericFieldType instanceof ParameterizedType) {
                    ParameterizedType aType = (ParameterizedType) genericFieldType;
                    Class fieldArgClass = (Class) aType.getActualTypeArguments()[0];
                    if (fieldArgClass == Integer.class) field.set(this, cfg.getIntegerList(path));
                    else if (fieldArgClass == Boolean.class) field.set(this, cfg.getBooleanList(path));
                    else if (fieldArgClass == Double.class) field.set(this, cfg.getDoubleList(path));
                    else if (fieldArgClass == Character.class) field.set(this, cfg.getCharacterList(path));
                    else if (fieldArgClass == Byte.class) field.set(this, cfg.getByteList(path));
                    else if (fieldArgClass == Float.class) field.set(this, cfg.getFloatList(path));
                    else if (fieldArgClass == Short.class) field.set(this, cfg.getFloatList(path));
                    else if (fieldArgClass == String.class) field.set(this, cfg.getStringList(path));
                } else field.set(this, cfg.getList(path)); // Hell knows what's kind of List was found :)
            } else
                throw new IllegalStateException("SimpleConfig did not supports class: " + field.getType().getName() + " for config field " + configFile.getName());
        } catch (Exception e) {
            Server.getInstance().getLogger().logException(e);
            return false;
        }
    }
    return true;
}
 

import java.lang.reflect.Field; //導入方法依賴的package包/類
/**
 * 參數解析 （支持：Byte、Boolean、String、Short、Integer、Long、Float、Double、Date）
 *
 * @param field
 * @param value
 * @return
 */
public static Object parseValue(Field field, String value) {

	Class<?> fieldType = field.getType();

	// parse list item
	if (field.getGenericType() instanceof ParameterizedType) {
		ParameterizedType fieldGenericType = (ParameterizedType) field.getGenericType();
		if (fieldGenericType.getRawType().equals(List.class)) {
			Type gtATA = fieldGenericType.getActualTypeArguments()[0];
			fieldType = (Class<?>) gtATA;
		}
	}

	PageFieldSelect apiRequestParam = field.getAnnotation(PageFieldSelect.class);

	if(value==null || value.trim().length()==0)
		return null;
	value = value.trim();

	 if (Byte.class.equals(fieldType) || Byte.TYPE.equals(fieldType)) {
		return parseByte(value);
	} else if (Boolean.class.equals(fieldType) || Boolean.TYPE.equals(fieldType)) {
		return parseBoolean(value);
	}/* else if (Character.class.equals(fieldType) || Character.TYPE.equals(fieldType)) {
		 return value.toCharArray()[0];
	}*/ else if (String.class.equals(fieldType)) {
		return value;
	} else if (Short.class.equals(fieldType) || Short.TYPE.equals(fieldType)) {
		 return parseShort(value);
	} else if (Integer.class.equals(fieldType) || Integer.TYPE.equals(fieldType)) {
		return parseInt(value);
	} else if (Long.class.equals(fieldType) || Long.TYPE.equals(fieldType)) {
		return parseLong(value);
	} else if (Float.class.equals(fieldType) || Float.TYPE.equals(fieldType)) {
		return parseFloat(value);
	} else if (Double.class.equals(fieldType) || Double.TYPE.equals(fieldType)) {
		return parseDouble(value);
	} else if (Date.class.equals(fieldType)) {
		 return parseDate(apiRequestParam, value);

	} else {
		throw new RuntimeException("request illeagal type, type must be Integer not int Long not long etc, type=" + fieldType);
	}
}