HibernateGenericDao.java 文件源码

private <T> Field getIdField(Class<T> entityClass){
    Field idField = ID_FIELD.get(entityClass);
    if(idField != null){
        return idField;
    }

    List<Field> fields = new ArrayList<Field>();
    Beans.getDeclaredFields(fields, entityClass);
    for(Field f : fields){
        if(f.getAnnotation(Id.class) != null || f.getAnnotation(EmbeddedId.class) != null){
            idField = f;
        }
    }

    ID_FIELD.put(entityClass, idField);
    Asserts.notNull(idField, String.format("%s实体中没有ID字段", entityClass));

    return idField;
}