EntityRefelectUtils.java 文件源码

public static Field getIdField(Object object) {
    List<Field> fieldList = new ArrayList<>();
    Field[] declaredFields = object.getClass().getDeclaredFields();

    for (Field field : declaredFields) {
        if (field.isAnnotationPresent(Id.class)) {
            fieldList.add(field);
        }
    }
    if (fieldList.size() == 0) {
        throw new RuntimeException(object.getClass().getSimpleName() + "实体类必须有一个包含@Id的字段");
    }
    if (fieldList.size() > 1) {
        throw new RuntimeException(object.getClass().getSimpleName() + "实体类必须有一个包含@Id的字段");
    }
    return fieldList.get(0);
}