阿超 > 写一个基于lambda的copyProperties

写一个基于lambda的copyProperties

2023-06-19

java

和任何人都认朋友，结果和任何人都交不成朋友。——佚名

代码仓库：

https://gitee.com/dromara/stream-query

相关提交：

https://gitee.com/dromara/stream-query/commit/31114dbc1374f78aad17daa4da615766d93194a2

使用方式：

1
2
3
4
5
6
7
8
9
@Test
void testCopyProperties() {
  LambdaExecutable source =
      LambdaHelper.resolve(
          (Serializable & Function<LambdaExecutable, String>) LambdaExecutable::getName);
  LambdaExecutable target = BeanHelper.copyProperties(source, null);
  Assertions.assertNotNull(target);
  Assertions.assertEquals(source.getName(), target.getName());
}

此处target为null会自动创建，只能copy到同类型，后续会支持不同类型的，尽请期待

目前的源码：

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
/**
 * 拷贝属性
 *
 * @param source 源对象
 * @param target 目标对象
 * @param <T> 对象类型
 */
public static <T> T copyProperties(T source, T target) {
  if (Objects.isNull(source)) {
    return target;
  }
  Class<T> clazz = SerFunc.<Class<?>, Class<T>>cast().apply(source.getClass());
  AtomicReference<T> targetRef = new AtomicReference<>(target);
  if (Objects.isNull(targetRef.get())) {
    SerFunc<Class<T>, Constructor<T>> getConstructor = Class::getConstructor;
    Constructor<T> constructor = getConstructor.andThen(ReflectHelper::accessible).apply(clazz);
    SerFunc<Constructor<T>, T> newInstance = Constructor::newInstance;
    targetRef.set(newInstance.apply(constructor));
  }
  Map<SerFunc<T, Object>, SerBiCons<T, Object>> getterSetterMap =
      LambdaHelper.getGetterSetterMap(clazz);
  getterSetterMap.forEach(
      (getter, setter) -> setter.accept(targetRef.get(), getter.apply(source)));
  return targetRef.get();
}