坏味道:
Long count = 0L;
List<Result> list = new ArrayList<>();
if (type == 0) {
count = dao.pageCountA(query);
if (count == 0) {
return;
}
list = dao.pageQueryA(query);
} else {
count = dao.pageCountB(query);
if (count == 0) {
return;
}
list = dao.pageQueryB(query);
}
坏味道：相同的代码多次出现
函数式接口 + Lambda实现类似功能：
函数式接口定义：
@FunctionalInterface
public interface PageCountHelper {
Long pageCount(Query query);
}
@FunctionalInterface
public interface PageQueryHelper {
List<Result> pageQuery(Query query);
}
配合Lambda使用：
PageCountHelper pageCountHelper = (Query query) -> dao.pageCountA(query);
PageQueryHelper pageQueryHelper = (Query query) -> dao.pageQueryA(query);
if (type != 0) {
pageCountHelper = (Query query) -> dao.pageCountB(query);
pageQueryHelper = (Query query) -> dao.pageQueryB(query);
}
Long count = pageCountHelper.pageCount(query);
if (count == 0) {
return;
}
List<Result> result = pageQueryHelper.pageQuery(query);
