工具类-简化steam操作

功能列表：

1. 通过简单的方式完成流 分组、循环
2. 列表对比

📦安装

🍊Maven

在项目的pom.xml的dependencies中加入以下内容:

<!-- https://mvnrepository.com/artifact/io.github.cShen-code/shen-tool -->
<dependency>
    <groupId>io.github.cShen-code</groupId>
    <artifactId>shen-tool</artifactId>
    <version>2.0.3-RELEASE</version>
</dependency>

🍐Gradle

// https://mvnrepository.com/artifact/io.github.cShen-code/shen-tool
implementation group: 'io.github.cShen-code', name: 'shen-tool', version: '2.0.3-RELEASE'

📥下载jar

点击以下链接，下载shen-tool-X.X.X.jar即可：

• Maven中央库

基础用法

@Data
@AllArgsConstructor
@NoArgsConstructor
public class TestBean {
    private Long id;
    private String name;

}

List<TestBean> testBeanList = new ArrayList<>();
testBeanList.add(new TestBean(1L, "one"));
testBeanList.add(new TestBean(3L, "three"));
testBeanList.add(new TestBean(4L, "four"));
testBeanList.add(new TestBean(4L, "four1"));
testBeanList.add(new TestBean(2L, "two"));


分组，每组取第一个
Stream<TestBean> stream = testBeanList.stream();
Map<Long, TestBean> collect = stream
    .collect(CollectorUtil.groupAndFist(TestBean::getId));
System.out.println(JSON.toJSONString(collect));

输出结果：
{1:{"id":1,"name":"one"},2:{"id":2,"name":"two"},3:{"id":3,"name":"three"},4:{"id":4,"name":"four"}}


// 分组，组内通过id排序
Map<Long, List<TestBean>> collect = testBeanList.stream()
    .collect(CollectorUtil
        .groupAndSort(TestBean::getId, (v1, v2) -> {
        //倒叙
            return (int) (v2.getId() - v1.getId());
        }));
System.out.println(JSON.toJSONString(collect));

输出结果：
{1:[{"id":1,"name":"one"}],2:[{"id":2,"name":"two"}],3:[{"id":3,"name":"three"}],4:[{"id":4,"name":"four"},{"id":4,"name":"four1"}]}

带下标的peek
long count = CollectorUtil.peekI(testBeanList.stream(), (v, i) -> {
    System.out.println(v);
    System.out.println(i);
}).count();

列表对比

List<ListCompareBean> oldCompareBeanList = new ArrayList<>();
oldCompareBeanList.add(new ListCompareBean(1L, "test1"));
oldCompareBeanList.add(new ListCompareBean(2L, "test2"));

List<ListCompareBean> newCompareBeanList = new ArrayList<>();
newCompareBeanList.add(new ListCompareBean(1L, "updateTest1"));
newCompareBeanList.add(new ListCompareBean(3L, "test3"));

ListCompareUtil.builder(oldCompareBeanList, newCompareBeanList, ListCompareBean::getId)
        // 批量回调
        .whenInsert(list -> {
            // 进行orm操作
            System.out.println("新增：" + JSON.toJSONString(list));
        })
        .whenUpdate(list -> {
            System.out.println("更新：" + JSON.toJSONString(list));
        })
        .whenRemove(list -> {
            // id列表
            System.out.println("删除：" + JSON.toJSONString(list));
        })
        .compare();

ListCompareUtil.builder(oldCompareBeanList, newCompareBeanList, ListCompareBean::getId)
        // 单个回调，for循环挨个回调
        .whenInsertOne(one -> {
            System.out.println("单个新增：" + JSON.toJSONString(one));
            return 0;
        })
        .whenUpdateOne(one -> {
            System.out.println("单个更新：" + JSON.toJSONString(one));
            return 0;
        })
        .whenRemoveOne(one -> {
            System.out.println("单个删除：" + JSON.toJSONString(one));
            return 0;
        })
        .compare();