51工具盒子你好，我是猿java。
下面代码对比了传统方式和lambda方式对list的合并
|---------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| 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 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 | import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper; import java.util.ArrayList; import java.util.Objects; /** * 按照 两个list中的对象的id一样进行合并，并且输出到一个新的list中 */ public class TestClass { // 传统方式 private List<PipelineJobAndRuntimeInfo> mergeData(List<PipelineJobEntity> jobs, List<JobRuntimeEntity> runtimes) { List<PipelineJobAndRuntimeInfo> list = new ArrayList<>(); for (int i = 0; i < jobs.size(); i++) { for (int j = 0; j < runtimes; j++) { if (Objects.equals(jobs.get(i), runtimes.get(j))) { PipelineJobAndRuntimeInfo info = new PipelineJobAndRuntimeInfo(); BeanUtils.copyProperties(jobs.get(i), info); info.setJobId(jobs.get(i).getId()); info.setWorker(runtimes.get(j).getWorker()); info.setUpdatedAt(runtimes.get(j).getUpdatedAt()); } } } } // lambda写法 private List<PipelineJobAndRuntimeInfo> mergeData(List<PipelineJobEntity> jobs, List<JobRuntimeEntity> runtimes) { List<PipelineJobAndRuntimeInfo> list; list = jobs.stream().map(jobEntity -> { PipelineJobAndRuntimeInfo info = new PipelineJobAndRuntimeInfo(); runtimes.stream().filter(runtimeEntity -> Objects.equals(jobEntity.getId(), runtimeEntity.getId())).forEach(runtimeEntity -> { BeanUtils.copyProperties(jobEntity, info); info.setJobId(jobEntity.getId()); info.setWorker(runtimeEntity.getWorker()); info.setUpdatedAt(runtimeEntity.getUpdatedAt()); }); return info; }).collect(Collectors.toList()); return list; } } |
本文为原创文章，转载请标明出处。
本文链接：https://www.yuanjava.cn/common/2022/04/20/java/merge.html
本文出自猿 java的博客
