1、Stream的distinct()方法distinct()是Java8中Stream提供的方法，返回一个由流中不同元素组成的流。distinct()使用hashCode()和eqauls()方法来获取不同的元素。因此，需要去重的类必须实现hashCode()和equals()方法。也就是说，我们可以通过重写自定义的hashCode()和equals()方法来实现一些特殊需求的去重。distinct()方法声明如下：Streamdistinct();1.1String列表去重因为String类重写了equals()和hashCode()方法，所以可以成功去重。@TestpublicvoidlistDistinctByStreamDistinct(){//1.对于String列表去重ListstringList=newArrayList(){{add("A");添加（“A”）；添加（“乙”）;添加（“乙”）;添加（“C”）；}};out.print("去重之前：");for(Strings:stringList){out.print(s);}out.println();stringList=stringList.stream().distinct().collect(Collectors.toList());out.print("去重后：");for(Strings:stringList){out.print(s);}out.println();}结果如下：去重前：AABBC去重后：ABC1.2实体类列表去重：代码中我们使用了Lombok插件的@Data注解，可以自动覆盖equals()和hashCode()方法。/***定义一个实体类*/@DatapublicclassStudent{privateStringstuNo;私有字符串名称；}@TestpublicvoidlistDistinctByStreamDistinct()throwsJsonProcessingException{ObjectMapperobjectMapper=newObjectMapper();//1.学生列表去重ListstudentList=getStudentList();out.print("去重之前：");out.println(objectMapper.writeValueAsString(studentList));studentList=studentList.stream().distinct().collect(Collectors.toList());out.print("去重后：");out.println(objectMapper.writeValueAsString(studentList));}结果如下：去重前：[{"stuNo":"001","name":"Tom"},{"stuNo":"002","name":"Mike"},{"stuNo":"001","name":"Tom"}]去重后：[{"stuNo"":"001","name":"Tom"},{"stuNo":"002","name":"Mike"}]2.根据List
