Java List T remove duplicate objects -java8

Stream syntax Detailed

Stream as an advanced version of Iterator. The original version of the Iterator, a user can traverse a certain element and perform operations; Advanced versions Stream, as long as the user needs to perform any given operation of its contained elements, such as "filter out the string length is greater than 10 '' get the first letter of each string, "and so on, how to apply these actions specific to each element, give enough Stream

 

1. Creating Stream;
2. Stream conversion, each conversion does not change the original Stream object and returns a new Stream object (there can be multiple conversions ** **);
3. Stream polymerization results (the Reduce) steps to obtain the desired

 

A, List remove duplicate String

 

 

public List<String> removeStringListDupli(List<String> stringList) {
    Set<String> set = new LinkedHashSet<>();
    set.addAll(stringList);

    stringList.clear();

    stringList.addAll(set);
    return stringList;
}

二、List中依据对象属性去重

List<Person> unique = persons.stream().collect(
             collectingAndThen(
                     toCollection(() -> new TreeSet<>(comparingLong(Person::getId))), ArrayList::new)
     );