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Java Collections - Collections.checkedSortedSet() Examples

Java Collections Java Java API 

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Class:

java.util.Collections

java.lang.Objectjava.lang.Objectjava.util.Collectionsjava.util.CollectionsLogicBig

Method:

public static <E> SortedSet<E> checkedSortedSet(SortedSet<E> s,
                                                Class<E> type)

Returns a dynamically typesafe view of the specified SortedSet.


Examples


package com.logicbig.example.collections;

import java.util.*;

public class CheckedSortedSetExample {

    public static void main(String... args) {
        Comparator comparator = (o1, o2) -> 1;
        SortedSet<Integer> set = new TreeSet<>(comparator);

        set.add(1);
        System.out.println(set);

        Set set2 = set;
        set2.add("two");
        System.out.println(set2);
    }
}

Output

[1]
[1, two]




Using checkedSortedSet 

package com.logicbig.example.collections;

import java.util.*;

public class CheckedSortedSetExample2 {

    public static void main(String... args) {
        Comparator comparator = (o1, o2) -> 1;
        SortedSet<Integer> set = new TreeSet<>(comparator);
        set = Collections.checkedSortedSet(set, Integer.class);

        set.add(1);
        System.out.println(set);

        Set set2 = set;
        set2.add("two");
        System.out.println(set2);
    }
}

Output

Caused by: java.lang.ClassCastException: Attempt to insert class java.lang.String element into collection with element type class java.lang.Integer
	at java.util.Collections$CheckedCollection.typeCheck(Collections.java:3037)
	at java.util.Collections$CheckedCollection.add(Collections.java:3080)
	at com.logicbig.example.collections.CheckedSortedSetExample2.main(CheckedSortedSetExample2.java:22)
	... 6 more

See Also