java.util.concurrent.ConcurrentHashMap#reduce ( )源码实例Demo

下面列出了java.util.concurrent.ConcurrentHashMap#reduce ( ) 实例代码，或者点击链接到github查看源代码，也可以在右侧发表评论。

源代码1 项目： Java-Coding-Problems 文件： Main.java

public static void main(String[] args) {

        ConcurrentHashMap<Integer, String> map = new ConcurrentHashMap<>();
        map.put(1, "Tylor");
        map.put(2, "Jenny");
        map.put(3, "Tymmy");
        map.put(4, "Anna");
        map.put(5, "Tysha");
        map.put(6, "Maria");

        System.out.println("Map: \n" + map);
        
        String result = map.reduce(2, (k, v) -> v = v + "   ", (t, v) -> t + v);
        System.out.println("\nNames concatenated and separated by tab via reduce():\n" + result);
        
        Integer maxKey = map.reduceKeys(2, (k1, k2) -> k1.compareTo(k2) > 0 ? k1 : k2);  
        System.out.println("\nMaximum key via reduceKeys(): " + maxKey);
        
        String resultValue = map.reduceValues(2, (v) -> v = v + "   ", (t, v) -> t + v);
        System.out.println("\nNames concatenated and separated by tab via reduceValues():\n" + resultValue);        
    }

源代码2 项目： javase 文件： ProgMainExecServConcurrentHashMap09.java

private static void testReduce() {
    ConcurrentHashMap<String, String> map = new ConcurrentHashMap<>();
    map.putIfAbsent("foo", "bar");
    map.putIfAbsent("han", "solo");
    map.putIfAbsent("r2", "d2");
    map.putIfAbsent("c3", "p0");

    String reduced = map.reduce(1, (key, value) -> key + "=" + value,
            (s1, s2) -> s1 + ", " + s2);

    System.out.println(reduced);
}

源代码3 项目： javacore 文件： ConcurrentHashMap1.java

private static void testReduce() {
    ConcurrentHashMap<String, String> map = new ConcurrentHashMap<>();
    map.putIfAbsent("foo", "bar");
    map.putIfAbsent("han", "solo");
    map.putIfAbsent("r2", "d2");
    map.putIfAbsent("c3", "p0");

    String reduced = map.reduce(1, (key, value) -> key + "=" + value, (s1, s2) -> s1 + ", " + s2);

    System.out.println(reduced);
}

源代码4 项目： java8-tutorial 文件： ConcurrentHashMap1.java

private static void testReduce() {
    ConcurrentHashMap<String, String> map = new ConcurrentHashMap<>();
    map.putIfAbsent("foo", "bar");
    map.putIfAbsent("han", "solo");
    map.putIfAbsent("r2", "d2");
    map.putIfAbsent("c3", "p0");

    String reduced = map.reduce(1, (key, value) -> key + "=" + value,
            (s1, s2) -> s1 + ", " + s2);

    System.out.println(reduced);
}

源代码5 项目： java-tutorial 文件： ConcurrentMapTest.java

/**
 * ConcurrentMap接口继承自Map接口，并定义了最实用的并发集合类型之一。
 * Java8通过将新的方法添加到这个接口，引入了函数式编程。
 * ConcurrentHashMap 是无序的
 */
public void concurrentMapDemo() {
    ConcurrentHashMap<String, String> map = new ConcurrentHashMap<>();
    map.put("foo", "bar");
    map.put("han", "solo");
    map.put("r2", "d2");
    map.put("c3", "p0");

    // 方法可以并行迭代映射中的键值对
    map.forEach(1, (k, v) ->
            System.out.printf("key: %s; value: %s; thread: %s\n",
                    k, v, Thread.currentThread().getName()));

    System.out.println("\n");
    // search 只要返回了非空的结果，就不会往下搜索了
    String result = map.search(1, (k, v) -> {
                System.out.println(Thread.currentThread().getName());
                if ("foo".equals(k)) {
                    return v;
                }
                return null;
            }
    );

    System.out.println("Result: " + result);

    System.out.println("\n");
    String result1 = map.search(1, (k, v) -> {
                System.out.println(Thread.currentThread().getName());
                if (v.length() > 3) {
                    return v;
                }
                return null;
            }
    );

    System.out.println("Result: " + result1);

    System.out.println("\n");
    String result2 = map.reduce(1,
            (k, v) -> {
                System.out.println("Transform: " + Thread.currentThread().getName());
                return k + "=" + v;
            },
            (s1, s2) -> {
                System.out.println("Reduce: " + Thread.currentThread().getName());
                return s1 + ", " + s2;
            }
    );
    System.out.println("Result: " + result2);
}