`
mwhgJava
  • 浏览: 97960 次
  • 性别: Icon_minigender_1
  • 来自: 广州
社区版块
存档分类
最新评论

parallelStream concurrent secure

parallelStreamconcurrentsecure 
阅读更多
About parallelStream  collect results. Please Use the collect method. The collect method is concurrent secure. 

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
import java.util.TreeSet;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.stream.Collectors;

import org.junit.Test;

import lombok.extern.slf4j.Slf4j;

@Slf4j
public class ParallelStreamTestcase {

    @Test
    public void test0Error() {
        int total = 100000;
        List<Integer> source = new ArrayList<>(total);
        for (int i = 0; i < total; i++) {
            source.add(i);
        }
        List<Integer> target = new ArrayList<>();
        source.parallelStream().forEach(iterator -> target.add(iterator));
        assertEquals(total, source.size());
        assertEquals(total, target.size());
    }

    @Test
    public void test1Error() {
        int total = 100000;
        List<Integer> source = new ArrayList<>(total);
        for (int i = 0; i < total; i++) {
            source.add(i);
        }
        HashSet<Integer> target = new HashSet<>();
        source.parallelStream().forEach(iterator -> target.add(iterator));
        assertEquals(total, source.size());
        assertEquals(total, target.size());
    }

    @Test
    public void test2Error() {
        int total = 100000;
        List<Integer> source = new ArrayList<>(total);
        for (int i = 0; i < total; i++) {
            source.add(i);
        }
        HashMap<Integer, Integer> target = new HashMap<>();
        source.parallelStream().forEach(iterator -> target.put(iterator, iterator));
        assertEquals(total, source.size());
        assertEquals(total, target.size());
    }

    @Test
    public void test00() {
        int total = 100000;
        List<Integer> source = new ArrayList<>(total);
        for (int i = 0; i < total; i++) {
            source.add(i);
        }
        List<Integer> targetList = source.parallelStream().collect(Collectors.toList());
        assertEquals(total, source.size());
        assertEquals(total, targetList.size());

        Set<Integer> targetSet = source.parallelStream().collect(Collectors.toSet());
        assertEquals(total, targetSet.size());

        Set<Integer> targetTreeSet = source.parallelStream().collect(Collectors.toCollection(() -> new TreeSet<>()));
        assertEquals(total, targetTreeSet.size());

        LinkedList<Integer> targetLinkedList = source.parallelStream().collect(Collectors.toCollection(() -> new LinkedList<>()));
        assertEquals(total, targetLinkedList.size());
    }

    @Test
    public void test22() {
        int total = 100000;
        List<Integer> source = new ArrayList<>(total);
        long sum = 0;
        for (int i = 0; i < total; i++) {
            sum += i;
            source.add(i);
        }
        log.debug("sum:{}", sum);
        System.err.println(String.format("sum:{%d}", sum));

        Map<Integer, Integer> target = source.parallelStream().collect(Collectors.toMap(iterator -> iterator, iterator -> iterator));
        long targetSum = 0;
        for (Integer value : target.values()) {
            targetSum += value;
        }
        log.debug("targetSum:{}", targetSum);
        System.err.println(String.format("targetSum:{%d}", targetSum));
        assertEquals(sum, targetSum);
        assertEquals(total, source.size());
        assertEquals(total, target.size());

        Map<Object, Integer> target2 = source.parallelStream().collect(Collectors.toMap(iterator -> iterator % 1000, iterator -> iterator, (t, u) -> t + u));
        long target2Sum = 0;
        for (Integer value : target2.values()) {
            target2Sum += value;
        }
        log.debug("target2Sum:{}", target2Sum);
        System.err.println(String.format("target2Sum:{%d}", target2Sum));
        assertEquals(sum, target2Sum);

        TreeMap<Object, Integer> target3 = source.parallelStream().collect(Collectors.toMap(iterator -> iterator % 1000, iterator -> iterator, (t, u) -> t + u, TreeMap::new));
        long target3Sum = 0;
        for (Integer value : target3.values()) {
            target3Sum += value;
        }
        log.debug("target3Sum:{}", target3Sum);
        System.err.println(String.format("target3Sum:{%d}", target3Sum));
        assertEquals(sum, target3Sum);

        boolean duplicateKeyExceptionForParallelStream = false;
        try {
            source.parallelStream().collect(Collectors.toMap(iterator -> iterator % 1000, iterator -> iterator));
        } catch (IllegalStateException e) {
            duplicateKeyExceptionForParallelStream = true;
        }
        assertTrue(duplicateKeyExceptionForParallelStream);

        boolean duplicateKeyExceptionForStream = false;
        try {
            source.parallelStream().collect(Collectors.toMap(iterator -> iterator % 1000, iterator -> iterator));
        } catch (IllegalStateException e) {
            duplicateKeyExceptionForStream = true;
        }
        assertTrue(duplicateKeyExceptionForStream);

    }

    @Test
    public void test222() {
        int total = 100000;
        List<Integer> source = new ArrayList<>(total);
        long sum = 0;
        for (int i = 0; i < total; i++) {
            sum += i;
            source.add(i);
        }
        log.debug("sum:{}", sum);
        System.err.println(String.format("sum:{%d}", sum));

        Map<Integer, Integer> target = source.parallelStream().collect(Collectors.toConcurrentMap(iterator -> iterator, iterator -> iterator));
        long targetSum = 0;
        for (Integer value : target.values()) {
            targetSum += value;
        }
        log.debug("targetSum:{}", targetSum);
        System.err.println(String.format("targetSum:{%d}", targetSum));
        assertEquals(sum, targetSum);
        assertEquals(total, source.size());
        assertEquals(total, target.size());

        Map<Object, Integer> target2 = source.parallelStream().collect(Collectors.toConcurrentMap(iterator -> iterator % 1000, iterator -> iterator, (t, u) -> t + u));
        long target2Sum = 0;
        for (Integer value : target2.values()) {
            target2Sum += value;
        }
        log.debug("target2Sum:{}", target2Sum);
        System.err.println(String.format("target2Sum:{%d}", target2Sum));
        assertEquals(sum, target2Sum);

        ConcurrentMap<Object, Integer> target3 = source.parallelStream()
                .collect(Collectors.toConcurrentMap(iterator -> iterator % 1000, iterator -> iterator, (t, u) -> t + u, ConcurrentHashMap::new));
        long target3Sum = 0;
        for (Integer value : target3.values()) {
            target3Sum += value;
        }
        log.debug("target3Sum:{}", target3Sum);
        System.err.println(String.format("target3Sum:{%d}", target3Sum));
        assertEquals(sum, target3Sum);

        boolean duplicateKeyExceptionForParallelStream = false;
        try {
            source.parallelStream().collect(Collectors.toConcurrentMap(iterator -> iterator % 1000, iterator -> iterator));
        } catch (IllegalStateException e) {
            duplicateKeyExceptionForParallelStream = true;
        }
        assertTrue(duplicateKeyExceptionForParallelStream);

        boolean duplicateKeyExceptionForStream = false;
        try {
            source.parallelStream().collect(Collectors.toConcurrentMap(iterator -> iterator % 1000, iterator -> iterator));
        } catch (IllegalStateException e) {
            duplicateKeyExceptionForStream = true;
        }
        assertTrue(duplicateKeyExceptionForStream);

    }

    @Test
    public void test2222() {
        int total = 100000;
        List<Integer> source = new ArrayList<>(total);
        long sum = 0;
        for (int i = 0; i < total; i++) {
            sum += i;
            source.add(i);
        }
        log.debug("sum:{}", sum);
        System.err.println(String.format("sum:{%d}", sum));

        Map<Integer, Integer> target = source.parallelStream().collect(Collectors.toConcurrentMap(iterator -> iterator, iterator -> iterator));
        long targetSum = 0;
        for (Integer value : target.values()) {
            targetSum += value;
        }
        log.debug("targetSum:{}", targetSum);
        System.err.println(String.format("targetSum:{%d}", targetSum));
        assertEquals(total, source.size());
        assertEquals(total, target.size());
        assertEquals(sum, targetSum);

        Map<Object, Integer> target2 = source.parallelStream().collect(Collectors.toConcurrentMap(iterator -> iterator % 1000, iterator -> iterator, (t, u) -> t + u));
        long target2Sum = 0;
        for (Integer value : target2.values()) {
            target2Sum += value;
        }
        log.debug("target2Sum:{}", target2Sum);
        System.err.println(String.format("target2Sum:{%d}", target2Sum));
        assertEquals(sum, target2Sum);

        ConcurrentMap<Object, Integer> target3 = source.parallelStream()
                .collect(Collectors.toConcurrentMap(iterator -> iterator % 1000, iterator -> iterator, (t, u) -> t + u, ConcurrentHashMap::new));
        long target3Sum = 0;
        for (Integer value : target3.values()) {
            target3Sum += value;
        }
        log.debug("target3Sum:{}", target3Sum);
        System.err.println(String.format("target3Sum:{%d}", target3Sum));
        assertEquals(sum, target3Sum);

        boolean duplicateKeyExceptionForParallelStream = false;
        try {
            source.parallelStream().collect(Collectors.toConcurrentMap(iterator -> iterator % 1000, iterator -> iterator));
        } catch (IllegalStateException e) {
            duplicateKeyExceptionForParallelStream = true;
        }
        assertTrue(duplicateKeyExceptionForParallelStream);

        boolean duplicateKeyExceptionForStream = false;
        try {
            source.parallelStream().collect(Collectors.toConcurrentMap(iterator -> iterator % 1000, iterator -> iterator));
        } catch (IllegalStateException e) {
            duplicateKeyExceptionForStream = true;
        }
        assertTrue(duplicateKeyExceptionForStream);

    }

}

分享到：
| org.springframework.scheduling.annotatio ...
评论
发表评论

您还没有登录,请您登录后再发表评论

相关推荐

    Parallel and Concurrent Programming in Haskell.pdf

    Parallel and Concurrent Programming in Haskell.pdf Parallel and Concurrent Programming in Haskell.pdf

    java8中parallelStream性能测试及结果分析

    * parallelStream 的线程池个数默认为 Runtime.getRuntime().availableProcessors() - 1，可以通过设置 -Djava.util.concurrent.ForkJoinPool.common.parallelism 来修改。 * 在阻塞场景下，parallelStream 的优势更...

    Parallel and Concurrent Programming in Haskell

    本书《Parallel and Concurrent Programming in Haskell》由Simon Marlow撰写，面向已经具备Haskell基础知识的读者，旨在指导他们通过Haskell语言的多个API和框架，编写支持并行和并发处理的程序。本书详细介绍了...

    [Parallel and Concurrent Programming in Haskell 2013 7 ] Simon Marlow 文字版

    《Parallel and Concurrent Programming in Haskell 2013》是Simon Marlow所著的一本关于Haskell编程语言在并行与并发编程方面的专著。在这本书中，作者深入探讨了Haskell语言的并行与并发能力，以及如何有效地利用...

    concurrent 摘自guava concurrent

    这个工程是为了学习guava concurrent中的AbstractFuture而建立的，里面有可以运行的例子，再配合我的博客：https://blog.csdn.net/o1101574955/article/details/82889851，可以看明白guava concurrent的基本设计思路...

    concurrent-1.3.4.jar

    concurrent-1.3.4.jar

    backport-util-concurrent.jar

    backport-util-concurrent.jarbackport-util-concurrent.jarbackport-util-concurrent.jar

    JDK concurrent

    标题 "JDK concurrent" 指的是Java开发工具包（JDK）中的并发编程相关知识。并发编程是在多线程环境中同时执行多个任务的技术，它在现代计算机系统中至关重要，尤其是在多核处理器和高并发应用中。Java JDK提供了一...

    backport-util-concurrent（2.2 /3.1）

    《backport-util-concurrent：Java并发编程的利器》 在Java的世界里，高效并发处理是提升应用程序性能的关键因素之一。backport-util-concurrent库，正如其名，是一种将Java 5及以上版本的并发特性“回移植”到Java...

    concurrent-1.3.2.jar

    concurrent-1.3.2.jar concurrent-1.3.2.jar

    Concurrent.Thread.js javascript多线程

    Concurrent.Thread.js 一个用来让javascript也进行多线程开发的包，感兴趣的快来下吧。

    Concurrent.Thread.js

    《并发编程：JavaScript中的Concurrent.Thread.js》 在IT领域，多线程编程是一种常见的优化技术，用于提高程序的执行效率。特别是在JavaScript这样的单线程环境中，由于其异步执行模型，多线程处理显得尤为重要。...

    concurrent线程池的实现技术分析

    Java的并发库（java.util.concurrent）提供了丰富的线程池实现，包括`ThreadPoolExecutor`，它是基于工作窃取算法的高效线程池。本文主要分析的是基于`concurrent`包的一个特定线程池实现，探讨其实现原理和源码。 ...

    Parallel_and_Concurrent_Programming_in_Haskell

    标题《Parallel and Concurrent Programming in Haskell》和描述表明，该文件是一本专注于Haskell语言在并行和并发编程领域的深入探讨。Haskell，作为一门纯粹的、懒惰的函数式编程语言，为开发者提供了强大的抽象...

    concurrent_.jar

    concurrent.jar web开发工具包

    concurrent 源代码

    在Java编程语言中，"concurrent"一词通常与多线程并发编程相关，它涉及到如何在多个执行线程之间高效、安全地共享资源。这里的"concurrent源代码"可能是指Java并发包(`java.util.concurrent`)中的源代码，这个包包含...

Magicbox
Global site tag (gtag.js) - Google Analytics