30.HarmonyOS App(JAVA)鸿蒙系统app多线程任务分发器

HarmonyOS App(JAVA)多线程任务分发器

打印时间，记录到编辑框textfield信息显示

同步分发，异步分发，异步延迟分发，分组任务分发，屏蔽任务分发，多次任务分发

参考代码注释

场景介绍

如果应用的业务逻辑比较复杂，可能需要创建多个线程来执行多个任务。这种情况下，代码复杂难以维护，任务与线程的交互也会更加繁杂。要解决此问题，开发者可以使用“TaskDispatcher”来分发不同的任务。

接口说明

TaskDispatcher是一个任务分发器，它是Ability分发任务的基本接口，隐藏任务所在线程的实现细节。

为保证应用有更好的响应性，我们需要设计任务的优先级。在UI线程上运行的任务默认以高优先级运行，如果某个任务无需等待结果，则可以用低优先级。

表1 线程优先级介绍
优先级	详细描述
HIGH	最高任务优先级，比默认优先级、低优先级的任务有更高的几率得到执行。
DEFAULT	默认任务优先级，比低优先级的任务有更高的几率得到执行。
LOW	低任务优先级，比高优先级、默认优先级的任务有更低的几率得到执行。

TaskDispatcher具有多种实现，每种实现对应不同的任务分发器。在分发任务时可以指定任务的优先级，由同一个任务分发器分发出的任务具有相同的优先级。系统提供的任务分发器有GlobalTaskDispatcher、ParallelTaskDispatcher、SerialTaskDispatcher 、SpecTaskDispatcher。

GlobalTaskDispatcher
全局并发任务分发器，由Ability执行getGlobalTaskDispatcher()获取。适用于任务之间没有联系的情况。一个应用只有一个GlobalTaskDispatcher，它在程序结束时才被销毁。
1. TaskDispatcher globalTaskDispatcher = getGlobalTaskDispatcher(TaskPriority.DEFAULT);
ParallelTaskDispatcher
并发任务分发器，由Ability执行createParallelTaskDispatcher()创建并返回。与GlobalTaskDispatcher不同的是，ParallelTaskDispatcher不具有全局唯一性，可以创建多个。开发者在创建或销毁dispatcher时，需要持有对应的对象引用。
1. String dispatcherName = "parallelTaskDispatcher";
2. TaskDispatcher parallelTaskDispatcher = createParallelTaskDispatcher(dispatcherName, TaskPriority.DEFAULT);
SerialTaskDispatcher
串行任务分发器，由Ability执行createSerialTaskDispatcher()创建并返回。由该分发器分发的所有的任务都是按顺序执行，但是执行这些任务的线程并不是固定的。如果要执行并行任务，应使用ParallelTaskDispatcher或者GlobalTaskDispatcher，而不是创建多个SerialTaskDispatcher。如果任务之间没有依赖，应使用GlobalTaskDispatcher来实现。它的创建和销毁由开发者自己管理，开发者在使用期间需要持有该对象引用。
1. String dispatcherName = "serialTaskDispatcher";
2. TaskDispatcher serialTaskDispatcher = createSerialTaskDispatcher(dispatcherName, TaskPriority.DEFAULT);
SpecTaskDispatcher
专有任务分发器，绑定到专有线程上的任务分发器。目前已有的专有线程为UI线程，通过UITaskDispatcher进行任务分发。

UITaskDispatcher：绑定到应用主线程的专有任务分发器，由Ability执行getUITaskDispatcher()创建并返回。由该分发器分发的所有的任务都是在主线程上按顺序执行，它在应用程序结束时被销毁。
1. TaskDispatcher uiTaskDispatcher = getUITaskDispatcher();

<?xml version="1.0" encoding="utf-8"?>
<DirectionalLayout
    xmlns:ohos="http://schemas.huawei.com/res/ohos"
    ohos:height="match_parent"
    ohos:width="match_parent"
    ohos:alignment="center"
    ohos:orientation="vertical">

    <Text
        ohos:id="$+id:text_helloworld"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:background_element="$graphic:background_ability_main"
        ohos:layout_alignment="horizontal_center"
        ohos:text="$string:mainability_HelloWorld"
        ohos:text_size="40vp"
        />
    <Button
        ohos:id="$+id:btn_tongbu"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:background_element="#EB0BF647"
        ohos:layout_alignment="horizontal_center"
        ohos:text="同步分发"
        ohos:text_size="40vp"
        />
    <Button
        ohos:id="$+id:btn_yibu"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:background_element="#EB3D5DFC"
        ohos:layout_alignment="horizontal_center"
        ohos:text="异步分发"
        ohos:text_size="40vp"
        />
    <Button
        ohos:id="$+id:btn_yibu_yanchi"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:background_element="#EB0BF647"
        ohos:layout_alignment="horizontal_center"
        ohos:text="异步延迟分发"
        ohos:text_size="40vp"
        />
    <Button
        ohos:id="$+id:btn_fenzhu_task"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:background_element="#EB3D5DFC"
        ohos:layout_alignment="horizontal_center"
        ohos:text="分组任务分发"
        ohos:text_size="40vp"
        />
    <Button
        ohos:id="$+id:btn_pingbi_task"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:background_element="#EB0BF647"
        ohos:layout_alignment="horizontal_center"
        ohos:text="屏蔽任务分发"
        ohos:text_size="40vp"
        />
    <Button
        ohos:id="$+id:btn_duoci_task"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:background_element="#EB3D5DFC"
        ohos:layout_alignment="horizontal_center"
        ohos:text="多次任务分发"
        ohos:text_size="40vp"
        />

    <Text
        ohos:id="$+id:text_label"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:background_element="$graphic:background_ability_main"
        ohos:layout_alignment="left"
        ohos:text="信息显示："
        ohos:multiple_lines="true"
        ohos:text_size="20vp"
        />
    <TextField
        ohos:id="$+id:text_filed_info"
        ohos:height="300vp"
        ohos:background_element="#FC0A84EF"
        ohos:text="信息显示区域"
        ohos:width="350vp"
        ohos:hint=""
        ohos:margin="2vp"
        ohos:text_size="20vp"/>
    <Clock
        ohos:id="$+id:clock"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:background_element="#FF80EF66"
        ohos:layout_alignment="left"

        ohos:text_size="20vp"
        />






</DirectionalLayout>

package com.example.myapplication.slice;

import com.example.myapplication.ResourceTable;
import ohos.aafwk.ability.AbilitySlice;
import ohos.aafwk.content.Intent;
import ohos.agp.components.*;
import ohos.app.dispatcher.Group;
import ohos.app.dispatcher.TaskDispatcher;
import ohos.app.dispatcher.task.TaskPriority;
import ohos.hiviewdfx.HiLog;
import ohos.hiviewdfx.HiLogLabel;

import java.util.function.Consumer;


public class MainAbilitySlice extends AbilitySlice {
    static final HiLogLabel label = new HiLogLabel(HiLog.INFO,0x00101,"shanshui");
    TextField textField;
    Clock clock2;
    @Override
    public void onStart(Intent intent) {
        super.onStart(intent);
        super.setUIContent(ResourceTable.Layout_ability_main);

        HiLog.info(label,  "hellocdtxw");
        HiLog.info(label,  "%{public}s World %d", "hellocdtxw", 3);
        HiLog.info(label,  "%{public}s World %d", "hellocdtxw", 3);
        System.out.println("hellocdtxw");

        Button btn_tongbu = (Button) findComponentById(ResourceTable.Id_btn_tongbu);
         textField = (TextField) findComponentById(ResourceTable.Id_text_filed_info);
         clock2 = (Clock) findComponentById(ResourceTable.Id_clock);
        clock2.setFormatIn24HourMode("yyyy-MM-dd HH:mm:ss");
        Button btn_yibu = (Button) findComponentById(ResourceTable.Id_btn_yibu);
        Button btn_delay = (Button) findComponentById(ResourceTable.Id_btn_yibu_yanchi);
        Button btn_group = (Button ) findComponentById(ResourceTable.Id_btn_fenzhu_task);
        Button btn_pingbi = (Button) findComponentById(ResourceTable.Id_btn_pingbi_task);
        Button btn_more_time = (Button) findComponentById(ResourceTable.Id_btn_duoci_task);
        btn_more_time.setClickedListener(new Component.ClickedListener() {
            @Override
            public void onClick(Component component) {
                MoreTimesTask();
            }
        });
        btn_delay.setClickedListener(new Component.ClickedListener() {
            @Override
            public void onClick(Component component) {
                YibuDealyTask();
            }
        });
        btn_group.setClickedListener(new Component.ClickedListener() {
            @Override
            public void onClick(Component component) {
                YibuGroupTask();
            }
        });
        btn_pingbi.setClickedListener(new Component.ClickedListener() {
            @Override
            public void onClick(Component component) {
                PingBiTask();
            }
        });
        btn_yibu.setClickedListener(new Component.ClickedListener() {
            @Override
            public void onClick(Component component) {
                YibuTask();
            }
        });
        btn_tongbu.setClickedListener(new Component.ClickedListener() {
            @Override
            public void onClick(Component component) {
                HiLog.info(label,  "hellocdtxw");
                HiLog.info(label,  "%{public}s World %d", "hellocdtxw", 3);
                HiLog.info(label,  "%{public}s World %d", "hellocdtxw", 3);
                System.out.println("hellocdtxw");
                TongBuTask();
            }
        });

    }
    /*
    同步分发任务,多线程，阻塞模式，会卡主界面，不常用
     */
    public void TongBuTask()
    {
        TaskDispatcher dispatcher =
                getGlobalTaskDispatcher(TaskPriority.DEFAULT);
         String time_str = clock2.getText();
        textField.append(time_str+":同步线程启动\n");
        dispatcher.syncDispatch(new Runnable() {
            @Override
            public void run() {
                try
                {
                   //getUITaskDispatcher().syncDispatch(()->{
                   // textField.append(clock2.getText()+":task1:"+Thread.currentThread().getName());
                   //});

                   Thread.sleep(1000);
                }
                catch (InterruptedException e)
                {
                    //getUITaskDispatcher().syncDispatch(()->{
                       //  textField.append(clock2.getText()+"任务失败");
                   // });

                }

            }
        });
        dispatcher.syncDispatch(new Runnable() {
            @Override
            public void run() {
                try
                {
                    //getUITaskDispatcher().syncDispatch(()->{
                    // textField.append(clock2.getText()+":task1:"+Thread.currentThread().getName());
                    //});

                    Thread.sleep(1000);
                }
                catch (InterruptedException e)
                {
                    //getUITaskDispatcher().syncDispatch(()->{
                    //  textField.append(clock2.getText()+"任务失败");
                    // });

                }

            }
        });
        dispatcher.syncDispatch(new Runnable() {
            @Override
            public void run() {
                try
                {
                    //getUITaskDispatcher().syncDispatch(()->{
                    // textField.append(clock2.getText()+":task1:"+Thread.currentThread().getName());
                    //});

                    Thread.sleep(1000);
                }
                catch (InterruptedException e)
                {
                    //getUITaskDispatcher().syncDispatch(()->{
                    //  textField.append(clock2.getText()+"任务失败");
                    // });

                }

            }
        });

    }
   //异步模式，鸿蒙系统app多线程
    public  void YibuTask()
    {
        TaskDispatcher dispatcher =
                getGlobalTaskDispatcher(TaskPriority.DEFAULT);
        String time_str = clock2.getText();
        textField.append(time_str+":异步线程启动\n");
        dispatcher.asyncDispatch(new Runnable() {
            @Override
            public void run() {
                try
                {
                    getUITaskDispatcher().asyncDispatch(()->{
                     textField.append(clock2.getText()+":task1:"+Thread.currentThread().getName()+"\n");
                    });

                    Thread.sleep(1000);
                }
                catch (InterruptedException e)
                {
                    getUITaskDispatcher().asyncDispatch(()->{
                      textField.append(clock2.getText()+"任务失败");
                     });

                }

            }
        });
        dispatcher.asyncDispatch(new Runnable() {
            @Override
            public void run() {
                try
                {
                    getUITaskDispatcher().asyncDispatch(()->{
                        textField.append(clock2.getText()+":task2:"+Thread.currentThread().getName()+"\n");
                    });

                    Thread.sleep(1000);
                }
                catch (InterruptedException e)
                {
                    getUITaskDispatcher().asyncDispatch(()->{
                        textField.append(clock2.getText()+"任务失败");
                    });

                }

            }
        });
        dispatcher.asyncDispatch(new Runnable() {
            @Override
            public void run() {
                try
                {
                    getUITaskDispatcher().asyncDispatch(()->{
                        textField.append(clock2.getText()+":task3:"+Thread.currentThread().getName()+"\n");
                    });

                    Thread.sleep(1000);
                }
                catch (InterruptedException e)
                {
                    getUITaskDispatcher().asyncDispatch(()->{
                        textField.append(clock2.getText()+"任务失败");
                    });

                }

            }
        });
    }
    //异步延迟任务分发
    public  void YibuDealyTask()
    {
        TaskDispatcher dispatcher =
                getGlobalTaskDispatcher(TaskPriority.DEFAULT);
        String time_str = clock2.getText();

        dispatcher.delayDispatch(()-> {
            getUITaskDispatcher().asyncDispatch(()->{
                textField.append(time_str+":异步延迟任务分发线程启动\n");
            });


        },1000);


    }
    //异步分组任务分发
    public  void YibuGroupTask()
    {
        TaskDispatcher dispatcher =
                getGlobalTaskDispatcher(TaskPriority.DEFAULT);
        String time_str = clock2.getText();
        Group group = dispatcher.createDispatchGroup();

        dispatcher.asyncGroupDispatch(group, new Runnable() {
            @Override
            public void run() {

                HiLog.info(label,  "%{public}s World %d", "hellocdtxw", 3);
            }

        });
        dispatcher.asyncGroupDispatch(group, new Runnable() {
            @Override
            public void run() {
                HiLog.info(label,  "%{public}s World %d", "hellocdtxw", 3);
            }

        });
        dispatcher.asyncGroupDispatch(group, new Runnable() {
            @Override
            public void run() {
                HiLog.info(label,  "%{public}s World %d", "hellocdtxw", 3);
            }

        });


    }
    //屏蔽任务分发
    public void PingBiTask()
    {
        TaskDispatcher dispatcher =
                createParallelTaskDispatcher("Dispatcher",
                        TaskPriority.DEFAULT);
        Group group = dispatcher.createDispatchGroup();
        dispatcher.asyncGroupDispatch(group,()->{
            try
            {
                Thread.sleep(1000);
                HiLog.info(label,  "%{public}s World %d", "hellocdtxw", 3);
            }
            catch (InterruptedException ex)
            {

            }

        });
        dispatcher.asyncGroupDispatch(group,()->{
            try
            {
                Thread.sleep(1000);
                HiLog.info(label,  "%{public}s World %d", "hellocdtxw", 3);
            }
            catch (InterruptedException ex)
            {

            }

        });
        dispatcher.asyncDispatchBarrier(()->{
            try
            {
                Thread.sleep(1000);
                getUITaskDispatcher().asyncDispatch(()->{
                    textField.append(clock2.getText()+":屏蔽任务分发线程启动\n");
                });
            }
            catch (InterruptedException ex)
            {

            }
        });
        dispatcher.asyncGroupDispatch(group,()->{
            try
            {
                Thread.sleep(1000);
                HiLog.info(label,  "%{public}s World %d", "hellocdtxw", 3);
            }
            catch (InterruptedException ex)
            {

            }

        });
        dispatcher.asyncGroupDispatch(group,()->{
            try
            {
                Thread.sleep(1000);
                HiLog.info(label,  "%{public}s World %d", "hellocdtxw", 3);
            }
            catch (InterruptedException ex)
            {

            }

        });
        dispatcher.asyncDispatchBarrier(()->{
            try
            {
                Thread.sleep(1000);
                getUITaskDispatcher().asyncDispatch(()->{
                    textField.append(clock2.getText()+":屏蔽任务分发线程启动\n");
                });
            }
            catch (InterruptedException ex)
            {

            }
        });

    }
    public void MoreTimesTask()
    {
        getGlobalTaskDispatcher(TaskPriority.DEFAULT).applyDispatch(new Consumer<Long>() {
            @Override
            public void accept(Long aLong) {
                getUITaskDispatcher().asyncDispatch(()->{
                    textField.append(clock2.getText()+":多次任务分发线程启动"+aLong.toString()+"\n");
                });
            }
        },10); //执行10次
    }

    @Override
    public void onActive() {
        super.onActive();
    }

    @Override
    public void onForeground(Intent intent) {
        super.onForeground(intent);
    }
}