HarmonyOS App(JAVA)多線程任務(wù)分發(fā)器

打印時間，記錄到編輯框textfield信息顯示

同步分發(fā)，異步分發(fā)，異步延遲分發(fā)，分組任務(wù)分發(fā)，屏蔽任務(wù)分發(fā)，多次任務(wù)分發(fā)

參考代碼注釋

場景介紹

如果應(yīng)用的業(yè)務(wù)邏輯比較復(fù)雜，可能需要創(chuàng)建多個線程來執(zhí)行多個任務(wù)。這種情況下，代碼復(fù)雜難以維護(hù)，任務(wù)與線程的交互也會更加繁雜。要解決此問題，開發(fā)者可以使用“TaskDispatcher”來分發(fā)不同的任務(wù)。

接口說明

TaskDispatcher是一個任務(wù)分發(fā)器，它是Ability分發(fā)任務(wù)的基本接口，隱藏任務(wù)所在線程的實(shí)現(xiàn)細(xì)節(jié)。

為保證應(yīng)用有更好的響應(yīng)性，我們需要設(shè)計任務(wù)的優(yōu)先級。在UI線程上運(yùn)行的任務(wù)默認(rèn)以高優(yōu)先級運(yùn)行，如果某個任務(wù)無需等待結(jié)果，則可以用低優(yōu)先級。

表1?線程優(yōu)先級介紹

優(yōu)先級	詳細(xì)描述
HIGH	最高任務(wù)優(yōu)先級，比默認(rèn)優(yōu)先級、低優(yōu)先級的任務(wù)有更高的幾率得到執(zhí)行。
DEFAULT	默認(rèn)任務(wù)優(yōu)先級， 比低優(yōu)先級的任務(wù)有更高的幾率得到執(zhí)行。
LOW	低任務(wù)優(yōu)先級，比高優(yōu)先級、默認(rèn)優(yōu)先級的任務(wù)有更低的幾率得到執(zhí)行。

TaskDispatcher具有多種實(shí)現(xiàn)，每種實(shí)現(xiàn)對應(yīng)不同的任務(wù)分發(fā)器。在分發(fā)任務(wù)時可以指定任務(wù)的優(yōu)先級，由同一個任務(wù)分發(fā)器分發(fā)出的任務(wù)具有相同的優(yōu)先級。系統(tǒng)提供的任務(wù)分發(fā)器有GlobalTaskDispatcher、ParallelTaskDispatcher、SerialTaskDispatcher 、SpecTaskDispatcher。

• GlobalTaskDispatcher

  全局并發(fā)任務(wù)分發(fā)器，由Ability執(zhí)行g(shù)etGlobalTaskDispatcher()獲取。適用于任務(wù)之間沒有聯(lián)系的情況。一個應(yīng)用只有一個GlobalTaskDispatcher，它在程序結(jié)束時才被銷毀。

  1. TaskDispatcher globalTaskDispatcher = getGlobalTaskDispatcher(TaskPriority.DEFAULT);
• ParallelTaskDispatcher

  并發(fā)任務(wù)分發(fā)器，由Ability執(zhí)行createParallelTaskDispatcher()創(chuàng)建并返回。與GlobalTaskDispatcher不同的是，ParallelTaskDispatcher不具有全局唯一性，可以創(chuàng)建多個。開發(fā)者在創(chuàng)建或銷毀dispatcher時，需要持有對應(yīng)的對象引用 。

  1. String dispatcherName = "parallelTaskDispatcher";
  2. TaskDispatcher parallelTaskDispatcher = createParallelTaskDispatcher(dispatcherName, TaskPriority.DEFAULT);
• SerialTaskDispatcher

  串行任務(wù)分發(fā)器，由Ability執(zhí)行createSerialTaskDispatcher()創(chuàng)建并返回。由該分發(fā)器分發(fā)的所有的任務(wù)都是按順序執(zhí)行，但是執(zhí)行這些任務(wù)的線程并不是固定的。如果要執(zhí)行并行任務(wù)，應(yīng)使用ParallelTaskDispatcher或者GlobalTaskDispatcher，而不是創(chuàng)建多個SerialTaskDispatcher。如果任務(wù)之間沒有依賴，應(yīng)使用GlobalTaskDispatcher來實(shí)現(xiàn)。它的創(chuàng)建和銷毀由開發(fā)者自己管理，開發(fā)者在使用期間需要持有該對象引用。

  1. String dispatcherName = "serialTaskDispatcher";
  2. TaskDispatcher serialTaskDispatcher = createSerialTaskDispatcher(dispatcherName, TaskPriority.DEFAULT);
• SpecTaskDispatcher

  專有任務(wù)分發(fā)器，綁定到專有線程上的任務(wù)分發(fā)器。目前已有的專有線程為UI線程，通過UITaskDispatcher進(jìn)行任務(wù)分發(fā)。

  UITaskDispatcher：綁定到應(yīng)用主線程的專有任務(wù)分發(fā)器， 由Ability執(zhí)行g(shù)etUITaskDispatcher()創(chuàng)建并返回。 由該分發(fā)器分發(fā)的所有的任務(wù)都是在主線程上按順序執(zhí)行，它在應(yīng)用程序結(jié)束時被銷毀。

  1. TaskDispatcher uiTaskDispatcher = getUITaskDispatcher();

<?xml version="1.0" encoding="utf-8"?>
<DirectionalLayoutxmlns:ohos="http://schemas.huawei.com/res/ohos"ohos:height="match_parent"ohos:width="match_parent"ohos:alignment="center"ohos:orientation="vertical"><Textohos: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="$string:mainability_HelloWorld"ohos:text_size="40vp"/><Buttonohos:id="$+id:btn_tongbu"ohos:height="match_content"ohos:width="match_content"ohos:background_element="#EB0BF647"ohos:layout_alignment="horizontal_center"ohos:text="同步分發(fā)"ohos:text_size="40vp"/><Buttonohos:id="$+id:btn_yibu"ohos:height="match_content"ohos:width="match_content"ohos:background_element="#EB3D5DFC"ohos:layout_alignment="horizontal_center"ohos:text="異步分發(fā)"ohos:text_size="40vp"/><Buttonohos:id="$+id:btn_yibu_yanchi"ohos:height="match_content"ohos:width="match_content"ohos:background_element="#EB0BF647"ohos:layout_alignment="horizontal_center"ohos:text="異步延遲分發(fā)"ohos:text_size="40vp"/><Buttonohos:id="$+id:btn_fenzhu_task"ohos:height="match_content"ohos:width="match_content"ohos:background_element="#EB3D5DFC"ohos:layout_alignment="horizontal_center"ohos:text="分組任務(wù)分發(fā)"ohos:text_size="40vp"/><Buttonohos:id="$+id:btn_pingbi_task"ohos:height="match_content"ohos:width="match_content"ohos:background_element="#EB0BF647"ohos:layout_alignment="horizontal_center"ohos:text="屏蔽任務(wù)分發(fā)"ohos:text_size="40vp"/><Buttonohos:id="$+id:btn_duoci_task"ohos:height="match_content"ohos:width="match_content"ohos:background_element="#EB3D5DFC"ohos:layout_alignment="horizontal_center"ohos:text="多次任務(wù)分發(fā)"ohos:text_size="40vp"/><Textohos:id="$+id:text_label"ohos:height="match_content"ohos:width="match_content"ohos:background_element="$graphic:background_ability_main"ohos:layout_alignment="left"ohos:text="信息顯示："ohos:multiple_lines="true"ohos:text_size="20vp"/><TextFieldohos:id="$+id:text_filed_info"ohos:height="300vp"ohos:background_element="#FC0A84EF"ohos:text="信息顯示區(qū)域"ohos:width="350vp"ohos:hint=""ohos:margin="2vp"ohos:text_size="20vp"/><Clockohos: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;@Overridepublic 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() {@Overridepublic void onClick(Component component) {MoreTimesTask();}});btn_delay.setClickedListener(new Component.ClickedListener() {@Overridepublic void onClick(Component component) {YibuDealyTask();}});btn_group.setClickedListener(new Component.ClickedListener() {@Overridepublic void onClick(Component component) {YibuGroupTask();}});btn_pingbi.setClickedListener(new Component.ClickedListener() {@Overridepublic void onClick(Component component) {PingBiTask();}});btn_yibu.setClickedListener(new Component.ClickedListener() {@Overridepublic void onClick(Component component) {YibuTask();}});btn_tongbu.setClickedListener(new Component.ClickedListener() {@Overridepublic 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();}});}/*同步分發(fā)任務(wù),多線程，阻塞模式，會卡主界面，不常用*/public void TongBuTask(){TaskDispatcher dispatcher =getGlobalTaskDispatcher(TaskPriority.DEFAULT);String time_str = clock2.getText();textField.append(time_str+":同步線程啟動\n");dispatcher.syncDispatch(new Runnable() {@Overridepublic 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()+"任務(wù)失敗");// });}}});dispatcher.syncDispatch(new Runnable() {@Overridepublic 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()+"任務(wù)失敗");// });}}});dispatcher.syncDispatch(new Runnable() {@Overridepublic 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()+"任務(wù)失敗");// });}}});}//異步模式，鴻蒙系統(tǒng)app多線程public  void YibuTask(){TaskDispatcher dispatcher =getGlobalTaskDispatcher(TaskPriority.DEFAULT);String time_str = clock2.getText();textField.append(time_str+":異步線程啟動\n");dispatcher.asyncDispatch(new Runnable() {@Overridepublic 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()+"任務(wù)失敗");});}}});dispatcher.asyncDispatch(new Runnable() {@Overridepublic 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()+"任務(wù)失敗");});}}});dispatcher.asyncDispatch(new Runnable() {@Overridepublic 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()+"任務(wù)失敗");});}}});}//異步延遲任務(wù)分發(fā)public  void YibuDealyTask(){TaskDispatcher dispatcher =getGlobalTaskDispatcher(TaskPriority.DEFAULT);String time_str = clock2.getText();dispatcher.delayDispatch(()-> {getUITaskDispatcher().asyncDispatch(()->{textField.append(time_str+":異步延遲任務(wù)分發(fā)線程啟動\n");});},1000);}//異步分組任務(wù)分發(fā)public  void YibuGroupTask(){TaskDispatcher dispatcher =getGlobalTaskDispatcher(TaskPriority.DEFAULT);String time_str = clock2.getText();Group group = dispatcher.createDispatchGroup();dispatcher.asyncGroupDispatch(group, new Runnable() {@Overridepublic void run() {HiLog.info(label,  "%{public}s World %d", "hellocdtxw", 3);}});dispatcher.asyncGroupDispatch(group, new Runnable() {@Overridepublic void run() {HiLog.info(label,  "%{public}s World %d", "hellocdtxw", 3);}});dispatcher.asyncGroupDispatch(group, new Runnable() {@Overridepublic void run() {HiLog.info(label,  "%{public}s World %d", "hellocdtxw", 3);}});}//屏蔽任務(wù)分發(fā)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()+":屏蔽任務(wù)分發(fā)線程啟動\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()+":屏蔽任務(wù)分發(fā)線程啟動\n");});}catch (InterruptedException ex){}});}public void MoreTimesTask(){getGlobalTaskDispatcher(TaskPriority.DEFAULT).applyDispatch(new Consumer<Long>() {@Overridepublic void accept(Long aLong) {getUITaskDispatcher().asyncDispatch(()->{textField.append(clock2.getText()+":多次任務(wù)分發(fā)線程啟動"+aLong.toString()+"\n");});}},10); //執(zhí)行10次}@Overridepublic void onActive() {super.onActive();}@Overridepublic void onForeground(Intent intent) {super.onForeground(intent);}
}

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