HarmonyOS Application Development - Sending POST Request and Obtaining Result

Function Introduction:¶

Send a POST request to upload data to the server and obtain the result, referring to the documentation HTTP Data Request.

Key Knowledge Points:¶

Familiar with sending asynchronous POST requests.
Parse returned JSON-formatted data.

Usage Environment:¶

API 9
DevEco Studio 4.0 Release
Windows 11
Stage Model
ArkTS Language

Required Permissions:¶

ohos.permission.INTERNET

Core Code Snippet:¶

Send an HTTP asynchronous request, obtain the response result, and finally parse the JSON data function:

  async onRequest() {
  this.enabledBtn = false;
  let httpRequest = http.createHttp();
  // Asynchronous request
  let promise = httpRequest.request(this.llmUrl, {
    method: http.RequestMethod.POST,
    header: { 'Content-Type': 'application/json; charset=utf-8' },
    // Data to send
    extraData: { "prompt": this.text }
  })
  promise.then((data) => {
    console.info('Return result: ' + data.result)
    // Convert result to JSON
    let result = JSON.parse(data.result.toString())
    // Parse the result
    this.response = result['response']
    this.enabledBtn = true
  }).catch((err) => {
    console.error('Error message: ' + JSON.stringify(err))
  })
}

Complete Code:¶

import http from '@ohos.net.http';

@Entry
@Component
struct Index {
  @State text: string = 'What is your name?'
  @State response: string = ''
  @State enabledBtn: boolean = true
  private llmUrl: string = "http://xxx.xxxxx"

  build() {
    RelativeContainer() {
      Text(this.response)
        // Left alignment
        .textAlign(TextAlign.Start)
        .width("100%")
        // Allow text copying
        .copyOption(CopyOptions.InApp)
        .padding({ top: 10, left: 5, right: 5 })
        // Show ellipsis for overflow
        .textOverflow({ overflow: TextOverflow.Ellipsis })
        .maxLines(20)
        .alignRules({
          top: { anchor: '__container__', align: VerticalAlign.Top },
        })
        .id('text1')

      Row() {
        TextInput({ placeholder: 'Please enter the text content to send', text: this.text })
          .width("70%")
          .height("100%")
          .onChange((value: string) => {
            this.text = value
          })
        Button("Send")
          .fontSize(16)
          .width("25%")
          .height("100%")
          .margin({ left: 10 })
          .onClick(() => {
            this.onRequest()
          })
          .enabled(this.enabledBtn)
      }
      .width("100%")
      .height(40)
      .margin({ bottom: 10 })
      .alignRules({
        // Align to the bottom of the parent component
        bottom: { anchor: '__container__', align: VerticalAlign.Bottom },
      })
      .id("row1")
    }
    .width("100%")
    .height("100%")
  }

  async onRequest() {
    this.enabledBtn = false;
    let httpRequest = http.createHttp();
    // Asynchronous request
    let promise = httpRequest.request(this.llmUrl, {
      method: http.RequestMethod.POST,
      header: { 'Content-Type': 'application/json; charset=utf-8' },
      // Data to send
      extraData: { "prompt": this.text }
    })
    promise.then((data) => {
      console.info('Return result: ' + data.result)
      // Convert result to JSON
      let result = JSON.parse(data.result.toString())
      // Parse the result
      this.response = result['response']
    }).catch((err) => {
      console.error('Error message: ' + JSON.stringify(err))
    }).finally(()=>{
      this.enabledBtn = true
    })
  }
}