Reading Custom JSON Files in HarmonyOS Using getRawFileContent

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Context

A developer is trying to read an intarray.json resource defined in a HarmonyOS project. They initially attempted to use the getStringArrayValueSync API from the ResourceManager but found it ineffective for accessing raw JSON data.

Description

The developer encountered difficulties retrieving a custom intarray.json file using typical resource manager methods intended for string or array resources. This file does not follow the standard element resource format (e.g., string, string-array) and thus requires a different approach for access and parsin

Solution / Approach

Instead of using getStringArrayValueSync, the correct method is:

Place the intarray.json file into the resources/rawfile directory.
Use the getRawFileContent() API from the ResourceManager to read its content as a Uint8Array.
Convert the byte array into a string and parse it using JSON.parse().

Example Demo:

import { common } from '@kit.AbilityKit';
import { BusinessError } from '@kit.BasicServicesKit';
import { buffer, JSON } from '@kit.ArkTS';

@Entry
@Component
struct Index {
  @State message: string = 'Hello World';
  private context = getContext(this) as common.Context;

  aboutToAppear(): void {
    try {
      this.context.resourceManager.getRawFileContent('intarray.json')
        .then((value: Uint8Array) => {
          let strParam = buffer.from(value.buffer).toString()
          let obj = JSON.parse(strParam) as Record<string, object>
          let array = obj['intarray'] as Record<string, Array<number>>
          Object.keys(array).forEach(key => {
            if (array[key]['name'] == 'aaa') {
              console.log(key, array[key]['value']);
            }
          });
          console.log('Get Value：' + JSON.stringify(array))
        })
        .catch((error: BusinessError) => {
          console.error("getRawFileContent promise error is " + error);
        });
    } catch (error) {
      let code = (error as BusinessError).code;
      let message = (error as BusinessError).message;
      console.error(`promise getRawFileContent failed, error code: ${code}, message: ${message}.`);
    }

  }

  build() {
    Column() {
      Text(this.message)
        .id('HelloWorld')
        .fontSize(50)
        .fontWeight(FontWeight.Bold)
    }
    .height('100%')
    .width('100%')
  }
}

Key Takeaways

Custom JSON files (like intarray.json) should be placed in resources/rawfile, not in element or string-array sections.
getRawFileContent() is the correct API to read such files.
Use buffer.from(...).toString() and JSON.parse() to convert and use the content.
getStringArrayValueSync is intended for standard string-array resources and is not suitable for raw JSON parsing.