从 Javascript 传递到 Java 时，具有高 Unicode 字符的字符串会损坏

Question

我将一个字符串从 Javascript 传递给 React Native 本机 Java 模块，然后返回给 Javascript。但是，任何高 Unicode 字符（例如表情符号）在传递给 Java 后都会损坏并变成一对问号。

例如字符串"testing123????"变成"testing123??"

我怎样才能解决这个问题，让角色保持他们的价值观？

编辑： React Native 后台上传库正在处理该字符串。以下是该库中将文本（位于 parameters 字段中）传递给 Java 模块的代码摘录：

import { NativeModules, DeviceEventEmitter } from 'react-native'
export type StartUploadArgs = {
  url: string,
  path: string,
  method?: 'PUT' | 'POST',
  // Optional, because raw is default
  type?: 'raw' | 'multipart',
  // This option is needed for multipart type
  field?: string,
  customUploadId?: string,
  // parameters are supported only in multipart type
  parameters?: { [string]: string },
  headers?: Object,
  notification?: NotificationArgs
}
const NativeModule = NativeModules.VydiaRNFileUploader || NativeModules.RNFileUploader // iOS is VydiaRNFileUploader and Android is NativeModules
//...
export const startUpload = (options: StartUploadArgs): Promise<string> => NativeModule.startUpload(options)

这里是处理字符串的 Java 代码的摘录：

  @ReactMethod
  public void startUpload(ReadableMap options, final Promise promise) {
//...
      HttpUploadRequest<?> request;

      if (requestType.equals("raw")) {
        request = new BinaryUploadRequest(this.getReactApplicationContext(), customUploadId, url)
                .setFileToUpload(filePath);
      } else {
        if (!options.hasKey("field")) {
          promise.reject(new IllegalArgumentException("field is required field for multipart type."));
          return;
        }

        if (options.getType("field") != ReadableType.String) {
          promise.reject(new IllegalArgumentException("field must be string."));
          return;
        }

        request = new MultipartUploadRequest(this.getReactApplicationContext(), customUploadId, url)
                .addFileToUpload(filePath, options.getString("field"));
      }


      request.setMethod(method)
        .setMaxRetries(2)
        .setDelegate(statusDelegate);
//...
      if (options.hasKey("parameters")) {
        if (requestType.equals("raw")) {
          promise.reject(new IllegalArgumentException("Parameters supported only in multipart type"));
          return;
        }

        ReadableMap parameters = options.getMap("parameters");
        ReadableMapKeySetIterator keys = parameters.keySetIterator();

        while (keys.hasNextKey()) {
          String key = keys.nextKey();

          if (parameters.getType(key) != ReadableType.String) {
            promise.reject(new IllegalArgumentException("Parameters must be string key/values. Value was invalid for '" + key + "'"));
            return;
          }
          request.addParameter(key, parameters.getString(key));
        }
      }
//...
      String uploadId = request.startUpload();
      promise.resolve(uploadId);
  }

Answer 1

java servlet 规范假定表单参数默认为 ISO-8859-1。假设您使用的是 tomcat，请参阅 https://cwiki.apache.org/confluence/display/TOMCAT/Character+Encoding 了解如何解决此问题

来自页面的相关引用

POST 请求应指定参数和值的编码 他们发送。由于许多客户端未能设置显式编码，因此 默认使用的是 US-ASCII 用于 application/x-www-form-urlencoded 和 ISO-8859-1 适用于所有其他内容类型。

相关SO帖子https://stackoverflow.com/a/19409520/1967484

请记住，您的控制台和数据库也可能不支持高 unicode 字符。

Answer 2

像这样修改后台上传库的代码解决了这个问题：

request = new MultipartUploadRequest(this.getReactApplicationContext(), customUploadId, url)
        .addFileToUpload(filePath, options.getString("field"))
        .setUtf8Charset(); // add this line