Google cloud platform 从salesforce中的google云平台获取令牌

我是一名salesforce开发人员，我们公司计划为全球用户扩展服务，因此我们决定使用google translate来改善客户体验

我已经阅读了google api文档，但是，我们在请求GCP访问令牌时遇到了一个问题，这是google在文档中提供的教程，支持不同的语言，如java、c#、python等。由于我们正在起诉apex（一种salesforce平台脚本），我们无法使用您的库获取GCP令牌

相反，我们还检查了“OAuth2.0服务器帐户”，不幸的是，这两个帐户都不能从我这里使用

---

有什么建议吗？

我通过下面的代码获得了令牌，我遇到的错误是由特殊字符编码引起的

public with sharing class SwitchLanguageByGoogleAPIController {
   private static final String ENDPOINT = '**';
   private static final String TOKEN_ENDPOINT = 'https://accounts.google.com/o/oauth2/token';
   private static final String SCOPE = 'https://www.googleapis.com/auth/cloud-platform';
   private static final String PROJECT_ID = '**';
   private static final String GLOSSARY_ID = '88';
   private static final String LOCATION_ID = 'us-central1';
   private static final String CLIENT_SECRET = '**';
   private static final String PRIVATE_KEY = '**';
   private static final String CLIENT_EMAIL = '**';

   public static void translateByGlossary() {
       Token token = getToken();

       HttpRequest request = new HttpRequest();
       request.setHeader('Content-Type', 'text/plain');
       request.setEndpoint(ENDPOINT + PROJECT_ID + '/locations/' + LOCATION_ID + ':translateText?access_token=' + token.access_token);
       request.setMethod('POST');
       String contents = 'Personal Information, Middle Name e, first First Name';
       String sourceLanguageCode = 'en';
       String targetLanguageCode = 'zh';
       request.setBody('{"sourceLanguageCode":"' + sourceLanguageCode + '","targetLanguageCode":"' + targetLanguageCode + '","contents":"'+ contents +'","glossaryConfig":{"glossary":"projects/' + PROJECT_ID +'/locations/' + LOCATION_ID + '/glossaries/' + GLOSSARY_ID + '"}}');

       HTTP http = new HTTP();
       HttpResponse reponse =  http.send(request);
       System.debug(reponse.getBody());
   }

   private static Token getToken() {
       Http http = new Http();
       HttpRequest req = new HttpRequest();
       HttpResponse res = new HttpResponse();
       //Making the call out
       req.setEndpoint(TOKEN_ENDPOINT);
       req.setMethod('POST');
       req.setHeader('Content-Type','application/x-www-form-urlencoded');

       string URLEncodedGrantType = encodingUtil.urlEncode('urn:ietf:params:oauth:grant-type:jwt-bearer','UTF-8');
       string jwtSigned = generateJWT();
       req.setBody('grant_type='+URLEncodedGrantType+'&assertion='+jwtSigned);

       res = http.send(req);
       system.debug('Response : '+res.getBody());

       return (Token)JSON.deserialize(res.getBody(), Token.Class);
   }

   private static String generateJWT() {
       Http http = new Http();
       HttpRequest req = new HttpRequest();
       HttpResponse res = new HttpResponse();

       String JWTHeader =  '{"typ":"JWT","alg":"RS256"}';
       String Base64EncodedJWTHeader = EncodingUtil.base64Encode(Blob.valueOf(JWTHeader));

       long issued_at = datetime.now().getTime()/1000;
       long expires_at = datetime.now().addHours(1).getTime()/1000;

       JWTClaimSet claimSet = new JWTClaimSet();
       claimSet.iss = CLIENT_EMAIL;
       claimSet.scope = SCOPE;
       claimSet.aud = TOKEN_ENDPOINT;
       claimSet.iat = issued_at;
       claimSet.exp = expires_at;

       String strClaimSetJSON = JSON.Serialize(claimSet);
       String Base64EncodedClaimset = EncodingUtil.base64Encode(Blob.valueOf(strClaimSetJSON));
       system.debug('Base64 Encoded Claimset::'+Base64EncodedClaimset);
       Base64EncodedClaimset = PerformPostBase64Encode(Base64EncodedClaimset);
       system.debug('persorm post Claimset::'+Base64EncodedClaimset);

       string Base64EncodedString = Base64EncodedJWTHeader + '.' + Base64EncodedClaimset;

       String algorithmName = 'RSA-SHA256';
       Blob privateKey = EncodingUtil.base64Decode(PRIVATE_KEY);

       Blob input = Blob.valueOf(Base64EncodedString);
       Blob Blobsign = Crypto.sign(algorithmName, input , privateKey);

       String base64EncodedSignature = EncodingUtil.base64Encode(Blobsign);
       base64EncodedSignature = PerformPostBase64Encode(base64EncodedSignature);

       system.debug('Base 64 encoded signature ::'+base64EncodedSignature );
       system.debug('Encoded assertion : ' + Base64EncodedString+'.'+base64EncodedSignature);

       string URLEncodedUTF8Assertion = encodingUtil.urlEncode(Base64EncodedString+'.'+base64EncodedSignature,'UTF-8');
       return URLEncodedUTF8Assertion;
   }

   public static String PerformPostBase64Encode(String s)
   {
       s = s.Replace('+', '-');
       s = s.Replace('/', '_');
       s = s.Split('=')[0];
       return s;
   }

   public class JWTClaimSet
   {
      public string iss {get;set;}
      public string scope {get;set;}
      public string aud {get;set;}
      public Long exp {get;set;}
      public Long iat {get;set;}
   }

   private class Token{
       private String access_token;
       private String token_type;
       private String expires_in;
 }
}