在IntelliJ IDEA配置Google API凭证时遇默认凭证未找到错误求助

问题场景 #

我在IntelliJ IDEA内置终端执行以下命令设置环境变量：

export GOOGLE_APPLICATION_CREDENTIALS="/Users/nunyito/IdeaProjects/mystic-river-api/src/main/resources/google-gemini/mysticriver.json"

对应的JSON凭证文件内容：

{
  "type": "service_account",
  "project_id": "mysticriver",
  "private_key_id": "c81d561c1z65159b925ddd7a00c895358855b855c",
  "private_key": "-----BEGIN PRIVATE KEY-----\nREDACTED\n-----END PRIVATE KEY-----\n",
  "client_email": "service-account-for-mystic-riv@mysticriver.iam.gserviceaccount.com",
  "client_id": "117167372461671003080",
  "auth_uri": "https://accounts.google.com/o/oauth2/auth",
  "token_uri": "https://oauth2.googleapis.com/token",
  "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
  "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/service-account-for-mystic-riv%40mysticriver.iam.gserviceaccount.com",
  "universe_domain": "googleapis.com"
}

随后运行Spring服务代码：

@Service
public class GoogleGeminiService {

    public static void main(String[] args) throws Exception {
       
        String projectId = "MysticRiver";
        String location = "us-central1";
        String modelName = "gemini-pro-vision";

        String output = simpleQuestion(projectId, location, modelName);
        System.out.println(output);
    }
}

运行后出现错误：

Exception in thread "main" java.io.IOException: Your default credentials were not found. To set up Application Default Credentials for your environment, see https://cloud.google.com/docs/authentication/external/set-up-adc.
    at com.google.auth.oauth2.DefaultCredentialsProvider.getDefaultCredentials(DefaultCredentialsProvider.java:127)

排查与解决步骤 #

1. 验证环境变量是否生效 #

在IntelliJ终端执行以下命令，确认环境变量已正确配置：

echo $GOOGLE_APPLICATION_CREDENTIALS

如果输出为空或路径错误，重新执行export命令，检查路径的引号、拼写是否正确。

2. 确保IntelliJ继承终端环境变量 #

• 若通过系统图标启动IntelliJ，终端设置的环境变量不会传递给IDE。需关闭IDE，从已设置环境变量的终端中重新启动（比如执行open -a "IntelliJ IDEA.app"）。
• 或直接在IDE运行配置中添加环境变量：
  1. 打开「Run/Debug Configurations」；
  2. 找到对应运行配置，切换到「Environment Variables」标签；
  3. 添加键值对：GOOGLE_APPLICATION_CREDENTIALS=/Users/nunyito/IdeaProjects/mystic-river-api/src/main/resources/google-gemini/mysticriver.json；
  4. 保存后重新运行。

3. 修复JSON文件语法错误 #

原JSON中project_id字段缺少闭合引号（原内容为"project_id": "mysticriver,），修正为：

"project_id": "mysticriver",

同时确认文件路径正确，当前用户拥有文件读取权限。

4. 代码中显式加载凭证（备选方案） #

若环境变量方式仍不生效，可在代码中直接指定凭证路径，同时注意projectId要与JSON中的project_id完全一致（原代码中大小写不匹配）：

import com.google.auth.oauth2.GoogleCredentials;
import com.google.cloud.vertexai.VertexAI;
import java.io.FileInputStream;

public class GoogleGeminiService {

    public static void main(String[] args) throws Exception {
        String projectId = "mysticriver";
        String location = "us-central1";
        String modelName = "gemini-pro-vision";

        // 显式加载凭证文件
        GoogleCredentials credentials = GoogleCredentials.fromStream(
            new FileInputStream("/Users/nunyito/IdeaProjects/mystic-river-api/src/main/resources/google-gemini/mysticriver.json")
        );

        try (VertexAI vertexAI = new VertexAI(projectId, location, credentials)) {
            String output = simpleQuestion(vertexAI, modelName);
            System.out.println(output);
        }
    }
}

内容的提问来源于stack exchange，提问作者Nunyet Calçada