为什么我会得到java.lang.ClassNotFoundException:com.amazonaws.auth.AWSCredentials错误？

我已经包含了Maven的依赖项，但是我看到了这个错误：

java.lang.ClassNotFoundException:com.amazonaws.auth.AWSCredentials

<dependency>
    <groupId>com.amazonaws</groupId>
    <artifactId>aws-java-sdk</artifactId>
    <version>1.8.5</version>
</dependency>

---

你到底是从哪里得到这个错误的？当我试图调用有这个错误的类时，我有一个类，我正在对它进行静态调用ThumbnailProcessor.processThumbnail（）；ThumbnailProcessor引用了AWSCredentialsy您需要提供发生这种情况的代码。在您的IDE中，您是否看到在构建路径中添加的jar？尝试更新/刷新项目。

    public static String processThumbnail(String link, String keyName , String secret ) {

        AmazonS3 s3Client = null;
        link = StringUtils.removeEnd(link, "/");
        int index = link.lastIndexOf("/");
        String fileName = StringUtils.substring(link, index + 1, link.length());
        String existingBucketName = "staticmedia";
            String fileNameWithoutExt = StringUtils.substringBefore(fileName, ".");
        String ext = StringUtils.substringAfter(fileName, ".");
        InitiateMultipartUploadResult initResponse = null;
        String randomname = null;
        try {
            URL url = new URL(link);
            BufferedImage image = ImageIO.read(url);
            image = Thumbnails.of(image).forceSize(150, 100).asBufferedImage();
            randomname = String.format("%s.%s",
                    RandomStringUtils.randomAlphanumeric(8), ext);
            StringBuilder sb = new StringBuilder(randomname);
            sb.insert(0, fileNameWithoutExt + "_");
            randomname = sb.toString();
            ImageIO.write(image, "jpg", new File("src/main/java/" + randomname));
            String filePath = "src/main/java/" + randomname;
            AWSCredentials awsCredentials = new BasicAWSCredentials(keyName,
                    secret);
            s3Client = new AmazonS3Client(awsCredentials);
            InitiateMultipartUploadRequest initRequest = new InitiateMultipartUploadRequest(
                    existingBucketName, randomname);
            initResponse = s3Client.initiateMultipartUpload(initRequest);
            File file = new File(filePath);

            PutObjectResult item = s3Client.putObject(new PutObjectRequest(
                    existingBucketName, randomname, file));
            return "https://s3-us-west-2.amazonaws.com/"
                    + randomname;
        } catch (Exception e) {
            e.printStackTrace();
            s3Client.abortMultipartUpload(new AbortMultipartUploadRequest(
                    existingBucketName, randomname, initResponse.getUploadId()));
        }
        return null;
    }
}