我正在尝试通过网页将文件上传到 Amazon S3 存储桶。
在 Eclipse 中使用 apache tomcat 服务器创建了一个“动态 Web 项目”。创建 JSP、Servlet 和 Java 文件。我使用了 aws-java-sdk-1.11.335.jar 文件。尝试通过单击提交按钮上传图像文件,发生类未找到异常。有人可以帮忙解决这个问题吗?
这里是 JSP、Servlet 和类文件的代码:
index.jsp:
<form method="post" action="UploadFileServlet" enctype="multipart/form-data">
<input type="submit" value="Upload" />
</form>
UploadFileServlet.java:
@WebServlet("/UploadFileServlet")
public class UploadFileServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public UploadFileServlet() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
UploadFilestoAWSS3 uploadfilestoawss3 = new UploadFilestoAWSS3();
uploadfilestoawss3.UploadFiles();
PrintWriter out = response.getWriter();
out.print("Files are uploaded to Bucket");
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
上传文件到AWSS3.java
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import com.amazonaws.AmazonServiceException;
import com.amazonaws.SdkClientException;
import com.amazonaws.auth.AWSStaticCredentialsProvider;
import com.amazonaws.auth.profile.ProfileCredentialsProvider;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3ClientBuilder;
import com.amazonaws.services.s3.model.CompleteMultipartUploadRequest;
import com.amazonaws.services.s3.model.InitiateMultipartUploadRequest;
import com.amazonaws.services.s3.model.InitiateMultipartUploadResult;
import com.amazonaws.services.s3.model.PartETag;
import com.amazonaws.services.s3.model.UploadPartRequest;
import com.amazonaws.services.s3.model.UploadPartResult;
public class UploadFilestoAWSS3 {
public void UploadFiles() throws IOException {
String clientRegion = "region";
String bucketName = "bucket name";
String filePath = "C:\\Users\\......\\imagefile.jpg";
File file = new File(filePath);
String keyName = file.getName();
long contentLength = file.length();
long partSize = 10 * 1024 * 1024; // Set part size to 10 MB.
try {
BasicAWSCredentials awsCreds = new BasicAWSCredentials("Access Key", "Secret Key");
AmazonS3 s3Client = AmazonS3ClientBuilder.standard()
.withRegion(clientRegion)
.withCredentials(new AWSStaticCredentialsProvider(awsCreds))
.build();
List<PartETag> partETags = new ArrayList<PartETag>();
InitiateMultipartUploadRequest initRequest = new InitiateMultipartUploadRequest(bucketName, keyName);
InitiateMultipartUploadResult initResponse = s3Client.initiateMultipartUpload(initRequest);
long filePosition = 0;
for (int i = 1; filePosition < contentLength; i++) {
partSize = Math.min(partSize, (contentLength - filePosition));
UploadPartRequest uploadRequest = new UploadPartRequest()
.withBucketName(bucketName)
.withKey(keyName)
.withUploadId(initResponse.getUploadId())
.withPartNumber(i)
.withFileOffset(filePosition)
.withFile(file)
.withPartSize(partSize);
UploadPartResult uploadResult = s3Client.uploadPart(uploadRequest);
partETags.add(uploadResult.getPartETag());
filePosition += partSize;
}
CompleteMultipartUploadRequest compRequest = new CompleteMultipartUploadRequest(bucketName, keyName,
initResponse.getUploadId(), partETags);
s3Client.completeMultipartUpload(compRequest);
}
catch(AmazonServiceException e) {
e.printStackTrace();
}
catch(SdkClientException e) {
e.printStackTrace();
}
}
}
错误是:
Type Exception Report
Message Servlet execution threw an exception
Description The server encountered an unexpected condition that prevented it from fulfilling the request.
Exception
javax.servlet.ServletException: Servlet execution threw an exception
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Root Cause
java.lang.NoClassDefFoundError: com/amazonaws/AmazonServiceException
com.shiva.amazonaws.UploadFileServlet.doGet(UploadFileServlet.java:51)
com.shiva.amazonaws.UploadFileServlet.doPost(UploadFileServlet.java:64)
javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Root Cause
java.lang.ClassNotFoundException: com.amazonaws.AmazonServiceException
org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1292)
org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1121)
com.shiva.amazonaws.UploadFileServlet.doGet(UploadFileServlet.java:51)
com.shiva.amazonaws.UploadFileServlet.doPost(UploadFileServlet.java:64)
javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
最佳答案
问题是找不到某些 Amazon Web Services SDK 类,特别是 com.amazonaws.AmazonServiceException
,它是 AWS SDK 的基本异常类型 - 表明可能所有Java 类路径中缺少 AWS 开发工具包文件。
请注意,文件 aws-java-sdk-1.11.335.jar
并不是整个 AWS SDK(正如人们可能想象的那样),仅包含一些元数据文件。 AWS Java SDK 分为多个工件 - 因为它太大,您不想使用包含所有类的单个 JAR 文件,您只想将 SDK 用于您正在使用的特定服务。
因为您使用的是 S3,所以您可能只需要 S3 JAR 及其依赖项,如 Maven repository page for the AWS S3 SDK 中所示。 。请注意,依赖项之一是 aws-java-sdk-core
,它是 com.amazonaws.AmazonServiceException
类所在的位置。
您还可以在http://central.maven.org/maven2/com/amazonaws/aws-java-sdk-s3/1.11.335/下的POM文件中查看所有依赖项(并导航目录以收集您需要的所有文件)。 .
一般来说,由于现在常见的复杂依赖结构,建议不要手动下载 JAR 并将它们一一放入 Eclipse 构建路径中,而是使用 Maven。
如果您在 Eclipse 中有一个标准 Java 项目,您可以在包资源管理器中右键单击项目名称,然后选择“配置”->“转换为 Maven 项目”,并在打开的对话框中填写一些详细信息(* )。完成后,Eclipse 将在项目的根目录中创建一个 pom.xml
文件 - 打开它,您将获得一个自定义编辑器来设置您的依赖项。单击标有“依赖项”的选项卡,然后单击“添加”,您应该能够搜索 aws-java-sdk-s3
,将其添加到您的依赖项列表中,然后 Maven 将自动下载所有内容所需的 JAR 文件并将它们自动添加到您的构建路径。
*) “Group ID”通常是项目的顶级包名称,它应该看起来像域名的倒转 - 例如我的域名是 geek.co.il
,所以我的 Group ID 将为 il.co.geek
; “Artifact ID”是您项目的单字标识符,例如 my-project
。
关于java - 无法在 Eclipse 中使用 localhost 将文件上传到 amazon S3 存储桶,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/50693000/