java断点续传前后端交互,后端用AmazonS3实现完整示例代码
时间: 2023-06-30 08:20:57 浏览: 166
断点续传后端代码.zip
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好的,以下是Java断点续传前后端交互,后端用AmazonS3实现的完整示例代码:
前端代码:
```html
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>文件上传</title>
</head>
<body>
<form action="/upload" method="post" enctype="multipart/form-data">
<input type="file" name="file">
<button type="submit">上传</button>
</form>
</body>
</html>
```
后端代码:
```java
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.UUID;
import com.amazonaws.AmazonClientException;
import com.amazonaws.AmazonServiceException;
import com.amazonaws.auth.AWSStaticCredentialsProvider;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.client.builder.AwsClientBuilder;
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.ObjectMetadata;
import com.amazonaws.services.s3.model.PartETag;
import com.amazonaws.services.s3.model.UploadPartRequest;
import com.amazonaws.services.s3.model.UploadPartResult;
public class UploadServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
private static final String BUCKET_NAME = "your-bucket-name";
private static final String ACCESS_KEY = "your-access-key";
private static final String SECRET_KEY = "your-secret-key";
private static final String ENDPOINT = "your-endpoint";
private AmazonS3 s3Client;
public UploadServlet() {
BasicAWSCredentials credentials = new BasicAWSCredentials(ACCESS_KEY, SECRET_KEY);
s3Client = AmazonS3ClientBuilder.standard()
.withCredentials(new AWSStaticCredentialsProvider(credentials))
.withEndpointConfiguration(new AwsClientBuilder.EndpointConfiguration(ENDPOINT, ""))
.build();
}
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
Path tempDirectory = Paths.get(System.getProperty("java.io.tmpdir"));
String fileName = UUID.randomUUID().toString();
Path tempFile = tempDirectory.resolve(fileName);
Part filePart = request.getPart("file");
try (InputStream inputStream = filePart.getInputStream()) {
Files.copy(inputStream, tempFile);
}
long contentLength = filePart.getSize();
String objectName = "uploads/" + fileName;
try {
InitiateMultipartUploadRequest initRequest = new InitiateMultipartUploadRequest(BUCKET_NAME, objectName);
InitiateMultipartUploadResult initResponse = s3Client.initiateMultipartUpload(initRequest);
long partSize = 5 * 1024 * 1024; // 5MB
long filePosition = 0;
for (int i = 1; filePosition < contentLength; i++) {
partSize = Math.min(partSize, (contentLength - filePosition));
UploadPartRequest uploadRequest = new UploadPartRequest()
.withBucketName(BUCKET_NAME)
.withKey(objectName)
.withUploadId(initResponse.getUploadId())
.withPartNumber(i)
.withFileOffset(filePosition)
.withInputStream(Files.newInputStream(tempFile))
.withPartSize(partSize);
UploadPartResult uploadResult = s3Client.uploadPart(uploadRequest);
filePosition += partSize;
PartETag partETag = uploadResult.getPartETag();
}
CompleteMultipartUploadRequest compRequest = new CompleteMultipartUploadRequest(BUCKET_NAME, objectName,
initResponse.getUploadId(), null);
s3Client.completeMultipartUpload(compRequest);
} catch (AmazonServiceException e) {
e.printStackTrace();
} catch (AmazonClientException e) {
e.printStackTrace();
} finally {
Files.deleteIfExists(tempFile);
}
response.sendRedirect("/");
}
}
```
请注意,您需要将代码中的 `your-bucket-name`,`your-access-key`,`your-secret-key` 和 `your-endpoint` 替换成您的实际值。
此示例代码使用 AmazonS3 的分段上传来支持断点续传功能。首先,上传文件的大小被确定。然后,调用 `initiateMultipartUpload()` 方法来初始化一个分段上传,并获取上传 ID。然后,该文件被分成若干个大小相等的部分,并逐个上传,直到整个文件都被上传。最后,调用 `completeMultipartUpload()` 方法来完成分段上传。
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