Java将图片上传至S3,一般前端页面上传过来的图片,在后端接收形式都为MultipartFile,而S3不支持MultipartFile形式的文件,只支持File类型,所以需要先转换类型再上传。注意:由于上传成功后,本地或者代码运行服务器中图片也会存在,为避免这个问题,上传成功需要本地删除图片。完整代码如下:
(只需要将下面Service中开始部分的变量改成你自己的就可以直接使用)
Controller:
//上传图片
@PostMapping("/uploadPicture")
public String uploadPicture(HttpServletRequest request
) {
MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
// 前端传过来的图片参数名为file
MultipartFile multipartFileImageFile = multipartRequest.getFile("file");
return uploadService.uploadPicture(multipartFileImageFile);
}
Service:
// 需要将这些变量改成你自己的,若只放到桶的根目录下,picturePath设为空
private String AWS_ACCESS_KEY = "xxxxxxxxxx";
private String AWS_SECRET_KEY = "xxxxxxxxxx";
private String region = "xxxx";
private String bucketName = "myBucket";
private String picturePath = "/picture/mypng"
// 初始化连接S3
@PostConstruct
public void init() {
BasicAWSCredentials basicAWSCredentials = new BasicAWSCredentials(AWS_ACCESS_KEY, AWS_SECRET_KEY);
s3 = AmazonS3ClientBuilder.standard().withRegion(region).withCredentials(new AWSStaticCredentialsProvider(basicAWSCredentials)).build();
}
public String uploadPicture(MultipartFile multipartFileTrayImageFile) {
// 调用toFile方法将MultipartFile类型转换为File类型
File file = toFile(multipartFileTrayImageFile);
String fileUrl = "";
long nowTime = System.currentTimeMillis();
try {
// 调用uploadToS3上传S3并获得图片URL,采用时间戳加文件名字命名,防止命名重复
fileUrl = uploadToS3(file, nowTime + "_" + file.getName());
// 注意!上传成功后删除,不占用本地或者服务器资源
file.delete();
} catch (IOException e) {
e.printStackTrace();
}
return fileUrl;
}
private String uploadToS3(File tempFile, String key) throws IOException {
try {
String bucketPath = bucketName + floderName;
//想要通过公网访问到图片,除了将桶的权限更改之外,还需要在代码中设置withCannedAcl(CannedAccessControlList.PublicRead)
s3.putObject(new PutObjectRequest(bucketPath, key, tempFile)
.withCannedAcl(CannedAccessControlList.PublicRead));
String url = cdn + key;
return url;
} catch (AmazonServiceException ase) {
ase.printStackTrace();
} catch (AmazonClientException ace) {
ace.printStackTrace();
}
return null;
}
private File toFile(MultipartFile file) {
File toFile = null;
if ("".equals(file) || file.getSize() <= 0) {
return null;
} else {
InputStream ins = null;
try {
ins = file.getInputStream();
toFile = new File(file.getOriginalFilename());
inputStreamToFile(ins, toFile);
ins.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return toFile;
}
private static void inputStreamToFile(InputStream ins, File file) {
try {
OutputStream os = new FileOutputStream(file);
int bytesRead = 0;
byte[] buffer = new byte[8192];
while ((bytesRead = ins.read(buffer, 0, 8192)) != -1) {
os.write(buffer, 0, bytesRead);
}
os.close();
ins.close();
} catch (Exception e) {
e.printStackTrace();
}
}
非常方便,粘贴后,将需要改的变量修改成自己的就可以直接使用!有问题评论,看到第一时间回复。