概览
- 使用Spring进行文件的上传和下载
- Spring上传文件接口设计
- dubbo接口设计
- 上传文件流的RPC的接口设计
- Spring文件下载接口设计
- dubbo接口设计
- 下载文件流的RPC的接口设计
- spring上传文件大小控制
使用Spring进行文件的上传和下载
本文主要介绍在Spring框架下面调用微服务的dubbo rpc接口进行文件的上传和下载，以及记录在实现过程中遇到的一些容易出错的地方。
Spring上传文件接口设计
contoller层的代码实现如下所示：
@PostMapping("/submitEvidence")
public BaseResponse<?> submitEvidence(@RequestParam("id") Long id, @RequestParam("label") String label,
@RequestParam(value = "file") MultipartFile file) {
uploadEvidence(id, label, file);
return BaseResponse.success().errorMsg("操作成功").build();
}
}
使用postman请求上传文件接口，具体参数如下图所示：
Service层代码实现如下所示：
public void uploadEvidence(Long takeDownId, String label, MultipartFile multipartFile) {
if(Objects.isNull(multipartFile)) {
throw new RunTimeException("上传的文件不能为空");
}
String fileName = multipartFile.getOriginalFilename();
InputStream file = null;
try {
file = multipartFile.getInputStream();
} catch (IOException e) {}
byte[] fileBytes = new byte[20 * 1024 * 1024];
InputStream inputStream = null;
ByteArrayOutputStream outputStream = null;
try {
outputStream = new ByteArrayOutputStream();
inputStream = multipartFile.getInputStream();
try {
byte[] buffer = new byte[1024];
int read = inputStream.read(buffer);
while (read != -1) {
outputStream.write(buffer, 0, read);
read = inputStream.read(buffer);
}
} catch (Exception e) {
log.error("处理返回值失败" + e.getMessage());
throw new RunTimeException("上传文件失败");
} finally {
try {
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
outputStream.flush();
fileBytes = outputStream.toByteArray();
} catch (IOException e) {
}finally {
if(outputStream != null) {
try {
outputStream.close();
} catch (IOException e1) {
e1.printStackTrace();
throw new RuntimeException("上传文件失败");
}
}
}
UploadEvidenceNetCraftReq req = UploadEvidenceNetCraftReq.builder()
.takeDownId(takeDownId.intValue()).label(label).fileName(fileName).fileBytes(fileBytes).build();
// outVendor是一个dubbo框架下的rpc服务，用于上传文件
BaseResponse baseResponse = outerVendorsService.uploadEvidence(req);
...
}
dubbo接口设计
上传文件流的RPC的接口设计
我们构建的RPC接口采用的是dubbo框架，最初始的接口设计，将HttpServletResponse作为接口的参数类型传参，结果报错
io.netty.handler.codec.EncoderException: java.lang.IllegalStateException: Serialized class
Dubbo报错：io.netty.handler.codec.EncoderException: java.lang.IllegalStateException: Serialized class
HttpServletResponse不能被dubbo作为接口参数序列化，于是转而求其次，将可序列化的类型byte[]作为传输流的参数
outerVendorsService服务提供的上传文件的rpc接口：uploadEvidence接口，具体代码设计如下所示：
BaseResponse<UploadEvidenceRsp> uploadEvidence(UploadEvidenceReq req);
@Data
@Builder
@Jacksonized
public class UploadEvidenceReq implements Serializable {
private Integer takeDownId;
//使用可序列化的byte数组作为入参
private byte[] fileBytes;
private String fileName;
private String label;
}
@Data
@Setter
@Getter
public class UploadEvidenceRsp implements Serializable {
private Integer file_id;
@JsonProperty("error_code")
private String errorCode;
@JsonProperty("error_message")
private String errorMessage;
}
Spring文件下载接口设计
文件下载的相关接口有两种实现：一种是将HttpServletResponse作为controller层的传参引入，将流写入到HttpServletResponse中，然后返回前端，但是在使用过程中，直接在HttpServletResponse的示例中setHeader失败，于是转而选择构ResponseEntity的方式来进行http返回值的构造，具体实现如下所示：
@GetMapping("/searchForEvidence")
public ResponseEntity searchForEvidence(@RequestParam String id) {
return searchForEvidence(id);
}
使用postman请求下载文件接口，具体参数如下图所示：
Service层代码实现如下所示：
public ResponseEntity fetchEvidence(Long takeDownId){
FetchEvidenceNetCraftReq req = FetchEvidenceNetCraftReq.builder().takeDownId(takeDownId.intValue()).build();
BaseResponse<QueryEvidenceRsp> rsp = outerVendorsService
.fetchEvidence(req);
if(Objects.isNull(rsp)) {
throw new RunTimeException("拉取文件失败");
}
byte[] outPutBytes = null;
if(Objects.nonNull(rsp) && rsp.isSuccess() == true) {
QueryEvidenceRsp evidenceRsp = rsp.getResult();
if(Objects.nonNull(evidenceRsp.getErrorCode())){
String message = "errorCode:" + evidenceRsp.getErrorCode() + ",errorMessage:" + evidenceRsp.getErrorMessage();
throw new RunTimeException(message);
}
outPutBytes = evidenceRsp.getFileBytes();
String fileName = evidenceRsp.getFileName();
HttpHeaders responseHeaders = new HttpHeaders();
responseHeaders.setContentType(MediaType.valueOf(MediaType.APPLICATION_OCTET_STREAM_VALUE));// 设置文件格式
responseHeaders.setContentLength(outPutBytes.length);
responseHeaders.set("Content-Disposition", "attachment;filename=" + fileName);// 设置文件名
return new ResponseEntity<>(outPutBytes, responseHeaders, HttpStatus.OK);
}
throw new RunTimeException("拉取文件失败");
}
public class QueryEvidenceRsp implements Serializable {
byte[] fileBytes;
String fileName;
String errorCode;
String errorMessage;
}
dubbo接口设计
下载文件流的RPC的接口设计
参照之前的上传文件的设计，服务提供的下载文件的rpc接口设计：
@Data
@Setter
@Getter
public class QueryEvidenceRsp implements Serializable {
byte[] fileBytes;
String fileName;
String errorCode;
String errorMessage;
}
@Data
@Builder
@Jacksonized
public class FetchEvidenceNetCraftReq implements Serializable {
private Integer takeDownId;
}
@Override
public BaseResponse fetchEvidence(FetchEvidenceNetCraftReq req) {
if(Objects.isNull(netCraftConfig) || Objects.isNull(netCraftConfig.getAccessNetCraftDomain())) {
log.error("netCraft config is not set");
return BaseResponse.fail().errorCode(ErrorCode.BUSINESS_EXCEPTION.getCode())
.errorMsg("netCraft config is not set").build();
}
String fetch_evidence = "https://" + netCraftConfig.getAccessNetCraftDomain()
+ netCraftConfig.getFETCH_EVIDENCE();
Map<String, String> headers = new HashMap<>();
headers.put("content-type", "application/json");
headers.put("Authorization", netCraftConfig.getAccessNetCraftAuthToken());
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
byte[] fileBytes;
String fileName;
try {
outputStream = new ByteArrayOutputStream();
fileName = getFromOctetStream(fetch_evidence + "?takedown_id="
+ req.getTakeDownId(), headers, outputStream);
if(Objects.isNull(fileName)) {
return BaseResponse.fail().errorCode(ErrorCode.BUSINESS_EXCEPTION.getCode())
.errorMsg("获取netcraft证据文件失败").build();
}
outputStream.flush();
fileBytes = outputStream.toByteArray();
} catch (Exception e) {
log.error("获取证据文件失败:" + e.getMessage());
return BaseResponse.fail().errorCode(ErrorCode.BUSINESS_EXCEPTION.getCode())
.errorMsg("获取netcraft证据文件失败").build();
} finally {
if(outputStream != null) {
try {
outputStream.close();
} catch (IOException e1) {
e1.printStackTrace();
}
}
}
NetCraftQueryEvidenceRsp rsp = new NetCraftQueryEvidenceRsp();
if(Objects.nonNull(fileName)) {
NetCraftErrorMessageRsp errorMessageRsp = JsonUtils.fromCamelJson(fileName, NetCraftErrorMessageRsp.class);
if(Objects.nonNull(errorMessageRsp)
&& Objects.nonNull(errorMessageRsp.getErrorCode())
&& Objects.nonNull(errorMessageRsp.getErrorMessage())) {
rsp.setErrorCode(errorMessageRsp.getErrorCode());
rsp.setErrorMessage(errorMessageRsp.getErrorMessage());
return BaseResponse.success(rsp).build();
}
rsp.setFileBytes(fileBytes);
rsp.setFileName(fileName);
return BaseResponse.success(rsp).build();
}
return BaseResponse.fail().errorCode(ErrorCode.BUSINESS_EXCEPTION.getCode())
.errorMsg("获取netcraft证据文件失败").build();
}
public static String getFromOctetStream(String url, Map<String, String> headers, OutputStream outputStream) {
return getFromOctetStream(url, headers, OK_HTTP_CLIENT_30s, outputStream);
}
public static String getFromOctetStream(String url, Map<String, String> headers, String client, OutputStream outputStream) {
Request.Builder requestBuilder = new Request.Builder();
requestBuilder.url(url);
if (headers != null && headers.size() > 0) {
for (String s : headers.keySet()) {
requestBuilder.addHeader(s, headers.get(s));
}
}
requestBuilder.get();
Request req = requestBuilder.build();
try (Response response = okHttpClientMap.get(client).newCall(req).execute()) {
log.info("okhttp send get,resp:{}", JsonUtils.toJson(response));
if (null != response.body()) {
InputStream inputStream = response.body().byteStream();
try {
byte[] buffer = new byte[1024];
int read = inputStream.read(buffer);
while (read != -1) {
outputStream.write(buffer, 0, read);
read = inputStream.read(buffer);
}
} catch (Exception e) {
log.error("处理返回值失败" + e.getMessage());
return null;
} finally {
try {
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
String contentDisposition = response.header("Content-Disposition");
if (Objects.isNull(contentDisposition)) {
log.error("调用netcraft获取证据接口, 获取文件名失败");
return outputStream.toString();
}
// 解析文件名
return contentDisposition.substring(contentDisposition.indexOf("filename=") + 9);
}
spring上传文件大小控制
在spring配置文件application.properties中，通过配置下面两个参数的值来限制文件的大小
spring.servlet.multipart.max-file-size=-1
spring.servlet.multipart.max-request-size=-1
spring.servlet.multipart.max-file-size配置限制上传单个文件的大小，为-1代表不限制
spring.servlet.multipart.max-request-size配置限制http中上传总文件的大小，为-1代表不限制
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