我正在使用springboot 2x。我们的项目使用Custom HttpServeletRequest，它扩展了HttpServletRequestWrapper并实现了MultipartHttpServletRequest。一切正常。但是当我想为文件上传工作时，它无法初始化Multipart请求。它显示错误：
java.lang.IllegalStateException: Multipart request not initialized
我的问题是，如何解决此错误。如何初始化Multipart请求。
我正在提供有关此事的所有代码。
public class XHttpServletRequest extends HttpServletRequestWrapper implements MultipartHttpServletRequest {
public XHttpServletRequest (HttpServletRequest request) {
super(request);
}
private MultiValueMap<String, MultipartFile> multipartFiles;
private String method;
@Override
public String getMethod() {
if (this.method == null) return super.getMethod();
return this.method;
}
public void setMethod(String method) {
this.method = method;
}
private Map<String,String[]> parameters = new LinkedHashMap<String,String[]>();
public void setParameter(String name, String value) {
parameters.put(name, new String[] {value});
}
@Override
public String getParameter(String name) {
if (parameters.get(name) != null) {
return parameters.get(name)[0];
}
HttpServletRequest req = (HttpServletRequest) super.getRequest();
return req.getParameter(name);
}
public Map<String, String[]> getParameterMap() {
Map<String, String[]> result = new LinkedHashMap<String, String[]>();
result.putAll(super.getRequest().getParameterMap());
result.putAll(parameters);
return Collections.<String, String[]>unmodifiableMap(result);
}
public Enumeration<String> getParameterNames() {
Set<String> result = new LinkedHashSet<String>(Collections.list(super.getRequest().getAttributeNames()));
result.addAll(parameters.keySet());
return new Vector<String>(result).elements();
}
public String[] getParameterValues(String name) {
if (parameters.get(name) != null) {
return parameters.get(name);
}
HttpServletRequest req = (HttpServletRequest) super.getRequest();
return req.getParameterValues(name);
}
@Override
public HttpServletRequest getRequest() {
return (HttpServletRequest) super.getRequest();
}
@Override
public HttpMethod getRequestMethod() {
return HttpMethod.resolve(getRequest().getMethod());
}
@Override
public HttpHeaders getRequestHeaders() {
HttpHeaders headers = new HttpHeaders();
Enumeration<String> headerNames = getHeaderNames();
while (headerNames.hasMoreElements()) {
String headerName = headerNames.nextElement();
headers.put(headerName, Collections.list(getHeaders(headerName)));
}
return headers;
}
@Override
public HttpHeaders getMultipartHeaders(String s) {
return null;
}
@Override
public Iterator<String> getFileNames() {
return getMultipartFiles().keySet().iterator();
}
@Override
public MultipartFile getFile(String name) {
return getMultipartFiles().getFirst(name);
}
@Override
public List<MultipartFile> getFiles(String name) {
List<MultipartFile> multipartFiles = getMultipartFiles().get(name);
if (multipartFiles != null) {
return multipartFiles;
}
else {
return Collections.emptyList();
}
}
@Override
public Map<String, MultipartFile> getFileMap() {
return getMultipartFiles().toSingleValueMap();
}
@Override
public MultiValueMap<String, MultipartFile> getMultiFileMap() {
return getMultipartFiles();
}
@Override
public String getMultipartContentType(String s) {
return null;
}
/**
* Set a Map with parameter names as keys and list of MultipartFile objects as values.
* To be invoked by subclasses on initialization.
*/
protected final void setMultipartFiles(MultiValueMap<String, MultipartFile> multipartFiles) {
this.multipartFiles =
new LinkedMultiValueMap<>(Collections.unmodifiableMap(multipartFiles));
}
/**
* Obtain the MultipartFile Map for retrieval,
* lazily initializing it if necessary.
* @see #initializeMultipart()
*/
protected MultiValueMap<String, MultipartFile> getMultipartFiles() {
if (this.multipartFiles == null) {
initializeMultipart();
}
return this.multipartFiles;
}
/**
* Lazily initialize the multipart request, if possible.
* Only called if not already eagerly initialized.
*/
protected void initializeMultipart() {
throw new IllegalStateException("Multipart request not initialized");
}
}
另一个类扩展了XHttpServletRequest，而不是我们项目中的HttpServeletRequest。以下代码：
public class YHttpRequest extends MutableHttpServletRequest {
private ByteArrayOutputStream cachedBytes;
public YHttpRequest(HttpServletRequest request) {
super(request);
}
@Override
public ServletInputStream getInputStream() throws IOException {
if (cachedBytes == null)
cacheInputStream();
return new CachedServletInputStream();
}
@Override
public BufferedReader getReader() throws IOException{
return new BufferedReader(new InputStreamReader(getInputStream()));
}
private void cacheInputStream() throws IOException {
/* Cache the inputstream in order to read it multiple times. For
* convenience, I use apache.commons IOUtils
*/
cachedBytes = new ByteArrayOutputStream();
IOUtils.copy(super.getInputStream(), cachedBytes);
}
public List<Map<String, Object>> getListData() throws RequestException {
List<Map<String, Object>> data = new ArrayList<>();
try {
ObjectMapper mapper = new ObjectMapper();
data = mapper.readValue(this.getInputStream(), new TypeReference<ArrayList<LinkedHashMap>>(){});
System.out.println(data);
}
catch (Exception e) {
// System.out.println(e.)
throw new RequestException("Unable to parse request data", e);
}
return data;
}
private Object cachedData = null;
public Object getRawData() throws RequestException {
Object data = new LinkedHashMap<>();
try {
ObjectMapper mapper = new ObjectMapper();
// data = mapper.readValue(this.getInputStream());
try {
data = mapper.readValue(this.getInputStream(), new TypeReference<HashMap>() {
});
}
catch (JsonMappingException e) {
// e.printStackTrace();
}
try {
data = mapper.readValue(this.getInputStream(), new TypeReference<List<HashMap>>() {
});
}
catch (JsonMappingException e) {
// e.printStackTrace();
}
System.out.println(data);
}
catch (Exception e) {
// System.out.println(e.)
throw new RequestException("Unable to parse request data", e);
}
return data;
}
public Object getData() throws RequestException {
if (this.cachedData == null) {
this.cachedData = this.getRawData();
}
return this.cachedData;
}
/* An inputstream which reads the cached request body */
public class CachedServletInputStream extends ServletInputStream {
private ByteArrayInputStream input;
public CachedServletInputStream() {
/* create a new input stream from the cached request body */
input = new ByteArrayInputStream(cachedBytes.toByteArray());
}
@Override
public boolean isFinished() {
return input.available() == 0;
}
@Override
public boolean isReady() {
return true;
}
@Override
public void setReadListener(ReadListener readListener) {
// throw new IOException("zubair says: Method not implemented in Cached Servlet Input Stream class");
}
@Override
public int read() throws IOException {
return input.read();
}
}
// Storage for Path variable
private Map<String, Object> pathVariableMap = null;
public Map<String, Object> getPathVariableMap() {
if (this.pathVariableMap == null) {
this.pathVariableMap = new LinkedHashMap<>();
this.pathVariableMap.putAll((Map<? extends String, ?>) this.getAttribute(HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE));
}
return this.pathVariableMap;
}
public Object getPathVariable(String key) {
return this.getPathVariableMap().get(key);
}
public FurinaHttpRequest setPathVariable(String key, Object value) {
this.getPathVariableMap().put(key, value);
return this;
}
public FurinaHttpRequest clearPathVariableMap() {
this.getPathVariableMap().clear();
return this;
}
}
控制器代码：
public String handleFileUpload(YHttpRequest request) {
if (request.getMethod().equalsIgnoreCase("GET")){
return "{}";
}
Map<String, MultipartFile> file= request.getFileMap();
try {
for(Map.Entry<String, MultipartFile> entry : file.entrySet()){
storageService.store(entry.getValue());
//model.addAttribute("message", "You successfully uploaded " + entry.getValue().getOriginalFilename() + "!");
files.add(entry.getValue().getOriginalFilename());
}
} catch (Exception e) {
//model.addAttribute("message", "FAIL to upload !");
}
return "{}";
}
答案 0 :(得分：0)
这将有效
public String handleFileUpload(YHttpRequest request) {
if (request.getMethod().equalsIgnoreCase("GET")){
return "{}";
}
StandardMultipartHttpServletRequest standardMultipartHttpServletRequest = new StandardMultipartHttpServletRequest(request);
Map<String, MultipartFile> file= request.getFileMap();
try {
for(Map.Entry<String, MultipartFile> entry : file.entrySet()){
storageService.store(entry.getValue());
//model.addAttribute("message", "You successfully uploaded " + entry.getValue().getOriginalFilename() + "!");
files.add(entry.getValue().getOriginalFilename());
}
} catch (Exception e) {
//model.addAttribute("message", "FAIL to upload !");
}
return "{}";
}