我想使用 GWT 将文件上传到 REST Web 服务。但是我在以下这些字段中得到了空值。
InputStream uploadedInputStream, FormDataContentDisposition fileDetail
以下是我的 GWT 客户端代码
public void onModuleLoad() {
Button button = new Button("Click Here");
final FormPanel form = new FormPanel();
final FileUpload fileUpload = new FileUpload();
form.setMethod(FormPanel.METHOD_POST);
form.setEncoding(FormPanel.ENCODING_MULTIPART);
fileUpload.setName("upload");
form.add(fileUpload);
form.setAction("http://localhost:8080/RestWeb/webresources/generic/upload");
RootPanel.get().add(form);
RootPanel.get().add(button);
button.addClickHandler(new ClickHandler() {
@Override
public void onClick(ClickEvent event) {
System.out.println(fileUpload.getFilename());
System.out.println(fileUpload.getName());
System.out.println(fileUpload.getStyleName());
fileUpload.setEnabled(true);
System.out.println(form.getTarget());
form.submit();
}
});
form.addSubmitHandler(new SubmitHandler() {
@Override
public void onSubmit(SubmitEvent event) {
Window.alert("Onsubmit");
}
});
form.addSubmitCompleteHandler(new SubmitCompleteHandler() {
@Override
public void onSubmitComplete(SubmitCompleteEvent event) {
Window.alert("OnsubmitComplete"+event.getResults());
}
});
}
}
以下是我的服务器端代码。我在客户端和服务器之间建立了连接，但只有空值。我不明白我的错误。我参考了很多网站，但我得到了相同的代码。
@Path("generic")
@WebService
public class GenericResource {
@Context
private UriInfo context;
@Context
private HttpServletResponse response;
private String content = "content";
/**
* Creates a new instance of GenericResource
*/
public GenericResource() {
}
@POST
@Path("/upload")
@Consumes(MediaType.MULTIPART_FORM_DATA)
public Response uploadFile(
@FormDataParam("file") InputStream uploadedInputStream,
@FormDataParam("file") FormDataContentDisposition fileDetail) {
String uploadedFileLocation = "C://Users/SPC/Parvathy/upload" + fileDetail.getFileName();
// save it
writeToFile(uploadedInputStream, uploadedFileLocation);
String output = "File uploaded to : " + uploadedFileLocation;
return Response.status(200).entity(output).build();
}
// save uploaded file to new location
private void writeToFile(InputStream uploadedInputStream,
String uploadedFileLocation) {
try {
OutputStream out = new FileOutputStream(new File(
uploadedFileLocation));
int read = 0;
byte[] bytes = new byte[1024];
out = new FileOutputStream(new File(uploadedFileLocation));
while ((read = uploadedInputStream.read(bytes)) != -1) {
out.write(bytes, 0, read);
}
out.flush();
out.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
public class CorsFilter extends OncePerRequestFilter {
@Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
throws ServletException, IOException {
// if (request.getHeader("Access-Control-Request-Method") != null && "OPTIONS".equals(request.getMethod())) {
// CORS "pre-flight" request
response.addHeader("Content-Type",
"multipart/form-data");
response.addHeader("Access-Control-Allow-Origin", "http://127.0.0.1:8888");
response.addHeader("Access-Control-Allow-Methods", "PUT, GET, POST, DELETE, OPTIONS");
response.addHeader("Access-Control-Allow-Headers","origin, access-control-allow-methods, content-type, access-control-allow-origin, access-control-allow-headers");
response.addHeader("Access-Control-Max-Age", "1800");//30 min
// }
filterChain.doFilter(request, response);
}
}
请帮我。提前致谢。