I have just installed GWT 2.6 and am now getting the error "Description Resource Path Location Type The file war\WEB-INF\lib\gwt-servlet.jar has a different size than GWT SDK library gwt-servlet.jar; perhaps it is a different version? gwt-servlet.jar /AwardTracker/war/WEB-INF/lib Unknown Google Web Toolkit Problem"
I downloaded the GWT 2.6 zip and then copied the directory "GWT-2.6.0" into "Eclipse\eclipse-jee-juno-SR1-win32\eclipse\plugins". I then right clicked on the project and selected "properties/Google/Web Toolkit/Configure SDKs.../Add". I then browsed to the "GWT-2.6.0" directory, added it and selected it.
I followed the solution from Braj and received the following errors when I recompiled:
Compiling module org.AwardTracker.AwardTracker Validating units: Ignored 2 units with compilation errors in first pass. Compile with -strict or with -logLevel set to TRACE or DEBUG to see all errors. Computing all possible rebind results for 'gwtupload.client.DecoratedFileUpload.DecoratedFileUploadImpl' Rebinding gwtupload.client.DecoratedFileUpload.DecoratedFileUploadImpl Could not find an exact match rule. Using 'closest' rule based on fall back values. You may need to implement a specific binding in case the fall back behavior does not replace the missing binding [ERROR] Errors in 'gwtupload/client/DecoratedFileUpload.java' [ERROR] Line 347: Rebind result 'gwtupload.client.DecoratedFileUpload.DecoratedFileUploadImpl' cannot be abstract
The above was fixed by downloading gwtupload-1.0.1.jar, using 'Add External JARS' to add it to the library and removing the old gwtupload-0.6.6.jar. I then recompiled and the compile work. However, now I have an error in my "MyCustomisedUploadServlet" on the line (this error was not present before):
protected static final String XML_ERROR_ITEM_NOT_FOUND = "<" + TAG_ERROR + ">item not found</" + TAG_ERROR + ">";
The rest of the code is:
package org.AwardTracker.server;
import gwtupload.server.UploadAction;
import gwtupload.server.exceptions.UploadActionException;
import gwtupload.shared.UConsts;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Hashtable;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileItem;
/**
* This is an example of how to use UploadAction class.
*
* This servlet saves all received files in a temporary folder,
* and deletes them when the user sends a remove request.
*
* @author Manolo Carrasco Moñino
*
*/
public class MyCustomisedUploadServlet extends UploadAction {
private static final long serialVersionUID = 1L;
protected static final String XML_ERROR_ITEM_NOT_FOUND = "<" + TAG_ERROR + ">item not found</" + TAG_ERROR + ">";
Hashtable<String, String> receivedContentTypes = new Hashtable<String, String>();
/**
* Maintain a list with received files and their content types.
*/
Hashtable<String, File> receivedFiles = new Hashtable<String, File>();
/**
* Override executeAction to save the received files in a custom place
* and delete this items from session.
*/
@Override
public String executeAction(HttpServletRequest request, List<FileItem> sessionFiles) throws UploadActionException {
String response = "";
@SuppressWarnings("unused")
int cont = 0;
for (FileItem item : sessionFiles) {
if (false == item.isFormField()) {
cont ++;
try {
/// Create a temporary file placed in the default system temp folder
File file = File.createTempFile("upload-", ".bin");
item.write(file);
/// Save a list with the received files
receivedFiles.put(item.getFieldName(), file);
receivedContentTypes.put(item.getFieldName(), item.getContentType());
/// Send a customised message to the client.
response += file.getAbsolutePath();
} catch (Exception e) {
throw new UploadActionException(e);
}
}
}
/// Remove files from session because we have a copy of them
removeSessionFileItems(request);
/// Send your customised message to the client.
return response;
}
/**
* Get the content of an uploaded file.
*/
@Override
public void getUploadedFile(HttpServletRequest request, HttpServletResponse response) throws IOException {
String fieldName = request.getParameter(UConsts.PARAM_SHOW);
File f = receivedFiles.get(fieldName);
if (f != null) {
response.setContentType(receivedContentTypes.get(fieldName));
FileInputStream is = new FileInputStream(f);
copyFromInputStreamToOutputStream(is, response.getOutputStream());
} else {
renderXmlResponse(request, response, XML_ERROR_ITEM_NOT_FOUND);
}
}
/**
* Remove a file when the user sends a delete request.
*/
@Override
public void removeItem(HttpServletRequest request, String fieldName) throws UploadActionException {
File file = receivedFiles.get(fieldName);
receivedFiles.remove(fieldName);
receivedContentTypes.remove(fieldName);
if (file != null) {
file.delete();
}
}
}
I simply commented this line out (" protected static final String XML_ERROR_ITEM_NOT_FOUND = "<" + TAG_ERROR + ">item not found";"), recompiled and ran it and it works fine. I hope all this helps others. Thank you to Braj for his help.
Whenever you change the GWT version you have to clean your project from the stub that is auto-generated by the previous GWT version as shown in below screenshots.
Problem: The file war\WEB-INF\lib\gwt-servlet.jar has a different size than GWT SDK library gwt-servlet.jar; perhaps it is a different version?
Solution: The problem in your case is gwt-servlet.jar that is auto-generated by previous GWT version. Just delete it along with other stub and re-compile project again.
This works for me very well
Select the warning, right click and choose "Quick fix" -> "Synchronize /WEB-INF/lib with SDK libraries"
"Done"
To copy the sdk in the plugin directory is not the corret way to add another SDK version.
Use Preferences -> Google -> Web Toolkit to add another GWT SDK version.
In your project choose:
project properties -> Goolge -> Web Toolkit you can choose the SDK the project should use.
I changed my compiler from 1.8 to 1.7 and lost this message.
来源：https://stackoverflow.com/questions/23455516/issue-with-installation-of-gwt-2-6