Not a very common implementation, but using Processing as a Java Servlet has been discussed in previous posts before (1, 2). I have been developing a program in Processing to use as a Java servlet. However, when I have code (such as like the first linked example) in a Processing sketch, I get the error message
The package 'javax.servlet' does not exist. You might be missing a library.
I have Tomcat 5.5 service running on XP, and my environment variables are as follows
CLASSPATH = C:\tomcat\common\lib\servlet-api.jar
CATALINA_HOME = C:\tomcat
JAVA_HOME = C:\Program Files\Java\jdk1.6.0_21
JRE_HOME = C:\Program Files\Java\jre6
I have been trying to diagnose why the javax.servlet packages are not recognized by Processing for many hours and there is nothing online that seems to yield an explanation other than fixing the environment variables to recognize the tomcat libraries. I have also tried to put the servlet-api.jar and jsp-api.jar files in Processing as a kind of custom Processing library but they are not recognized there either, nor when I try to run the program within the tomcat/webapps folder.
I also have tried
javap -classpath my;class;path javax.servlet.Servlet
on the cmd and it gave me the same error.
I'm not that good with Tomcat yet so please forgive me if this is a result of my unfamiliarity. If anyone more knowledgeable than I can shed some light as to why Processing cannot recognize this package would be tremendous. Thanks so much~
CLASSPATH = C:\tomcat\common\lib\servlet-api.jar
This is the problem . Your classpath should be one level up i.e
CLASSPATH = C:\tomcat\common\lib\
This should work fine.
Right Click on MyComputer->Properties->Advanced->Environment Variables->
Set a new user variable name as classpath and give the variable value where your servlet-api.jar file is located (applicable for tomcat webserver), for example:->
variablename: classpath
variablevalue: D:\Tomcat\lib\servlet-api.jar
Now you can run your disassembler to find out the servlet class and interface information
If you are not able to load the servlet package, try setting the environment variable CLASSPATH to .;C:\tomcat\common\lib\servlet-api.jar. That should help.
Ok!.. i bought a new laptop and was faced the same problem, well i hope this would fix the issue on your windows 10 device as well.
First of all know that the error is just due to incorrect or incomplete path or classpath. After Installing Tomcat and JDK set the environment variable as follows(Location may vary as per your installation):
JAVA_HOME = C:\Program Files (x86)\Java\jdk1.7.0_80
JRE_HOME = C:\Program Files (x86)\Java\jre7
CATALINA_HOME = C:\Program Files (x86)\Apache Software Foundation\Tomcat 7.0
PATH = C:\Program Files (x86)\Java\jdk1.7.0_80\bin; C:\Program Files (x86)\Apache Software Foundation\Tomcat 7.0\bin;
CLASSPATH = C:\Program Files (x86)\Apache Software Foundation\Tomcat 7.0\lib\servlet-api.jar; C:\Program Files (x86)\Java\jdk1.7.0_80\lib\tools.jar; JAVA_HOME\lib
make sure that your classpath directs the mentioned jar files, as javax is included in it(try using winrar for checking the inner contents).
After saving the setting, Test using javap javax.servlet.Servlet
Well if you still face any issue please share the error message and screenshot.
Probably because Tomcat is not in the Java Build Path. Try add Tomcat to your library
1) Right-click on your project folder > Build Path > Configure Build Path
2) Click on Library tab > click Add Library button
3) Select Server Runtime > click Next button
4) Select your server > click Finish button
Related
I want to run edumips.jar. Whenever I try to open, Java control panel is opened.
When I execute:
strong text
It is first time to download java and excecute .jar file.
What I want:
Please tell me what I'm doing wrong...
UPDATE: there is now an MSI installer for EduMIPS64 which allows you to install and run the simulator without worrying about installing a JRE and configuring it: https://github.com/EduMIPS64/edumips64/releases/download/v1.2.8/EduMIPS64-1.2.8.msi (version 1.2.8 was released at the time of updating this answer, there might be more recent ones).
You need to make sure the Java runtime is associated with the .jar extension to open it with double-click.
To open it once, try right-clicking on the JAR file select Open With... and find the Java runtime binary (it's "OpenJDK Platform Binary" on my Windows machine).
You may also be able to fix this by re-installing the Java Runtime (JRE): usually installers associate .jar files to the Java binary automatically.
Worst case, if Java is installed and the PATH is set up correctly, you can run it from the command line by using the command java -jar edumips64-1.2.6-standalone.jar.
To open the command line, press Win+x and choose Windows PowerShell. Your JAR might be in the Downloads directory so try java -jar Downloads\edumips64-1.2.6-standalone.jar.
It's been a few days since I've been trying to export a very simple project made in JavaFX but I have a very frustrating problem: To run the jar I need to open cmd navigate to the jdk folder and execute the following code java --module-path %path_to_JavaFX_on_my_pc% --add modules=javafx.controls,javafx.fxml,javafx.graphics -jar %path_to_jar% where I point to the jfx folder on the pc and add the necessary modules to run the jar.
run the jar using java java -jar %path_to_jar% results in the following error: Error: JavaFX runtime components are missing, and are required to run this application
The project is modular, having declared module-info.java with the following code:
module Timer {
requires java.prefs;
requires com.jfoenix;
requires javafx.base;
requires javafx.controls;
requires javafx.fxml;
requires javafx.graphics;
requires javafx.media;
requires javafx.web;
requires javafx.swing;
opens main;
exports main;
}
when exporting the artifact I include all the .jar contained in the javafx, so why should I point to it externally?
The app runs well when I run it through the IDE, I didn't even have to add VM options.
My goal is to create an application that can actually be distributed, without the user needing to have any knowledge beyond the basics to run it, no jre, jdk, jfx, cmd code, etc... just click twice and done.
The question is: How do I generate an executable file that can be opened with 2 clicks like any other application on the pc on *any pc?
finally I got a solution to my problem.
1 ° - It was necessary to solve the problem when generating a java artifact using javaFx in intelliJ: In JDK 13 the IDE threw the following error
Can't build artifact - fx: deploy is not available in this JDK
the easiest solution for that was to return on JDK 9 ond the javaFx was still built in and everything worked fine. Having done that, I was able to generate .jar artifacts that worked without the need to use command line tools.
2 ° -So I needed to generate a native executable for my application: In this topic there is an excellent list of tools that create launchers for java artifacts (Ideal was to convert but there gets a little complicated). What worked best for me was Jsmooth where I was able to set up a launcher that built in my .jar and where I could also attach a copy of the JRE for distribution on computers without Java
It is worth noting that I develop desktop applications just for my use and that of some friends, they do not work with sensitive data and do not require a high level of security and therefore there is no problem using an old version of jdk, in any other case, no recommend this approach.
Thank you all for your help.
I ran into the same problem with JavaFX 11. The way I did it, to be able to generate the jar artifact, I set the Project Settings - Artifacts - Type to JAR rather than JavaFX Application. That enabled me to create a jar in the out directory of my project. Afterwards, I wrote a batch file that created a custom jre for my app (as small as ~40 MB for a small app), including JavaFX. I called that bat file create.bat and placed that bat file in the same folder as my jar artifact.
Now, provided
my jar artifact is called app.jar,
path to JDK is D:\jdks\jdk11,
path to JFX mods is D:\jdks\jfx11\jmods,
module name is com.epsilon, and
path to Main class is com.epsilon.Main,
below is the contents of the bat file to create a custom JRE, including JavaFX. It created a custom JRE in the folder dist, the launch file is in the dist\bin directory called run.bat.
rem This sets the variable DIR to the current directory with the jar artifact
set DIR=%~dp0
rem This creates a temporary mod file
D:\jdks\jdk11\bin\jmod create --class-path %DIR%app.jar %DIR%temp.mod
rem This creates distributable JRE
D:\jdks\jdk11\bin\jlink ^
--compress=2 ^
--strip-debug ^
--no-man-pages ^
--launcher run=com.epsilon/com.epsilon.Main ^
--module-path D:\jdks\jdk11\jmods;D:\jdks\jfx11\jmods;%DIR% ^
--add-modules com.epsilon ^
--output %DIR%dist
rem This command deletes the temporary mod file
del %DIR%temp.mod
rem You can create a shortcut to your app above the "dist" folder and enter the below line to the shortcut's target property
rem %windir%\system32\cmd.exe /c start "" "%CD%\dist\bin\javaw.exe" -m com.epsilon/com.epsilon.Main
So, this has enabled me to create a working distributable without downgrading Java.
I have made the appropriate modification as found in this thread to enable the Qt sqlite plugin to load extensions. However, when I run SELECT load_extension('spatialite_mod'), I now get the error The specified module could not be found
On a Windows Qt installation, where do I need to put the spatialite_mod.dll file so that it can be found a runtime? I have already tried putting it in the binary directory without any success.
This turned out to be a multi-part problem.
The answer to the original question is that Qt looks for the libraries in the working directory (QDir::currentPath()) and in the Windows PATH.
Part 1:
On Windows, the specified module could not be found error also can mean that one of mod_spatialite.dll dependencies was not found. In my case, I had forgotten to move these dependencies to the same directory as mod_spatialite.dll. They include:
libgcc_s_dw2-1.dll
libstdc++-6.dll
libsqlite3-0.dll
libxml2-2.dll
zlib1.dll
libfreexl-1.dll
libgeos_c-1.dll
libgeos-3-5-0.dll
libiconv-2.dll
liblzma-5.cll
libproj-9.dll
Part 2:
The libgcc_s_dw2-1.dll and libstdc++-6.dll libraries shipped with libspatialite do not work with Windows 10. Read more about this here and here. They would crash the program when loaded. The fix for me was to grab the same libraries from my Qt installation at C:\Qt\5.11.3\mingw53_32.
I am learning about shared objects (.so) / dynamic link libraries (.dll). Since I'm on Linux only .so files are relevant. Anyway, when I compile a shared library, I get multiple .so files - most of which are only links. Here is a screenshot:
Then I created another Qt console application project to test this SO. I had set up all the header files, copied every .so file from previous screenshot to this new project and added
LIBS += "libAritmeticnoKodiranjeDLL.so"
to project settings. If I compile the project it goes through OK. But when running my test app I get this error:
./DLLTester: error while loading shared libraries: libAritmeticnoKodiranjeDLL.so.1: cannot open shared object file: No such file or directory
Where is the problem and why do I get so many .so files?
Just do:
LIBS += -lAritmeticnoKodiranjeDLL
The specifics of the libraries prefix ("lib") and suffix (".so") will be taken care of by the linker.
Note how all except one are just symbolic links, and the actual file is the one with most precise version. This is to support different versions of the library, the symbolic links determine which exact version is used when version is not fully defined. If you are installing libs to system library folders, this is kind of important, but if you are just distributing one non-shared version along with your application, then you can use the name without version number.
When running application with custom libraries, you need to add the directory to LD_LIBRARY_PATH environment variable, so runtime linker finds them. See https://stackoverflow.com/search?q=LD_LIBRARY_PATH . For troubleshooting, you can run ldd yourprogram to see what shared libraries are actually loaded, and echo $LD_LIBRARY_PATH will let you make sure LD_LIBRARY_PATH is what you think it is.
I can definitely confirm from my current experience that QtCreator 4.0.3 with Qt 5.7 under Linux (Ubuntu 16.04) when building a shared library (using TEMPLATE = lib) then resulting target is libName.so (when CONFIG += unversioned_libname) or libNAME.so.1.0.0 (when CONFIG unchanged). However an application built with the very same environment links correctly against that library (LIBS += -Lfolder -lNAME) during linking but unfortunately during run-time it requests for linName.so.1 because "Application Output" says error while loading shared libraries: libNAME.so.1: cannot open shared object file: No such file or directory (I can see libName.so.1 in the generated binary of the app but NOWHERE else - not in Make files). I have spent 2 working days to figure this all out. The only way is to manually change the name of generated .so file to fit what application requests.
I have installed Tomcat 5.5 in windows vista home basic. I have set classpath to
"C:\program files\apache software foundation\tomcat 5.5\common\lib\servlet-api.jar".
now there are two problems.
1. I could not compile my servlets. It says package javax.servlet.* dosenot exist.
2. I could not connect with local host in chrome nor in explorer.
these errors are appearing inspite of server instance running.
Classpath to java sdk and tomcat are different. is it the matter of concern.
Please help.
I have invested considerable amount of time figuring out the problem.
thanx in advance.
I could not compile my servlets. It says package javax.servlet.* dosenot exist.
It means that the classpath for javac is not been correctly specified. It should go like so:
javac -cp .;"/path with spaces/to/servlet-api.jar" com/example/YourServlet.class
Note that you need to surround a path with spaces by doublequotes.
I could not connect with local host in chrome nor in explorer. These errors are appearing inspite of server instance running.
Then you used the wrong domain/port. When running Tomcat at the local machine, the domain should at least be localhost. The actual port can be determined in Tomcat/conf/server.xml file. It defaults to 8080, but can be changed during the Windows setup wizard. The final URL should look like http://localhost:8080. If you use port 80 which is the default HTTP port, then the :80 part can be omitted from the URL.
Classpath to java sdk and tomcat are different.
The %CLASSPATH% environment variable is worthless. Use -cp argument. If you want to avoid long typing/remembering everytime, consider using a .bat file with the command, or a build tool like Ant, or an IDE like Eclipse.
The %JAVA_HOME% environment variable is however important. Tomcat needs to know it in order to have access to the toolset to compile JSP files. The %JAVA_HOME% should point to the installation directory of the JDK.
I have set classpath to "C:\program
files\apache software
foundation\tomcat
5.5\common\lib\servlet-api.jar"
If this means CLASSPATH environment variable, you're learning a valuable lesson: it's worthless. javac.exe and java.exe ignore it; so do all Java EE app servers like Tomcat; so do all IDEs like IntelliJ.
You'll have to add servlet-api.jar to your CLASSPATH using javac.exe -cp every time you compile in a command shell, or add it to your IDE project CLASSPATH, or set it up in Ant.
If you can't connect to localhost using Chrome or Explorer, it probably means that you haven't packaged or deployed your app properly. Make sure you create a valid WAR file and put it in the Tomcat 5.x /webapps directory to deploy.