So I have been working with the free version of JWrapper for some time now and have been quite pleased with the results; however, I have now purchased a license and would like to use it but I am unable to find the method with which to activate my JWrapper. I do not use the graphical interface version of JWrapper; rather I have created a xml installation file and pass that directly via commandline to JWrapper for building. Is there a special xml tag for specifying the license location? I was unable to find this information on JWrapper's homepage or support docs.
I received an answer from the support team. In order to use the license without using the JWrapperApp gui to build your application you will simply have to have the jwlicense.txt file in the same directory as your jwrapper.jar
After some tests it appears that the jwlicence.txt file must be in the current directory. So the best is to have all the files (jwrapper jar, jwrapper.xml and jwlicence.txt) in the same folder and run the compiler from that folder.
Related
I'm using Qt Creator 3.5.1 (opensource) with Qt 5.5.1. There I've created a shared library, and I can successfully build it. In the resulting build folder I find the so-file as expected, but I can't find the header files which are needed to use the library. Are the header files not expected to turn up here? I though the build folder would contain everything needed in order to make use of the library. Is that not the case?
I don't think they should be placed there. That is the build directory, not the installation directory. You can however also define the installation behaviour; see Advanced Usage - Installing Files. You choose which headers to distribute and which are private and place the public ones in the proper position.
How can I send my java application to a friend without having to send the entire project and being dependent on him having JDK? I'm aware of the .jar-file's existence, but I don't know how to proceed. I would like to be able to just send him the .jar-file or an executable file.
Any ideas?
Compile it to native code using a compiler such as http://en.wikipedia.org/wiki/GNU_Compiler_for_Java
Also, he doesn't need the JDK, just the JRE.
Did what #Barranka said regarding the dist folder, didn't know that worked until I read the readme file as #Barranka suggested.
So to quote what #Barranka said:
If you work with NetBeans, when you "build" your project, a dist
folder is generated, and your "packed" app is stored there. You can
send the contents of this folder. Read the "readme" file in that
folder. – Barranka
You can send the JAR file alone provided your program does not depend on other libraries. Assuming that there is a main() method and Main Class is configured in the JAR's manifest, the person can run it by Double Clicking (on windows) or use the command line
java -jar <jar_file_name>.jar
You cannot execute a Java application without a Java Virtual Machine, so you need one.
Your friend has to download a JRE/JDK, or you can provide it with your application directly as it (the JRE and your project in an archive) or provide it as a native compile code using GCJ or Excelsior Jet which will compile your application and a JRE.
As you can see the is no solution for your question, but there is one for your problem : ask your friend to download a JRE.
I'm trying to access a MySql database from a Qt application but I get the following error:
QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QSQLITE2
I find this very strange cause I have libqsqlmysql.so on my Qt folder. I have even tried to compile the MySql driver as a static plugin and add it to my .pro file as:
QTPLUGIN += qsqlmysql
But this also generates the same runtime error (it must've found the plugin cause there's no error compiling the application)
What am I missing? I would like to avoid having to compile Qt from source cause this will have to work seamlessly on the deploy machines as well.
BTW: Even though I'm developing and testing on Linux I will need to support Windows. Will I experience this same issue on Windows? How can I compile and link the MySql driver in both Linux and Windows?
The solution:
After following #Sergey's recommendations I did an strace of the application redirecting the output to grep so I could search for 'mysql' and for my surprise the application wasn't looking for the plugin at QTDIR/plugins/sqldrivers where I had libqsqlmysql.so, it was looking at QTDIR/lib. After copying the plugin to the lib folder the MySql connection worked.
Try opening the shared library with dlopen() and see if it loads and if not, what dlerror() tells you. I always run into similar problems on Windows. LoadLibrary()/GetLastError() saved me numerous times (last time it was because of a wrong version of some libiconv/libintl DLL). Running ldd on the plugin may also help.
If dlopen() works fine, try to load the plugin with QPluginLoader. If it doesn't load, then check the buildkey of the plugin. I usually do it the dirty way by running strings on the plugin and then looking for strings like "buildkey" or "QT_PLUGIN_VERIFICATION_DATA". Just looking at the build key and around it may give you an idea. For example, you may realize that you have compiled your plugin in the release mode while your application is compiled in the debug mode. In such case the build key won't match and the plugin won't load. Everything in the build key must match your configuration. Note that the version and the build key are checked differently: the build key must match exactly (or match some black magic called QT_BUILD_KEY_COMPAT), but in the version only the major version must match exactly, the minor version must be the version of Qt the plugin was compiled with or later and the patch level is ignored. So if your plugin was compiled with Qt 4.x.y then it will work with Qt versions 4.z.* where z>=x. This actually makes sense.
If the build key looks okay (which is unlikely if you got to this point), you may wish to look at QLibraryPrivate::isPlugin() source code to figure out what's wrong, but that doesn't look like an easy task to me (although running this in a debugger may help).
If QPluginLoader does load the plugin, check if it is in the right directory and has correct permissions. If you still didn't solve the problem by this point, it's time to look at the SQL module source code that actually loads these plugins. But it is extremely unlikely. I ran into this problem many, many times and it was always either the library not loading or the build key not matching.
Another way to go after QPluginLoader loads the plugin successfully is to use strace to figure out whether the program at least tries to open the plugin file. Searching for something like "sqldrivers" or "plugins" in the strace output should also give away the directory where Qt is searching for its plugins and specifically SQL drivers.
Update
Is it possible to compile the driver as a static plugin and don't worry about anything? Let's try:
d:\Qt4\src\plugins\sqldrivers\psql>qmake CONFIG+=static LIBS+=-Ld:/programs/Post
greSQL/lib INCLUDEPATH+=d:/programs/PostgreSQL/include
d:\Qt4\src\plugins\sqldrivers\psql>make
It compiles fine and now I got libqsqlpsql.a (release) and libqsqlpsqld.a (debug) in QTDIR/plugins/sqldrivers (it is the right place on Windows). I am using PostgreSQL driver here, but I don't think it will be any different for MySQL which I just don't have installed. Ok, let's compile some real program with it:
d:\alqualos\pr\archserv>qmake QTPLUGIN+=qsqlpsql PREFIX=d:/alqualos LIBS+=-Ld:/g
nu/lib INCLUDEPATH+=d:/gnu/include LIBS+=-Ld:/programs/PostgreSQL/lib LIBS+=-lpq
Note that I had to manually link to libpq, otherwise the linker would complain about undefined references. The funny thing is, qmake knows that qsqlpsql is located in QTDIR/plugins/sqldrivers and sets compiler and linker options accordingly. So it still needs to be in the right place to work, only you don't have to worry about your users running into the same problem as it is only used during compilation. An alternative would be to just use LIBS+=-Lpath/to/plugin LIBS+=-lqsqlpsql instead of QTPLUGIN+=qsqlpsql, at least the docs say that it should work, but I haven't tested it.
In order for the application to actually use the plugin I had to put the following in my main unit (CPP file):
#include <QtPlugin>
Q_IMPORT_PLUGIN(qsqlpsql)
It works! Also, from what I've been able to figure out from the sources, the build key and the version are checked only when a plugin is dynamically loaded (all the relevant stuff is in the QLibrary's private class, not even QPluginLoader's). So the resulting executable may (or may not, depending on the binary compatibility) work even with different versions and builds of Qt, although using it with older versions may trigger some bugs that were fixed later.
It is also worth noting that the order for loading SQL drivers is this: use the driver statically linked into Qt if available, then look for a driver registered manually with QSqlDatabase::registerSqlDriver(), then look for a driver statically imported into the application (the way described above), and finally try to load a shared plugin. So when you link statically, your users won't be able to use dynamically linked drivers they may already have, but will be able to use drivers linked statically into Qt (like in Ubuntu).
I compiled QT first and then realised that I need mysql as well. So I compiled mysql plugin by
executing following command in QT-DIR\src\plugins\sqldrivers\mysql folder.
Mysql plugin compile command
qmake "INCLUDEPATH+=$$quote(C:\Program Files\MySQL\MySQL Server 5.5\include)" "LIBS+=$$quote(C:\Program Files\MySQL\MySQL Server 5.5\lib\libmysql.lib)" mysql.pro
Plugings are then created in created in folder QT-DIR\plugins\sqldrivers.
However, when I tried to use it in my code. It failed with following error.
Error msg
QSqlDatabase: QMYSQLDriver driver not loaded
Solution
After some googling and checking Path variable I realised that the Mysql server lib
( C:\Program Files\MySQL\MySQL Server 5.5\lib) directory was not in my Path variable. I expect that the dll in this folder are used by the plugin at runtime. After including Mysql server lib in Path variable everything worked smoothly. Hope this information saves some hair on other programmers scalp, as I uprooted quite a few. :D
Last time I looked at this you needed to rebuild Qt from source and include the appropriate MySQL source.
Building Qt from the sources is not hard, it just takes a while. You are likely to have the required tools already.
A possible workaround may be to access the back-end over ODBC instead.
In order for your app to pick up the plugin at runtime, the shared library implementing the MySQL plugin needs to be placed in the correct directory. The best way of determining that directory is to check the output of QCoreApplication::libraryPaths. You can also force specific paths by using a qt.conf file.
Please note that plugins must be placed in subdirectories within the plugin path, and the final part of the path name (i.e., the parent directory of the shared libraries) cannot be changed. SQL drivers need to go in a directory named sqldrivers, i.e. <pluginpath>/sqldrivers. For more details on plugin directories, see How to Create Qt Plugins.
I was experiencing this same issue as well. I've been installing and experimenting with a lot of different Python tools and UIs. I then uninstalled everything python related. I did a fresh install of Python 3.2, PyQT 3.2, and Eric5. No more errors with the QMySQL driver.
well i have had this issue, and after a lot of time, and different tools, i found that QT ( on windows, have not been able to test on Linux.) loads the "QSQLMYSQL.." when requested, but before runtime the lib ("QSQLMYSQL..") file must reside on one of the searched paths (QApp.libraryPaths()) inside a folder called "sqldrivers".. otherwise QT will just ignore the file, even if it is at some other point inside the searched path.
what i did was to monitor the dependency of a sample app, and when i removed the "QSQLMYSQL.." dll from "plugins\sqldrivers\" it failed, but when i maded a folder inside the app folder, called "sqldrivers" and placed the "QSQLMYSQL..." inside there, it loaded.
what i have is mysql 5.5, qt 4.7.4.
hope anyone can use this, and if anyone knows more about it, i would like to know where to find it(http://doc.qt.nokia.com/stable/sql-driver.html, is the closest you can get to the information about the folder structur). :P
This may also happen if your QMYSQL plugin is linked against the "wrong" mysql_client.a or it isn't in the LD_LIBRARY_PATH. I had this problem on OSX because mysql was installed via ports, and I fixed it with:
install_name_tool -change libmysqlclient.18.dylib /usr/local/mysql/lib/libmysqlclient_r.18.dylib libqsqlmysql.dylib
I was successfully able to compile and run my Qt application. However, when I move the .exe file outside its original path, I found out that I have to manually copy the Qt DLLs (e.g. mingw10.dll, qtcore4.dll). Is there any dynamic way to link these libraries with my application?
I think you mean you want to "statically" link these libraries with your application.
Basically this means that everything will be rolled inside your exe, and you will have no need of those dlls anymore.
There are advantages to to static linking, but there are also disadvantages as well. You should be absolutely sure that this is what you want to do before you go this way.
Check out this link which explains the difference in depth Dynamic Linking vs Static Linking
As for your specific issue, if you are sure you want to use static linking you will have to change your Qt setup to be built statically. By default the Qt distribution is setup to use dynamic linking. There is a handy guide for that here.
Basically when you setup the build you have to run "configure -static" to change all the project settings to use static linking instead of dynamic linking. And then build Qt over again.
You should also verify your Qt license. If you are using the Qt LGPL license and you want to to link statically you will have to include all your object files (.o and .obj) as Mihai Limbășan wisely explained in his comment. If you have bought and paid for Qt, then you have no problem.
If the DLLs are on the PATH for the application, then they will be found and work. So, you could add where your Qt binaries/dlls are into the %PATH% environment variable. If you're going to create an installer for your application, you'll need to either package these libraries in so they're in the bin directory - or you'll have to expect every user to install and possibly compile Qt themselves (hint: go with the first option. :) )
I want to created a JAR file and I want to run it on a client machine.So, I have a couple of questions:
How can I convert the JAR file to an EXE file?
How can I encrypt the JAR file's contents? The jar file could be extracted with WinRAR and the classes could be decompiled with any Java decompiler.
How can I create an installer? My clients doesn't have any JVM and I don't want to ship JDK or JRE along, because they have big size.
See this link: Java to Exe. It also explains what valid reasons are to do this, and when you should not.
You can't really encrypt binaries as the machine has to understand them. That said, an optimized executable is very difficult to decompile, while plain class files are ease.
If you have an exe there are installers enough.
JSmooth is a application which will wrap your Jar in an exe
it also allows you to check if the correct version of JRE is available on the system you're deploying to
http://jsmooth.sourceforge.net/
As for 1): I guess you can not. There may be tools out there, but you cannot do that with standard tools shipped with JDK, as it would destroy platform independance. (See other answers providing links to such 3rd party tools)
As for 3): Use InnoSetup to create the installer. Include JRE within setup and let InnoSetup install it on the fly.
You can't prevent decompilation. The best you can do is make it harder or more time-consuming to do so. As an answer to your question though, I believe you can use gcj to compile Java into EXEs.
May be Excelsior JET will satisfy your needs.) IMHO very mature product.
1) I have recently tried the program jarToExe and like it.
Some features are:
free basic version or very cheap ($30) for 'enterprise'
ability to have windows task manager list your app's name instead of the default java.exe
extra obfuscation
runtime check that java is installed
2) You can make it harder to reverse engineer using proguard or other obfuscator
3) nsis is a very powerful, free scripting language to create windows installers. Good documentation on the site wiki and support on stack overflow as well.
Launch4j worked for me while some tools hadn't been working. It also have a good guide here.
Hope this help!
We use a 7zip SFX install launcher. This is an open source simple tool. It will package your jar, a version of jre so it's not mandatory for the installing systems to have jre installed and a self extracting version of 7zip. Here is a tutorial which explains how to bundle and GitHub link
The project is not maintained but works perfectly(tested until Java 1.8)
1) To create the exe, you can use Launch4j
2) As I have seen, you cannot encrypt the jar contents. I'm not sure though.
3) To create the installer you can use the exe you just created and use InnoSetup to create the files. You have to embed the jre inside the installer and also any other libraries and extra files that may need in the runtime. When embedding the jre, the setup gets large and if you want to avoid that, you can ask the clients to install java in the machines. That way, you wont need to ship with the jre.