I am working with a simple JDBC program. While executing the program i notice the following behaviour.
The program works only when the mysql-connector-java-5.1.35-bin file is copied in the location C:\Program Files\Java\jdk1.6.0_43\jre\lib\ext
I changed the mysql-connector-java-5.1.35-bin file to the location(C:\Program Files\Java\jdk1.6.0_43\bin) and changed the classpath to C:\Program Files\Java\jdk1.6.0_43\bin. But in this case the program execution fails with
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver exception
So my question is, Is it mandatory to copy the mysql-connector-java-5.1.35-bin in C:\Program Files\Java\jdk1.6.0_43\jre\lib\ext ?
Don't put any file under the JDK installation directory. Add the jar file itself to the classpath, and not the directory containing the jar file:
java -cp c:\path\to\mysql-connector-java-5.1.35-bin.jar;yourApplication.jar com.foo.bar.YourMainClass
Related
When I am compiling the Java code, I have written the command line shows the following:
C:\HTML>javac Jdbc.java
Jdbc.java:5: error: package com.mysql does not exist
Class.forName(com.mysql.jdbc.Driver);
^
1 error
I have installed XAMPP and started the Apache, MySQL and Tomcat and they are working. I have installed MySQL Connector which is platform independent and latest. I have copied the JAR executable file to the JDK folder. I have added the jar executable file path in the edit system environment variables,
''' Class.forName(com.mysql.jdbc.Driver);'''
If you reference classes from a library, you should add that library to the classpath (i.e. javac -cp .;path\to\your\mysql-connector.jar Jdbc.java). However, that would immediately result in a different error, because that code should be Class.forName("com.mysql.jdbc.Driver") (passing a String).
Some further remarks:
I have copied the JAR executable file to the JDK folder.
You should never manually copy files to the JDK folder (in older versions there was the ext mechanism, but this no longer exists in recent Java versions). In addition, MySQL Connector/J is a library, not an executable jar.
I have added the jar executable file path in the edit system environment variables
Java JARs do not belong on the PATH. In theory you can add them to CLASSPATH environment variable, but that is generally considered a bad idea: most ways of executing Java do not actually use it, and if it does get used, it can result in unexpected behaviour because of conflicting or unexpected libraries on the classpath, etc.
I want to export may project (game) to different desktop platforms. I exported it from eclipse (on Windows) and I get JAR file. On my machine I can start it, but on other it won't work. I guess JRE is missing there.
So, I followed LibGDX instructions how to deploy on different platforms:
https://github.com/libgdx/libgdx/wiki/Deploying-your-application
But when I run that packr.jar app I get following output:
D:\packing>java -jar packr.jar windows.json
Output directory 'D:\packing\windows' exists, deleting
Unpacking JRE
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
copying resources
minimizing JRE
unpacking rt.jar
packing rt.jar
Done!
After that I really get my exe file, all together with jre dir, my original game jar file and some config.json file, but that exe file just won't run. No failure message, just won't run. Any idea what's going on here? Or maybe there is some other tool for packing jar files?
All I need is to make my game runnable on desktop platforms: Windows, Mac & Linux.
For windows OS you could use something like launch4j which simply puts a wrapper around your jar file.
It also has the capability to provide a given jre. So your users do not need to have one installed.
Ok, solved this.
So I've found out that if I run exe file from console (cmd) and redirect output to file I can have some error report regarding the run attempt. So I did that:
myapp.exe > log.txt
and get log this log file:
Loading JVM runtime library ...
Passing VM options ...
# -Xmx1G
Creating Java VM ...
Error occurred during initialization of VM
Unable to load ZIP library: D:\packing\windows\jre\bin\zip.dll
Zip file was there, but something was wrong with it so I replaced it with one I had in my Java installation (my was larger). After that I was able to run exe file well.
I have downloaded the JDBC driver for MySQL "mysql-connector-java-gpl-5.1.26.msi" from http://dev.mysql.com/downloads/connector/j/. But i can't figure out how to use it. The documentation at http://dev.mysql.com/doc/refman/5.6/en/connector-j-binary-installation.html says it is a zip file which has the required jar file. But what i got is a .msi file. When i execute the msi file it just starts installing and disappears. Any ideas how i can get the jar file from the msi?
The msi installation places the file at C:\Program Files\MySQL\MySQL Connector J\mysql-connector-java-5.1.26-bin.jar.
You can also download the platform independent zip file and extract the jar file whereever you want.
I had the same issue with the installer. use the drop down menu under Select Platform:, and select Platform Independent. If you don't know how to use a TAR archive, download the zip file, unzip and there is the .bin file. For eclipse, drop this into the project directory, find the file, right click, and build path. This method may cause issues if you download a java update.
You can directly used it from C:\Program Files\MySQL\MySQL Connector J\mysql-connector-java-5.1.26-bin.jar after installing the msi. If you are using IDE like Netbeans and Eclipse just go to your project then right click the Libraries folder then click add jar option then go the mysql connector directory and then select the mysql connector jar file.
I have a GUI application that connects to a SQL Server 2008 database using sqljdbc4.jar. If I run this from the command line it works great.
However, once I wrap it into an executable JAR, I get a "No suitable driver found for jdbc:sqlserver://myServer:1433;databaseName=myDb" error. I know that my Windows system CLASSPATH is ignored once it's in a JAR, but I can't figure out include the sqljdbc4.jar within the executable JAR and get a portable application.
My most recent attempt to fix this is as follows:
My MANIFEST.MF file:
Manifest-Version: 1.0
Class-Path: lib/sqljdbc4.jar
Created-By: 1.7.0_11 (Oracle Corporation)
Main-Class: MyApp
The command I use to compile the JAR:
jar cmf MANIFEST.MF MyApp.jar MyApp.class help.html lib
My directory structure is below. I am running the jar command inside the MyApp directory.
+ MyApp
+ lib
- sqljdbc.jar
- help.html
- MANIFEST.MF
- MyApp.class
- MyApp.java
When I create the JAR and run it inside the MyApp directory, it works fine. As soon as I pull it out of the directory, I get the error. How can I make the JAR access the sqljdbc.jar that is available internally?
Thanks in advance.
When you have an executable jar MyApp.jar with entry in the manifest.mf:
Class-Path: lib/sqljdbc4.jar
This means that the jar has an external dependency to sqljdbc4.jar in the (relative) folder lib. It is not included in the jar you created! So you need to make sure that there is a lib-folder containing sqljdbc4.jar relative to that jar when you execute it. So the folder structure when executing needs to be;
+ (a folder)
+ lib
- sqljdbc.jar
- MyApp.jar
I've been using Flashdevelop (version 4.4) for some time now with zero problems. I recently reinstalled Windows 7 however, and after installing Flashdevelop it is demanding Java 1.6 and won't compile without it. Let me be more specific, here is the error I get when I try to compile a simple HelloWorld-type test:
"Running process: C:\Program Files (x86)\FlashDevelop\Tools\fdbuild\fdbuild.exe "C:\Users\marc\Documents\DeleteMe\DeleteMe\DeleteMe.as3proj" -ipc 01be003c-6cb5-4d0b-9c35-c59dd2ea7a19 -version "4.6.0; 3.3" -compiler "C:\Program Files (x86)\FlashDevelop\Tools\flexsdk" -library "C:\Program Files (x86)\FlashDevelop\Library" -cp "C:\Program Files (x86)\Java\jdk1.6.0_34\bin" -cp "C:\Program Files (x86)\Java\jdk1.6.0_34"
Building DeleteMe
mxmlc -load-config+=obj\DeleteMeConfig.xml -debug=true -incremental=true -swf-version=16 -o obj\DeleteMe634829909556672047
Starting java as: C:\Program Files (x86)\Java\jdk1.6.0_34\bin\java.exe;\bin\java.exe
Unable to start java.exe: The system cannot find the file specified
Could not compile because the fcsh process could not be started.
Build halted with errors (fcsh).
INITIALIZING: Failed, unable to run compiler
Done(1)"
The GlobalClasspath setting for the Java 1.6 JDK is set to: C:\Program Files (x86)\Java\jdk1.6.0_34\bin
I have also set my JAVA_HOME environment variable to the same location as well. Might I be neglecting to set another environment variable?
JAVA_HOME should be
C:\Program Files (x86)\Java\jdk1.6.0_34
and not
C:\Program Files (x86)\Java\jdk1.6.0_34\bin
FlashDevelop currently doesn't support that your JAVA_HOME environment var contains several paths (C:\Program Files (x86)\Java\jdk1.6.0_34\bin\java.exe, \bin\java.exe).
Modify it to only indicate the first path (C:\Program Files (x86)\Java\jdk1.6.0_34\bin\java.exe).
As someone who was dealing with this, I just found an answer that doesn't involve mucking with the PATH variables.
Go into your Flex SDK, /bin directory, look for the JVM config file conveniently named jvm.config
Inside, there is a param 'java.home' which, if left empty, will cause it to search for it's own value. Enter in the main path to the JRE - in my case,
java.home=C:\Program Files\Java\jre1.6.0_07\
I found mine by going to "Control Panel > Java > Java tab > View... button" to see all the installed versions and their paths
I prefer this method because I feel like you shouldn't have to modify settings on your whole system to get 1 program to work, if you have the option instead to just modify that program's settings.
jvm.config in C:\Program Files (x86)\FlashDevelop\Tools\flexsdk\bin\jvm.config is much more better than path variable.
Please avoid Path variable.
In jvm.config just set jre URL directory
java.home=C:\Program Files\Java\jre1.6.0_07
May be you update the Java, last version of Java ask you to delete older version. Then go into the file
C:\Program Files (x86)\FlashDevelop\Tools\flexsdk\bin\jvm.config
and replace
java.home=C:\Program Files\Java\jre1.6.0_07\
by the folder were is your new version
java.home=C:\Program Files (x86)\Java\jre1.8.0_25\