Error while creating a jar file with BlueJ - java

I was trying to create a jar file with Bluej and for some reason BlueJ would not let me include libraries that I was using (Specifically the Amazon SDK for Java)
It gave off an error "jar file could not be written correctly, check for access rights" or something along the lines of that. Is this just a BlueJ problem or is there something I need to do before creating a jar file that needs to include third party libraries?
Thanks.

I believe the answer to your question can be found here, at the BlueJ FAQ website:
https://www.bluej.org/faq.html#faq_How_do_I_use_custom_class_libraries__JARs__
The website describes three ways of doing this in BlueJ. The first way is via the "Preferences" dialog. Open the "Preferences" dialogue and select the "Libraries" tab. Then add the location where your classes are as a library path. Restart BlueJ - done. The selected libraries will now be available in all projects that you open.

Related

Google OR-Tools: Using in an IDE

I have the Problem that i want to add OR-Tools into my project via eclipse IDE. I want to use the Linear Solver. I added the two jars form the downloaded Zip file. Now i want to run the SimpleLpExample from the OR-Tools site. I've got the Error that no jniortools in java.library.path. I see that at other posts they say you have to run make third_party and make java, but i don't know where i have to run these commands.
When somebody added it successfully into an IDE it would be glade when this person can explain how he does it. Thanks for help.
No. You need to add the path to the jniortools shared library I'm eclipse.
All dynamic libraries are located in the lib/ directory of the extracted archive.
To add the correct path, please follow these instructions:

How do I add LWJGL 3.1.1 to netbeans to use in a Java project?

I want to use the Light Weight Java Gaming Library(LWJGL) to my Netbeans so I can use it in my Java application. The only videos that I can find show the zip file that they downloaded with separate src and doc folders inside of it. The zip file that I download has everything in one directory. I went to lwjgl.org/download and clicked on Stable and then Generate Bundle. What am I missing?
I had the same problem recently.
So, to begin you want to go to Tools in the context menu and select Libraries (as shown). Next you can add a new library and name it e.g. LWJGL-3.1.1 confirm with ok. You can find 3 tabs in the current window Classpath, Sources and Javadoc. There you add your jar files accordingly (in the downloaded .zip file you find .jar files with different names like lwjgl-{whatever}-sources.jar or lwjgl-{whatever}-javadocs.jar) make sure you put them in the right place. You have to repeat this process for all of the jar files you want. The javadoc files are not required but recommended. Make sure you also collect all the native .dll files and merge them in a folder called \natives. You find them in these jar files that are called like: lwjgl-{whatever}-{your-OS}.jar.
Once you have finished the setup for your library right click on your current project and choose Add Library.... In the window that pops up you scroll down until you find your library that you have just created and you are almost done now.
Last but not least go to the project settings. Select Run and make sure that you set the classpath in VM options to something like in the image: -Djava.library.path="C:\java_workspace\LWJGL Library 3.1\natives. Now this classpath tells netbeans where your native files are located. Your \natives folder that you should have created in the beginning is where this path should lead to. That's it. This is all you have to do for a setup without the use of maven, gradle, ...
You can test if it is working with the code provided by LWJGL HelloWorld example.
I hope this solved your problem.
Best regards.

How to set a classpath automatically during the installation of an excutable java application?

I am writing down an example of what I was trying to do.
But this is just one example, I am sure there would be many. So I want a generalised answer for this.
I was trying to make a java desktop application which reads the word documents. I realized I need some Apache libraries/APIs that would help me do it.
So I downloaded the library.
But now I need to set the classpath of the files from the library.
I am a developer and I can do it, but imagine giving such instructions of setting a classpath to a complete non-developer user.
I was wondering if when I am over with the making of this java application, I would make it executable (exe) application and when someone installs it, the classpaths are set automatically during the installation and the apache library files are automatically extracted.
How can I do it? Can someone explain me in detail - step-by-step?
Please consider using some development IDE, like (free) eclipse for instance.
Then crate new folder (clled lib for example) in your project, copy the library into it,
then click on your library by the right button and select "add to build path"
As already mentioned - best way to do it is to use Manifest file in your jar. Official documentation: https://docs.oracle.com/javase/tutorial/deployment/jar/downman.html

Attach the Source in Eclipse of a jar

I added a Student.jar into my Build Path in my eclipse like this-
Right click on the project->BuildPath->Configure Build
Path->Libraries->Add External Jars
There is one class named StudentTest in Student.jar file. When I was debugging my code in eclipse, I stepped into that StudentTest class in the Student.jar.
And after that eclipse shows me like this-
The JAR file S:\some_location\Student.jar has no source attachment.
You can attach the source by clicking Attach Source below
Now I am not sure how should I attach the source in my eclipse. And from where? Can anyone provide me step by step what I need to do.
Update:-
I tried unzipping the Student.jar and I got Student folder. And after that I tried pointing the source to Student folder But still I am not able to see the class properly so that I can debug it properly, it shows the same above behavior.
Use Java Source Attacher !
It does what eclipse should do - a right click context menu that says "Attach Java Source.
It automatically downloads the source for you and attaches it. I've only hit a couple libraries it doesn't know about and when that happens it lets you contribute the url back to the community so no one else will have a problem with that library.
Eclipse is showing no source found because there is no source available . Your jar only has the compiled classes.
You need to import the project from jar and add the Project as dependency .
Other option is to go to the
Go to Properties (for the Project) -> Java Build Path -> Libraries , select your jar file and click on the source , there will be option to attach the source and Javadocs.
A .jar file usually only contains the .class files, not the .java files they were compiled from. That's why eclipse is telling you it doesn't know the source code of that class.
"Attaching" the source to a JAR means telling eclipse where the source code can be found. Of course, if you don't know yourself, that feature is of little help. Of course, you could try googling for the source code (or check wherever you got the JAR file from).
That said, you don't necessarily need the source to debug.
This worked for me for Eclipse-Luna:
Right Click on the *.jar in the Referenced Libraries folder under your project, then click on Properties
Use the Java Source Attachment page to point to the Workspace location or the External location to the source code of that jar.
Go back in to where you added the jar. I believe its the libraries tab, I don't have Eclipse open but that sounds right. to the left of the jar file you added there should be an arrow pointing right, click that and 3 or 4 options expand, one of them being the source file of the library. Click on that and click edit(I think you can also double click it) then locate the file or folder on your hard disk, you probably have to click apply or okay and you're good to go, same with javadoc and i think the last one is native libraries. I don't pay much attention when I'm in there anymore if you couldn't tell. That's what you were asking, right?
I Know it is pretty late but it will be helpful for the other user, as we can do Job using three ways... as below 1)1. Atttach your source code using i.e, Right click on the project then properties --> Java build path--> attach your source in the source tab or you can remove jar file and attach the source in the libraries tab
2. Using eclipse source Analyzer In the eclipse market you can download the plugin java source analyzer which is used to attach the open source jar file's source code. we can achieve it after installing the plugin, by right click on the open source jar and select the attach source option.
3. Using Jadclipse in eclipse you can do it last not the least, you can achieve the decompile your code using this plugin. it is similar way you can download the plugin from the eclipse market place and install in your eclipse.
in jadclipse view you can see your .class file to decomplile source format note here you cannot see the comment and hidden things I think in your scenario you can use the option one and option three, I prefer option three only if i want to the source code not for the debug the code. else i ll code the option 1, as i have the source already available with.
Simply import the package of the required source class in your code from jar.
You can find jar's sub packages in
Eclipse -- YourProject --> Referenced libraries --> yourJars --> Packages --> Clases
Like-- I was troubling with the mysql connector jar issue
"the source attachment does not contain the source"
by giving the path of source folder it display this statement
The source attachment does not contain the source for the file StatementImpl.class
Then I just import the package of mysql connector jar which contain the required class:
import com.mysql.jdbc.*;
Then program is working fine.
I faced the same issue and solved using the below steps. Go to Windows->preferences->Editors->File Associations
Here click on Add
then type .class
click on OK
again click on Add
then type .classwithoughtsource
click on OK
Now you will be able to see JadClipse option under Java section in Windows->Preferences
Please provide the path of jad.exe file as shown below.
Path for Decompiler-C:\Users\ahr\Documents\eclipse-jee-galileo-SR2-win32\jad.exe
Directory for temporary Files-C:\Users\ahr.net.sf.jadclipse
click on Apply
Now you should be able to see the classfiles in proper format.
It is quite possible, just go to the jar in the Build Path and choose to attach a source just like follow.
Download JDEclipse from http://java-decompiler.github.io/
Follow the installation steps
If you still didn't find the source, right click on the jar file and select "Attach Library Source" option from the project folder, as you can see below.
I am using project is not Spring or spring boot based application.
I have multiple subprojects and they are nested one within another.
The answers shown here supports on first level of subproject.
If I added another sub project for source code attachement, it is not allowing me saying folder already exists error.
Looks like eclipse is out dated IDE. I am using the latest version of Eclipse version 2015-2019.
It is killing all my time.
My intension is run the application in debug mode navigate through the sub projects which are added as external dependencies (non modifiable).
I have faced same problem and resolved it by using following scenario.
First we have to determine which jar file's source code we want along with version number. For Example "Spring Core" » "4.0.6.RELEASE"
open https://mvnrepository.com/ and search file with name "Spring Core" » "4.0.6.RELEASE".
Now Maven repository will show the the details of that jar file.
In that details there is one option "View All" just click on that.
Then we will navigate to URL "https://repo1.maven.org/maven2/org/springframework/spring-core/4.0.6.RELEASE/".
there so many options so select and download "spring-core-4.0.6.RELEASE-sources.jar" in our our system and attach same jar file as a source attachment in eclipse.
Try removing the breakpoints. :)

How to use image4j Library?

I'm trying to create a program that can display *.ico file, so when I tried to search on google it's display for this library. I'm running with bluej and try to run the sample test.java and it's shown an error "package net.sf.image4j.codec.ico does not exist"
I'm running this with bluej, so I tried to add image4j-example.jar to bluej library but nothing happen. What am I supposed to do?
thanks
I would check the list of packages that are included in the image4j-example.jar file. It sounds from the name like that JAR file contains examples of how to use the library but not the image4j library itself. You can go here to download the image4j library:
http://image4j.sourceforge.net/
Once you download the .zip file from there and unpack it you should see a folder titled 'image4j-core-0.7'. Inside that folder is an image4j.jar file. I checked it in my IDE and that JAR file does have the net.sf.image4j.codec.ico package. Add that library to your project and give it another shot.

Categories

Resources