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I'm posting this query after doing lots of googling and trying out different options for last few days. Is there an easy way to attach source in Eclipse? is the closest answer I found to my question.
From above post, I tried all solutions but each time Eclipse is opening .class file instead of .java file.
Eclipse Details:
Kepler Service Release 2
Build id:20140224-0627
Please let me know if this is a bug with Eclipse or if I am missing something.
If you are using Maven, try this:
Double click on your project in eclipse -> Maven -> Enable Workspace Resolution
This is most likely because Eclipse actually use the class file for declaring the item you have requested the declaration for, and not the source file you think it should be using.
The typical reason for this is if you have a jar file containing previously compiled classes on your build path before (or instead) of the project containing the source you want. This is very rarely desirable as it can take quite a while to discover that your edits do not take effect.
Examine your build path carefully and ensure it is as you want it to be.
Maven is likely supplying a Classpath Container to your project, and generating entries for the Java Build Path based on the pom.xml contents (the JRE System Library is another example of this). Its entries will not have source attachment unless the container decides it will, which is why the Installed JREs preference page offers to let you set Source Attachments. If the pom.xml has something like that, see if you can use it. If not, see if you can configure the Maven container from its context menu. Otherwise, you may simply be stuck.
I had this same problem: when I pressed F3 or tried to open Declaration (after right click) for any element, it took me to the bytecode .class file.
My solution:
I went to the project in Project Explorer:
right click on project name->Properties
Then in Porject Properties window,
Java Build Path->"Order and Export" tab
There I selected the folder with the .java files (source code), which was below the folder having the .class files -in my case "JRE System Library [java-11-openjdk-amd64]", and pressed 'Top' button on the right frame. Then the folder with source files moved to the top.
Finally, pressed "Apply and Close" button.
That solved my problem forever and ever.
The folder
I installed a plug-in which allows me to download the sources for a maven project.
I'm not by my develop machine right now, but I think it was this:
http://marketplace.eclipse.org/content/m2e-dynamic-sources-lookup#.U8gjGWIaySM
With this, you can select a project an have maven download the sources and make then available when you navigate the code in Eclipse. All without "leaving" Eclipse.
Check into your project modules the Java Build Path, look inside the Source tab and verify if you have "Allow output folders for source folders" checkbox flagged; in this case you just need to uncheck it and you will be able to see again the right source from java files.
This is related to the Call Hierarchy in Eclipse IDE.
If you are in a situation, where you're seeing duplicate methods inside the call hierarchy showing Members calling 'myMethod(...)', double-clicking on one of the listed methods may open the .class file instead of the .java file.
When this happens, the solution is to set the search scope in the call hierarchy to Project instead of Workspace.
After setting the search scope, you won't be seeing duplicate methods listed in the call hierarchy, and double-clicking on the listed methods will only open the .java files.
(Using Eclipse DevStyle Dark Theme)
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. :)
I wanted to learn Java, as recommended by most of the people I downloaded "Thinking in Java" eBook and Source Code Example Lesson files from mindviewinc.com it's download location is this http://www.mindviewinc.com/TIJ4/CodeInstructions.html
These files don't work with Eclipse IDE for some reasons. So we have to build the files using the Build.xml file included in it's source code (Honestly, I do not have any idea what does "build" means here)
I tried building myself but of no use.. It did started building but after reaching some folder it stopped and gave error to install jboss-osgi-installer-1.0.0.jar .. After downloading it, I had no idea what to do with it, so I double clicked it and it asked me the location to install and I installed it in the default location, which was C:\Users\Username/jboss-osgi-1.0.0 and when I tried C:\Program Files\Java** the installation gave error that "this directory cannot be written, please choose another directory!" but anyway I installed it in the default location and it installed..
and again when I tried to build it, it gave me the same error and asked to Install Jboss....... I'm stuck.. This is happening again and again, wasted many days and didn't even crossed 100 pages of it's pdf because of this reason. It's a good eBook though.
I'm stuck in this from months... Please some one build it and make it like a project which could be easily and send me the project file, it would be really appreciated as I can not the solution to this anywhere on search engines..
Ok here's what I did to succesfully import the sources found in the "accesss" folder of you code samples:
Download the javassist jar as per Bruce's instructions, from here:
http://repo2.maven.org/maven2/javassist/javassist/3.9.0.GA/javassist-3.9.0.GA.jar
You must create an Eclipse project for the sources that are used as dependencies for most of the examples, that's the sources in the "net" folder:
in eclipse make new java project.
select the "net" directory, copy it, then in eclipse select the "src" entry in the project you just made, right click on it and select paste.
after eclipse finishes and auto-builds, it will complain about the missing javaassist jar. Right click on the project ->properties->java build path (on the left)->libraries (on the top)-> add external jars... (on the right), browse and select the javassist jar from where you down load it.
now the "net" project should be ok in eclipse
Now let's create the project for the sources in the "access" folder:
create a new java project in eclipse
Now, because Bruce structured his classes like crap, we'll have to make the proper structure in eclipse for them. This means:
a.create a new package called "access"
go to where your the access folder is on your drive, open it, select ONLY the folders (cookie2, desser, mypackage), copy them, then return to eclipse, right click on the "access" package u just made and click paste
now go back to the access dir on your drive, select ONLY the .java files (all of them, not the dirs), copy them, the back to eclipse, click on the src entry in the access project and click paste.
The access project in elcipse will still complain about missing classes form the "net" resouce. Right click on the project in eclipse->properties->java build path->projects (on the top)-> add(on the right)-> check the net project you created earlier-> click ok twice.
Now it should be ok
I hope you got the idea on how dependencies work in eclipse with this example.
For the other parts of you code samples, create separate java projects, add the classes to the proper package (create the packages if Bruce forgot to), and if you are missing external jars, go to http://search.maven.org search and download the jars. Good luck
"This code is designed to work outside of IDEs. Because packages are not introduced until later chapters, and some of the fancier IDEs like Eclipse require all code to be in packages, if you want to use the code inside those IDEs you will have to make some adjustments" - yep, bruce eckel would say that, cause that's the kind of guy he is. He also said there's ONLY checked exceptions in java, and asked for unchecked exeptions to be added as a bonus.
Now, if your sample code has no package, aka it's in the default package, aka when you look in the .java file, right at the top there's no line saying "package what.ever.bla" then all you have to do is:
-in Eclipse create a new Java se project
- open a windows explorer, go to your .java files, select them and copy them
- then in eclipse, right click the src folder in your project and chose "paste"
The files should be added to a "default" package in your eclipse project, without any error
Here is the simplest steps that I find to create a clean Eclipse project for the TIJ4 source code:
Download the source code zip from: http://www.mindviewinc.com/TIJ4/CodeInstructions.html, and unzip it to a folder, say 'TIJ4-code';
Download the additional libraries as in the previous URL, copy tools.jar from your current JDK's lib directory, and put them into TIJ4-code/lib;
Go into the 'TIJ4-code' folder, and run 'python Eclipse.py' (you need python installed on your system). This script adds the missing "package xxx" line to those source java files which don't yet have them, so as to make Eclipse happy. It also generates the Eclipse project files, which doesn't work well for some reason (beyond my limited knowledge on Eclipse), but they aren't needed here;
Open Eclipse and create a new empty java project, say with name 'TIJ4', choose JRE version 1.5, and "create separate folders for sources and class files";
Copy TIJ4-code/lib directory to your new Eclipse project folder;
Right click on the new project and select "Build Path" >> "Configure Build Path", then go to tab "Libraries", "add jars", then select all the jars under your project's lib folder;
Go to "File >> import", choose "General >> File System", select the unzipped folder 'TIJ4-code' as your "From directory". Check the root 'TIJ4-code' in the left panel of the import window, Click on "filter types" and select the .java, so that unnecessary files of other extensions, like *.class, *.py, *.xml, etc can be ignored during the import;
The zipped folder is no longer needed after the new Eclipse project is built. I hope you find this instruction helpful, and have fun learning TIJ4.
If you want to use this code in IDE rather than Eclipse and so on, for example in Intelij Idea or any other, the best way is to compile necessary classes from the TIJ4 with Ant, but it is not easy for the beginners, although it will be a good practice for you. You should make some changes in build.xml files which exists in every directory of TIJ4. Why?
to change version of Java(now we all use Java version higher than 1.5)
to include javaassist.jar library in the "classpath"
to put all compiled files in 'bin' directory(by default without adjustments TIJ4 build.xml puts .class files in the same directory with .java files. That is not a good deal.
For example you need to import and use within IDE(I use Intelij Idea) the class named net.mindview.util.Print ( see Chapter 3):
download TIJ4 and unzip in any directory you want(for example it would be c:\eckel)
download and install AntApache (you can find detailed instructions how to do it in Google) The result is - type in your console ant -version and you should see the answer. So Ant is working.
download javaassist.jar from http://jboss-javassist.github.io/javassist/ . Unzip to any directory, take out javassist.jar and past it to c:\eckel\net
4.There is build.xml file in c:\eckel\net. Now you should make adjustments. Open it with NotePad++ or other editor.
If you don't have Java 1.5 installed on your PC, so change all 'vesion1.5' to 'vesrion1.8' or other version that you have installed.
after tag description put property name = "classpath" value="./;./javassist.jar"/>
<property name = "src_util" value="./mindview/util"/>
<property name = "src_simple" value="./mindview/simple"/>
<property name = "src_atunit" value="./mindview/atunit"/>
<property name = "destdir" value="bin"/>
Then we make targets that will complile util simple or atunit automatically
Change tag available <available
classname="javassist.bytecode.ClassFile"
classpath="${classpath}"
property="javassist"
/>
Now classpath of available = property named 'classpath'. Classpath is the path where java compiler looks for .class files because some of your .java files want them by having import statement. There won't be error message "You must install the Javassist library " any more
Create targets for compiling util simple and so on See the following link with code
Code with targets
You can modify exists targets not to write all the code.
at the top of build.xml file change default="simple"
open cmd, then cd c:\eckel\net , then ant -simple or just ant (simple will run as default)
Please write if you will have some problems. Possibly i forgot mention about something.
Go to Intellij Idea, press Ctrl+Alt+Shift+S
Press +,
Library or directories
choose your c:\eckel\net\bin
5.now you can use import statement for all classes that exist in net.mindview
6.you can make the same with other dirs.
If you wish to you skip the entire Ant build process, I have converted the project to a Maven project (over JDK8), which you can simply import into your Eclipse workspace.
https://github.com/gauravojha/tij4-maven
Thanks to #Sergey Oliv's example. In addition, I needed to provide uncompiled javaassist package with all java files in the 'net' folder too. The .jar wouldn't work by itself.
I must say, this was a lot of work to get going.
In eclipse I have an error related to my build path.
The error:
Project 'XX' is missing required library: 'middlegen-2.1.jar'
But the library is deleted before the build path configuration.
Is there perhaps a problem with cache or so?
Has anyone an idea why eclipse say that the library is required even though the library was deleted before the build path configuration.
With Best
I guess you've deleted the library from a directory, but you've not updated the project Build Path. Right click on the project name, select "Properties", go to "Java Build Path", choose the "Libraries" tab, and see that your library is not in the list. If it's still in that list, remove it with the "Remove" button.
This error is due to probably either missing required library or due to caching of eclipse
Solution 1
Open project explorer window.
Right click on the project and goto Buildpath -> ConfigureBuildPath
Under the libraries tab check whether all the used jar files are physically located in the directory/web application library.If something is showing "RED X" mark then fix them by either putting the jar in the place or remove it or add it newly using add JARs
Solution 2
1.Try cleaning the project's using Menu->Project->clean (select the projects and clean it)
Solution 3
If your build path is very clear i.e no Red "x" marks then the error could be of eclipse caching.Then do below step
1.Right click on the project choose "close project".
2.Once the project is closed again right click on the project select open project
This solution will clear the eclipse cache.
Hope any of the solution should resolve your problem.
I had this same problem, but the steps above didn't help. I did a search through files in the Eclipse workspace and found files named .markers and .markers.snap that contained the bad path names under the folders in .projects that were named for the projects that weren't building. I exited Eclipse, backed up those files, removed them from the Eclipse workspace, and restarted Eclipse. The problem went away.
Your project configuration includes a reference to middlegen-2.1.jar on the build path. That file is missing. You can either a) put the file there, b) change the configuration to point to the file in another location, or c) remove the reference, cross your fingers, and hope the project compiles and runs without the jar.
I don't know what "the library was deleted soon" means, so if that is important to your question, you might want to rephrase.
This problem has been frustrating me for some time...
A lot of sites like Sourceforge use SVN or Subversion to manage their code. I have little problem compiling SVN code in C++, but when it comes to Java, my IDE gives me a headache.
I've installed Subclipse for SVN support for Eclipse, and it works. I can check out any code into my Workspace. Now Subclipse will put the whole thing into a special project of some sort that can't be compiled. So I search Google for something and I come up with modifying the eclipse XML file to specify the 'nature' to be a Java project.
Okay, now it's a Java project. Say I have a folder structure like:
\src
\data
\graphics
I get 800 compiler errors complaining the package name is org.company.SomePackage instead of src.org.company.SomePackage.
Then what I do is create packages called src, data, graphics, etc, instead of just folders. I cut and paste everything in the folders into the packages and finally I can compile it.
What is a better way to do this?
EDIT: I can only check out anything SVN as a SVN project, and there's no way within Eclipse to change that to a Java project. How can I check out the SVN as a java project in the first place?
I get 800 compiler errors complaining
the package name is
org.company.SomePackage instead of
src.org.company.SomePackage.
Right click on Project -> Properties -> Java Build Path -> Source Tab -> Add "src" as a source folder and remove any others.
it thinks your source is stored in root folder. you need to specify to the project that /src is the source folder.
In general when we have an Eclipse project, which contains Java code – but we didn’t set it up as a Java project when we created or checked out this project, we are struck. And Eclipse doesn’t allow to change the project type inside the Gui. So we need to add the java nature as below.
1. Close your project.
2. Open your project file (which is located in your root directory of the appropriate project) called .project with your default editor. Search for
< natures>
< /natures>
and change it to as below
< natures>
<nature>org.eclipse.jdt.core.javanature</nature>
< /natures>
Save the changed file.
3. Open the project again – now it should become a java project.
Then do the following as explained by Kevin
On the Project Explorer Window ->Right click on the specific Project -> Properties -> Java Build Path -> Source Tab -> Add "src" as a source folder and remove any others.
For me when I went into “Source Tab” – the “src” folder was already added, but it was not giving me the desired result (ie I was still not seeing the .java files in the project explorer window). So I removed the “src” filed that was already added in the Source Tab and then added them again. And then all worked fine.
You have to configure proper source paths. Some open source projects make this automatic by checking their .project and .classpath files in with the rest of their files. For others, you'll have exactly the problem you are having. You need to set the classpath so the Java compiler knows where to find the source. You right click on the project and select properties and configure an arbitrary classpath, but the answer given by Kevin is easier for a beginner.