I've been tasked with picking up someone elses Java code and adding some functionality to it.
I'ved pull down the source tree from CVS and see a bunch of .jar files in different folders. I'm guessing the developer did not use Eclipse.
I am new to Java (coming from .NET background) and have used Eclipse so far to create one Java project. I'm wondering now that I have this guys files (he has classpath.jar and other .jar files along with some subfolders each with 'java' files in them), how do I open them? I tried opening one at a time, etc.. but doesn't seem to work. IS tehre an easy way to do this? I thought there' might be some kind of 'import existing code' thing in Eclipse but I can find it. How can I do this? Do I re-create the folder structure and just add the existing files one a time?
Thanks much for any help
something like 'create project from existing source'?
http://www.stanford.edu/class/cs108/JavaTools/eclipse-guide/
if the existing code is not structured well, you are either going to have to heavily configure your project sources, or just change the project structure.
File -> new
Than select general->folder.
To make developing easier in eclipse i recommend some refactoring to the project.
create a new eclipse project using the parent folder as the home.
every folder that's the root of a hierarchy of java classes becomes a folder in the "source" tab (either on creation, or add through "project->properties").
every jar (at least the ones he's using, there may be extras) gets added in the project->properties libraries tab.
This is assuming that all of the hierarchies belong together and that the thing isn't structured to build little sub-projects out of pieces of the hierarchy. If there's a build file for this thing you might want to be sure that if the build file is doing that you're building things appropriately.
File->Import->General->Existing Projects into Workspace
OR
File->New->Java Project
This will create a sample java project for you. You can add the files appropriately.
Below is an example of a j2ee Project:
http://java.sun.com/blueprints/code/projectconventions.html
If C:\Workspace is the folder you are using as the workspace and you have your existing project placed as "C:\Workspace\ExistingProject"
Open Eclipse Got to File->New Project
Select the type of Project you want to create Use the name as "ExistingProject" for the project and click Finish or complete the remaining steps of project creation wizard normally.
Internally a .project file would be created in the ExistingProject folder and a .metadata folder would be generated under Workspace folder.
If you want to place the ExistingProject not under the workspace u follow the same steps.
There's 2 possibilities:
Import project from file system:
Create a blank Eclipse Project.
Then select File -> Import -> General -> File System. Select project, and point it to your created project.
Importing from CVS
Goto File -> Import -> CVS -> Project from CVS
Enter your CVS Host, Repository Path, Username and Password, and click next,....
Add what you need and click next (follow the instructions) until you're satisfied and click finish.
Hope this helps.
A simple tutorial that incorporates my 1st option and commmits it to CVS: http://thedesignspace.net/MT2archives/000662.html
Two options:
Maven - highly recommended but rather read this: http://maven.apache.org/guides/getting-started/maven-in-five-minutes.html than have me re-write it here. Maven might seem like more effort up front but it pays for itself a hundred times over during the course of even a simple project.
Do it yourself (assuming Helios):
Move the source code Java files to ~/development/MyProject/src/java. Move the jars to ~/development/MyProject/resources.
In Eclipse, File > New > Java Project. Type in your project name.
Untick "Use default location" and browse to ~/development/MyProject.
Select src/java as your source folder (if Eclipse doesn't pick it up automatically).
Finish.
Then, for each error, you will need to find the corresponding JAR and add it as a library to your classpath in the project properties.
The important thing to bear in mind is that Eclipse is not like Visual Studio - you cannot easily just edit one file at a time and that is not what it is designed for. People can get frustrated with Eclipse after working with VS but if you just allow it to do things the way it wants you, your life will be much easier.
trick is finding the root folder. Generally, developers use the following:
project root
-- src
-- bin
at least, what's what Eclipse does by default. There are other ways it can be organized as Maven uses the following:
project root
-- src
-- -- main
-- -- -- java
etc...
More info on how Maven standardizes here:
That said, finding out how the source is organized shouldn't be too hard. Open up one of the .java files and look for the line at the top that starts with "package ". Should be something like this:
package com.somecompany.client.utils
Note, that's just an example, it won't be that exactly although it should start with "package". The value after package represents the path that the file should be in relative to the root of the source folder.
source
folder/com/somecompany/client/utils
So, if you follow the default way that Eclipse organizes things, it should look look like this:
project root
-- src
-- -- com
-- -- -- somecompany
-- -- -- -- client
... etc
SO, as other people have mentioned, you'll import from existing filesystem, point to the folder at the project root. You may need to configure it to point to "src" folder as a source folder. You may also need to import those .jar files into your project as well.
Good luck
Related
Situation::
Trying to search and open up a Java file. In a nest project.
And so, we have the file here, these 2 files the exactly same file,
but, when the project is nested inside, Eclipse search opens up the file that has no syntax highlight or source code link (ie: unable to ctrl click on the code).
(ie: Eclipse opens up the Java file as if the Java file is not on a build path)
(though, if I search directly on that nested project, instead of on the parent project, then things are fine)
I have to manually open up the file in the Project Explorer, to get the file with syntax highlight or source code link.
Ask::
How can I let Eclipse directly open up the Java file with syntax highlight (when I search on the parent project)
(so that I dont need to manually search & click all the way through)?
You seems to be using Maven and you probably imported your project in Eclipse as Maven project.
The problem with Maven and Eclipse is that usually Maven project are split as project aggregator (a pom.xml with only <module>) which m2e will import: such aggregator project use a directory hierarchy.
Eclipse, on the other hand, does not scan files as file system file, but as project related file: that's the main reason for your duplicate. The child project being contained in its parent, the same file is shown twice because for Eclipse, these are two distinct path.
And since for the parent project, the file is simply a regular file it does not offer anything beside syntax highlighting.
You can:
close each aggregator project one by one; for Eclipse, there are no really useful anyway.
don't import them (and I wish m2e-core would suggest it).
You could also create a bug or vote for this one which seems related: https://bugs.eclipse.org/bugs/show_bug.cgi?id=533440
Note that this also affect other screen such as Show Resources (which is the subject of bug 533440).
The workaround I am using::
workaround 01
Find the files in the nest projects as I did before, then get the class name, then ctrl shift t to search that class again.
Cons:
You have to manually copy and search the class name.
There are possible other classes with same name (and you have to tell which one you want to go to).
You will not be able to jump to the desire line.
workaround 02
Just search in the whole workspace. And directly open in the file in the child-project (ignore the results from parent-project).
Cons:
Time consuming when search the whole workspace (though, you can terminate it when you get the desire files, hopefully no missing results when you do that).
There are a lot duplicate / unnecessary results.
You may not want to search the whole workspace.
Now that I've learned a bit more, I can ask a more direct question.
Scenario:
I have a Java project in IntelliJ Idea, with the end goal of making a standalone .jar capable of running on Windows or Linux, either run from the command line with java -jar jarname.jar or simply by being double-clicked like any normal, simple jar.
I've written a handful of classes, located in my src/package/name directory. However, one of my classes requires the use of an external class, i.e. a class not located in my source directory or is not part of Java's default set of .jar's in the JDK.
How do I go about configuring IntelliJ to build the .jar artifact AND include the necessary resources inside of it, with everything needed put in the proper place, so that my class can use the resource by an ordinary import statement? An answer given in example form would be awesome; I've almost figured it out, but there must be just one thing I'm not doing correctly.
Thanks for your time,
Yankee
Sources:
http://tukaani.org/xz/java.html
Viewing the directory structure of that source gives a better idea:
http://git.tukaani.org/?p=xz-java.git;a=tree
One does not simply package Mordor into their jar.
After much experimentation, I found a solution that, while maybe not the right way to do it, definitely works. The key is to:
Define your external library (a .jar in my case) as a module dependency.
Add your external resources as (what IntelliJ calls) an "Extracted Directory."
For the first item, go to File -> Project Structure. Click "Modules" in the Project Settings list on the left. In the list just to the right, you will see a list of modules (whatever they are) which belong to your project. Leave that alone, but make sure that it is highlighted/selected as the current module. What you want is the settings for that module, which will show in the window on the right. Go to the "Dependencies" tab. On the rightmost part of the screen will be a little green plus sign. Click that, choose "Jars or directories" and navigate to your relevant resource you want to bring along with your finished jar.
Note: don't be fooled by the check box that says "Export." Its only purpose is to cause endless pain and suffering as you wonder why the dependency isn't exported along with your jar. Always remember, the export box is trying to get you to click on it. It wants to be ticked :3
Next, add that resource as an extracted directory by going to File -> Project Structure. Then "Artifacts" in the Project Settings list on the left. Click the green plus sign at the top to make a new "Jar" artifact "From modules with dependencies." In the right hand window, under the "Output Layout" tab, click the little green plus sign and choose "Extracted Directory." Once again, browse to your precious jar.
You should now be able to successfully build a jar artifact that contains all the resources it needs to run as you designed it.
Here is a reference section on configuring external libraries as module dependencies - link. Regarding artifacts construction - it's possible to precisely specify its content (including dependency libraries content) - link.
Read How classes are found...
It is OK (expected that you) to ship your program in your own jar, and dependent 'libraries' as separate jars
You are expected to provide a way to run your program with the correct -classpath argument to the java command so that java can find both your jar, and the dependent jars... there are multiple ways to do that... see the link above.
Rolf
I usually have multiple copies of a project, for example: a copy of the trunk and another of the last release branch. To cleanly separate my project files from Eclipse, they are checked out from Subversion in a directory outside the Eclipse workspace.
I want to make the project easily importable to Eclipse and followed instructions from multiple answers.
The problem is that my .launch files have the project name hardcoded. When a new project is imported, the launch files will display in the Run Configurations menu just if the project has exactly the same name of the exported one. This forbids me to have two versions of the same project.
It looks like the only way to do it is to have the .launch and .project files generated from an Ant task, but I don't see anyone using this solution. Maybe I should have multiple workspaces and the project always with the same name.
What's the best way to do it?
Edit: I'm marking VonC as the answer, but don't miss the comments.
Remember that the .launch configuration files don't have to be in your workspace.
They can be in your <project>/.settings as I mentioned in the answer you refer to.
That means you cannot import in your eclipse workspace two versions of the same project.
You need separate workspaces (not versioned themselves), each one referring to a project in a different path.
Each path represents different working trees (like different working directories for Subversion).
The OP adds:
The project must have the same name, but the project checkout dir can have any name.
To make the launch file work, you have to reference any file using the variable ${workspace_loc:ProjectName}.
Java files can be referenced using a path like: '/ProjectName/src/package/MyFile.java'
This way, it is easier to use any tool to interact with the subversion repository.
I want to make life easier for who uses Eclipse, but I don't want to force anyone to use it.
My recommendation is to tie the workspace to the checkout location, and then you can use the launch configurations for the relevant projects in Subversion.
My directory structure looks like this:
{checkout root}
|
+code
|
-workspace
In your case, that would mean a workspace for the trunk, and any other branch/tag you check out. I also keep all my projects outside the workspace. The workspace directory in Subversion is empty; I just recursively add the project reference(s) to the workspace from the sibling tree. It also helps if you export your Eclipse settings, as you can then re-import them into each new workspace.
I derived this approach from a pair of IBM and Rational white papers for using Eclipse with Rational ClearCase. This should work unless you need to have multiple versions of the same project open in the same workspace.
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.
I have several somewhat separate programs, that conceptually can fit into a single project. However, I'm having trouble telling Eclipse to make several folders inside a project folder.
A simple form of the structure would be:
/UberProject
/UberProject/ProgramA/
/UberProject/ProgramA/com/pkg/NiftyReader.java
/UberProject/ProgramB/
/UberProject/ProgramB/com/pkg/NiftyWriter.java
That is, ProgramA and ProgramB are both projects (in fact, they're currently existing Java projects), which conceptually fit into UberProject.
I don't think I'm supposed to make UberProject be a Java project; it's not a classpath, for instance. ProgramA and ProgramB do seem like they should be Java projects (they might use different build dependencies as well), but I see no way in Eclipse 3.3 to create two folders under UberProject that are intended to contain Java code. I thought about adding a .project file to each of the two sub-projects, but I'm not sure that's appropriate, either. Eclipse help isn't being helpful, and I didn't see anything on SO about this specific problem.
Just to be clear: assume as given the necessity of the existence of UberProject. UberProject can be a Java project, or not; it doesn't matter. (Incidentally, it does contain other folders that do not contain Java code.)
There are probably several ways to do this:
1) UberProject is your JavaProject. Right click ProgramA -> Build Path -> Use as source folder. Right click ProgramB -> Build Path -> Use as source folder. Both ProgramA and ProgramB will do incremental builds to the same directory.
2) Two java projects (ProgramA and ProgramB). You can use UberProject as your eclipse workspace which would be easiest or you can use an outside workspace and import ProgramA and ProgramB as external projects.
There are probably other ways as well (maven multi-module project). Your choice probably depends on whether you have cyclic dependencies between projects. It should be relatively easy to try both 1 and 2 and see what works best for you.
You can have multiple source directories in a single project, but your description makes it sound like you want multiple sub-projects in a project, which eclipse doesn't allow (as far as I know).
If you really just want multiple source directories, where ProgramA, ProgramB, etc. contain only java files and nothing else, then you can do this relatively easy. Right-click on your project in the package explorer, and select Build Path -> Configure Build Path.... In the dialog that pops up, make sure Java Build Path is selected in the left pane, click the Source tab, then click the Add Folder... button. Pick ProgramA from the list, and repeat for ProgramB, etc.
If you want each source folder to have its own output folder, just check the Allow output folders for source folders checkbox and edit the output folders as desired.
If that is not, in fact, what you want to do, then another option might be to group your projects into a working set. A working set is not an UberProject, but it does help keep your projects organized in the package explorer.
Do you need UberProject? I have the same layout but have multiple top-level projects created with File|New project. If not, can you make it a General rather than Java project?
So you can do it via having two Java projects in your workspace.
Then the question is how to group the two projects together under "UberProject"
One way is to have an "UberProject" workspace, and switch workspaces between UberProjects.
An alternative is to define "UberProject" as a working set (Window:Working Sets) and add PrmgramA and ProgramB as projects of that working set. Select that working set, and you see only those projects.
You can have one java project, and define multiple source folders for it. That is normally do that for "main" vs "test" hierarchies within the same project.
There are ways, and ways. Pick one that works for you :-)