So I am working on a java project that requires me to analyze the Dijkstra and Bellman Ford algorithms by running time.
Now I am trying to write my collected data to an xls or xlsx file. I have found the Apache POI: http://poi.apache.org/download.html#POI-3.10-beta2 which will help me do that.
My only issue is that I'm having trouble adding the source to my existing project to use. Apache POI comes as a src folder. Dragging and dropping the folder into eclipse adds the files but the packages aren't right.
For example, in one of the java files the package is declared as:
package org.apache.poi.hpsf.examples;
But when dragged into eclipse the package becomes examples.src.org.apache.poi.hpsf.examples... This causes eclipse to throw the "The declared package "org.apache.poi.hpsf.examples" does not match the expected package "examples.src.org.apache.poi.hpsf.examples"
Now I could simply move this package to the right folder but there are dozens of packages with this same problem?
How would I properly add these files to eclipse so I could use them?
I would write to CSV then import the CSV to Excel, unless there's a compelling reason specifically for using Excel. The benefits of this are:
No need for extra libraries.
You can open the file in other things (emacs, load into R to draw graphs).
If you really just want to use POI, the thing to do is download the JAR file, go to Options > Properties > Build Path > Libraries > Add JARs and then select the jar. (You should see a dialog like this.)
Right click on the project name -> Properties -> Java Build Path and on the the source tab, select the examples/src dir.
BUT, if I correctly understood the problem, you want to use the POI library, so in that case get a jar version of it, and then right click on the project name -> Properties -> Java Build Path and on the the libraries tab, select the location of the jar file.
This way, you can write your own java classes and import the POI library into your project.
Try the File menu, then select Import, then expand General, then "Existing Projects into Workspace". You will have the option of whether or not to create a new copy of the whole directory in your workspace directory as well.
Related
I have no experience with package structure. I added two external libraries (from Joda) to my eclipse project. The code makes use of the libraries with no problems. However, when I export the Archived File and open it on another computer, the libraries are no where to be found. Much sadness.The error looks like a little red exclamation point next to my project in the package explorer. Checkboxes next to the libraries have been checked/applied.
Right click on your project
Navigate to build paths -> configure build path
In order and export tab check whether the library is in the list or not
If it is not selected, tick the Checkbox and click apply
Someone told me that I need to export it as a executable jar.
Recently I worked on a project on a mac, using eclipse. When I was done with the project I copied certain .java files and their corresponding .class files onto a USB drive and brought it to my personal computer. When I try to use the import feature on eclipse and import everything, my main method is not recognized by eclipse. It will work if I create a new eclipse "class" by the name I have in the program and copy paste the code. I have many classes so I can not do this for each one. Is there any way for me to change all .java/.class files into files that will be read by the system?
Thanks
An eclipse project contains a lot of meta information. Just open the project directory in a file browser, and have a closer look. There are files like .classpath for example.
When you just copy your source code, you leave all the meta information behind!
You should either copy the complete project directory, or simply use the export task to create a ZIP file of your project. (to later import that in other systems).
There is one other way you can do this. Just create a new project with the SAME EXACT PROJECT NAME that you did at school or wherever. After you create your project, go to your file explorer and navigate to the following place:
<"Directory to work-space">/<"Project Name">/src/
For ex: in Windows, it is Generally:
C:/Users/your_name/workspace/projectName/src
In here, copy all your ".java" files.
Now go to eclipse, right click on your project and hit refresh. You will find all your .java files there. Right-click on your project and hit "Run"->"Run as a Java Project". It should run! hope this helps.
PS: You do not need your class if you are executing it in Eclipse. Eclipse will create its own class files.
I'm new to Java Programming using Eclipse, so would really appreciate your help for this question.
I have doing Java programming both at college and home. At home, I have all my Java classes under a single project-(Java Reference). Now, in college, the java programs are compiled on the lab machines. And I would really like to have all these programs in a single project, on my laptop.
I had recently copied all the .class and .java files from the programs we did in college labs, so I could have them under the "Java Reference" project in my laptop. I copied the .class and .java files under the "bin" and "src" folders of the java project, on my laptop. However, I don't see anyway to import them through Eclipse.
From what I read here, it looks like having an entire project(created somewhere else) could be copied into one place, through the import option, but in my case, I only have the .class and .java files.
First, you don't need the .class files if they are compiled from your .java classes.
To import your files, you need to create an empty Java project. They you either import them one by one (New -> File -> Advanced -> Link file) or directly copy them into their corresponding folder/package and refresh the project.
You can import a bunch of .java files to your existing project without creating a new project. Here are the steps:
Right-click on the Default Package in the Project Manager pane
underneath your project and choose Import
An Import Wizard window will display. Choose File system and select the Next button
You are now prompted to choose a file
Simply browse your folder with .java files in it
Select desired .java files
Click on Finish to finish the import wizard
Check the following webpage for more information:
http://people.cs.uchicago.edu/~kaharris/10200/tutorials/eclipse/Step_04.html
create a new java project in Eclipse and copy .java files to its src directory, if you don't know where those source files should be placed, right click on the root of the project and choose new->class to create a test class and see where its .java file is placed, then put other files with it, in the same directory, you may have to adjust the package in those source files according to the new project directory structure.
if you use external libraries in your code, you have two options: either copy / download jar files or use maven if you use maven you'll have to create the project at maven project in the first place, creating java projects as maven projects are the way to go anyway but that's for another post...
I had the same problem. But What I did is I imported the .java files and then I went to Search->File-> and then changed the package name to whatever package it should belong in this way I fixed a lot of java files which otherwise would require to go to every file and change them manually.
import class folder does not work for me, but add jar worked!
1. put the class folder under the project folder
2. Zip the class folder
3. Highlight project name, click "Project" in the top toolbar, click "Properties", click "Libraries" tab, click "Add External jars".
4. Add the zip file. Done!
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'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