Eclipse says there's an error, but where? - eclipse

If I do Project -> Clean and then Build, everything is fine, but if I try to run this Android-project, a dialog comes up: "Your project contains errors. Fix them before running application", and there's a red cross on the project name.
There's no cross on any item in the project tree, and nothing in Console view or LogCat view. So, where's the error?
The only difference for this project and an earlier working version was that I removed a link to an external .jar file, created folder "lib" and put the .jar in there, and added that .jar to the build path. The .jar is the exact same as the external referenced.

You may need to Refresh your project in order to see the errors. Also, bring up the Problems tab for more specific information (Window > Show View > Other > General > Problems).

Eclipse shows the Errors in the Problems View.

It's difficult to guess but I would check the build path (right click the project and see), if some entry is missing there then there can be this error sign. Another reason of this red error sign is, if this project includes some other java project in path which has any errors (compilation or build path), then it will also display errors.

I had this error when I deleted a library, but did not remove it from the build path. Go to Properties - Java Build Path - Libraries. And see if you see something like "can't find library" and remove it.

Related

Eclipse does not show source code of maven dependencies in debug view

I've filed a bug by now: 495662 - Source Lookup: Not seeing source code in the debug view.
My issue sounds familiar but it can't be since that issue appears to be fixed. However,
I have set a breakpoint in a class coming from a dependency (via maven). The source code got downloaded but as the program reaches the line all I get to see is
Source not found.
I've tried to add lookup paths by clicking at "Edit Source Lookup Path..." but nothing changed. I don't know what I have to add such that the debugger finds the sources.
It appears that this stopped working for all my dependencies.
How did I break my source lookups and how can I fix it?
Could be important:
I am running my tomcat from a maven build these goals:
tomcat7:run-war -am -pl mz-web-server -Denv=dev
but this hasn't been a problem so far.
Further, none of my maven dependencies e.g. gwt-user*.jar or `spring*.jar or anything are listed in the Source Lookup Path. There is only the "Default" path which doesn't contain it either - shouldn't those jars be somewhat listed there?
After downloading Eclipse Mars 2, removing my project completely and re-importing it without any .settings, .project or .classpath files, I am still seeing this problem. I can't tell if this is really an Eclipse bug but at this point I don't know what else it could be.
I also tried removing C:\Users\<username>\.eclipse and restarted the IDE without different results.
These are the included libraries under Maven Dependencies. As you can see e.g. spring-security-core-*.jar is included and the source is pointing to the local maven repository. Clicking on edit I see the full path C:/Users/Stefan/.m2/repository/org/springframework/security/spring-security-core/4.0.3.RELEASE/spring-security-core-4.0.3.RELEASE-sources.jar and yes, the file is really there.
My Classpath Variables:
I don't know what the actual problem was and why it stopped working. As you can take out of my question I actually downloaded a clean version of Eclipse, checked out the naked project and imported it with maven without results.
However, I found this com.ifedorenko.m2e.sourcelookup plugin. The link was provided in "Java Debugging: Source not found".
Go to Help > Install New Software .. and use
http://ifedorenko.github.com/m2e-extras/
to search for the links. After installing this plugin I was finally able to debug the source code of dependencies.
Tested for Eclipse Neon:
Press 'Edit Source lookup ...', press Add button for 'Java Classpath Variable' in dialog and choose M2_REPO variable and press 'Extend...'.
Then choose source jar file for wanted dependency from file system tree.
After that press 'OK' on all dialogs and relaunch debug process.

.class file opens instead of .java while debugging

Current setup:
MainProject which is a Library Project
BranchProject which is a new projects and has MainProject as a Reference
Whenever I debug and a file from MainProject is on focus (actually BranchProject has only graphic and xml layout changes) the Debug window opens a .class file which is read only. I want it to open the .java file so I can edit it directly.
Skyler's answer from this post worked for me:
Opening source code from debug view edits .class after Android R18 update
Here is a summary:
The fix is to right click the Project name in the debug view, and select "Edit Source Lookup..." from the menu. From there, remove the Default lookup path. After that, manually add the associated projects (not jars) that your project references. This is done by clicking Add, selecting Java Project, then checking the appropriate projects.
When you're using a Library project one of the things you're in fact doing is compiling your Library project into a jar and then referencing that jar in your calling Project.
If you right click the Project, and select "Configure Build Path" you'll see a tab called "Libraries", if you look inside "Android Dependencies" you'll notice a list of jar's corresponding to your Library projects.
These jars are expandable, showing you that they have a slot for a source attachment. Usually this would be editable allowing you to directly link the source but in terms of ADT these are already filled and are uneditable.
When debugging these files you're linked to a read-only class file with this attached source. This is because you're not running against source files directly, you're running against a pre-compiled class file. Until the ADT team get this functionality in place, you're pretty much forced to jump to the direct source code and rebuild everything.
EDIT
See #Steven linked answer :)
I faced the same issue while debugging the a .java file using Eclipse IDE. As per my understanding this issue comes when we put the xyz.class file of xyz.java file or JAR at the project build path. Delete the .class or JAR file from the project class path and rerun .java file in the debug mode. This time you see a source not found window. Click on "Source not found" button and check "Find duplicates..." at the bottom of the window. Done your problem is solved :)
The problem is that the class file is preferred over the java (by default), here is how you can change that for Eclipse (tested on NEON 2):
Right-click on the Project in the Project-Explorer, click Properties
On the new window select: Run/Debug Settings
Create a new configuration (or duplicate another one)
Select the new config and click Edit...
Go to the tab Source
Select the Default and Remove
Create a new path with Add..., select Java Library, then JRE System Library
Create a new path with Add..., select the location where the sourcecode is by Workspace folder (if it is a project in the same workspace) or File System directory (it it is not)
I think this depends on, how you set up the dependency in eclipse. You should set up your BranchProject to depend on the source-Files of your MainProject. If you depend on compiles Class-Files is obvious that the debugger opens the class files, because it does not know about the source files.
I found a good solution for me here:
Using Android library in eclipse and jumping to class files instead of source file that is within eclipse workspace
Simply, select each library project your project depends on, and use Top or Up to move it above the projects outputs. Eg. move all library projects to the top.
Open main project properties -> Java Build Path -> Projects tab and add there projects the main project depend on.
Switch to Order and Export tab and uncheck Android Dependencies
Enjoy
If you tried all above hints and it still doesn't work try this solution, it worked form me:
Right-click on the Project in the Package-Explorer, click Build Path -> Configure Build Path...
Select tab Order and Export
select library that you can't reach code and then click on button Bottom
Then click on Apply and Close
hope this can help you
Most of the time it happens when specific source folder are not added in build path Sources tab.
Right-click on the Project in the Package-Explorer, click Build Path -> Configure Build Path -> Source Tab
Add the source folder if your project source folder is not there.
Select Add folder -> select your project source folder specifically. Eg: project_name/src . Then Apply it and restart server.

What does the red exclamation point icon in Eclipse mean?

What does the red exclamation point icon in Eclipse mean? There are lots of different search results on the Internet about "red exclamation point icons" and "red exclamation mark decorators" and "red bang icons," no doubt because lots of plugins and programming-related tools use red exclamation point icons. So, to be clear, this is the one I mean:
It appears as a decorator on projects in the Package Explorer view.
In my case, the icon went away when a missing build path variable was filled in. I'm using MyEclipse 9.0, but I don't think this is MyEclipse-specific. Other people on the Internet have reported that it has to do with other issues, including Subclipse, the .svn folder and moving files between working copies.
According to the documentation:
Decorates Java projects and working
sets that contain build path errors
In practice, I've found that a "build path error" may be caused by any number of reasons, depending on what plugins are active. Check the "Problems" view for more information.
It means there is a problem with the build path in your project. If it is an android project then it mostly means the target value specified in project.properties file cannot be found. This can also be caused because of other kinds of built problems. But it is shown mostly for built problems only. See here for more details. It is about built error decorater seen in eclipse.
An extract from that page:
Build path problems are sometimes easy to miss among other problems in a project. The Package Explorer and Project Explorer views now show a new decorator on Java projects and working sets that contain build path errors:
The concrete errors can be seen in the Problems view, and if you open the view menu and select Group By > Java Problem Type, they all show up in the Build Path category:
I also faced a similar problem when i tried to import Source file and JAR file from one machine to another machine. The path of the JAR was different on new machine compared to old machine. I resolved it as belows
Right click on the "Project name"
Select "Build path"
Then select "Configure Build Path"
Click on "Libraries"
Remove all the libraries which were referring to old path
Then, the exclamation symbol on the "Project name" was removed.
There can be several reasons. Most of the times it may be some of the below reasons ,
You have deleted some of the .jar files from your /lib folder
You have added new .jar files
you have added new .jar files which may be conflict with others
So what to do is we have to resolve those missing / updating / newly_added jar files.
right click on the project and go to properties
Select Java Build Path
go to the Libraries tab
Remove the jar file references which you have removed already. There will be a red mark near them so you can identify them easily.
Add the references to the newly added .jar files by using Add JARs
Refresh the project
This will solve the problem if it's because one of the above reasons.
I found another scenario in which the red exclamation mark might appear. I copied a directory from one project to another. This directory included a hidden .svn directory (the original project had been committed to version control). When I checked my new project into SVN, the copied directory still contained the old SVN information, incorrectly identifying itself as an element in its original project.
I discovered the problem by looking at the Properties for the directory, selecting SVN Info, and reviewing the Resource URL. I fixed the problem by deleting the hidden .svn directory for my copied directory and refreshing my project. The red exclamation mark disappeared, and I was able to check in the directory and its contents correctly.
What I did was peculiar but somehow it fixed the problem. Pick any project and perform a fake edit of the build.properties file (e.g., add and remove a space and then save the file). Clean and rebuild the projects in your workspace.
Hope this solve some of your problems.
Make sure you don't have any undefined classpath variables (like M2_REPO).
I had the same problem and Andrew is correct. Check your classpath variable "M2_REPO". It probably points to an invalid location of your local maven repo.
In my case I was using mvn eclipse:eclipse on the command line and this plugin was setting the M2_REPO classpath variable. Eclipse couldn't find my maven settings.xml in my home directory and as a result was incorrectly the M2_REPO classpath variable. My solution was to restart eclipse and it picked up my settings.xml and removed the red exclamation on my projects.
I got some more information from this guy:
http://www.mkyong.com/maven/how-to-configure-m2_repo-variable-in-eclipse-ide/
The solution that worked for me is the following one given by Steve Hansen Smythe. I am just pasting it here. Thanks Steve.
"I found another scenario in which the red exclamation mark might appear. I copied a directory from one project to another. This directory included a hidden .svn directory (the original project had been committed to version control). When I checked my new project into SVN, the copied directory still contained the old SVN information, incorrectly identifying itself as an element in its original project.
I discovered the problem by looking at the Properties for the directory, selecting SVN Info, and reviewing the Resource URL. I fixed the problem by deleting the hidden .svn directory for my copied directory and refreshing my project. The red exclamation mark disappeared, and I was able to check in the directory and its contents correctly."
Also be sure you dont have any closed project in the Projects tab ->
https://i.stack.imgur.com/StGEu.png
The solution that worked for me is the following one given..
I selected the particular project> right click >Build path>configure Build path> Libraries> I noticed that JRE system Library was showing(Unbound) hence..
selected that Library>click on Remove>click on Apply>click on add Library>JRE system Library>next>workspace default JRE>click on Finish>Apply>ok.
now you will not see these exclamation icon in your project.

The project cannot be built until the build path errors are resolved.

While compiling an android project in eclipse 3.4.2, I am getting The project cannot be built until the build path errors are resolved.
I got a temporary solution from the blog http://www.scottdstrader.com/blog/ether_archives/000921.html
The resolution was to force a resave of the selected projects (and their .classpath files):
Open the project properties
Select Java Build Path > Libraries
Add a new, arbitrary library (to be deleted later) > OK
Wait for the workspace to refresh (or force a refresh of the project)
The error(s) will go away
Remove the dummy library
The only other references I could find were to make minor alterations of contents of the .classpath file.
Is there any permanent fix for this issue?
Have you tried using Project > Clean... from the menu? This will force a new build on the selected projects in Eclipse.
1-Right CLick on your project folder, Choose Build Path > Configure Build Path
2-Select Libraries Tab and delete any arbitrary library present there.
3-Click on Add Library option, Select JRE System Library and click Next.
4-Choose last Radiobutton option Workspace default JRE and click Finish.
5-press f5 for refresh.
6-run ur program .
This what fixed it for me...
I was having an issue with my spring-core.jar.
I deleted the entire release directory located here. (I'm on win 10).
C:\Users********.m2\repository\org\springframework\spring-core\4.3.1.RELEASE
I right clicked on the project > Maven > Update project and my exclamation mark disappeared. No problems any more.
Here is the source where I found the information:
http://crunchify.com/cannot-be-read-or-is-not-a-valid-zip-file-how-to-fix-maven-build-path-error-with-corrupted-jar-file/
This happens when libraries added to the project doesn't have the correct path.
Right click on your project (from package explorer)
Got build path -> configure build path
Select the libraries tab
Fix the path error (give the correct path) by editing jars or classes at fault
This works for me: close the project then re-open it, this will force eclipse to reload a fresh project and detects the correct build path.
None of the other answers worked for me. Even after fixing my build path issues, doing a refresh, clean, rebuild, and restart (of both eclipse and the computer), I was still getting the little red exclamation point.
I fixed it by closing the project (right-click, close project) and reopening it (double-click the closed project), which seemed to force eclipse to "notice" that the build path problems had been corrected.
For my mac osx Eclipse, I followed following steps:
Right CLick on your project, Choose Build Path > Configure Build Path
Select Libraries Tab and delete any arbitrary library or anything else causing errors in Build Path.
Click on Add Library button, Select JRE System Library and click Next.
Choose last Radiobutton option Workspace default JRE and click Finish.
Clean and build your project.
get a cmd and run
mvn eclipse:eclipse
This is what worked for me:
Go to ~/.m2/repository and deleted everything there by running rm
-rf. Make sure everything is deleted.
Re-launch eclipse or STS
Right click on project -> Maven -> update project.
On my Mac this is what worked for me
Project > Clean (errors and warnings will remain or increase after this)
Close Eclipse
Reopen Eclipse (errors show momentarily and then disappear, warnings remain)
You are good to go and can now run your project
I've seen this problem a few times (got it again right now on my home computer with Eclipse 4.2).
Forcing a resave (by changing the classpath e.g. by adding a library, save, change-back) works temporarily. But the problem comes back when Eclipse is restarted :(
Nuking the Eclipse workspace from orbit will permanently fix it (until next time). But there must be a better way!
just check if any unnecessary Jars are added in your library or not. if yes, then simply remove that jars from your library and clean your project once. Its worked for me.
In Eclipse this worked for me: right click project. -> Properties -> Library Section; Add (any library at all) -> select library and click remove -> press okay.
I ran into this annoying issue with the Play framework. It would be nice if there was some way of knowing what build errors Eclipse is unhappy about, but it's not going to tell you. With one project, I was able to close the project, rebuild the Eclipse configuration with sbt eclipse, and reopen. With an almost identical project, that didn't work. But deleting the project, rebuilding the Eclipse configuration with sbt eclipse, and importing, did the trick.
If you think you've done everything correctly but Eclipse still complains about the jars, refresh the folder where the jars are and make sure eclipse knows they've been added to the project. Specifying the file path alone is (apparently) not enough
I've faced this issue a couple of times and following the below steps has resolved both the times.
1. Navigate to C:\Users\
2. locate the ".m2" folder and delete it.
Now navigate to the particular project in eclipse and Right-click on the project > Maven > Update Project
wait until the project is updated and in my case following the above steps resolved both the times.
I was getting an additional warning
The compiler compliance specified is 1.6 but a JRE 1.8 is used
Resolving this warning make the error also go away. The steps are as follows:
I right-clicked on it, then clicked on Quick Fix. From the dialog that opened I selected Open the Compiler Compliance property page, and clicked the Finish button.
(This is same as Java Compiler section.)
In this dialog I found the Compiler compliance level drop down and changed 1.6 to 1.8, and clicked on Apply and close.
I got a message box Compiler Settings Changed which asked if I wanted to Build the project now?. I clicked on Yes.
The build path error went away.
Go to > Right CLick on your project folder > Build Path > Configure Build Path > Libraries Tab > remove project and external dependencies > apply & close
Now, Gradle refresh your project.
Added below to pom.xml file and it worked eventually:
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.0</version>
<scope>provided</scope>
</dependency>
Goto to Project=>Build Automatically . Make sure it is ticked

Red exclamation mark in Eclipse with mercurial

I have imported a project with Mercurial (hg clone ...).
When opening it with Eclipse, a red exclamation mark appears by the project's name in the Project Explorer, and it cannot be built. Silly messages like "import java.util cannot be resolved" appear, and errors in files are not marked in the Package Explorer.
How can I resolve this?
Check the problem view. By exclamation it is usually means a problem with build path
Check the Build Path of the project by right clicking the project and select Build Path -> Configure Build Path.
One problem I often encountered is different people using different Java SDK and so when the exact SDK is not available in your machine, you need to change to your Java SDK (via JRE System Library -> Alternate JRE). A better way to avoid this problem is to always select the JRE System Library from Workspace default JRE or Execution Environment.
I solved the problem by adding the external .jar file in to my project.
RightClick on the project -> Properties -> Java Build path -> libraries tab -> Add jar
Select your jar file and added it
Thats it the red ! mark gone.
Some times it happens that you have added a jar file earlier but currently not using it. Then after some time you delete the jar file from your system. But since you are not using the library file, so you will not get any error.But then you will see the red exclamation mark for the project. So all you need is to remove the added jar from the Build Path.
Done.....
The Java Runtime Library was defined wrong for the pulled project.
It had to be reset under Project | Properties | Java Build Path | Libraries.
It means there is a problem with the build path in your project. If it is an android project then it mostly means the target value specified in project.properties file cannot be found. This can also be caused because of other kinds of built problems. But it is shown mostly for built problems only. See here for more details. It is about built error decorater seen in eclipse.
An extract from that page:
Build path problems are sometimes easy to miss among other problems in a project. The Package Explorer and Project Explorer views now show a new decorator on Java projects and working sets that contain build path errors:
The concrete errors can be seen in the Problems view, and if you open the view menu and select Group By > Java Problem Type, they all show up in the Build Path category:
I figured out each time i am trying to import a library into my android project, i have a red exclamation mark with both ActionBarSherlock and Facebook libraries
This is how i solved it:
After adding the library into your project "project properties->Android->Librairy->add"
If you are using Eclipse, all you have to do is to clean your project and build all your workspace:
"project -> clean... -> "clean selected project" -> build the entire workspace
For me, the problem was a simple one - the reference project was compiled in 1.5 and my project 1.6. Matching the two solved the issue.
Right-hand-click on the project, select properties, select java compiler.
This is how I solved this problem:- Right-Click to project->properties->Java Build Path->Libraries(tab)->Remove the Jar which is already present there with a Path given along.