Eclipse error - Can't find Maven installation - eclipse

I have been using maven in eclipse (with m2e) just fine, until recently when I renamed one of the folders on my hard drive where maven is installed.
The folder was renamed from Computer local to ComputerLocal
After renaming the folder I received the following error in eclipse when I attempted to do a maven build:
Can't find Maven installation C:\Computer local\apache-maven-3.0.4
Which of course makes perfect sense.
The problem is that when I re-named the folder on the installation directory path back to it's original name I kept receiving the same error as before:
Can't find Maven installation C:\Computer local\apache-maven-3.0.4
When I copy-past the directory path from the error into a explorer window it finds the directory just fine.
So what I'd really like to know is where can I find the configuration in eclipse where I can see path to the maven installation that is being used? Perhaps from there I can re-set it or re-configure it?

"Can't find Maven installation EMBEDDED" means it is that you are facing the issue with your eclipse version.
You just need to restart the and Check your eclipse settings
Windows-->Preferences-->Maven-->Installations
You can find the Embedded version of Maven.
This can be done by selecting your project and setting up with few goals in "Runtime Configurations" and few settings for Java and Environemnt Variables.
Right clicking on your parent POM file.
Select "Run As"-->"Maven Build"
In the Run Configurations window,
a) Enter project name, b) select your parent-project, c) provide some goals eg., clean install
Choose your External Maven from the dropdown. If you can not find your External Maven (other than embedded maven), Clicking on Configure and click on Add button and add your maven home location folder.
Setup your environmental variables with variable M2_HOME to your maven home location folder and also set PATH variable to %M2_HOME%\bin
In Eclipse, goto Window-> Preference -> Java -> Installed JREs -> Edit and pass VM Arguments as -Dmaven.multiModuleProjectDirectory=M2_HOME for windows and -Dmaven.multiModuleProjectDirectory=$M2_HOME for Linux and Mac OS X.
For versions Maven 3.x, and above, the variable can also be named as $MAVEN_HOME.
-Dmaven.multiModuleProjectDirectory=MAVEN_HOME for Windows
-Dmaven.multiModuleProjectDirectory=$MAVEN_HOME for Linux and Mac OS X
However, It is better to use M2_HOME as it supports for both Maven 2 and 3.

Related

pom.properties (The system cannot find the path specified)

I am facing below issues while executing a project in Eclipse:
Publishing failed with multiple errors
File not found: D:\Programs\j2ee\OnlineLibrary\target\m2e-wtp\web-resources\META-INF\maven\OnlineLibrary\OnlineLibrary\pom.properties.
D:\Programs\j2ee\OnlineLibrary\target\m2e-wtp\web-resources\META-INF\maven\OnlineLibrary\OnlineLibrary\pom.properties (The system cannot find the path specified)
File not found: D:\Programs\j2ee\OnlineLibrary\target\m2e-wtp\web-resources\META-INF\maven\OnlineLibrary\OnlineLibrary\pom.xml.
D:\Programs\j2ee\OnlineLibrary\target\m2e-wtp\web-resources\META-INF\maven\OnlineLibrary\OnlineLibrary\pom.xml (The system cannot find the path specified)
System Configuration:
OS: Windows 8.1 (64-bit)
Tomcat: 8.0.30 (64-bit)
Java: jdk 1.8.0_45 (64-bit)
Maven version: 3.3.9 on C:/
Eclipse: Luna 4.4.2
Steps followed:
Configure maven in eclipse
Updated the settings.xml file with custom repositories path placed on C:\apache-maven-3.3.9\conf
In Eclipse:
Click Project-->Preferences-->Maven. Selected the artifacts download options
Click Maven-->Installations. Added the maven installation (C:\apache-maven-3.3.9) and set it as default
Click Maven-->Templates. Below mention Templates are in "Off" mode
"m2e profile","m2e-wtp activation,"m2e-wtp JAX-RS activation","m2e-wtp JPA activation","m2e-wtp JSF activation",
"m2e-wtp's specific context root property".
Click Maven-->User Settings. Global Setting, Local Settings points to C:\apache-maven-3.3.9\conf\settings.xml
Local Repository points to custom repositories path as below:
D:\Programs\Maven\Maven_Repositories
Created a new dynamic web project (project name: OnlineLibrary). Renamed the src folder as per Maven project structure.
Right clicked on project -->Configure-->Convert to Maven Project. Right click on the project-->Maven. Selected Resolve
dependency from workspace projects.
Added required dependencies to the project.
Project Build successful as per Maven clean, build, install process.
But when I try to execute/Run the project on server error is displayed:
This does not explain the problem but i resolved same problem with Maven->Update Project(s)
Go to "Servers" tab and start server first. Make sure this is same server which your project is using. If server is not already added then add new server.
Now run you project, it will ask for server to "Continue" to "Restart Server". Choose "Continue" and it should run fine. It worked for me.

Maven multimodule projects linking in eclipse

I have a maven multi module project which has 5 modules. Some of my modules depend on one or more other modules, I am successfully able build the project and in eclipse also I am not getting any errors. However there is one problem which is bothering me, when i ctrl + click in my code and the class is defined on some other project eclipse does not open the file in the editor. I know i can attach the source code using maven but still i wont be able to make changes to that file.
Is there any way to be able to link projects in eclipse through maven?
Is there any way to be able to link projects in eclipse through maven?
That behaviour is the default. To check if for some reason that default is not in effect for your project, right click your project (the project you want to jump from) and go to "Maven". If there is an option "Disable Workspace Resolution" the workspace resolution is switched on, meaning you can theoretically jump from that project.
If you still cannot jump, then the project you want to jump to is not in your workspace. Take into account that for eclipse to identfy one project as dependency of another, everything including version must match.
Also check what rest_day said. You must have the projects importet as maven projects, but running eclipse:eclipse is not required anymore with current (up to ca 2 year old) eclipse.
Did you import the projects as Maven projects?
Also, could you go to the root of the project and run mvn eclipse:eclipse
eclipse:eclipse
Full name:
org.apache.maven.plugins:maven-eclipse-plugin:2.10:eclipse
Description:
Generates the following eclipse configuration files:
.project and .classpath files
.setting/org.eclipse.jdt.core.prefs with project specific compiler settings various configuration files for WTP (Web Tools Project), if the parameter wtpversion is set to a valid version (WTP configuration is not generated by default)
If this goal is run on
a multiproject root, dependencies between modules will be configured
as direct project dependencies in Eclipse (unless useProjectReferences
is set to false).
Instead of Ctrl+Click, click on the identifier and press F3. If you now see a red text reading "Current text selection cannot be opened in an editor", you've been hit by this bug.
See this question for a solution: How do I get rid of "Current text selection cannot be opened in an editor" in Eclipse?

Tools jar does not exist Eclipse JAVA

The archive: C:/Java/jdk1.6.0_26-32/lib/tools.jar which is referenced by the classpath, does not exist.
This is the error I have when run Tomcat. There was no problem cleaning or publishing - only when i start the Tomcat server.
Now, I checked my folders and there is a tools.jar in file path C:\Java\jdk1.6.0_34\lib
What am i missing?
using jre6 and have jdk1.6.0_34 installed
I found this question trying to build my project using Ant in Eclipse, and I would get the same error message as above. The suggestions in #Parth's and other answers to edit the Installed JREs is the first step. What I also needed to run Ant successfully was
Right click on build.xml, select "Run As", select "Ant Build..." (note the ...)
Click on the JRE tab
Change the Runtime JRE to the same thing that you updated in the first stage, and press Apply. (That is, the runtime JRE as you specified by "Preferences" -> "Java" -> "Installed JREs", as in #Parth's answer.)
Otherwise it seems that Ant will still try to build with the old JRE that doesn't have tools.jar. Hope this helps someone.
Right click on your eclipse project, In Preferences go to Java > Installed JREs, select your JDK and click on Edit. In the new Dialog you can add external jars like tools.jar to your execution environment.
I found the solution to resolve this.
Go to Run Configurations > classpath and under User Enteries you will have tools.jar and its path would be pointing to the old folder. Remove that and click on "Add External Jars" to add the tools.jar from the new path. And that is it.
This worked for me on Eclipse:
Windows -> Preferences -> Select Java -> Select Installed JREs -> Add
-> Add your JDK -> Establish it as default -> Apply -> OK.
After this, I've to establish project related settings too:
Right click on your Project Name (in Project explorer ) -> Properties ->
Java Build Path -> Click on JRE System Libraries -> Edit ->
Select Workspace Default JRE (jdk included above)
Check your "run configurations" (Eclipse Menu Run -> Run Configurations ....) also, since therein the classpath may be wrong or has gotten obsolete.
Tomcat needs a full JDK/SDK to run but under C:/Java/jdk1.6.0_26-32/, you only have a JRE installed.
Cleaning and deploying is done by Eclipse, no Tomcat code is involved so this works.
You need to configure your environment so that Tomcat uses C:\Java\jdk1.6.0_34 as Java VM. Check the values of JAVA_HOME and the content of setenv.bat
Right click on project->Properties->Compiler->Configure workspace settings->go to configure->installed jre->give jdk path
In my case with using ANT build I had to change the setting
Add tools.jar in the below location.
Windows --> Preferences --> Ant --> Runtime --> Global Entries.
In my case the Tomcat server in Eclipse has been created under older JDK (just a few builds). My solution was to remove the sever and add it again (now using current JDK).
I had the same problem (I can reproduce it) and my solution sounds like the integration in Eclipse is really screwed up but I actually fixed it by starting Eclipse with the same JDK version.
Add/edit the following in your eclipse.ini (which is in the Eclipse directory):
-vm
path/to/jdk/bin
Where path/to/jdk/bin is the path to the JDK bin directory of the version you are using for ant/tomcat.
Note that tools.jar is NOT included in a JRE distribution.
If you are running Ant build file and getting this error in eclipse, then your eclipse is configured to use two differently named JRE's. i.e. One from the jre folder and another jre from inside the jdk's folder. Adding tools.jar may be a workaround but I used the JRE inside the JDK's folder(C:\Program Files\Java\jdk1.8.0_121). Inorder to change this,
Check in Installed JRE section which JRE is cheked(I had jdk1.8.0_121 checked and jre1.8.0_121 left unchecked).
Update your eclipse classpath by navigating to Window > Preferences > Java > Installed JRE > Execution Environments.
Now select the JavaSE-1.x on the left side and select the compatible JRE[perfect match]. Select the same JRE(jdk1.8.0_121) you had it checked above and click Ok. Optionally you can delete the JRE(jre1.8.0_121) which is unused to avoid confusion if it is not used in any other projects.
Now your project will build and you can run the Ant build files. Check the image below.
Try to add the tools.jar as an external JAR.
For eclipse,
Right click the project name and select Properties
Go to Java "Build Path"
Select tab "Libraries"
Click "Add External JARs"
Select the relevant .jar file from the file selection
I am not sure it applies to all situations, but if you right click Ant script and there is an item "External tools configuration" under "Run as" menu, select it, and go to JRE tab. As far as I can say, it may be configured independently from your project and point to the JRE, not JDK, in which case there would be missing tools.jar
I remove server (Tomcat 6.0) from window -> preferences -> server -> Runtime environment.
And add again. Then, I add my project to server again. The problem is destroyed.
If You are getting this error while running the ANT build then follow the below steps.
In the Eclipse go-to window-> preferences-> ANT-> RUNTIME
then select classpath tab then select Global Entries and add tools.jar as an external jar.
Run the ANT build.

Maven dynamic web project in eclipse deploys invalid jar files for dependent project(s)

I have a maven web project that imported into eclipse. I have another maven project (generates a jar file) that the web project depends on.
Both of these projects work correctly when executed from the command line. mvn package creates a war file which pulls the jar it depends on from the maven repository for the web project. mvn package creates a valid jar file when run for the library.
When I import the library into Eclipse, m2e recognizes that the web project depends on the library and updates parts of the project to take advantage of the fact that both maven projects are hosted within a single Eclipse workspace. The "Maven Dependencies" section of the "Libraries" tab of the "Java Build Path" preference for the web project removes the library jar file and replaces it with the library project. As the library is updated in Eclipse, the web project recognizes those changes without having to install/deploy the library.
The problem occurs when I attempt to run the web application in Eclipse. Because Eclipse is actually building the Web project against the version of the library in Eclipse, it does not deploy the library file from the maven repository, it creates a new jar file that's a snapshot of the current version of the library in Eclipse. All of this has generally worked well for me, but on the project I'm currently working on there's a problem with the jar file that Eclipse is creating. Instead of inserting the class files for the library, it appears that it's taking the "src" directory of my Maven project and zipping it up as the jar file. The contents of the jar file look something like:
-main
-java
-com
-... *.java
-resources
-...
-test
-java
-com
-... *.java
Where I would expect it to look more like:
-com
-... *.class
Since I have successfully used this type of project before, I'm trying to figure out if there's something I need to configure or if I've just run into a bug.
I'm using the latest update of m2e (1.0.200.20111228-1245) on Eclipse Indigo (Build id: 20120216-1857).
In Eclipse, we can disable the "Workspace Resolution" so that it will use our dependencies directly from the local maven repository as the following steps: -
Disable Workspace Resolution
Right click at the project inside the eclipse
Select "Maven" from the context menu.
If it display "Disable Workspace Resolution" which means it is enable. We click it with purpose to disable it. Please note, after that it will display "Enable Workspace Resolution" which means we have disabled already.
We may need to update the project configuration and other related dependencies as the following steps: -
Update Project Configuration
Right click at the project inside the eclipse
Select "Maven" from the context menu.
Click the "Update Project Configuration..."
The "Update Maven Dependencies" windows will be displayed.
Select the required projects and click "OK".
Update Dependencies
Right click at the project inside the eclipse
Select "Maven" from the context menu.
Click the "*Update Dependencies"
The "Update Maven Dependencies" windows will be displayed.
Select the required projects and click "OK".
Please take a note, since we not use the related dependencies directly from the workspace anymore, It will use directly from our local maven repository. Then all related artifacts should be installed to our local maven repository by using the following command line.
mvn install
Anyhow it can be done by using the context menu inside the Eclipse as the following steps:-
Right click at the project inside the eclipse
Select "Run As" ---> "Maven Install".
Here's the solution that I came up with.
It appears that in my case the rules for the "Deployment Assembly" for the library project are still followed.
To change it go to the library properties->Deployment Assembly
In my case that just contained a mapping from '/src' -> '/'. I removed that entry and replaced it with a mapping from '/target/classes' -> '/' and '/src/main/resources' -> '/'.
Once I had that mapping in place, when the jar file was deployed it contained exactly what I had configured in the Deployment Assembly. That allows Eclipse to continue to be used without explicitly republishing the library for every change. But, it doesn't seem to auto redeploy to tomcat for me when the library is updated -- I still need to manually restart tomcat for library changes to be reflected.
It's still not entirely clear to me what's going on with this project. I do have previous projects that have a similar structure, and in those projects the Deployment Assembly has not been updated to explicitly include the class files and yet the proper jar file is still deployed.

How do you install JDK?

I have eclipse and I can test run java apps but I am not sure how to compile them. I read that I should type javac -version into my cmd.exe and see if it is recognized. It is not. So I went to sun's website and downloaded/installed JDK v6. Yet it still says 'javac' is an unrecognized command. What am I doing wrong?
Thanks!
UPDATE
OK after reading some replies it seems like what I am trying to do is create a .jar file that can be ran on another computer (with the runtime). However I am having trouble figuring out how to do that. This might be because I am using Flex Builder(eclipse), but I added the ability to create java projects as well.
Thanks
UPDATE
OK I do not want to make a JAR file, I am not trying to archive it...the whole point of making a program is to send it to users so they can use the program...THAT is what I am trying to do...why is this so hard?
To setup Eclipse to use the JDK you must follow these steps.
1.Download the JDK
First you have to download the JDK from Suns site. (Make sure you download one of them that has the JDK)
2.Install JDK
Install it and it will save some files to your hard drive.
On a Windows machine this could be in c:\program files\java\jdk(version number)
3.Eclipse Preferences
Go to the Eclipse Preferences -> Java -> Installed JREs
4.Add the JDK
Click Add JRE and you only need to located the Home Directory. Click Browse... and go to where the JDK is installed on your system. The other fields will be populated for you after you locate the home directory.
5.You're done
Click Okay. If you want that JDK to be the default then put a Check Mark next to it in the Installed JRE's list.
You don't need a separate compiler, eclipse already compiles the application for you. What you probably want to do is to create an "executable" JAR file, which you can do in eclipse by selecting File->Export->Runnable JAR file.
Note, however, that the resulting JAR file is not a "real" (i.e. Windows binary) executable - it still needs a JRE installed on the target computer. There isn't really a way to create windows binaries; that's not how Java works. On the upside, it will work without recompilation on a Linux or MacOS machine (if it has a JRE installed).
javac is located in the "bin" folder of your JDK installation. In order to run it you must either use full path or add this directory to your systems search path via the Control Panel.
If you installed to c:\program files\java\jdk1.6.0 your call will have to look like this:
c:\> "c:\program files\java\jdk1.6.0\bin\javac" -version
Umm, eclipse is an IDE, it compiles things as you go. You don't need javac.
If you have Eclipse installed and you can write new java apps from within it, your compilation should work already..
Eclipse automatically builds/compiles your system when you're saving new Java files. Just try to write a new simple Hello world app, printing something to the console (just type sysout and Ctrl+Space inside Eclipse)
Eclipse automatically compiles all project in the workspace. YOu can disable this option if you like under Project->Build Automatically.
A JAR file can function as an executable, when you export your project as a JAR file in Eclipse (as Michael Borgwardt pointed out) you can specify what's the executable class, that meaning which one has the entry point [aka public static void main(String[] args)]
If the user installed the JRE he/she can double-click it and the application would be executed.
EDIT: For a detailed explanation of how this works, see the "How do I create executable Java program?"
Eclipse to use the JDK you must follow these steps.
1.Download the JDK
First you have to download the JDK from oracle site.
Download link - > https://www.oracle.com/technetwork/es/java/javasebusiness/downloads/index.html
2.Install JDK
Install it and it will save some files to your hard drive. On a Windows machine this could be in c:\program files\java\jdk(version number)
3.Eclipse Preferences
Go to the Eclipse Preferences -> Java -> Installed JREs
4.Add the JDK
Click Add JRE and you only need to located the Home Directory. Click Browse... and go to where the JDK is installed on your system. The other fields will be populated for you after you locate the home directory.
5.You're done
Click Ok. If you want that JDK to be the default then put a Check Mark next to it in the Installed JRE's list.