Grails can't find classes in jars - grails

I have an app in Grails that uses a .java to manage paypal MassPay feature. Like many .java, it needs some jars that enclose the classes that jar uses. Ok, i import that jars and the errors in the .java dissapears. But now, when I try to run the app, i receive 25 messages like this:
myapproute/grails-app/controllers/com/mycompany/widget/MassPay.java:3: package com.paypal.sdk.profiles does not exist
import com.paypal.sdk.profiles.APIProfile;
That file in the MassPay.java does not throw any error, since i imported the jar where that class is enclosed. But it doesn't allow me to run the project.
Any help? thanks.
Im using Eclipse, not NetBeans (i have read that there is a bug in Netbeans)

Adding JARs to the Eclipse project build path is not sufficient to make them visible to Grails. You need to either put them in the application's lib directory and run grails compile --refresh-dependencies or (better) if the JARs are available in a Maven-compatible repository simply declare your dependencies in BuildConfig.groovy and let Grails download the JARs itself.

Run this - it will work
grails clean

Related

How to add a “non-mavenized” jar dependency to a grails project (Grails 3.x)

I'm trying to find documentation and code samples on how to add a local / non-maven jar file to my Grails 3.x project?
I found the separate thread How to add a non-maven jar to grails - but that's only to grails 2.3, and the file structure and configuration has undergone a big overhaul in 3.x.
Any help and (especially) code samples would be wonderful! The .jar is in the local project directory, and I intend to package with the .war for deployment.
Additionally, once i add the dependency, should i just be able to call it's methods from the controller & service files? or do i need to include them in those as well?
thx!
Grails 3 uses Gradle, so there's nothing Grails specific about including a local jar. It's as easy as adding a file dependency to the dependencies block of your build.gradle file.
Per the Gradle documentation on File Dependencies:
To add some files as a dependency for a configuration, you simply pass a file collection as a dependency:
dependencies {
...
compile files('libs/a.jar', 'libs/b.jar')
// or
compile fileTree(dir: 'libs', include: '*.jar')
}
The above example shows two ways to include jars that exist in a local libs/ directory; you can do either/or. The jar(s) can be anywhere on the filesystem, just make sure you point to the correct path.
To use the classes from the dependency in your application, you'll include them in your services, controllers and all other classes like you normally would. Say libs/a.jar has a class org.example.Something, you'd add an import to the top of your Grails class like so:
import org.example.Something

Grails lib directory doesn't work

I use Grails 2.2.3. I have put jar file in lib directory, IDEA immediately resolved the dependency. But when I start app I get NullPointerException on class from this library. If I try it second time or more I get java.lang.NoClassDefFoundError. I found a lot of advice how to resolve this issue but none were useful in my case.
Library (mylib-1.jar) compiled in maven and added to lib dir. In BuildConfig.groovy, dependency is mentioned as:
dependencies {
compile 'com.mylib:mylib:1'
}
I tried
grails clean
grails compile --refresh-dependencies
grails refresh-dependencies
but nothing helps. In result war file I can see this library in WEB-INF/lib, but even if deploy this war I get the same error.
How can this be resolved?
You're confusing NoClassDefFoundError with ClassNotFoundException. ClassNotFoundException happens when a class you want isn't there, but you get a NoClassDefFoundError when the class is there, but a class it depends on isn't. So you're missing another jar file that this jar file depends on.
This is one of the many reasons why it's best to use dependency management instead of manually copying jar files to the lib directory. If you use a Maven repo where the jars have proper POM files, their dependencies are specified, and the resolver can download the entire tree of dependencies for you, rather than you having to find all of the jars yourself.

Grails Project missing Java library at runtime

I was trying to add some Java Libraries (AWS SDK for Java, Apache Commons Math, etc.) to my Grails project since some of my Java source code (placed in src/java) had dependencies. By following this answer, I was able to resolve compile errors by adding the jar files to the /lib folder and add it to the build path, as answered here: Add Java Libraries to a Netbeans Grails Project
However, when I call my Java source code from my controller during runtime, it is unable to find the Java libraries that I added, showing a NoClassDefFoundError. Should I be adding something to the BuildConfig.groovy file? I'm not sure what the name convention for the jar files to be added to the dependencies.
The question you refer to is 5 years old. You should use newer resources :)
The preferred approach now is to use dependencies in BuildConfig.groovy, and let Grails (via Ivy or Maven) download the jars for you once and reuse them for various projects.
It's not always obvious what the syntax is, and I find that http://mvnrepository.com/ is a great resource. For example if you search for "commons math" and click through to http://mvnrepository.com/artifact/org.apache.commons/commons-math you'll see a few versions. Click on version 2.2 and you'll see the Maven dependency XML but you can click on the Gradle tab and it's going to be similar to what you need for Grails. So I'd add
dependencies {
compile 'org.apache.commons:commons-math:2.2'
}
and if necessary change compile to runtime, build, etc. depending on what you need the jar in the build process.
In the rare case that you do have a jar that isn't available in a Maven repo (e.g. a shared library at your company) then you can put the jar file in the lib directory. As you've seen, Grails doesn't auto-detect it (this is as of version 2.0). But you can run grails compile --refresh-dependencies to get your jar added to the classpath.
My issue turns out to be the fact that AWS Java SDK had dependencies (Apache HTTP Client) that were not installed yet and that I was unaware of.
This is what I had to configure this for my BuildConfig.groovy file
dependencies {
runtime 'org.apache.httpcomponents:httpclient:4.2.5'
runtime 'com.amazonaws:aws-java-sdk:1.4.7'
}
All the dependencies for AWS Java SDK 1.4.7 can be found here: http://mvnrepository.com/artifact/com.amazonaws/aws-java-sdk/1.4.7. All the dependencies outside of HTTP client were already installed for me, but may not be for your Grails setup.

Referencing external dependencies in GGTS by convention

How do I reference a dependency by convention within my project build path? Allow me to elaborate...
I'm using the Groovy/Grails Tool Suite (GGTS 3.0). I'm referencing the dependency as such in my BuildConfig.groovy:
dependencies {
compile 'tgt:jaxb-utils:1.0'
}
The referenced jar file is successfully pulled down from the Artifactory repo - I can find the jar file on my local file system in the Ivy cache. When I run any grails targets (grails compile, grails run-app, grails run-tests), it works fine - meaning my code that imports the classes from the jar has no problems. When I run grails war, the referenced jar file is packed into the constructed war.
However, and here is the crux of this post - the project build path does not reference this jar file by default or convention, so my java or groovy code that imports the classes from the jar file reports a unable to resolve class ... error.
One solution is to simply add the jar file to the lib folder and update the build path accordingly, or modify the build path to reference the jar file in the Ivy cache folder. However, I'd have to do this for any/all dependencies pulled down in this way. Any jars in the lib folder will get saved to the team source code repository, and that seems like wasted space since the grails commands work fine with just the dependency reference in BuildConfig.groovy.
Am I just being too idealistic (ie - difficult) here, or is there a better way to clean up the unable to resolve class ... errors in my IDE without having to manually add the dependent jar files to my lib folder and update my build path? Ideas?
Eclipse / STS / GGTS : If you have Grails plugin installed, you can do the following :
Right click on your project -> Grails Tools -> Refresh dependencies (or shortcut "Alt+G, R")

How to install gradle-grails-plugin?

Complete gradle nooby here.
I want to be able to execute grails build commands like "grails compile", "grails test-app" and so forth from gradle.
I found the grails-gradle-plugin from Peter Ledbrook at: https://github.com/grails/grails-gradle-plugin.
Cloning the repository I get some files and folders. In the readme file it says " include the required JARs via buildscript {} and 'apply' the plugin". The apply part sure I get but how do I add the JAR? And which jar? Do I need to use gradle on the build file in the folder of the downloaded plug-in and compile a jar? And ones I get the jar where do I place it and how do I include it in my projects build.gradle file?
I have a feeling this is going to be ridiculously easy but I just can't get it to work.
In Gradle, the jars are added to build script or to your application class path through dependencies closure e.g.
dependencies {
compile "org.grails:grails-crud:1.3.4"
compile "org.grails:grails-gorm:1.3.4"
compile "ch.qos.logback:logback-core:1.0.7"
compile "org.slf4j:slf4j-api:1.7.2"
}
compile is a name of one of the many configurations (there are also test, runtime etc.) and e.g. "org.grails:grails-crud:1.3.4" is a reference to a jar in one of the public repositories, which are also specified in your scripts in repositories closure.
You can read more about Gradle dependency management in http://gradle.org/docs/current/userguide/dependency_management.html.
For your Grails project you need to define a build.gradle file which looks similar to what is described in the README.
Though I tried today to just create a simple Grails project using that plugin and gradle init command and it didn't work. I have created an issue for that: https://github.com/grails/grails-gradle-plugin/issues/16.

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