spring boot; using java -jar; not executing but no error - java

I was trying to execute spring boot; it works fine with mvn spring-boot:run. But when i try to package it as jar (I moved dependencies to lib, and binary to bin and resources to resources folder)
command was java -cp lib/;bin/;resource/* com.sample.SampleBoot
(SampleBoot's jar is available in bin)
This starts and print the line mentioned in main, but while calling application.run(args) [application is instance of SpringApplication), it is coming back with out starting the server.
It is not throwing any error or exception as well. So it is tough to debug.
Any help or advise?

I think you should create the jar like this
mvn package spring-boot:repackage
https://docs.spring.io/spring-boot/docs/current/reference/html/build-tool-plugins-maven-plugin.html

Creating a simple runnable jar file won't include the libraries in pom.xml.
If you're using eclipse, run this maven command below to create a runnable jar file in Spring Boot to include all libraries:
clean package
Reference to almost same question Exporting Spring Boot application as JAR file in eclipse

Related

What are auto executable jars?

I was going through spring-boot-maven-plugin documentation and came across a term auto executable jar.
Could someone please explain me what is an auto executable jar and how is it different then normal jar files and how they are auto executed?
spring-boot-maven-plugin documentation mentions the term but does not go further to explain it
repackage: create a jar or war file that is auto-executable. It can replace the regular artifact or can be attached to the build lifecycle with a separate classifier.
Could someone please explain me what is an auto executable jar
A fully executable jar can be executed like any other executable
binary or it can be registered with init.d or systemd. This makes it
very easy to install and manage Spring Boot applications in common
production environments.
So In conclusion is like any other executable when you use a executable jar
how is it different then normal jar files and how they are auto executed?
Well a java file you need to run with java -jar
From Spring Docs
The Maven build of a Springboot application first build your own application and pack it into a JAR file.
In the second stage (repackage) it will wrap that jar with all the jar files from the dependency tree into a new wrapper jar archive. It will also generate a Manifest file where is defined what's the application Main class is (also in the wrapper jar).
After mvn package you can also see 2 jar files in your target directory. The original file and the wrapped jar file.
You can start a Springboot application with a simple command like:
java -jar my-springboot-app.jar
I may suggest that auto executable means that you supplied main method so that it can be launched with java -jar options, otherwise it may be just a java library.
Here is a quote from https://docs.spring.io/spring-boot/docs/current/maven-plugin/repackage-mojo.html
Repackages existing JAR and WAR archives so that they can be executed from the command line using java -jar. With layout=NONE can also be used simply to package a JAR with nested dependencies (and no main class, so not executable).
Executable jar - the one that has main class declared in manifest and can be run with java -jar yourJarFile.jar command
Other jars - jars jars without delcared main calss. Can be anything - application, library, etc. Still can run application by providing fully.qualified.class.name as entry point like java -cp yourJarFile.jar my.bootstrap.BootstrapClass
Autoexecutable jars - never heard about it :)

Running Standalone Jar need to add jar on server to run

I created a spring boot job which relies on properties on the server and I can get it to run like so, no modifying manifest.
/bin/java -Dspring.config.location=/var/tmp/com.jdbc.properties -jar my.jar
and it works. But the application relies upon another jar that is an internal jar that lives under /usr/local/share/jni/foo.jar which I want to add to this mix.
I have tried countless runs trying such things as:
java -cp /usr/local/share/jni/foo.jar -Dspring(picking up original line)
When I start to google this, it takes me on magical tours of running:
'org.springframework.boot.loader.JarLauncher'
or
'org.springframework.boot.loader.PropertiesLauncher'
then mucking with manifest etc.
Spent last 4 hours with no success. Is there a best practice to run a standalone jar that needs to consume remote properties file and an additional jar file? Would like to keep it simple if possible.
If you are using Spring Boot and want to have a Fat-jar that encapsulates all your dependencies, the best way is to add the required Jar as a dependency to your project.
Assuming you are using Maven to build your project, the "foo.jar" needs to be added as a Maven dependency to your project. Then, spring Boot maven plugin will pick up the jar and includes it in your Fat-jar.
Even if the "foo.jar" does not exist in any Maven repo, you still can add it manually to your local Maven repo using the Maven command mvn install:install-file (See Maven doc).
Did you try using foo.jar as a provided dependency within your maven/gradle dependencies and building the project as executable war file?
See spring boot's maven plugin description of building executable war files.
Overall. Run spring boot standalone jar on a Linux server. Additionally read the database properties from a static file on the server, and path in a jar file that adds functionality that only lives on the server. Cannot include in the boot lib.
command line run (will convert to shell) and ran.
/path/to/..openjdk-1.7.0.55.x86_64/bin/java -cp /usr/somewhere/jni/Foo.jar:/path/where/lib/MYBOOTJAR.jar org.springframework.boot.loader.JarLauncher --spring.config.location=/path/to/properties/on/server/com.xxx.yyy.zzz.jdbc.properties
Seems like using the JarLauncher (no modifications to manifest, except excluding the Foo.jar from local)
Hope this helps someone else.

ClassNotFound exception after renaming package

I have a Spring Boot application in which I renamed package where starting class is in. Application runs without any problem when launching from IDE (Spring Tools Suite) but when I build it with maven and run from command line with
java -jar <application_name.jar>
It says that class in old_package cannot be found. Things I've tried so far:
Clean project
Delete metadata from workspace
Copy project somewhere else and import it from there
Deleting Run Configuration and creating new one with main class in new package.
I also unzipped jar located in target folder and checked its manifest file and Start-Class param is set to old package.
You didn't update your pom.xml, and it contains references written in the form <old_package>.MyClass, whereas this should be <new_package>.MyClass. Your IDE (I'm not an expert with STS though) uses its own rules for compilation, so your program can run in it.

Exporting Spring Boot application as JAR file in eclipse

I'm using the Spring STS in Eclipse to create a simple web-based spring boot project. I can run it fine in Eclipse, but when I try to export it as a JAR file I get:
rg.springframework.context.ApplicationContextException: Unable to start embedded container; nested exception is org.springframework.context.ApplicationContextException: Unable to start EmbeddedWebApplicationContext due to missing EmbeddedServletContainerFactory bean.
My public static void mainis located in Application.java, with the #SpringBootApplication annotation.
I've double checked all the Maven dependencies a hundred times.
What am I doing wrong?
Most likely, you're using the built-in Eclipse exporter to generate your jar, which only includes the target files actually produced in that project. In order to have a "fat" (standalone executable) jar, you need to use the Spring Boot Maven or Gradle plugin to "repackage" the jar.
First, make sure that you have the repackage goal included in your build setup, then use the Maven package target. The simplest way to do this is to run mvn package from the command line (you may need to install the Maven CLI package for your OS); you can also right-click the POM in Eclipse and "Run As" to execute specific Maven operations from within Eclipse.
It is a single line command, on window 7/10 machine, with command prompt to your project folder (Inside your project workspace). I do not do with Eclipse IDE POM maven goals, but you can do with maven goal there also. ON window machine I prefer cmd.exe for exporting and running.
mvnw clean package
on unix kernel based
./mvnw clean package
You have to go inside workspace and than to the project root folder. You will see a maven wrapper mvnw, with that you don't need to have maven installed and .mvn folder at the same level provides necessary jar for that.
For a project
D:\workspace\Zuteller Workspace\zusteller>mvnw clean package
it will create zusteller-0.0.1-SNAPSHOT.jar in the target folder at the same level.
D:\workspace\Zuteller Workspace\zusteller>java -jar target\zusteller-0.0.1-SNAPSHOT.jar
You can run self-contained application(embedded Tomcat) and access at localhost:8080/your project

Maven to Eclipse build issue while creating web application

I'm trying to build web Service using maven and eclipse. Here is steps I followed.
Generated mvn folder struture using comman prompt
mvn archetype:generate - DarchetypeArtifactId=maven-archetype-webapp
Converted the mvn project into eclipse.
mvn eclipse:eclipse -Dwtpversion=2.0
Imported the project into my workspace.
Changed the project facets such as java version, servlet version, added cxf and jaxb feature and server runtime.
Copied the WSDL to Resources folder.
Since I do not want to add dependencies(as somebody else would be doing this job for me). I added spring and CXF lib into build path. and also to deployment assembly.
Generated the jaxb classes and operations from wsdl. Here all the java classes created instead of going to src/main/java to went to src/main/resources.
I run the app on tomcat. web.xml is invoked from that cxf framework got invoked and also spring bean creation got invoked. but while creating the bean for the webservice class it threw Class not found error.
When I opened up the war I could notice that while packaging instead of placeing the class files, the eclipse placed java file as it is in the war file.
Could some one help me in fixing this problem. Not sure how to configure eclipse to compile and place .class files in the war instead of .java filee.
Figured out the problem, while importing the file eclipse is adding command, exclude all the java files from src/main/resources in srource tab of java build path On removing it worked fine

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