（springboot）jar无法在其他计算机上执行

Question

I have a spring Boot application. I package it with maven, and I execute it with java -jar xxx.jar. The application is running. However if I copy the jar on another machine (same java version, same OS) I get a dependency error:

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name
'org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaConfiguration':...
...
Unsatisfied dependency expressed through constructor parameter 0 
...
Bean instantiation via factory method failed
...
 Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: 
Failed to instantiate [javax.sql.DataSource]: 
Factory method 'dataSource' threw exception; nested exception is java.lang.NullPointerException

I added debug=true to show the classpath during execution, but it seems the same on both machines (there were issues with classpath order between maven execution and java execution)

EDIT: actually the problem is not changing machine: if I just move the jar in another folder, I get the same error. If I look at the correct running process it seems fairly obvious that in the classpath there are references to ther project target folder that cannot be satisfied...

Original machine is iOS, I tried the jar on other iOS and a Centos machine with same result.

I thought jar was very portable for deployment, so I don't understand if there is a better way of deploying the application or some environment variable I'm not taking into account

EDIT: I use maven. I do

mvn package

or mvn clean install

and I have the dependencies mentioned in the answer

   <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
   </dependency>

<plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin</artifactId>
</plugin>

Answer 1

You need to create a Fat jar (a jar file with all the dependencies), you can find a more detailed info here , but to let some code in the answer:

Basically what you have to do is check that you have the right dependencies in your pom

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
        <version>2.0.1.RELEASE</version>
    </dependency>
</dependencies>

<plugins>
    <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
        <version>2.0.1.RELEASE</version>
    </plugin>
</plugins>

Then you should do

mvn clean install

And run it!

java -jar <artifact-name> 

EDIT

What do you see if you do a repackage? mvn clean package spring-boot:repackage

Answer 2

Your HibernateJpaConfiguration bean cannot be created. It looks it has some property declared in a @Configuration annotated class or in the application.properties resource file. Some property that has a relative path in it, and when you move the jar it cannot find that property.

Answer 3

Actually it was a trivial issue: a directory had to be listed from a relative path and in order to execute the jar somewhere else I had to just create that directory.

The error wasn't properly catched so the stacktrace was showing failure in dependencies and I missed the simple reality: java.lang.NullPointerException....

Thanks to @AndyWilkinson for making me read the stacktrace again...