CODEWITHSUNDEEP
springexecutableuber-api
Sloan
Sloan

Reputation: 11

running uber jar spring @value null

I needed to create a single executable jar from my maven module (Java+Spring) and its dependencies. So I included the maven-shade-plugin in my POM, and looks like it packaged all that was needed.

When I run this jar, it fails with a NullPointerException. It looks like it fails to locate the values referenced by @Value in my main class, and I end up getting a NPE. I do see that the applicationContext and properties files are inside the jar. What might be the reason for this?

applicationContext.xml - 

<context:property-placeholder location="classpath:props.properties" ignore-unresolvable="true"/>

Main.java - 

@Value("${property.inside.props.file}")
private String propertyName;

pom.xml - 

<plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-shade-plugin</artifactId>
            <version>2.4.1</version>
            <executions>
              <execution>
                <phase>package</phase>
                <goals>
                  <goal>shade</goal>
                </goals>
                <configuration>
                <transformers>
                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                    <manifestEntries>
                        <Main-Class>com.sloan.Main.java</Main-Class>
                    </manifestEntries>
                </transformer>
        <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                  <resource>META-INF/spring.handlers</resource>
                </transformer>
                <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                  <resource>META-INF/spring.schemas</resource>
                </transformer>
            </transformers>
                 <filters>
                 <filter>
                      <artifact>*:*</artifact>
                      <excludes>
                        <exclude>META-INF/*.SF</exclude>
                        <exclude>META-INF/*.DSA</exclude>
                        <exclude>META-INF/*.RSA</exclude>
                      </excludes>
                    </filter>
                    </filters>
                </configuration>
              </execution>
            </executions>
          </plugin>

I have tried doing the same thing with the assembly plugin, but that brought up the NPE as well.

Upvotes: 0

Views: 332

Answers (2)

Sloan
Sloan

Reputation: 11

I found what I was missing, loading the Spring context! So now my Main.java loads the context first thing - 

ApplicationContext applicationContext = new ClassPathXmlApplicationContext("META-INF\\spring\\applicationContext.xml");

Things are working after making this change and reinstalling.

Upvotes: 1

J&#225;n Srniček
J&#225;n Srniček

Reputation: 525

Your are missing a @Bean that is responsible for resolving this annotations

Add this bean to your configuration class

@Bean
public static PropertyPlaceholderConfigurer getValueResolver()
{
    return new PropertyPlaceholderConfigurer();
}

for XML based tutorial look here http://www.mkyong.com/spring/spring-propertyplaceholderconfigurer-example/

Upvotes: 0

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