Failed to process import candidates for configuration class

Question

I've a spring boot project that I can run successfully from within IntelliJ, but when I package an executable jar I can no longer run it. Here is the stack trace of the exception:

18:13:55.254 [main] INFO  o.s.c.a.AnnotationConfigApplicationContext - Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@b3d7190: startup date [Wed Sep 07 18:13:55 CEST 2016]; root of context hierarchy
18:13:55.403 [main] WARN  o.s.c.a.AnnotationConfigApplicationContext - Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanDefinitionStoreException: Failed to process import candidates for configuration class [el.dorado.App]; nested exception is java.lang.IllegalArgumentException: No auto configuration classes found in META-INF/spring.factories. If you are using a custom packaging, make sure that file is correct.
18:13:55.414 [main] ERROR o.s.boot.SpringApplication - Application startup failed
org.springframework.beans.factory.BeanDefinitionStoreException: Failed to process import candidates for configuration class [el.dorado.App]; nested exception is java.lang.IllegalArgumentException: No auto configuration classes found in META-INF/spring.factories. If you are using a custom packaging, make sure that file is correct.
    at org.springframework.context.annotation.ConfigurationClassParser.processDeferredImportSelectors(ConfigurationClassParser.java:489)
    at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:191)
    at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:321)
    at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:243)
    at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:273)
    at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:98)
    at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:681)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:523)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759)
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:369)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:313)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1185)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1174)
    at dz.lab.jpmtask.App.main(App.java:33)
Caused by: java.lang.IllegalArgumentException: No auto configuration classes found in META-INF/spring.factories. If you are using a custom packaging, make sure that file is correct.
    at org.springframework.util.Assert.notEmpty(Assert.java:276)
    at org.springframework.boot.autoconfigure.EnableAutoConfigurationImportSelector.getCandidateConfigurations(EnableAutoConfigurationImportSelector.java:145)
    at org.springframework.boot.autoconfigure.EnableAutoConfigurationImportSelector.selectImports(EnableAutoConfigurationImportSelector.java:84)
    at org.springframework.context.annotation.ConfigurationClassParser.processDeferredImportSelectors(ConfigurationClassParser.java:481)
    ... 13 common frames omitted

My configuration is something like:

@Configuration
@EnableAutoConfiguration
public class AppConfig {
  ... some beans
}

I've added META-INF/spring.factories under the project resources folder as described in 43.2 Locating auto-configuration candidates as follows But this didn't fix the problem:

org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
el.dorado.AppConfig

Here is the project pom.xml:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">

  <modelVersion>4.0.0</modelVersion>

  <groupId>el.dorado</groupId>
  <artifactId>ElDorado</artifactId>
  <packaging>jar</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>ElDorado</name>
  <url>http://maven.apache.org</url>

  <properties>
     <junit.version>4.12</junit.version>
  </properties>

  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.4.0.RELEASE</version>
  </parent>

  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>

    <dependency>
      <groupId>com.h2database</groupId>
      <artifactId>h2</artifactId>
    </dependency>

    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>${junit.version}</version>
      <scope>test</scope>
    </dependency>

  </dependencies>

  <build>
    <plugins>
      <plugin>
        <artifactId>maven-assembly-plugin</artifactId>
        <configuration>
          <archive>
            <manifest>
              <mainClass>el.dorado.App</mainClass>
              <addDefaultImplementationEntries>true</addDefaultImplementationEntries>
            </manifest>
          </archive>
          <descriptorRefs>
            <descriptorRef>jar-with-dependencies</descriptorRef>
          </descriptorRefs>
        </configuration>
        <executions>
          <execution>
            <id>make-assembly</id> <!-- this is used for inheritance merges -->
            <phase>package</phase> <!-- bind to the packaging phase -->
            <goals>
              <goal>single</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
      <plugin>
        <groupId>org.jacoco</groupId>
        <artifactId>jacoco-maven-plugin</artifactId>
        <!--<version>0.7.8-SNAPSHOT</version>-->
        <executions>
          <execution>
            <id>jacoco-initialize</id>
            <goals>
              <goal>prepare-agent</goal>
            </goals>
          </execution>
          <execution>
            <id>jacoco-site</id>
            <phase>verify</phase>
            <goals>
              <goal>report</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>

</project>

Answer 1

I just figure it out, I should have been using Spring Boot maven plugin instead. Now the build section of my pom.xml looks like:

<build>
<plugins>
  <plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin</artifactId>
    <configuration>
      <fork>true</fork>
      <mainClass>dz.lab.jpmtask.App</mainClass>
    </configuration>
    <executions>
      <execution>
        <goals>
          <goal>repackage</goal>
        </goals>
      </execution>
    </executions>
  </plugin>
  <plugin>
    <groupId>org.jacoco</groupId>
    <artifactId>jacoco-maven-plugin</artifactId>
    <!--<version>0.7.8-SNAPSHOT</version>-->
    <executions>
      <execution>
        <id>jacoco-initialize</id>
        <goals>
          <goal>prepare-agent</goal>
        </goals>
      </execution>
      <execution>
        <id>jacoco-site</id>
        <phase>verify</phase>
        <goals>
          <goal>report</goal>
        </goals>
      </execution>
    </executions>
  </plugin>
</plugins>
</build>

I build the project with mvn clean package and then java -jar target/myproject.jar and it works like a charm.

Answer 2

I think that you have forgotten to use Annotation in your AppConfig.

Add following three annotations to your AppConfig class:

@Configuration
@EnableWebMvc
@ComponentScan("Scan_Package_Name") 
public class AppConfig {
  ... some beans
}