"unable to locate Spring NamespaceHandler" error

I'm creating a stand-alone Sava application with Spring, to handle the JDBC access. The application works fine on every test and I decided that I need a jar to be deployed our clients.

They might not have spring in their classpath, so I used maven-assembly-plugin to handle the jar creation with dependencies.

However when I try to run the application:

java -jar target/myproject-0.0.1-SNAPSHOT-jar-with-dependencies.jar

Which throws the following error:

Exception in thread "main" org.springframework.beans.factory.parsing.BeanDefinitionParsingException: Configuration problem: Unable to locate Spring NamespaceHandler for XML schema namespace [http://www.springframework.org/schema/p]
Offending resource: class path resource [applicationContext.xml]

at org.springframework.beans.factory.parsing.FailFastProblemReporter.error(FailFastProblemReporter.java:68)
at org.springframework.beans.factory.parsing.ReaderContext.error(ReaderContext.java:85)
at org.springframework.beans.factory.parsing.ReaderContext.error(ReaderContext.java:80)
...and so on to the database access class of this project.

The applicationContext.xml file is in projectbase/src/main/resources. And its placed at target/packagename base.

The applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?&开发者_JAVA技巧gt;
<beans xmlns="http://www.springframework.org/schema/beans"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xmlns:p="http://www.springframework.org/schema/p"
   xmlns:context="http://www.springframework.org/schema/context"
   xsi:schemaLocation="http://www.springframework.org/schema/beans
   http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
   http://www.springframework.org/schema/context
   http://www.springframework.org/schema/context/spring-context-3.0.xsd">


    <bean id="dataSourceDesenv" class="org.apache.commons.dbcp.BasicDataSource"... />

    <bean id="simpleJdbcDaoSupport" class="org.springframework.jdbc.core.simple.SimpleJdbcDaoSupport"
      p:dataSource-ref="dataSourceDesenv" />

    <bean id="simpleJdbcTemplate" class="org.springframework.jdbc.core.simple.SimpleJdbcTemplate">
        <constructor-arg ref="dataSourceDesenv" />
    </bean>

</beans>

I ran into this problem today with the maven-assembly-plugin. A search brought me to this question, and a look a the bug report suggested that perhaps I was using the wrong plugin. So I switched to the maven-shade-plugin. It works perfectly, as far as I can tell. I have an executable jar that incorporates a number of Spring modules as well as Apache MQ. Here's the relevant bit from my pom.xml:

<build>
<finalName>sample-broker</finalName>
<plugins>
  ...
  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-shade-plugin</artifactId>
    <version>2.0</version>
    <executions>
      <execution>
        <phase>package</phase>
        <goals>
          <goal>shade</goal>
        </goals>
        <configuration>
          <transformers>
            <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>
            <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
              <mainClass>org.XYZ</mainClass>
            </transformer>
          </transformers>
        </configuration>
      </execution>
    </executions>
  </plugin>
</plugins>
</build>

I found the error, the bug lies in an unfixed bug in the maven-assembly plugin. I used the following workaround:

First commented out the maven-assembly code in my pom. Then I copied the dependencies to a lib folder at the target using the maben-dependency-plugin:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-dependency-plugin</artifactId>
    <executions>
        <execution>
            <id>copy-dependencies</id>
            <phase>package</phase>
            <goals>
                <goal>copy-dependencies</goal>
            </goals>
            <configuration>
                <outputDirectory>${project.build.directory}/lib</outputDirectory>
            </configuration>
        </execution>
    </executions>
</plugin>

Then I used the maven-jar-plugin to setup my executable jar:

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <version>2.3.1</version>
            <configuration>
                <archive>
                    <index>true</index>
                    <manifest>
                        <addClasspath>true</addClasspath>
                        <mainClass>org.foo.myproject.App</mainClass>
                    </manifest>
                    <manifestEntries>
                        <mode>development</mode>
                        <url>${pom.url}</url>
                        <key>value</key>

                    </manifestEntries>
                </archive>
            </configuration>
        </plugin>

Finally I created a bash script that is deployed with the application that runs my app with its libs and any provided arguments:

java -cp lib/*:myproject-0.0.1-SNAPSHOT.jar org.foo.myproject.App $@

I should have built the app in python =/

Looks like a bug in the Maven Assembly Plugin - MASSEMBLY-360, and as discussed in this blog entry here.

In short, the meta-data files in the Spring JARs that handle the Spring namespaces are being mangled by maven.

onejar-maven-plugin lets you resolve maven and spring contradiction by creating a single jar file with dependencies. It creates a wrapper around your jar file by placing it inside another jar (one-jar).

    <plugin>
            <groupId>org.dstovall</groupId>
            <artifactId>onejar-maven-plugin</artifactId>
            <version>1.4.4</version>
            <executions>
              <execution>
                <goals>
                    <goal>one-jar</goal>
                </goals>
              </execution>
            </executions>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <version>2.3.2</version>
            <configuration>
                <archive>
                    <manifest>
                        <mainClass>your.package.App</mainClass>
                    </manifest>
                </archive>
            </configuration>
        </plugin>

<!-- outside build tag in pom.xml -->
<pluginRepositories>
        <pluginRepository>
            <id>onejar-maven-plugin.googlecode.com</id>
            <url>http://onejar-maven-plugin.googlecode.com/svn/mavenrepo</url>
        </pluginRepository>
</pluginRepositories>

In addition to the solution posted by @GrampaJohn, I also had to make sure that I was packaging the required libraries into the generated JAR file instead of extracting them into the generated JAR.

In Eclipse Mars, after making changes to the pom.xml (added maven-shade plugin as suggested by @GrampaJohn), follow the steps:

File -> Export -> Select Java folder -> Runnable JAR File -> enter the Launch configuration (main file), export destination, and in Library Handling, select "Package required Libraries into generated JAR -> Click finish

.

(Assuming that you've added all the right headers for the XML, if you're still facing this issue which was my case) I know that the question was asked with Maven but I'm using Gradle and I faced the exact same problem. For anyone else who's using Gradle to package Jars and are facing this problem, here's how I solved it,

jar {
    manifest {
        attributes("Created-By"      : ".....",
                "Specification-Title": ".....",
                "Main-Class"         : "$mainClassName",
                "Class-Path"         : configurations.compile.collect { it.getName() }.join(' '))
    }
}

Adding "Class-Path" as a compile collect solved it for me.

If anyone comes across this error after using the above code,

 Cannot change dependencies of configuration ':compile' after it has been resolved.

You need to move this block after your "dependencies" block.