persistence.xml not found in Eclipse Maven Project

问题

I cannot fix the persistence.xml file not found eclipse problem, this is a simple test project (Maven Nature) for a very basic EJB testing, the file is indeed in src/main/resources/META-INF/... this is the pom.xml contents. Tried adding the folder to the project's build path, updating maven project. No luck so far, any help would be greatly appreciated, thanks!

<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/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>LibEE</groupId>
  <artifactId>LibEE</artifactId>
  <packaging>jar</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <build>
    <sourceDirectory>src</sourceDirectory>
    <plugins>
      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.1</version>
        <configuration>
          <source>1.7</source>
          <target>1.7</target>
        </configuration>
      </plugin>

      <plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>2.2</version>
<configuration>
<archive>
<manifest>
<mainClass>main.resources.Main</mainClass>

</manifest>
</archive>
</configuration>
</plugin>
   </plugins>
  </build>

  <dependencies>
    <dependency>
    <groupId>org.eclipse.persistence</groupId>
    <artifactId>javax.persistence</artifactId>
    <version>2.1.0</version>
    </dependency>

     <dependency>
    <groupId>org.ow2.spec.ee</groupId>
    <artifactId>ow2-ejb-3.0-spec</artifactId>
    <version>1.0.13</version>
</dependency>

<dependency>
<groupId>org.glassfish.extras</groupId>
<artifactId>glassfish-embedded-all</artifactId>
<version>3.0.1</version>
<scope>test</scope>
</dependency>


  </dependencies>
</project>

And this is the persistence.xml:

    <?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
version="2.0">

<persistence-unit name="LibEE" transaction-type="JTA">
    <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
    <jta-data-source>jdbc/LibEE</jta-data-source> <!-- Refers to data source in Enterprise server -->
    <class>main.java.entities.Book</class>
<properties>
    <property name="eclipselink.ddl-generation" value="drop-and-create-tables"/>
    <property name="eclipselink.logging.level" value="INFO"/>
</properties>


</persistence-unit>

</persistence>

回答1:

persistence.xml file MUST be added to the classpath to resovle this issue.

Try as following:

Create/Update a directory src/main/resources/META-INF, place persistence.xml file here
Run Maven->Update project configuration
Verify that src/main/resources was added to source folders (Java Resources) by Right click on your project in Eclipse IDE > Properties > Java Build Path > Source tab. You will found /src/main/resources here.
Select Maven->Update project configuration or Project->Clean
If you build your applicaiton, check for persistence.xml file under target//WEB-INF/classes/META-INF/persistence.xml (or how you have configured your classpath).
That's it!

回答2:

I had a similar problem (but using JDeveloper 11) where src/META-INF/persistence.xml was not included into my project's JAR (at /META-INF/persistence.xml).

My fix was adding the following to the pom.xml (inside <build>):

<resources>
    <resource>
        <directory>src</directory>
        <includes>
            <include>META-INF/persistence.xml</include>
        </includes>
    </resource>
</resources>

回答3:

The top answer is correct; however this persistently (pun intended) failed to work no matter what I tried, until I included the hibernate entitymanager in my dependencies in Maven.

<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-entitymanager</artifactId>
    <version>4.3.1.Final</version>
</dependency>

After that it worked just fine.

回答4:

Solution 1. In your pom.xml replace <sourceDirectory>src</sourceDirectory> with <sourceDirectory>src/main/resources</sourceDirectory>

Solution 2. Add this under build tag

<resources>
        <resource>
            <directory>src</directory>
            <includes>
                <include>**</include>
            </includes>
            <excludes>
                <exclude>**/*.java</exclude>
            </excludes>
        </resource>
 </resources>

Solution 3. In your pom.xml remove <sourceDirectory>src</sourceDirectory> then maven will look for default layout

回答5:

Add this code to your pom.xml (in section "build")

<resources>
    <resource>
        <directory>src</directory>
        <includes>
            <include>**</include>
        </includes>
        <excludes>
            <exclude>**/*.java</exclude>
        </excludes>
   </resource>

Put you persistence.xml into src/main/resources/META-INF
Go to Project/Properties/Java Build Path/Source, select all folders, click "Remove", "OK"
Rightclick project/Maven/Update Project..., "OK"

The problem seems to be, that the m2e-plugin adds "Excluded: **" to the src/main/resources folder (see Project/Properties/Java Build Path/Source).

回答6:

All the answers seem to be correct. The problem, no one explains whats going on. For more understanding, I followed a resource provided by maven here.

<project>
  ...
  <name>My Resources Plugin Practice Project</name>
  ...
  <build>
    ...
    <resources>
      <resource>
        <directory>[your directory]</directory>
        <includes>
          <include>[resource file #1]</include>
          <include>[resource file #2]</include>
          <include>[resource file #3]</include>
          ...
          <include>[resource file #n]</include>
        </includes>
      </resource>
      ...
    </resources>
    ...
  </build>
  ...
</project>