Can not find the declaration of element 'persistence'

Question

Have put the persistence.xml in the classpath of the project in eclipse because before the error was that the file was not found. Now gives this error:

<

Answer 1

There is something slightly wrong with the XML provided, perhaps a missing version, perhaps the XML definition. Could also be a strange character or a typo somewhere.

A working template is below, try that instead.

<?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> 

Answer 2

I have faced similar problem (Cannot find the declaration of element 'entity-mappings') in the past when I had persistence.xml with JPA version 2.0 & orm.xml file with version 2.1. I think the error reported above are similar.

Working samples for JPA 2. Read the sample below carefully and note their version. Ensure they are of same versions as in the samples. You may use JPA 2.1 and approprite schema reference as well.

persistence.xml

<persistence version="2.0" 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">
    <persistence-unit name="SANJUSEJB" transaction-type="JTA">
        <jta-data-source>jdbc/sanjusDataSourceXA</jta-data-source>
        <mapping-file>META-INF/orm.xml</mapping-file>
        <class>org.sanjus.pa.ejb.entity.UserEntity</class>
    </persistence-unit>
</persistence>

orm.xml

<entity-mappings xmlns="http://java.sun.com/xml/ns/persistence/orm" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://java.sun.com/xml/ns/persistence/orm orm_2_0.xsd" version="2.0">
    <named-query name="findUserJSONById">
        <query>SELECT a.userJson FROM UserEntity a WHERE a.userId = :userId</query>
    </named-query>
</entity-mappings>

Answer 3

The problem is that you mix JPA 2.0 and JPA 2.1 notation.

Either this

<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence
                                 http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd"
  version="2.1">

for JPA 2.1 or this

<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">

for JPA 2 but not a mix thereof.

See http://www.oracle.com/webfolder/technetwork/jsc/xml/ns/persistence/index.html for details.

Answer 4

Solved!

I do not know exactly what was wrong, but it worked well:

<persistence version="2.0"   
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">    

<persistence-unit name="default" transaction-type="RESOURCE_LOCAL">    
    <provider>org.hibernate.ejb.HibernatePersistence</provider>    

    <properties>    
        <property name="javax.persistence.jdbc.driver" value="org.postgresql.Driver" />    
        <property name="javax.persistence.jdbc.url" value="jdbc:postgresql://localhost:5432/Automoveis" />    
        <property name="javax.persistence.jdbc.user" value="postgres" />    
        <property name="javax.persistence.jdbc.password" value="1234" />    
        <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect" />               
        <property name="hibernate.hbm2ddl.auto" value="update" />    
        <property name="hibernate.show_sql" value="true" />    
        <property name="hibernate.format_sql" value="true"/>    
    </properties>    
</persistence-unit>