Spring Data java configuration doesn't find the org.postgresql.Driver

Question

I have a project based on Spring Framework and it is initialized based only on Java configuration.

TECHNOLOGIES USED:

• Java 8
• Spring framework 4.2.1.RELEASE
• Hibernate ORM 5.0.4.Final
• Spring Tool Suite IDE 3.6.2
• Maven 3
• Tomcat 7

pom.xml ....

 <dependencies>
        <!-- Spring -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${org.springframework-version}</version>
            <exclusions>
                <!-- Exclude Commons Logging in favor of SLF4j -->
                <exclusion>
                    <groupId>commons-logging</groupId>
                    <artifactId>commons-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${org.springframework-version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${org.springframework-version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>${org.springframework-version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>${org.springframework-version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>${org.springframework-version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>${org.springframework-version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-commons-core</artifactId>
            <version>1.4.1.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-rest-core</artifactId>
            <version>2.4.1.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-jpa</artifactId>
            <version>1.9.1.RELEASE</version>
        </dependency>

        <!-- Servlet -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>jsp-api</artifactId>
            <version>2.1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
            <scope>provided</scope>
        </dependency>

        <dependency>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging</artifactId>
            <version>1.2</version>
        </dependency>

        <!-- Annotations -->
        <dependency>
            <groupId>com.fasterxml.jackson.module</groupId>
            <artifactId>jackson-module-jaxb-annotations</artifactId>
            <version>2.6.3</version>
        </dependency>

        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.6.3</version>
        </dependency>

        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.6.3</version>
        </dependency>

        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.6.3</version>
        </dependency>

        <!-- Postgres -->
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <version>9.4-1205-jdbc42</version>
        </dependency>

        <!-- MySQL Connector -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.37</version>
        </dependency>

        <!-- Hibernate -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>5.0.4.Final</version>
        </dependency>

        <dependency>
            <groupId>org.hibernate.javax.persistence</groupId>
            <artifactId>hibernate-jpa-2.1-api</artifactId>
            <version>1.0.0.Final</version>
        </dependency>

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

        <!-- Transaction -->
        <dependency>
            <groupId>javax.transaction</groupId>
            <artifactId>jta</artifactId>
            <version>1.1</version>
        </dependency>

        <!-- @Inject -->
        <dependency>
            <groupId>javax.inject</groupId>
            <artifactId>javax.inject</artifactId>
            <version>1</version>
        </dependency>

    </dependencies>

....

Database Configuration Files

I created the following configuration class.

whereas SystemSettings holds the username,password and url of the Database

@Service
@Configuration
public class SystemSettings implements Settings {  

    public static final String DS_URL = "datasource.app.url";
    public static final String DS_USERNAME = "datasource.app.username";
    public static final String DS_PASSWORD = "datasource.app.password";

    @Autowired
    private Environment env;

    @Override
    public String get(String key) {
        return env.getProperty(key);
    }

}

The values are picked up from an application.properties file as its denoted in the PersistenceContext class.

PersistenceContext

@Component
@EnableTransactionManagement
@PropertySource("classpath:application.properties")
public class PersistenceContext {

    @Autowired
    private Environment env;

    @Bean
    @Primary
    public DataSource dataSource() throws ClassNotFoundException {
        org.apache.tomcat.jdbc.pool.DataSource ds = new org.apache.tomcat.jdbc.pool.DataSource();

        String url = env.getProperty(SystemSettings.DS_URL);
        String user = env.getProperty(SystemSettings.DS_USERNAME);
        String pass = env.getProperty(SystemSettings.DS_PASSWORD);

        ds.setDriverClassName("org.postgresql.Driver");
        ds.setUrl(url);
        ds.setUsername(user);
        ds.setPassword(pass);

        return ds;
    }

    @Bean
    LocalContainerEntityManagerFactoryBean entityManagerFactory(DataSource dataSource) {
        LocalContainerEntityManagerFactoryBean entityManagerFactoryBean = new LocalContainerEntityManagerFactoryBean();
        entityManagerFactoryBean.setDataSource(dataSource);
        entityManagerFactoryBean.setJpaVendorAdapter(new HibernateJpaVendorAdapter());
        entityManagerFactoryBean.setPackagesToScan("com.project.app.services.entities");

        Properties jpaProperties = new Properties();

        // Configures the used database dialect. This allows Hibernate to create SQL
        // that is optimized for the used database.
        jpaProperties.put("hibernate.dialect", env.getRequiredProperty("hibernate.dialect"));

        // Specifies the action that is invoked to the database when the Hibernate
        // SessionFactory is created or closed.
        jpaProperties.put("hibernate.hbm2ddl.auto",
                env.getRequiredProperty("hibernate.hbm2ddl.auto"));  

        // If the value of this property is true, Hibernate writes all SQL
        // statements to the console.
        jpaProperties.put("hibernate.show_sql", env.getRequiredProperty("hibernate.show_sql"));

        // If the value of this property is true, Hibernate will format the SQL
        // that is written to the console.
        jpaProperties.put("hibernate.format_sql", env.getRequiredProperty("hibernate.format_sql"));

        entityManagerFactoryBean.setJpaProperties(jpaProperties);

        return entityManagerFactoryBean;
    }

    @Bean
    JpaTransactionManager transactionManager(EntityManagerFactory entityManagerFactory) {
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(entityManagerFactory);
        return transactionManager;
    }
}

Ans ALSO the properties file

hibernate.dialect=org.hibernate.dialect.PostgreSQLDialect
hibernate.hbm2ddl.auto=create-drop hibernate.show_sql=false
hibernate.format_sql=true

datasource.app.type=POSTGRESQL
datasource.app.driverClassName=org.postgresql.Driver
datasource.app.url=jdbc:postgresql://localhost:5432/app
datasource.app.username=user
datasource.app.password=pass

Unfortunately now i get this error

SEVERE: Unable to create initial connections of pool. java.sql.SQLException: org.postgresql.Driver at ...... Caused by: java.lang.ClassNotFoundException: org.postgresql.Driver at......

I dont know why it gives me this exception. The maven dependency is there, the driver is also in classpath. . Any help?

This is my project's structure. ou can see the libraries added in build path. As suggested in comments the problem might be that the postgres jar isnt in the tomcat libraries. How do i add it there?

Answer 1

In case you need any class from the Postgres JDBC jar, Modify your dependency to provided. If not just remove it.

   <!-- Postgres -->
    <dependency>
        <groupId>org.postgresql</groupId>
        <artifactId>postgresql</artifactId>
        <version>9.4-1205-jdbc42</version>
        <scope>provided</scope>
    </dependency>

And then add the Postgres JDBC jar to the lib path of tomcat

{tomcat7_home_path}/lib