JPA column with underscore - CustomPhysicalNamingStrategy is throwing NullPointer exeption

Question

After some research , referring to these post i tried setting the custom naming strategy

Here is my custom naming Strategy

public class CustomPhysicalNamingStrategy implements PhysicalNamingStrategy {

    @Override
    public Identifier toPhysicalCatalogName(final Identifier identifier, final JdbcEnvironment jdbcEnv) {
        return convertToSnakeCase(identifier);
    }

    @Override
    public Identifier toPhysicalColumnName(final Identifier identifier, final JdbcEnvironment jdbcEnv) {
        return convertToSnakeCase(identifier);
    }

    @Override
    public Identifier toPhysicalSchemaName(final Identifier identifier, final JdbcEnvironment jdbcEnv) {
        return convertToSnakeCase(identifier);
    }

    @Override
    public Identifier toPhysicalSequenceName(final Identifier identifier, final JdbcEnvironment jdbcEnv) {
        return convertToSnakeCase(identifier);
    }

    @Override
    public Identifier toPhysicalTableName(final Identifier identifier, final JdbcEnvironment jdbcEnv) {
        return convertToSnakeCase(identifier);
    }

    private Identifier convertToSnakeCase(final Identifier identifier) {
        final String regex = "([a-z])([A-Z])";
        final String replacement = "$1_$2";
        final String newName = identifier.getText().replaceAll(regex, replacement).toLowerCase();
        return Identifier.toIdentifier(newName);
    }

LocalContainerEntityManagerFactoryBean :

@Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
        LocalContainerEntityManagerFactoryBean localContainerEntityManagerFactoryBean = new LocalContainerEntityManagerFactoryBean();
        localContainerEntityManagerFactoryBean.setDataSource(dataSource());
        localContainerEntityManagerFactoryBean.setPackagesToScan(basePackage);
        JpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        localContainerEntityManagerFactoryBean.setJpaVendorAdapter(vendorAdapter);
        localContainerEntityManagerFactoryBean.setJpaProperties(customProperties());
        return localContainerEntityManagerFactoryBean;
    }

customProperties()

Properties customProperties() {
        Properties properties = new Properties();
        properties.setProperty("hibernate.dialect",
                ResourceConfig.getProperties().getProperty(PropertyConstants.SPRING_JPA_HIBERNATE_DIALECT));
        properties.setProperty("hibernate.hbm2ddl.auto", ddl);
        properties.setProperty("hibernate.show_sql", showSQL);
        properties.setProperty("hibernate.temp.use_jdbc_metadata_defaults", metaDataDefaults);
        properties.setProperty("hibernate.jdbc.lob.non_contextual_creation", contextualCreation);
        properties.setProperty("hibernate.physical_naming_strategy", "com.config.CustomPhysicalNamingStrategy");
        return properties;
    }

But when starting the springboot application it throwst the below exception :

Caused by: java.lang.NullPointerException
    at com.config.CustomPhysicalNamingStrategy.convertToSnakeCase(CustomPhysicalNamingStrategy.java:47)

Exaclty to the line in CustomPhysicalNamingStrategy

final String newName = identifier.getText().replaceAll(regex, replacement).toLowerCase();

did i miss some configuration, or am i doing it in a wrong way?

Using spring boot - 2.2.4.RELEASE

score 1 · Answer 1 · answered Apr 15 '20 at 15:10

The problem was with the CustomPhysicalNamingStrategy:

It should have been :

public class CustomPhysicalNamingStrategy extends PhysicalNamingStrategyStandardImpl {

    private static final long serialVersionUID = 1L;

    public static final CustomPhysicalNamingStrategy INSTANCE = new CustomPhysicalNamingStrategy ();

    @Override
    public Identifier toPhysicalTableName(Identifier name, JdbcEnvironment context) {
        return new Identifier(addUnderscores(name.getText()), name.isQuoted());
    }

    @Override
    public Identifier toPhysicalColumnName(Identifier name, JdbcEnvironment context) {
        return new Identifier(addUnderscores(name.getText()), name.isQuoted());
    }

    protected static String addUnderscores(String name) {
        final StringBuilder buf = new StringBuilder(name);
        for (int i = 1; i < buf.length() - 1; i++) {
            if (Character.isLowerCase(buf.charAt(i - 1)) &&
                    Character.isUpperCase(buf.charAt(i)) &&
                    Character.isLowerCase(buf.charAt(i + 1))) {
                buf.insert(i++, '_');
            }
        }
        return buf.toString().toLowerCase();
    } 
}

Please find the link below :

Custom Physical Naming Strategy

JPA column with underscore - CustomPhysicalNamingStrategy is throwing NullPointer exeption

1 Answers1