带下划线的JPA列-CustomPhysicalNamingStrategy正在抛出NullPointer exeption

Question

经过一些研究，参考这些帖子，我尝试设置自定义命名策略

Hibernate命名策略

下划线不正确的JPA列

以下是我的自定义命名策略

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;
    }

但是当启动springboot应用程序时，它会抛出以下异常：

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

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

使用spring Boot-2.2.4.发布

Answer 1

问题出在CustomPhysicalNamingStrategy上：

应该是：

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();
    } 
}

请找到下面的链接：

自定义物理命名策略