BAEL-7296: Calling Custom Database Functions with JPA (#15869)

persistence-modules/spring-boot-persistence-4/pom.xml

@@ -62,6 +62,11 @@
             <artifactId>modelmapper</artifactId>
             <version>${modelmapper.version}</version>
         </dependency>
+        <dependency>
+            <groupId>commons-codec</groupId>
+            <artifactId>commons-codec</artifactId>
+            <version>${commons-codec.version}</version>
+        </dependency>
         <dependency>
             <groupId>org.projectlombok</groupId>
             <artifactId>lombok</artifactId>
@@ -88,6 +93,7 @@
         <hypersistence-utils.version>3.7.0</hypersistence-utils.version>
         <jackson.version>2.16.0</jackson.version>
         <modelmapper.version>3.2.0</modelmapper.version>
+        <commons-codec.version>1.16.1</commons-codec.version>
         <lombok.version>1.18.30</lombok.version>
     </properties>
 

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/customfunc/CustomFunctionApplication.java

@@ -0,0 +1,13 @@
+package com.baeldung.customfunc;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class CustomFunctionApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(CustomFunctionApplication.class, args);
+    }
+
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/customfunc/CustomH2Dialect.java

@@ -0,0 +1,25 @@
+package com.baeldung.customfunc;
+
+import org.hibernate.boot.model.FunctionContributions;
+import org.hibernate.dialect.H2Dialect;
+
+import org.hibernate.query.sqm.function.FunctionKind;
+import org.hibernate.query.sqm.function.SqmFunctionRegistry;
+import org.hibernate.query.sqm.produce.function.PatternFunctionDescriptorBuilder;
+import org.hibernate.type.spi.TypeConfiguration;
+
+public class CustomH2Dialect extends H2Dialect {
+
+    @Override
+    public void initializeFunctionRegistry(FunctionContributions functionContributions) {
+        super.initializeFunctionRegistry(functionContributions);
+        SqmFunctionRegistry registry = functionContributions.getFunctionRegistry();
+        TypeConfiguration types = functionContributions.getTypeConfiguration();
+
+        new PatternFunctionDescriptorBuilder(registry, "sha256hex", FunctionKind.NORMAL, "SHA256_HEX(?1)")
+                .setExactArgumentCount(1)
+                .setInvariantType(types.getBasicTypeForJavaType(String.class))
+                .register();
+    }
+
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/customfunc/CustomHibernateConfig.java

@@ -0,0 +1,16 @@
+package com.baeldung.customfunc;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.boot.autoconfigure.orm.jpa.HibernatePropertiesCustomizer;
+
+import java.util.Map;
+
+@Configuration
+public class CustomHibernateConfig implements HibernatePropertiesCustomizer {
+
+    @Override
+    public void customize(Map<String, Object> hibernateProperties) {
+        hibernateProperties.put("hibernate.dialect", "com.baeldung.customfunc.CustomH2Dialect");
+    }
+
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/customfunc/Product.java

@@ -0,0 +1,31 @@
+package com.baeldung.customfunc;
+
+import jakarta.persistence.*;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+import lombok.NoArgsConstructor;
+
+@Entity
+@Table(name = "product")
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+@EqualsAndHashCode(of = {"id"})
+@NamedStoredProcedureQuery(
+        name = "Product.sha256Hex",
+        procedureName = "SHA256_HEX",
+        parameters = @StoredProcedureParameter(mode = ParameterMode.IN, name = "value", type = String.class)
+)
+public class Product {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    @Column(name = "product_id")
+    private Integer id;
+
+    private String name;
+
+}

persistence-modules/spring-boot-persistence-4/src/main/java/com/baeldung/customfunc/ProductRepository.java

@@ -0,0 +1,24 @@
+package com.baeldung.customfunc;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.jpa.repository.query.Procedure;
+import org.springframework.data.repository.query.Param;
+
+import java.util.List;
+
+public interface ProductRepository extends JpaRepository<Product, Integer> {
+
+    @Procedure(name = "Product.sha256Hex")
+    String getSha256HexByNamedMapping(@Param("value") String value);
+
+    @Query(value = "CALL SHA256_HEX(:value)", nativeQuery = true)
+    String getSha256HexByNativeCall(@Param("value") String value);
+
+    @Query(value = "SELECT SHA256_HEX(name) FROM product", nativeQuery = true)
+    List<String> getProductNameListInSha256HexByNativeSelect();
+
+    @Query(value = "SELECT sha256Hex(p.name) FROM Product p")
+    List<String> getProductNameListInSha256Hex();
+
+}

persistence-modules/spring-boot-persistence-4/src/test/java/com/baeldung/customfunc/ProductRepositoryIntegrationTest.java

@@ -0,0 +1,58 @@
+package com.baeldung.customfunc;
+
+import org.apache.commons.codec.binary.Hex;
+import org.apache.commons.codec.digest.DigestUtils;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.nio.charset.StandardCharsets;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+@SpringBootTest(classes = CustomFunctionApplication.class, properties = {
+        "spring.jpa.show-sql=true",
+        "spring.jpa.properties.hibernate.format_sql=true",
+        "spring.jpa.generate-ddl=true",
+        "spring.jpa.defer-datasource-initialization=true",
+        "spring.sql.init.data-locations=classpath:product-data.sql"
+})
+@Transactional
+public class ProductRepositoryIntegrationTest {
+
+    private static final String TEXT = "Hand Grip Strengthener";
+    private static final String EXPECTED_HASH_HEX = getSha256Hex(TEXT);
+
+    @Autowired
+    private ProductRepository productRepository;
+
+    private static String getSha256Hex(String value) {
+        return Hex.encodeHexString(DigestUtils.sha256(value.getBytes(StandardCharsets.UTF_8)));
+    }
+
+    @Test
+    void whenGetSha256HexByNamedMapping_thenReturnCorrectHash() {
+        var hash = productRepository.getSha256HexByNamedMapping(TEXT);
+        assertThat(hash).isEqualTo(EXPECTED_HASH_HEX);
+    }
+
+    @Test
+    void whenGetSha256HexByNativeCall_thenReturnCorrectHash() {
+        var hash = productRepository.getSha256HexByNativeCall(TEXT);
+        assertThat(hash).isEqualTo(EXPECTED_HASH_HEX);
+    }
+
+    @Test
+    void whenCallGetSha256HexNative_thenReturnCorrectHash() {
+        var hashList = productRepository.getProductNameListInSha256HexByNativeSelect();
+        assertThat(hashList.get(0)).isEqualTo(EXPECTED_HASH_HEX);
+    }
+
+    @Test
+    void whenCallGetSha256Hex_thenReturnCorrectHash() {
+        var hashList = productRepository.getProductNameListInSha256Hex();
+        assertThat(hashList.get(0)).isEqualTo(EXPECTED_HASH_HEX);
+    }
+
+}

persistence-modules/spring-boot-persistence-4/src/test/resources/product-data.sql

@@ -0,0 +1,17 @@
+CREATE ALIAS SHA256_HEX AS '
+    import java.sql.*;
+    @CODE
+    String getSha256Hex(Connection conn, String value) throws SQLException {
+        var sql = "SELECT RAWTOHEX(HASH(''SHA-256'', ?))";
+        try (PreparedStatement stmt = conn.prepareStatement(sql)) {
+            stmt.setString(1, value);
+            ResultSet rs = stmt.executeQuery();
+            if (rs.next()) {
+                return rs.getString(1);
+            }
+        }
+        return null;
+    }
+';
+
+INSERT INTO product(name) VALUES('Hand Grip Strengthener');