eugenp · eric-martin · Dec 13, 2024 · Nov 22, 2024
diff --git a/spring-boot-modules/spring-boot-data-3/pom.xml b/spring-boot-modules/spring-boot-data-3/pom.xml
@@ -43,6 +43,19 @@
             <artifactId>spring-boot-starter-test</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>com.querydsl</groupId>
+            <artifactId>querydsl-jpa</artifactId>
+            <version>${querydsl.version}</version>
+            <classifier>jakarta</classifier>
+        </dependency>
+        <dependency>
+            <groupId>com.querydsl</groupId>
+            <artifactId>querydsl-apt</artifactId>
+            <version>${querydsl.version}</version>
+            <classifier>jakarta</classifier>
+            <scope>provided</scope>
+        </dependency>
         <dependency>
             <groupId>org.openjfx</groupId>
             <artifactId>javafx-controls</artifactId>
@@ -53,6 +66,12 @@
             <artifactId>javafx-fxml</artifactId>
             <version>${javafx.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>${lombok.version}</version>
+            <scope>compile</scope>
+        </dependency>
     </dependencies>
 
     <build>
@@ -61,12 +80,38 @@
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-maven-plugin</artifactId>
             </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>11</source>
+                    <target>11</target>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>com.mysema.maven</groupId>
+                <artifactId>apt-maven-plugin</artifactId>
+                <version>1.1.3</version>
+                <executions>
+                    <execution>
+                        <phase>generate-sources</phase>
+                        <goals>
+                            <goal>process</goal>
+                        </goals>
+                        <configuration>
+                            <outputDirectory>target/generated-sources</outputDirectory>
+                            <processor>com.mysema.query.apt.jpa.JPAAnnotationProcessor</processor>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
         </plugins>
     </build>
 
     <properties>
         <start-class>com.baeldung.startwithoutdb.StartWithoutDbApplication</start-class>
         <hypersistence-utils-hibernate-60.version>3.7.3</hypersistence-utils-hibernate-60.version>
+        <querydsl.version>5.1.0</querydsl.version>
         <javafx.version>19</javafx.version>
     </properties>
 

diff --git a/...s/spring-boot-data-3/src/main/java/com/baeldung/dynamicquery/DynamicQueryApplication.java b/...s/spring-boot-data-3/src/main/java/com/baeldung/dynamicquery/DynamicQueryApplication.java
@@ -0,0 +1,15 @@
+package com.baeldung.dynamicquery;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
+
+@SpringBootApplication
+@EnableJpaRepositories("com.baeldung.dynamicquery.repository")
+public class DynamicQueryApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(DynamicQueryApplication.class, args);
+    }
+
+}
diff --git a/...boot-modules/spring-boot-data-3/src/main/java/com/baeldung/dynamicquery/model/School.java b/...boot-modules/spring-boot-data-3/src/main/java/com/baeldung/dynamicquery/model/School.java
@@ -0,0 +1,43 @@
+package com.baeldung.dynamicquery.model;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.OneToMany;
+import jakarta.persistence.Table;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+import java.util.List;
+
+@Entity
+@Table
+@Getter
+@Setter
+@EqualsAndHashCode(of = "id")
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public class School {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    @Column
+    private Long id;
+
+    @Column
+    private String name;
+
+    @Column
+    private String borough;
+
+    @OneToMany(mappedBy = "school")
+    private List<Student> studentList;
+
+}
diff --git a/...oot-modules/spring-boot-data-3/src/main/java/com/baeldung/dynamicquery/model/Student.java b/...oot-modules/spring-boot-data-3/src/main/java/com/baeldung/dynamicquery/model/Student.java
@@ -0,0 +1,42 @@
+package com.baeldung.dynamicquery.model;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.OneToMany;
+import jakarta.persistence.Table;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+@Entity
+@Table
+@Getter
+@Setter
+@EqualsAndHashCode(of = "id")
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public class Student {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    @Column
+    private Long id;
+
+    @Column
+    private String name;
+
+    @Column
+    private Integer age;
+
+    @ManyToOne
+    private School school;
+
+}
diff --git a/...ring-boot-data-3/src/main/java/com/baeldung/dynamicquery/repository/SchoolRepository.java b/...ring-boot-data-3/src/main/java/com/baeldung/dynamicquery/repository/SchoolRepository.java
@@ -0,0 +1,7 @@
+package com.baeldung.dynamicquery.repository;
+
+import com.baeldung.dynamicquery.model.School;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface SchoolRepository extends JpaRepository<School, Long> {
+}
diff --git a/...ing-boot-data-3/src/main/java/com/baeldung/dynamicquery/repository/StudentRepository.java b/...ing-boot-data-3/src/main/java/com/baeldung/dynamicquery/repository/StudentRepository.java
@@ -0,0 +1,9 @@
+package com.baeldung.dynamicquery.repository;
+
+import com.baeldung.dynamicquery.model.Student;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
+import org.springframework.data.querydsl.QuerydslPredicateExecutor;
+
+public interface StudentRepository extends JpaRepository<Student, Long>, QuerydslPredicateExecutor<Student>, JpaSpecificationExecutor<Student> {
+}
diff --git a/...spring-boot-data-3/src/main/java/com/baeldung/dynamicquery/spec/StudentSpecification.java b/...spring-boot-data-3/src/main/java/com/baeldung/dynamicquery/spec/StudentSpecification.java
@@ -0,0 +1,26 @@
+package com.baeldung.dynamicquery.spec;
+
+import com.baeldung.dynamicquery.model.School;
+import com.baeldung.dynamicquery.model.Student;
+import jakarta.persistence.criteria.Join;
+import org.springframework.data.jpa.domain.Specification;
+
+public class StudentSpecification {
+
+    public static Specification<Student> nameEndsWithIgnoreCase(String name) {
+        return (root, query, criteriaBuilder) ->
+                criteriaBuilder.like(criteriaBuilder.lower(root.get("name")), "%" + name.toLowerCase());
+    }
+
+    public static Specification<Student> isAge(int age) {
+        return (root, query, criteriaBuilder) -> criteriaBuilder.equal(root.get("age"), age);
+    }
+
+    public static Specification<Student> isSchoolBorough(String borough) {
+        return (root, query, criteriaBuilder) -> {
+            Join<Student, School> scchoolJoin = root.join("school");
+            return criteriaBuilder.equal(scchoolJoin.get("borough"), borough);
+        };
+    }
+
+}
diff --git a/...ng-boot-modules/spring-boot-data-3/src/main/resources/application-dynamicquery.properties b/...ng-boot-modules/spring-boot-data-3/src/main/resources/application-dynamicquery.properties
@@ -0,0 +1,9 @@
+spring.datasource.url=jdbc:h2:mem:testdb
+spring.datasource.driverClassName=org.h2.Driver
+spring.datasource.username=sa
+spring.datasource.password=
+spring.h2.console.enabled=true
+
+# JPA Configuration
+spring.jpa.database-platform=org.hibernate.dialect.H2Dialect
+spring.jpa.hibernate.ddl-auto=update
diff --git a/...ring-boot-data-3/src/test/java/com/baeldung/dynamicquery/DynamicQueryIntegrationTest.java b/...ring-boot-data-3/src/test/java/com/baeldung/dynamicquery/DynamicQueryIntegrationTest.java
@@ -0,0 +1,95 @@
+package com.baeldung.dynamicquery;
+
+import com.baeldung.dynamicquery.model.QStudent;
+import com.baeldung.dynamicquery.model.School;
+import com.baeldung.dynamicquery.model.Student;
+import com.baeldung.dynamicquery.repository.SchoolRepository;
+import com.baeldung.dynamicquery.repository.StudentRepository;
+import com.baeldung.dynamicquery.spec.StudentSpecification;
+import com.querydsl.core.types.dsl.*;
+import jakarta.inject.Inject;
+import java.util.List;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.TestInstance;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.data.domain.Example;
+import org.springframework.data.domain.ExampleMatcher;
+import org.springframework.data.jpa.domain.Specification;
+import org.springframework.test.context.ActiveProfiles;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@DataJpaTest
+@ActiveProfiles("dynamicquery")
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+public class DynamicQueryIntegrationTest {
+
+    @Inject
+    private SchoolRepository schoolRepository;
+
+    @Inject
+    private StudentRepository studentRepository;
+
+    @BeforeAll
+    void setup() {
+        School school1 = schoolRepository.save(School.builder()
+                .name("University of West London")
+                .borough("Ealing")
+                .build());
+
+        School school2 = schoolRepository.save(School.builder()
+                .name("Kingston University")
+                .borough("Kingston upon Thames")
+                .build());
+
+        studentRepository.saveAll(List.of(
+                Student.builder().name("Emily Smith").age(20).school(school2).build(),
+                Student.builder().name("James Smith").age(20).school(school1).build(),
+                Student.builder().name("Maria Johnson").age(22).school(school1).build(),
+                Student.builder().name("Michael Brown").age(21).school(school1).build(),
+                Student.builder().name("Sophia Smith").age(22).school(school1).build()
+        ));
+    }
+
+    @Test
+    void givenQueryByExample_whenSelectExample_thenReturnStudentsWhoAreAge20() {
+        School schoolExample = new School();
+        schoolExample.setBorough("Ealing");
+
+        Student studentExample = new Student();
+        studentExample.setAge(20);
+        studentExample.setName("Smith");
+        studentExample.setSchool(schoolExample);
+
+        ExampleMatcher customExampleMatcher = ExampleMatcher.matching()
+                .withMatcher("name", ExampleMatcher.GenericPropertyMatchers.endsWith().ignoreCase());
+
+        Example<Student> example = Example.of(studentExample, customExampleMatcher);
+        List<Student> studentList = studentRepository.findAll(example);
+        assertThat(studentList).hasSize(1);
+    }
+
+    @Test
+    void givenQueryBySpecification_whenSelectByDsl_thenReturn() {
+        Specification<Student> studentSpec = Specification
+                .where(StudentSpecification.nameEndsWithIgnoreCase("smith"))
+                .and(StudentSpecification.isAge(20))
+                .and(StudentSpecification.isSchoolBorough("Ealing"));
+
+        List<Student> studentList = studentRepository.findAll(studentSpec);
+        assertThat(studentList).hasSize(1);
+    }
+
+    @Test
+    void givenQueryByQueryDsl_whenSelectByDsl_thenReturn() {
+        QStudent qStudent = QStudent.student;
+        BooleanExpression predicate = qStudent.name.endsWithIgnoreCase("smith")
+                .and(qStudent.age.eq(20))
+                .and(qStudent.school.borough.eq("Ealing"));
+
+        List<Student> studentList = (List<Student>) studentRepository.findAll(predicate);
+        assertThat(studentList).hasSize(1);
+    }
+
+}