BAEL-2520 code moved to java-jpa module (#6525)

* BAEL-2520 code changes done * BAEL-2520 moved code to java-jpa module * BAEL-2520 moved code to java-jpa module
2019-03-12 22:11:02 +05:30
parent 2cdae3f8b9
commit 527e3440ac
9 changed files with 297 additions and 244 deletions
@@ -0,0 +1,49 @@
+package com.baeldung.jpa.criteria.entity;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.Table;
+
+@Table(name = "item")
+@Entity
+public class Item {
+
+    @Id
+    private Long id;
+    private String color;
+    private String grade;
+    private String name;
+
+    public String getColor() {
+        return color;
+    }
+
+    public String getGrade() {
+        return grade;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setColor(String color) {
+        this.color = color;
+    }
+
+    public void setGrade(String grade) {
+        this.grade = grade;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+}
@@ -0,0 +1,12 @@
+package com.baeldung.jpa.criteria.repository;
+
+import java.util.List;
+
+import com.baeldung.jpa.criteria.entity.Item;
+
+public interface CustomItemRepository {
+
+    List<Item> findItemsByColorAndGrade();
+
+    List<Item> findItemByColorOrGrade();
+}
@@ -0,0 +1,77 @@
+package com.baeldung.jpa.criteria.repository.impl;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.Persistence;
+import javax.persistence.criteria.CriteriaBuilder;
+import javax.persistence.criteria.CriteriaQuery;
+import javax.persistence.criteria.Predicate;
+import javax.persistence.criteria.Root;
+
+import com.baeldung.jpa.criteria.entity.Item;
+import com.baeldung.jpa.criteria.repository.CustomItemRepository;
+
+public class CustomItemRepositoryImpl implements CustomItemRepository {
+
+    private EntityManager entityManager;
+
+    public CustomItemRepositoryImpl() {
+        super();
+        EntityManagerFactory factory = Persistence.createEntityManagerFactory("jpa-h2-criteria");
+        entityManager = factory.createEntityManager();
+    }
+
+    @Override
+    public List<Item> findItemsByColorAndGrade() {
+
+        CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
+        CriteriaQuery<Item> criteriaQuery = criteriaBuilder.createQuery(Item.class);
+        Root<Item> itemRoot = criteriaQuery.from(Item.class);
+
+        Predicate predicateForBlueColor = criteriaBuilder.equal(itemRoot.get("color"), "blue");
+        Predicate predicateForRedColor = criteriaBuilder.equal(itemRoot.get("color"), "red");
+        Predicate predicateForColor = criteriaBuilder.or(predicateForBlueColor, predicateForRedColor);
+
+        Predicate predicateForGradeA = criteriaBuilder.equal(itemRoot.get("grade"), "A");
+        Predicate predicateForGradeB = criteriaBuilder.equal(itemRoot.get("grade"), "B");
+        Predicate predicateForGrade = criteriaBuilder.or(predicateForGradeA, predicateForGradeB);
+
+        // final search filter
+        Predicate finalPredicate = criteriaBuilder.and(predicateForColor, predicateForGrade);
+
+        criteriaQuery.where(finalPredicate);
+
+        List<Item> items = entityManager.createQuery(criteriaQuery)
+            .getResultList();
+        return items;
+    }
+
+    @Override
+    public List<Item> findItemByColorOrGrade() {
+
+        CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
+        CriteriaQuery<Item> criteriaQuery = criteriaBuilder.createQuery(Item.class);
+        Root<Item> itemRoot = criteriaQuery.from(Item.class);
+
+        Predicate predicateForBlueColor = criteriaBuilder.equal(itemRoot.get("color"), "red");
+        Predicate predicateForGradeA = criteriaBuilder.equal(itemRoot.get("grade"), "D");
+        Predicate predicateForBlueColorAndGradeA = criteriaBuilder.and(predicateForBlueColor, predicateForGradeA);
+
+        Predicate predicateForRedColor = criteriaBuilder.equal(itemRoot.get("color"), "blue");
+        Predicate predicateForGradeB = criteriaBuilder.equal(itemRoot.get("grade"), "B");
+        Predicate predicateForRedColorAndGradeB = criteriaBuilder.and(predicateForRedColor, predicateForGradeB);
+
+        // final search filter
+        Predicate finalPredicate = criteriaBuilder.or(predicateForBlueColorAndGradeA, predicateForRedColorAndGradeB);
+
+        criteriaQuery.where(finalPredicate);
+
+        List<Item> items = entityManager.createQuery(criteriaQuery)
+            .getResultList();
+        return items;
+    }
+}