From 2ab76e2daba73f3f9ebb2ddc98c11b95172db623 Mon Sep 17 00:00:00 2001
From: Struchkov Mark <mark@struchkov.dev>
Date: Sat, 2 Jul 2022 18:14:07 +0300
Subject: [PATCH] Fix Variant

---
 .../hibernate/nbfe/fix/FixProblem.java        | 38 +++++++++++++++++++
 .../nbfe/{no_fix_set => fix}/domain/Post.java | 10 ++---
 .../domain/PostComment.java                   |  3 +-
 .../nbfe/{no_fix_set => fix}/domain/Tag.java  |  2 +-
 .../nbfe/no_fix_set/NoFixSetMain.java         | 34 -----------------
 src/main/resources/META-INF/persistence.xml   |  6 +--
 6 files changed, 49 insertions(+), 44 deletions(-)
 create mode 100644 src/main/java/dev/struchkov/example/hibernate/nbfe/fix/FixProblem.java
 rename src/main/java/dev/struchkov/example/hibernate/nbfe/{no_fix_set => fix}/domain/Post.java (83%)
 rename src/main/java/dev/struchkov/example/hibernate/nbfe/{no_fix_set => fix}/domain/PostComment.java (85%)
 rename src/main/java/dev/struchkov/example/hibernate/nbfe/{no_fix_set => fix}/domain/Tag.java (81%)
 delete mode 100644 src/main/java/dev/struchkov/example/hibernate/nbfe/no_fix_set/NoFixSetMain.java

diff --git a/src/main/java/dev/struchkov/example/hibernate/nbfe/fix/FixProblem.java b/src/main/java/dev/struchkov/example/hibernate/nbfe/fix/FixProblem.java
new file mode 100644
index 0000000..6750387
--- /dev/null
+++ b/src/main/java/dev/struchkov/example/hibernate/nbfe/fix/FixProblem.java
@@ -0,0 +1,38 @@
+package dev.struchkov.example.hibernate.nbfe.fix;
+
+import dev.struchkov.example.hibernate.nbfe.fix.domain.Post;
+import jakarta.persistence.EntityManager;
+import jakarta.persistence.EntityManagerFactory;
+import jakarta.persistence.Persistence;
+
+import java.util.List;
+
+public class FixProblem {
+
+    public static void main(String[] args) {
+        final EntityManagerFactory emf = Persistence.createEntityManagerFactory("Blog");
+        final EntityManager entityManager = emf.createEntityManager();
+
+        final long startTime = System.currentTimeMillis();
+        List<Post> posts = entityManager.createQuery("""
+                        select distinct p
+                        from Post p
+                        left join fetch p.comments
+                        where p.id between :minId and :maxId""", Post.class)
+                .setParameter("minId", 1L)
+                .setParameter("maxId", 50L)
+                .getResultList();
+
+        posts = entityManager.createQuery("""
+                        select distinct p
+                        from Post p
+                        left join fetch p.tags t
+                        where p in :posts""", Post.class)
+                .setParameter("posts", posts)
+                .getResultList();
+
+        final long finishTime = System.currentTimeMillis();
+        System.out.println("Performance: " + (finishTime - startTime));
+    }
+
+}
diff --git a/src/main/java/dev/struchkov/example/hibernate/nbfe/no_fix_set/domain/Post.java b/src/main/java/dev/struchkov/example/hibernate/nbfe/fix/domain/Post.java
similarity index 83%
rename from src/main/java/dev/struchkov/example/hibernate/nbfe/no_fix_set/domain/Post.java
rename to src/main/java/dev/struchkov/example/hibernate/nbfe/fix/domain/Post.java
index eeddac6..a165d72 100644
--- a/src/main/java/dev/struchkov/example/hibernate/nbfe/no_fix_set/domain/Post.java
+++ b/src/main/java/dev/struchkov/example/hibernate/nbfe/fix/domain/Post.java
@@ -1,4 +1,4 @@
-package dev.struchkov.example.hibernate.nbfe.no_fix_set.domain;
+package dev.struchkov.example.hibernate.nbfe.fix.domain;
 
 import jakarta.persistence.CascadeType;
 import jakarta.persistence.Entity;
@@ -11,8 +11,8 @@ import jakarta.persistence.OneToMany;
 import lombok.Getter;
 import lombok.Setter;
 
-import java.util.HashSet;
-import java.util.Set;
+import java.util.ArrayList;
+import java.util.List;
 
 @Entity
 @Getter
@@ -30,7 +30,7 @@ public class Post {
             cascade = CascadeType.ALL,
             orphanRemoval = true
     )
-    private Set<PostComment> comments = new HashSet<>();
+    private List<PostComment> comments = new ArrayList<>();
 
     @ManyToMany(
             cascade = {
@@ -43,7 +43,7 @@ public class Post {
             joinColumns = @JoinColumn(name = "post_id"),
             inverseJoinColumns = @JoinColumn(name = "tag_id")
     )
-    private Set<Tag> tags = new HashSet<>();
+    private List<Tag> tags = new ArrayList<>();
 
     public void addComment(PostComment postComment) {
         postComment.setPost(this);
diff --git a/src/main/java/dev/struchkov/example/hibernate/nbfe/no_fix_set/domain/PostComment.java b/src/main/java/dev/struchkov/example/hibernate/nbfe/fix/domain/PostComment.java
similarity index 85%
rename from src/main/java/dev/struchkov/example/hibernate/nbfe/no_fix_set/domain/PostComment.java
rename to src/main/java/dev/struchkov/example/hibernate/nbfe/fix/domain/PostComment.java
index d875459..41abda9 100644
--- a/src/main/java/dev/struchkov/example/hibernate/nbfe/no_fix_set/domain/PostComment.java
+++ b/src/main/java/dev/struchkov/example/hibernate/nbfe/fix/domain/PostComment.java
@@ -1,4 +1,4 @@
-package dev.struchkov.example.hibernate.nbfe.no_fix_set.domain;
+package dev.struchkov.example.hibernate.nbfe.fix.domain;
 
 import jakarta.persistence.Entity;
 import jakarta.persistence.GeneratedValue;
@@ -22,3 +22,4 @@ public class PostComment {
     private String review;
 
 }
+
diff --git a/src/main/java/dev/struchkov/example/hibernate/nbfe/no_fix_set/domain/Tag.java b/src/main/java/dev/struchkov/example/hibernate/nbfe/fix/domain/Tag.java
similarity index 81%
rename from src/main/java/dev/struchkov/example/hibernate/nbfe/no_fix_set/domain/Tag.java
rename to src/main/java/dev/struchkov/example/hibernate/nbfe/fix/domain/Tag.java
index 9f8555b..d86837f 100644
--- a/src/main/java/dev/struchkov/example/hibernate/nbfe/no_fix_set/domain/Tag.java
+++ b/src/main/java/dev/struchkov/example/hibernate/nbfe/fix/domain/Tag.java
@@ -1,4 +1,4 @@
-package dev.struchkov.example.hibernate.nbfe.no_fix_set.domain;
+package dev.struchkov.example.hibernate.nbfe.fix.domain;
 
 import jakarta.persistence.Entity;
 import jakarta.persistence.GeneratedValue;
diff --git a/src/main/java/dev/struchkov/example/hibernate/nbfe/no_fix_set/NoFixSetMain.java b/src/main/java/dev/struchkov/example/hibernate/nbfe/no_fix_set/NoFixSetMain.java
deleted file mode 100644
index ac230b4..0000000
--- a/src/main/java/dev/struchkov/example/hibernate/nbfe/no_fix_set/NoFixSetMain.java
+++ /dev/null
@@ -1,34 +0,0 @@
-package dev.struchkov.example.hibernate.nbfe.no_fix_set;
-
-import dev.struchkov.example.hibernate.nbfe.no_fix_set.domain.Post;
-import jakarta.persistence.EntityManager;
-import jakarta.persistence.EntityManagerFactory;
-import jakarta.persistence.Persistence;
-
-import java.util.List;
-
-public class NoFixSetMain {
-
-    public static void main(String[] args) {
-        final EntityManagerFactory emf = Persistence.createEntityManagerFactory("Blog");
-        final EntityManager entityManager = emf.createEntityManager();
-
-        final long startTime = System.currentTimeMillis();
-        final List<Post> posts = entityManager.createQuery(
-                        """
-                                SELECT p
-                                FROM Post p
-                                LEFT JOIN FETCH p.comments
-                                LEFT JOIN FETCH p.tags
-                                WHERE p.id BETWEEN :minId AND :maxId
-                                """, Post.class
-                )
-                .setParameter("minId", 1L)
-                .setParameter("maxId", 50L)
-                .getResultList();
-
-        final long finishTime = System.currentTimeMillis();
-        System.out.println("Performance: " + (startTime - finishTime));
-    }
-
-}
diff --git a/src/main/resources/META-INF/persistence.xml b/src/main/resources/META-INF/persistence.xml
index 70b42b9..71147ad 100644
--- a/src/main/resources/META-INF/persistence.xml
+++ b/src/main/resources/META-INF/persistence.xml
@@ -4,9 +4,9 @@
 http://xmlns.jcp.org/xml/ns/persistence_2_1.xsd">
 
     <persistence-unit name="Blog">
-        <class>dev.struchkov.example.hibernate.nbfe.no_fix_set.domain.Post</class>
-        <class>dev.struchkov.example.hibernate.nbfe.no_fix_set.domain.PostComment</class>
-        <class>dev.struchkov.example.hibernate.nbfe.no_fix_set.domain.Tag</class>
+        <class>dev.struchkov.example.hibernate.nbfe.fix.domain.Post</class>
+        <class>dev.struchkov.example.hibernate.nbfe.fix.domain.PostComment</class>
+        <class>dev.struchkov.example.hibernate.nbfe.fix.domain.Tag</class>
         <exclude-unlisted-classes>true</exclude-unlisted-classes>
         <properties>
             <property name="jakarta.persistence.jdbc.driver" value="org.h2.Driver"/>