[CRJVM206] Avoid N+1 selects problem

CHANGELOG.md

@@ -116,6 +116,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Update ecocode-rules-specifications to 1.4.6
 
+## [unreleased]
+
+- #188 Add Hibernate N+1 query detection for lazy-loaded relationship access inside loops and streams
+
+## [2.1.2] - 2026-05-20
+
 [unreleased](https://github.com/green-code-initiative/creedengo-java/compare/2.1.2...HEAD)
 [2.1.2](https://github.com/green-code-initiative/creedengo-java/compare/2.1.1...2.1.2)
 [2.1.1](https://github.com/green-code-initiative/creedengo-java/compare/2.1.0...2.1.1)

src/it/test-projects/creedengo-java-plugin-test-project/src/main/java/org/greencodeinitiative/creedengo/java/checks/CRJVM206/AvoidHibernateLazyRelationAccessInLoopCheckSample.java

@@ -0,0 +1,56 @@
+import java.util.List;
+
+class AvoidHibernateLazyRelationAccessInLoopCheckSample {
+
+    void badForEachLoop(List<Product> products) {
+        for (Product product : products) {
+            product.getOrders(); // Noncompliant
+        }
+    }
+
+    void badForLoop(List<Product> products) {
+        for (int i = 0; i < products.size(); i++) {
+            products.get(i).getOrders(); // Noncompliant
+        }
+    }
+
+    void badStreamForEach(List<Product> products) {
+        products.forEach(product -> {
+            product.getOrders(); // Noncompliant
+        });
+    }
+
+    void badStreamMap(List<Product> products) {
+        products.stream()
+                .map(product -> product.getOrders().size()); // Noncompliant
+    }
+
+    void goodSimpleGetter(List<Product> products) {
+        for (Product product : products) {
+            product.getName();
+        }
+    }
+
+    void goodIdGetter(List<Product> products) {
+        for (Product product : products) {
+            product.getId();
+        }
+    }
+
+    class Product {
+        List<Order> getOrders() {
+            return null;
+        }
+
+        String getName() {
+            return "";
+        }
+
+        Long getId() {
+            return 1L;
+        }
+    }
+
+    class Order {
+    }
+}

src/main/java/org/greencodeinitiative/creedengo/java/JavaCheckRegistrar.java

@@ -38,6 +38,7 @@ public class JavaCheckRegistrar implements CheckRegistrar {
             IncrementCheck.class,
             AvoidUsageOfStaticCollections.class,
             AvoidGettingSizeCollectionInLoop.class,
+            AvoidHibernateLazyRelationAccessInLoopCheck.class,
             AvoidRegexPatternNotStatic.class,
             NoFunctionCallWhenDeclaringForLoop.class,
             AvoidStatementForDMLQueries.class,

src/main/java/org/greencodeinitiative/creedengo/java/checks/AvoidHibernateLazyRelationAccessInLoopCheck.java

@@ -0,0 +1,69 @@
+package org.greencodeinitiative.creedengo.java.checks;
+
+import org.sonar.check.Rule;
+import org.sonar.plugins.java.api.IssuableSubscriptionVisitor;
+import org.sonar.plugins.java.api.tree.BaseTreeVisitor;
+import org.sonar.plugins.java.api.tree.MethodInvocationTree;
+import org.sonar.plugins.java.api.tree.Tree;
+
+import java.util.Arrays;
+import java.util.List;
+
+@Rule(key = "CRJVM206")
+public class AvoidHibernateLazyRelationAccessInLoopCheck extends IssuableSubscriptionVisitor {
+
+    private static final String MESSAGE =
+            "Potential Hibernate N+1 query detected: avoid accessing a lazy relationship inside a loop. "
+                    + "Use JOIN FETCH, EntityGraph, or batch fetching.";
+
+    @Override
+    public List<Tree.Kind> nodesToVisit() {
+        return Arrays.asList(
+                Tree.Kind.FOR_EACH_STATEMENT,
+                Tree.Kind.FOR_STATEMENT,
+                Tree.Kind.WHILE_STATEMENT,
+                Tree.Kind.DO_STATEMENT,
+                Tree.Kind.METHOD_INVOCATION
+        );
+    }
+
+    @Override
+    public void visitNode(Tree tree) {
+        if (tree.is(Tree.Kind.METHOD_INVOCATION)) {
+            MethodInvocationTree methodInvocationTree = (MethodInvocationTree) tree;
+
+            if (isStreamOperation(methodInvocationTree)) {
+                checkInsideTree(tree);
+            }
+        } else {
+            checkInsideTree(tree);
+        }
+    }
+
+    private void checkInsideTree(Tree tree) {
+        tree.accept(new BaseTreeVisitor() {
+            @Override
+            public void visitMethodInvocation(MethodInvocationTree methodInvocationTree) {
+                if (isPotentialLazyRelationGetter(methodInvocationTree)) {
+                    reportIssue(methodInvocationTree, MESSAGE);
+                }
+                super.visitMethodInvocation(methodInvocationTree);
+            }
+        });
+    }
+
+    private boolean isStreamOperation(MethodInvocationTree methodInvocationTree) {
+        String methodName = methodInvocationTree.symbol().name();
+        return "forEach".equals(methodName)
+                || "forEachOrdered".equals(methodName)
+                || "map".equals(methodName)
+                || "peek".equals(methodName);
+    }
+
+    private boolean isPotentialLazyRelationGetter(MethodInvocationTree methodInvocationTree) {
+        String methodName = methodInvocationTree.symbol().name();
+        return methodName.startsWith("get")
+                && methodName.length() > 4
+                && methodName.endsWith("s");
+    }
+}

src/main/resources/org/greencodeinitiative/creedengo/java/creedengo_way_profile.json

@@ -18,6 +18,7 @@
 	"GCI78",
 	"GCI79",
 	"GCI82",
-	"GCI94"
+	"GCI94",
+    "CRJVM206"
   ]
 }

src/test/java/org/greencodeinitiative/creedengo/java/checks/CRJVM206/AvoidHibernateLazyRelationAccessInLoopCheckTest.java

@@ -0,0 +1,33 @@
+/*
+ * creedengo - Java language - Provides rules to reduce the environmental footprint of your Java programs
+ * Copyright © 2024 Green Code Initiative (https://green-code-initiative.org/)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.greencodeinitiative.creedengo.java.checks.CRJVM206;
+
+import org.greencodeinitiative.creedengo.java.checks.AvoidHibernateLazyRelationAccessInLoopCheck;
+import org.junit.jupiter.api.Test;
+import org.sonar.java.checks.verifier.CheckVerifier;
+
+class AvoidHibernateLazyRelationAccessInLoopCheckTest {
+
+    @Test
+    void test() {
+        CheckVerifier.newVerifier()
+                .onFile(System.getProperty("testfiles.path") + "/CRJVM206/AvoidHibernateLazyRelationAccessInLoopCheckSample.java")
+                .withCheck(new AvoidHibernateLazyRelationAccessInLoopCheck())
+                .verifyIssues();
+    }
+}