Fix for mybatis#1794 Comparing TypeVariable must be done by equals()

piotrponikowski · Jan 4, 2020 · 02716da · 02716da
1 parent 35acc5a
commit 02716da
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Showing 2 changed files with 30 additions and 2 deletions.
diff --git a/src/main/java/org/apache/ibatis/reflection/TypeParameterResolver.java b/src/main/java/org/apache/ibatis/reflection/TypeParameterResolver.java
@@ -179,7 +179,7 @@ private static Type scanSuperTypes(TypeVariable<?> typeVar, Type srcType, Class<
       }
       if (declaringClass == parentAsClass) {
         for (int i = 0; i < parentTypeVars.length; i++) {
-          if (typeVar == parentTypeVars[i]) {
+          if (typeVar.equals(parentTypeVars[i])) {
             return parentAsType.getActualTypeArguments()[i];
           }
         }
@@ -202,7 +202,7 @@ private static ParameterizedType translateParentTypeVars(ParameterizedType srcTy
     for (int i = 0; i < parentTypeArgs.length; i++) {
       if (parentTypeArgs[i] instanceof TypeVariable) {
         for (int j = 0; j < srcTypeVars.length; j++) {
-          if (srcTypeVars[j] == parentTypeArgs[i]) {
+          if (srcTypeVars[j].equals(parentTypeArgs[i])) {
             noChange = false;
             newParentArgs[i] = srcTypeArgs[j];
           }

diff --git a/src/test/java/org/apache/ibatis/reflection/TypeParameterResolverTest.java b/src/test/java/org/apache/ibatis/reflection/TypeParameterResolverTest.java
@@ -26,6 +26,9 @@
 import java.util.Date;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
 
 import org.apache.ibatis.reflection.typeparam.Calculator;
 import org.apache.ibatis.reflection.typeparam.Calculator.SubCalculator;
@@ -429,4 +432,29 @@ class D extends C<Integer> {}
     Field field = A.class.getDeclaredField("id");
     assertEquals(Integer.class, TypeParameterResolver.resolveFieldType(field, clazz));
   }
+
+  @Test
+  void shouldTypeVariablesBeComparedWithEquals() throws Exception {
+    // #1794
+    ExecutorService executor = Executors.newFixedThreadPool(2);
+    Future<Type> futureA = executor.submit(() -> {
+      Type retType = TypeParameterResolver.resolveReturnType(IfaceA.class.getMethods()[0], IfaceA.class);
+      return ((ParameterizedType) retType).getActualTypeArguments()[0];
+    });
+    Future<Type> futureB = executor.submit(() -> {
+      Type retType = TypeParameterResolver.resolveReturnType(IfaceB.class.getMethods()[0], IfaceB.class);
+      return ((ParameterizedType) retType).getActualTypeArguments()[0];
+    });
+    assertEquals(AA.class, futureA.get());
+    assertEquals(BB.class, futureB.get());
+    executor.shutdown();
+  }
+
+  // @formatter:off
+  class AA {}
+  class BB {}
+  interface IfaceA extends ParentIface<AA> {}
+  interface IfaceB extends ParentIface<BB> {}
+  interface ParentIface<T> {List<T> m();}
+  // @formatter:on
 }