bug fix for ObjectReaderImplMapTyped, fix issue #557

alibaba · Jul 14, 2022 · 97a6b2c · 97a6b2c
1 parent 61ee908
commit 97a6b2c
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Showing 2 changed files with 63 additions and 2 deletions.
diff --git a/core/src/main/java/com/alibaba/fastjson2/reader/ObjectReaderImplMapTyped.java b/core/src/main/java/com/alibaba/fastjson2/reader/ObjectReaderImplMapTyped.java
@@ -4,6 +4,8 @@
 import com.alibaba.fastjson2.util.ReferenceKey;
 import com.alibaba.fastjson2.util.TypeUtils;
 
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Modifier;
 import java.lang.reflect.Type;
 import java.util.Collection;
 import java.util.HashMap;
@@ -25,6 +27,8 @@ class ObjectReaderImplMapTyped
     final long features;
     final Function builder;
 
+    final Constructor defaultConstructor;
+
     ObjectReader valueObjectReader;
     ObjectReader keyObjectReader;
 
@@ -40,6 +44,18 @@ public ObjectReaderImplMapTyped(Class mapType, Class instanceType, Type keyType,
         this.valueClass = TypeUtils.getClass(valueType);
         this.features = features;
         this.builder = builder;
+
+        Constructor defaultConstructor = null;
+        Constructor[] constructors = this.instanceType.getDeclaredConstructors();
+        for (Constructor constructor : constructors) {
+            if (constructor.getParameterCount() == 0
+                    && !Modifier.isPublic(constructor.getModifiers())) {
+                constructor.setAccessible(true);
+                defaultConstructor = constructor;
+                break;
+            }
+        }
+        this.defaultConstructor = defaultConstructor;
     }
 
     @Override
@@ -92,9 +108,12 @@ public Object createInstance(Map input, long features) {
     public Object createInstance(long features) {
         if (instanceType != null && !instanceType.isInterface()) {
             try {
+                if (defaultConstructor != null) {
+                    return defaultConstructor.newInstance();
+                }
                 return instanceType.newInstance();
-            } catch (InstantiationException | IllegalAccessException e) {
-                throw new JSONException("create map error");
+            } catch (Exception e) {
+                throw new JSONException("create map error", e);
             }
         }
         return new HashMap();

diff --git a/core/src/test/java/com/alibaba/fastjson2/issues/Issue557.java b/core/src/test/java/com/alibaba/fastjson2/issues/Issue557.java
@@ -0,0 +1,42 @@
+package com.alibaba.fastjson2.issues;
+
+import com.alibaba.fastjson2.JSONFactory;
+import com.alibaba.fastjson2.JSONObject;
+import com.alibaba.fastjson2.TypeReference;
+import com.alibaba.fastjson2.reader.ObjectReader;
+import com.alibaba.fastjson2.reader.ObjectReaderImplMap;
+import org.junit.jupiter.api.Test;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class Issue557 {
+    static {
+        ObjectReader objectReader1 = ObjectReaderImplMap.of(new TypeReference<Map<String, Object>>() {
+        }.getType(), TestPublicMap.class, 0);
+        JSONFactory.getDefaultObjectReaderProvider().register(TestPublicMap.class, objectReader1);
+
+        ObjectReader objectReader2 = ObjectReaderImplMap.of(new TypeReference<Map<String, Object>>() {
+        }.getType(), TestPrivateMap.class, 0);
+        JSONFactory.getDefaultObjectReaderProvider().register(TestPrivateMap.class, objectReader2);
+    }
+
+    @Test
+    public void test() {
+        Map<String, Object> a = JSONObject.parseObject("{'a':'b'}").to(TestPublicMap.class);
+        assertEquals("b", a.get("a"));
+
+        Map<String, Object> b = JSONObject.parseObject("{'a':'b'}").to(TestPrivateMap.class);
+        assertEquals("b", b.get("a"));
+    }
+
+    public static class TestPublicMap
+            extends HashMap<String, Object> {
+    }
+
+    private static class TestPrivateMap
+            extends HashMap<String, Object> {
+    }
+}