improved support kotlin data class. #1374

src/main/java/com/alibaba/fastjson/parser/JavaBeanInfo.java

@@ -286,9 +286,10 @@ class JavaBeanInfo {
                 Type[] getGenericParameterTypes = fieldGenericSupport //
                     ? creatorConstructor.getGenericParameterTypes() //
                     : parameterTypes;
-                    
+
+                Annotation[][] paramAnnotationArrays = creatorConstructor.getParameterAnnotations();
                 for (int i = 0; i < parameterTypes.length; ++i) {
-                    Annotation[] paramAnnotations = creatorConstructor.getParameterAnnotations()[i];
+                    Annotation[] paramAnnotations = paramAnnotationArrays[i];
                     JSONField fieldAnnotation = null;
                     for (Annotation paramAnnotation : paramAnnotations) {
                         if (paramAnnotation instanceof JSONField) {
@@ -341,8 +342,9 @@ class JavaBeanInfo {
                             ? factoryMethod.getGenericParameterTypes() //
                             : parameterTypes;
 
+                    Annotation[][] paramAnnotationArrays = factoryMethod.getParameterAnnotations();
                     for (int i = 0; i < parameterTypes.length; ++i) {
-                        Annotation[] paramAnnotations = factoryMethod.getParameterAnnotations()[i];
+                        Annotation[] paramAnnotations = paramAnnotationArrays[i];
                         JSONField fieldAnnotation = null;
                         for (Annotation paramAnnotation : paramAnnotations) {
                             if (paramAnnotation instanceof JSONField) {
@@ -397,10 +399,11 @@ class JavaBeanInfo {
                                 ? creatorConstructor.getGenericParameterTypes() //
                                 : parameterTypes;
 
+                        Annotation[][] paramAnnotationArrays = creatorConstructor.getParameterAnnotations();
                         for (int i = 0; i < parameterTypes.length; ++i) {
                             String paramName = parameters[i];
 
-                            Annotation[] paramAnnotations = creatorConstructor.getParameterAnnotations()[i];
+                            Annotation[] paramAnnotations = paramAnnotationArrays[i];
                             JSONField fieldAnnotation = null;
                             for (Annotation paramAnnotation : paramAnnotations) {
                                 if (paramAnnotation instanceof JSONField) {

src/main/java/com/alibaba/fastjson/util/TypeUtils.java

@@ -15,25 +15,14 @@
  */
 package com.alibaba.fastjson.util;
 
+import java.lang.annotation.Annotation;
 import java.lang.reflect.*;
 import java.math.BigDecimal;
 import java.math.BigInteger;
 import java.security.AccessControlException;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
-import java.util.ArrayList;
-import java.util.Calendar;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.Date;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Iterator;
-import java.util.LinkedHashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.TreeSet;
+import java.util.*;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 
@@ -926,6 +915,8 @@ public class TypeUtils {
         Map<String, FieldInfo> fieldInfoMap = new LinkedHashMap<String, FieldInfo>();
         Map<Class<?>, Field[]> classFieldCache = new HashMap<Class<?>, Field[]>();
 
+        boolean kotlin = TypeUtils.isKotlin(clazz);
+
         Field[] declaredFields = clazz.getDeclaredFields();
         if (!fieldOnly) {
             List<Method> methodList = new ArrayList<Method>();
@@ -954,6 +945,11 @@ public class TypeUtils {
                 }
             }
 
+            // for kotlin
+            Constructor[] constructors = null;
+            Annotation[][] paramAnnotationArrays = null;
+            String[] paramNames = null;
+            short[] paramNameMapping = null;
 
             for (Method method : methodList) {
                 String methodName = method.getName();
@@ -970,6 +966,46 @@ public class TypeUtils {
                     annotation = getSupperMethodAnnotation(clazz, method);
                 }
 
+                if (annotation == null && kotlin) {
+                    if (constructors == null) {
+                        constructors = clazz.getDeclaredConstructors();
+                        if (constructors.length == 1) {
+                            paramAnnotationArrays = constructors[0].getParameterAnnotations();
+                            paramNames = TypeUtils.getKoltinConstructorParameters(clazz);
+
+                            if (paramNames != null) {
+                                String[] paramNames_sorted = new String[paramNames.length];
+                                System.arraycopy(paramNames, 0,paramNames_sorted, 0, paramNames.length);
+                                Arrays.sort(paramNames_sorted);
+
+                                paramNameMapping = new short[paramNames.length];
+                                for (short p = 0; p < paramNames.length; p++) {
+                                    int index = Arrays.binarySearch(paramNames_sorted, paramNames[p]);
+                                    paramNameMapping[index] = p;
+                                }
+                                paramNames = paramNames_sorted;
+                            }
+
+                        }
+                    }
+                    if (paramNames != null && paramNameMapping != null && methodName.startsWith("get")) {
+                        String propertyName = decapitalize(methodName.substring(3));
+                        int p = Arrays.binarySearch(paramNames, propertyName);
+                        if (p >= 0) {
+                            short index = paramNameMapping[p];
+                            Annotation[] paramAnnotations = paramAnnotationArrays[index];
+                            if (paramAnnotations != null) {
+                                for (Annotation paramAnnotation : paramAnnotations) {
+                                    if (paramAnnotation instanceof JSONField) {
+                                        annotation = (JSONField) paramAnnotation;
+                                        break;
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+
                 if (annotation != null) {
                     if (!annotation.serialize()) {
                         continue;

src/test/java/com/alibaba/json/bvt/kotlin/DataClassTest.java

@@ -18,7 +18,7 @@ public class DataClassTest extends TestCase {
 
         String json = "{\"aa\":1001,\"bb\":1002}";
         Object obj = JSON.parseObject(json, clazz);
-        assertEquals("{\"a\":1001,\"b\":1002}", JSON.toJSONString(obj));
+        assertEquals("{\"aa\":1001,\"bb\":1002}", JSON.toJSONString(obj));
     }
 
     public static class ExtClassLoader extends ClassLoader {

src/test/java/com/alibaba/json/bvt/kotlin/MyStateObjectTest.java

+package com.alibaba.json.bvt.kotlin;
+
+import com.alibaba.fastjson.JSON;
+import junit.framework.TestCase;
+import org.apache.commons.io.IOUtils;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * Created by wenshao on 06/08/2017.
+ */
+public class MyStateObjectTest extends TestCase {
+    public void test_user() throws Exception {
+        ExtClassLoader classLoader = new ExtClassLoader();
+        Class clazz = classLoader.loadClass("MyStateObject");
+
+        String json = "{\"name\":\"wenshao\",\"age\":99}";
+        Object obj = JSON.parseObject(json, clazz);
+        assertEquals("{\"age\":99,\"name\":\"wenshao\"}", JSON.toJSONString(obj));
+    }
+
+    public static class ExtClassLoader extends ClassLoader {
+
+        public ExtClassLoader() throws IOException {
+            super(Thread.currentThread().getContextClassLoader());
+
+            {
+                byte[] bytes;
+                InputStream is = Thread.currentThread().getContextClassLoader().getResourceAsStream("kotlin/MyStateObject.clazz");
+                bytes = IOUtils.toByteArray(is);
+                is.close();
+
+                super.defineClass("MyStateObject", bytes, 0, bytes.length);
+            }
+        }
+    }
+}