bug fiexd for Long Value Field, fixed issue '#534'

src/main/java/com/alibaba/fastjson/serializer/IntegerCodec.java

@@ -50,7 +50,7 @@ public void write(JSONSerializer serializer, Object object, Object fieldName, Ty
             return;
         }
 
-        if (fieldType == long.class) {
+        if (fieldType == long.class || fieldType == Long.class) {
             out.writeLong(value.longValue());
         } else {
             out.writeInt(value.intValue());

src/test/java/com/alibaba/json/bvt/bug/Bug_for_Issue_534.java

@@ -0,0 +1,30 @@
+package com.alibaba.json.bvt.bug;
+
+import org.junit.Assert;
+
+import com.alibaba.fastjson.JSON;
+
+import junit.framework.TestCase;
+
+public class Bug_for_Issue_534 extends TestCase {
+    public void test_for_issue() throws Exception {
+        Value value = new Value();
+        value.aLong = 2459838341588L;
+
+        String text = JSON.toJSONString(value);
+        Assert.assertEquals("{\"aLong\":2459838341588}", text);
+    }
+
+    class Value {
+
+        private Long aLong;
+
+        public Long getaLong() {
+            return aLong;
+        }
+
+        public void setaLong(Long aLong) {
+            this.aLong = aLong;
+        }
+    }
+}