@@ -0,0 +1,985 @@
+package com.alibaba.json.bvt;%0D%0A%0D%0Aimport org.junit.Assert;%0D%0A%0D%0Aimport com.alibaba.fastjson.JSON;%0D%0Aimport com.alibaba.fastjson.annotation.JSONField;%0D%0Aimport com.alibaba.fastjson.serializer.SerializeConfig;%0D%0Aimport com.alibaba.fastjson.serializer.SerializerFeature;%0D%0A%0D%0Aimport junit.framework.TestCase;%0D%0A%0D%0Apublic class StringFieldTest2 extends TestCase %7B%0D%0A%0D%0A    public void test_codec_null_1() throws Exception %7B%0D%0A        V0 v = new V0();%0D%0A%0D%0A        SerializeConfig mapping = new SerializeConfig();%0D%0A        %0D%0A%0D%0A        String text = JSON.toJSONString(v, mapping, SerializerFeature.WriteMapNullValue);%0D%0A        Assert.assertEquals(%22%7B%5C%22value%5C%22:%5C%22%5C%22%7D%22, text);%0D%0A    %7D%0D%0A%0D%0A    public static class V0 %7B%0D%0A%0D%0A        @JSONField(serialzeFeatures=SerializerFeature.WriteNullStringAsEmpty)%0D%0A        private String value;%0D%0A%0D%0A        public String getValue() %7B%0D%0A            return value;%0D%0A        %7D%0D%0A%0D%0A        public void setValue(String value) %7B%0D%0A            this.value = value;%0D%0A        %7D%0D%0A%0D%0A    %7D%0D%0A%7D%0D%0A

add testcase