@@ -0,0 +1,895 @@
+package com.alibaba.json.bvt.parser.bug;%0A%0Aimport com.alibaba.fastjson.JSON;%0Aimport com.alibaba.fastjson.serializer.BeanContext;%0Aimport com.alibaba.fastjson.serializer.ContextValueFilter;%0Aimport junit.framework.TestCase;%0A%0Apublic class Bug_for_zitao extends TestCase %7B%0A    public void test_for_issue() throws Exception %7B%0A        Model m = new Model();%0A        ContextValueFilter v = new ContextValueFilter() %7B%0A%0A            public Object process(BeanContext context, Object object, String name, Object value) %7B%0A                if (value == null && context != null && Number.class.isAssignableFrom(context.getFieldClass())) %7B%0A                    return -1;%0A                %7D%0A                return null;%0A            %7D%0A        %7D;%0A%0A        String json = JSON.toJSONString(m, v);%0A        assertEquals(%22%7B%5C%22value%5C%22:-1%7D%22, json);%0A    %7D%0A%0A    public static class Model %7B%0A        public Number value;%0A    %7D%0A%7D%0A

add testcase