问题描述

在springmvc中使用fastjson,在前台发现了"$ref": "$.apis.我的[1].methods[2].bodyobject.jsondocTemplate"这一种引用.

解决方案

通过设置DisableCircularReferenceDetect来禁用循环引用:

1. 前端js单独处理

   var FastJson = {
    isArray: function(a) {
        return "object" == typeof a && "[object array]" == Object.prototype.toString.call(a).toLowerCase();
    },
    isObject: function(a) {
        return "object" == typeof a && "[object object]" == Object.prototype.toString.call(a).toLowerCase();
    },
    format: function(a) {
        if (null == a) return null;
        "string" == typeof a && (a = eval("(" + a + ")"));
        return this._format(a, a, null, null, null);
    },
    _randomId: function() {
        return "randomId_" + parseInt(1E9 * Math.random());
    },
    _getJsonValue: function(a, c) {
        var d = this._randomId(),
        b;
        b = "" + ("function " + d + "(root){") + ("return root." + c + ";");
        b += "}";
        b += "";
        var e = document.createElement("script");
        e.id = d;
        e.text = b;
        document.body.appendChild(e);
        d = window[d](a);
        e.parentNode.removeChild(e);
        return d;
    },
    _format: function(a, c, d, b, e) {
        d || (d = "");
        if (this.isObject(c)) {
            if (c.$ref) {
                var g = c.$ref;
                0 == g.indexOf("$.") && (b[e] = this._getJsonValue(a, g.substring(2)));
                return
            }
            for (var f in c) b = d,
            "" != b && (b += "."),
            g = c[f],
            b += f,
            this._format(a, g, b, c, f);
        } else if (this.isArray(c)) for (f in c) b = d,
        g = c[f],
        b = b + "[" + f + "]",
        this._format(a, g, b, c, f);
        return a;
    }
   };
   

2. 后台序列化前设置禁用循环引用 重点在SerializerFeature feature = SerializerFeature.DisableCircularReferenceDetect;这句.

   import com.alibaba.fastjson.JSON;
   import com.alibaba.fastjson.serializer.SerializerFeature;
   public class Test {
    public static void main(String[] args) {
        Map<String, Student> maps = new HashMap<String, Student>();
        Student s1 = new Student("s1", 16);
        maps.put("s1", s1);
        maps.put("s2", s1);
        SerializerFeature feature = SerializerFeature.DisableCircularReferenceDetect;
        byte[] bytes = JSON.toJSONBytes(maps, feature);
        System.out.println(new String(bytes));
    }
   }
   

3. 字段名称上配置

   // 字段名上添加
   @JSONField(serialize = false)
   

4. spring mvc中配置转换禁用循环引用

    <bean id="fastJsonHttpMessageConverter" class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter">
        <property name="supportedMediaTypes">
            <list>
                <value>application/json;charset=UTF-8</value>
                <value>text/html;charset=UTF-8</value>
            </list>
        </property>
        <property name="features">
            <list>
                <value>QuoteFieldNames</value>
                <value>WriteDateUseDateFormat</value>
                <!-- 禁用循环检测 -->
                <value>DisableCircularReferenceDetect</value>
            </list>
        </property>
    </bean>
   

参考文章

1. 前台解决Json数据中出现”$ref”的问题
2. 加上FastJsonHttpMessageConverter之后，前端获取不到数据
3. fastjson在使用hibernate关系模型转json出现$ref解决办法
4. 在springmvc中解决FastJson循环引用的问题