我们先来看一个例子:
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package com.elong.bms; import java.io.OutputStream; import java.util.HashMap; import java.util.Map; import com.alibaba.fastjson.JSON; 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); byte [] bytes = JSON.toJSONBytes(maps); System.out.println( new String(bytes)); } } |
输出:
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{ "s1" :{ "age" :16, "name" : "s1" }, "s2" :{ "$ref" : "$.s1" }} |
可以看到,这个json如果发到前端是无法使用的,幸好FastJson提供了解决办法,我们来看下,解决办法为禁用循环引用检测,代码如下:
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package com.elong.bms; import java.io.OutputStream; import java.util.HashMap; import java.util.Map; 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)); } } |
输出如下:
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{ "s1" :{ "age" :16, "name" : "s1" }, "s2" :{ "age" :16, "name" : "s1" }} |
问题是如果我们在spring mvc中使用的时候,需要将SerializerFeature注入到MessageConverter里面, FastJsonHttpMessageConverter
但是SerializerFeature是一个enum类型的,又是一个array,考虑到大部分人对这个不熟悉,直接上代码了。
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< bean id = "jsonConverter" class = "com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter" > < property name = "supportedMediaTypes" value = "application/json;charset=UTF-8" /> < property name = "features" > < array value-type = "com.alibaba.fastjson.serializer.SerializerFeature" > < value >DisableCircularReferenceDetect</ value > </ array > </ property > </ bean > < bean id = "DisableCircularReferenceDetect" class = "org.springframework.beans.factory.config.FieldRetrievingFactoryBean" > < property name = "staticField" value = "com.alibaba.fastjson.serializer.SerializerFeature.DisableCircularReferenceDetect" ></ property > </ bean > |
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持服务器之家。
原文链接:http://asialee.iteye.com/blog/2101915