初识json

josn包所需要的依赖有一下五个

<!-- 引入json依赖  -->

<dependency>
<groupId>net.sf.json-lib</groupId>
<artifactId>json-lib</artifactId>
<version>2.4</version>
<classifier>jdk15</classifier>
</dependency>
<dependency>
<groupId>commons-beanutils</groupId>
<artifactId>commons-beanutils</artifactId>
<version>1.7.0</version>
</dependency>
<dependency>
<groupId>commons-collections</groupId>
<artifactId>commons-collections</artifactId>
<version>3.1</version>
</dependency>
<dependency>
<groupId>commons-lang</groupId>
<artifactId>commons-lang</artifactId>
<version>2.5</version>
</dependency>
<dependency>
<groupId>net.sf.ezmorph</groupId>
<artifactId>ezmorph</artifactId>
<version>1.0.3</version>
</dependency>

常用有三种json解析jackson、fastjson、gson。

1. jackson依赖包

           <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
       <dependency>
           <groupId>com.fasterxml.jackson.core</groupId>
           <artifactId>jackson-databind</artifactId>
           <version>2.9.3</version>
       </dependency>
       <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-core -->
       <dependency>
           <groupId>com.fasterxml.jackson.core</groupId>
           <artifactId>jackson-core</artifactId>
           <version>2.9.3</version>
       </dependency>
       <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-annotations -->
       <dependency>
           <groupId>com.fasterxml.jackson.core</groupId>
           <artifactId>jackson-annotations</artifactId>
           <version>2.9.3</version>
       </dependency>

2. fastjson
   xml <!-- https://mvnrepository.com/artifact/com.alibaba/fastjson --> <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.2.47</version> </dependency>
   ####遇到对象转json字符串时,如果对象中的属性字段为null，则不会显示出来。解决方法
   JSONObject.toJSONString(bean,SerializerFeature.WriteMapNullValue)

3. gson
   ````xml
   
   
   com.google.code.gson
   gson
   2.8.2

   ````