【fastjson】java.lang.IllegalStateException Failed to introspect Class

【报错】Caused by: java.lang.ClassNotFoundException: com.fasterxml.jackson.core.util.DefaultPrettyPrinter

参考1

参考2

参考3

• 把原来SSM项目里的jackson换成fastjson后，开始报错

Caused by: java.lang.ClassNotFoundException: com.fasterxml.jackson.core.util.DefaultPrettyPrinter

和

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.http.converter.json.MappingJackson2HttpMessageConverter#0'

• 检查后发现是在spring-mvc.xml里配置了这个，这个乱码过滤器是对应jackson的，且配置了@ResponseBody是由jackson解析的

  	  <!--JSON乱码问题配置-->
          <mvc:annotation-driven>
             <mvc:message-converters register-defaults="true">
                  <bean class="org.springframework.http.converter.StringHttpMessageConverter">
                      <constructor-arg value="UTF-8"/>
                  </bean>
                  <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
                      <property name="objectMapper">
                          <bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
                              <property name="failOnEmptyBeans" value="false"/>
                          </bean>
                      </property>
                  </bean>
              </mvc:message-converters>
          </mvc:annotation-driven>
  

  
  

• 使用fastjson的，配置这个乱码过滤器

  	<!--配置@ResponseBody由fastjson解析，以及乱码过滤-->
  	<mvc:annotation-driven>
          <mvc:message-converters register-defaults="true">
              <!-- 配置Fastjson支持 -->
              <bean class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter">
                  <property name="supportedMediaTypes">
                      <list>
                          <value>text/html;charset=UTF-8</value>
                          <value>application/json</value>
                      </list>
                  </property>
                  <property name="features">
                      <list>
                          <value>WriteMapNullValue</value><!--是否输出值为null的字段,默认为false -->
                          <value>QuoteFieldNames</value><!--输出key时是否使用双引号,默认为true -->
                      </list>
                  </property>
              </bean>
          </mvc:message-converters>
      </mvc:annotation-driven>