Build path is incomplete. Cannot find class file for org/codehaus/jackson/JsonProcessingException

spring配置文件中 json转换器报错，遇到这个问题后，找出的解决办法！

jackson版本变化太大，有三个jar包。用fastjson只有一个jar包

在maven导入这三个jar

	<dependency>
		<groupId>com.fasterxml.jackson.core</groupId>
		<artifactId>jackson-core</artifactId>
		<version>2.8.5</version>
	</dependency>
	<dependency>
		<groupId>com.fasterxml.jackson.core</groupId>
		<artifactId>jackson-databind</artifactId>
		<version>2.8.5</version>
	</dependency>
	<dependency>
		<groupId>com.fasterxml.jackson.core</groupId>
		<artifactId>jackson-annotations</artifactId>
		<version>2.8.5</version>
	</dependency>

如果报错没有消失 接下来

<bean id="mappingJacksonHttpMessageConverter"  
        class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">  
        <property name="supportedMediaTypes">  
            <list>  
                <value>text/html;charset=UTF-8</value>  
            </list>  
        </property>  
</bean> 

class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter"

改为

class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"

对应的 jackson版本