spring 3.x升级到Spring 4.x 依赖的相关 json jar 包加上即可。（注意事项和步骤）

1. 参考：http://www.sojson.com/blog/145.html

2. 

3. <!-- Spring 升级4+ 依赖的JSON包 -->
4. <dependency>
5. <groupId>com.fasterxml.jackson.core</groupId>
6. <artifactId>jackson-databind</artifactId>
7. <version>2.7.4</version>
8. </dependency>
9. <dependency>
10. <groupId>com.fasterxml.jackson.core</groupId>
11. <artifactId>jackson-core</artifactId>
12. <version>2.7.4</version>
13. </dependency>
14. <dependency>
15. <groupId>com.fasterxml.jackson.core</groupId>
16. <artifactId>jackson-annotations</artifactId>
17. <version>2.7.4</version>
18. </dependency>
19. <!-- /Spring 升级4+ 依赖的JSON包 -->