Not found org.springframework.http.converter.json.MappingJacksonHttpMessageConverter

　　緣由spring3跟spring4的jackson不同。

　　解決方案：

　　1）spring3.x是org.springframework.http.converter.json.MappingJacksonHttpMessageConverter

　　spring4.x是org.springframework.http.converter.json.MappingJackson2HttpMessageConverter

　　2）添加依賴的包。

　　<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>