关于Struts下集成rest调用外部接口时的问题

前提：

    项目原为Struts框架，未集成相关的webservice。
    集成了RestTemplate来调用接口，并引入了相关JAR包，对WEB.XML做了修改，并添加了相应的rest-servlet.xml.

RestTemplate相关jar包：

RestTemplate.jpg

---

WEB.XML:

---

<servlet>
//配置一个Servlet，有这个Servlet统一调度页面的请求
<servlet-name>springRest</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/platform/rest-servlet.xml</param-value>
</init-param>
// <async-supported>true</async-supported>
<load-on-startup>1</load-on-startup>
</servlet>

---

rest-servlet.xml:

    <beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="
    http://www.springframework.org/schema/beans     
    http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
    http://www.springframework.org/schema/context 
    http://www.springframework.org/schema/context/spring-context-4.2.xsd
    http://www.springframework.org/schema/mvc
    http://www.springframework.org/schema/mvc/spring-mvc-4.2.xsd">
<context:component-scan base-package="com.tobacco" />
<mvc:annotation-driven />
<bean id="mappingJacksonHttpMessageConverter"
      class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
    <property name="supportedMediaTypes">
        <list>
            <value>application/json;charset=UTF-8</value>
        </list>
    </property>
</bean>
<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
    <property name="messageConverters">
        <list>
            <ref bean="mappingJacksonHttpMessageConverter"/>
        </list>
    </property>
</bean>

</beans>

需求：

    调用外部接口。接口为public String xxx(String inJson) throws IOException{……}
    引用了spring 的RestTemplate作为调用接口方式。
    RestTemplate rest = new RestTemplate();//创建rest对象
    String str = rest.postForObject(url, inJson, String.class).toString();// 调用接口

    正确输出了接口地址和参数。

[19-9-29 11:03:50:180 CST] 00000092 SystemOut O http://10.29.3.17/crm/restful/CUST_ACC_INFO_SYNC_SERVICE/updateCustAccInfoLn
[19-9-29 11:03:50:180 CST] 00000092 SystemOut O {"HEAD":{"SOURCE":"东软结算"},"BODY":{"DATASET":[{"CUST_ID":"211002100025","COM_ID":"11112110","BANK_ID":"03","PAYMENT_MODE":"1"}]}}

报错：

[19-9-29 11:03:50:181 CST] 00000092 ServletWrappe E com.ibm.ws.webcontainer.servlet.ServletWrapper service SRVE0014E: 未捕获到 service() 异常的根本原因 /jsp/visitsales/bank/customerPaySave.jsp：com.ibm.websphere.servlet.error.ServletErrorReport: java.lang.NoSuchMethodError: org/springframework/util/CollectionUtils.unmodifiableMultiValueMap(Lorg/springframework/util/MultiValueMap;)Lorg/springframework/util/MultiValueMap;

原因为： RestTemplate--的相关支持jar包与spring-2.0.4冲突，且后者优先级更高，导致在调用RestTemplate的实体对象中的方法时找不到，故而有java.lang.NoSuchMethodError异常。