springmvc的controller可以访问但不能返回map类型的数据

今天药忘吃喽~ 2022-05-14 08:06 176阅读 0赞

1、首先，web.xml加上这一段配置：

<bean
    		class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
    		<property name="messageConverters">
    			<list>
    				
    				<ref bean="mappingJacksonHttpMessageConverter" />
    			</list>
    		</property>
    	</bean>
    	<bean
    		class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
    		<property name="messageConverters">
    			<list>
    				<ref bean="mappingJacksonHttpMessageConverter" />
    			</list>
    		</property>
    	</bean>
    
    	<bean id="mappingJacksonHttpMessageConverter"
    		class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
    		<property name="supportedMediaTypes">
    			<list>
    				<bean class="org.springframework.http.MediaType">
    					<constructor-arg index="0" value="text" />
    					<constructor-arg index="1" value="plain" />
    					<constructor-arg index="2" value="UTF-8" />
    				</bean>
    				<bean class="org.springframework.http.MediaType">
    					<constructor-arg index="0" value="*" />
    					<constructor-arg index="1" value="*" />
    					<constructor-arg index="2" value="UTF-8" />
    				</bean>
    				<bean class="org.springframework.http.MediaType">
    					<constructor-arg index="0" value="text" />
    					<constructor-arg index="1" value="*" />
    					<constructor-arg index="2" value="UTF-8" />
    				</bean>
    				<bean class="org.springframework.http.MediaType">
    					<constructor-arg index="0" value="application" />
    					<constructor-arg index="1" value="json" />
    					<constructor-arg index="2" value="UTF-8" />
    				</bean>
    			</list>
    		</property>
    	</bean>

2、 controller这样写：

@Controller
    @RequestMapping("/dfc")
    public class dfcController {
    	@Autowired
    	@Qualifier("dataflow_connectionInfo_service")
    	private Idataflow_connectionInfo service = new dataflow_connectionInfo_service_impl();
    	
    	// 查询数据
    	@RequestMapping(value="/getDFC",method=RequestMethod.GET)
    	@ResponseBody
    	public Map<String, Object> doSelectDfc() {
    		return service.findAllDfc();
    	}
    	
    	@RequestMapping("/getJson")
    	@ResponseBody
    	public String doGet() {
    		return "11111111";
    	}
    	
    	// 插入数据
    	@RequestMapping("/insertDFC")
    	public Object doInsertDfc(dataflow_connectionInfo info) {
    
    		if (service.addDfc(info)) {
    			return true;
    		} else {
    			return false;
    		}
    	}
    }

3、 重新导2.7版本的jackson相关包：   
**jackson-databind-2.7.4.jar**   
**jackson-annotations-2.7.4.jar**   
**jackson-core-2.7.4.jar**

以上jar包下载地址（拷贝下面URL在新页面打开，不然下载不了）：   
[http://cdn.sojson.com/file/16-05-03-20-51-11/json-jar.zip][http_cdn.sojson.com_file_16-05-03-20-51-11_json-jar.zip]

参考：[https://blog.csdn.net/gsycwh/article/details/56675836][https_blog.csdn.net_gsycwh_article_details_56675836]

[http_cdn.sojson.com_file_16-05-03-20-51-11_json-jar.zip]: http://cdn.sojson.com/file/16-05-03-20-51-11/json-jar.zip
[https_blog.csdn.net_gsycwh_article_details_56675836]: https://blog.csdn.net/gsycwh/article/details/56675836