SpringMVC 4.1 新特性（一）JSONP的支持

为了启用@ResponseBody和ResponseEntity方法的JSONP支持，需声明一个@ControllerAdvice的bean，它扩展了AbstractJsonpResponseBodyAdvice，如下所示其中constructor参数指示JSONP查询参数名称：

package com.somnus.advice;
 
import org.springframework.core.annotation.Order;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.AbstractJsonpResponseBodyAdvice;
 
/**
 * 对使用HttpMessageConverter的@ResponseBody的支持 
 */
@Order(2)  
/* 需要被扫描 */
@ControllerAdvice(basePackages = "com.somnus")//配置你需要路径下的控制器
public class JsonpAdvice extends AbstractJsonpResponseBodyAdvice {
    public JsonpAdvice() {
        super("callback"); //指定jsonpParameterNames
    }
}

@Controller
@RequestMapping(value = "response")
public class ResponseBodyBindController {
 
    @GetMapping(value="responsebodybind3")
    @ResponseBody
    public Account responsebodybind2(String username,String password){
        Account account = new Account(username,password);
        System.out.println("responsebodybind3:" + account);
        return account;
    }
}

• 访问http://localhost:8080/SpringMVC/response/responsebodybind

• 访问http://localhost:8080/SpringMVC/response/responsebodybind?callback=callback

并且值得一提的是，如果你希望可以支持多种参数，都能支持JSONP，构造方法可以设置多个值，如：

@ControllerAdvice(basePackages = "com.somnus")//配置你需要路径下的控制器
public class JsonpAdvice extends AbstractJsonpResponseBodyAdvice {
    public JsonpAdvice() {
        super("callback", "jsonp"); //指定jsonpParameterNames
    }
}

那么你将惊喜的看到

<mvc:view-resolvers>
    <mvc:content-negotiation>
        <mvc:default-views>
            <bean class="org.springframework.web.servlet.view.json.MappingJackson2JsonView">
                <property name="jsonpParameterNames">
                    <set>
                        <value>jsonp</value>
                        <value>callback</value>
                    </set>
                </property> 
            </bean>
        </mvc:default-views>
    </mvc:content-negotiation>
    <mvc:jsp prefix="/WEB-INF/views/" suffix=".jsp" />
</mvc:view-resolvers>

/**
 * <p>.json结尾返回json</p>  
 * <p>.xml结尾返回xml</p>   
 * @author：Somnus
 * @return
 */
@RequestMapping(value="viewResolver", method = {RequestMethod.GET})
public ModelAndView viewResolver(){
    ModelAndView mv = new ModelAndView();
    Account account = new Account();
    account.setUsername(WebUtil.getRequest().getParameter("username"));
    account.setPassword(WebUtil.getRequest().getParameter("password"));
    mv.addObject(account);
    mv.setViewName("viewResolver");
    return mv;
}

• http://localhost:8080/SpringMVC/account/viewResolver.json?username=aa&password=123

• http://localhost:8080/SpringMVC/account/viewResolver.json?username=aa&password=123&callback=callback

• http://localhost:8080/SpringMVC/account/viewResolver.json?username=aa&password=123&jsonp=callback