SPRINGMVC return to map and return JSON example

Spring MVC supports the following return methods: Modelandview, Model, Modelmap, Map,view, String, void.

Map

@RequestMapping ("/demo2/show") public     map<string, string> getmap () {         map<string, string> Map = new Hashmap<string, string> ();         Map.put ("Key1", "value-1");         Map.put ("Key2", "value-2");         return map;     

The value can be obtained straight through ${key1} in the JSP page, and Map.put () is equivalent to the Request.setattribute method.

The page reads:

<c:forEach items="${map}"var="entry">

        <c:out value= "${entry.key}" />          <c:out value= "${entry.value}" /> </c:forEach>

Return to the JSON example (using Jackson):

@RequestMapping ("/load1")    @ResponseBody public    string Load1 (@RequestParam string name, @RequestParam string Password) throws ioexception{        System.out.println (name+ ":" +password);          Return name+ ":" +password;        Mydog dog=new Mydog ();        Dog.setname ("Xiao Ha");d og.setage ("1 years old");d Og.setcolor ("dark grey");        Objectmapper objectmapper = new Objectmapper ();        String jsonstring=objectmapper.writevalueasstring (dog);        System.out.println (jsonstring);        return jsonstring;    }

Summary:
1. The return value type using String as the request processing method is a more general method, so the returned logical view name does not bind to the request URL, and the model data can be controlled by Modelmap.
2. When using Void,map,model, return the corresponding logical view name real URL is: prefix prefix + view name +suffix suffix.

<bean
class= "Org.springframework.web.servlet.view.InternalResourceViewResolver" >
<property name= "prefix" value= "/web-inf/jsp/"/>
<property name= "suffix" value= ". jsp"/>
<property name= "Viewclass"
Value= "Org.springframework.web.servlet.view.JstlView"/>
</bean>

3. Using String,modelandview to return the view name can be not bound by the requested URL, Modelandview can set the returned view name.

SPRINGMVC return to map and return JSON example