How does the controller of the java ssm framework pass parameters to the page?

The ssm controller passes parameters to the page

Use Map to pass parameters

Add a Map type parameter A in the controller method. The key-value pair B is put to the put method of parameter A. The key-value pair B can be obtained on the page.

1.java background code writing, the operation and application key-value pairs are put

@RequestMapping("/edit_form")
    public String editApplicationFormPage(Map<String, Object> map,
            HttpServletRequest request, String applicationId) {
        map.put("operation", "edit");
        Application application = applicationService
                .getApplicationById(applicationId);
        if(application.getSysBigIcon()==null||application.getSysBigIcon().equals("")){
            application.setSysBigIcon("/www/images/default.png");
        }
        if(application.getSysIcon()==null||application.getSysIcon().equals("")){
            application.setSysIcon("/www/images/default.png");
        }
        if (application != null) {
            map.put("application", application);
        }
        return "/frame/system/application/application_form";
    }

2. The page uses the key-value pairs passed from the background.

The method used is that the key-value pairs must be wrapped with ${}. For example: ${operation} and ${application.orgId}, ${operation} is the operation key-value pair that refers to the background map put, and ${application.orgId} is an object that refers to the application entity of the background map put.

<script type="text/javascript">
    window.WWWROOT = "${ctx}";
    window.DefaultOrgId  = "<%=user.getDefaultOrgId()%>";
    window.Operation = "${operation}";
    window.OrgId = "${application.orgId}";
    window.TaskAppId = "${application.taskAppId}";
    window.MenuType = "${application.menuType}";
</script>
            <title>${operation eq &#39;add&#39;?&#39;添加&#39;:(operation eq
                &#39;edit&#39;?&#39;编辑&#39;:&#39;查看&#39;)}应用系统</title>

Use PrintWriter to pass parameters

Write some content to PrintWriter. Just return these contents to the page.

1. Writing background code

Add a PrintWrite type parameter writer to the controller method, and use the writer.write() method to write content. The page can return this content. The code is as follows:

@RequestMapping("/add")
    public void  add(HttpServletRequest request, HttpServletResponse response,MenuRight menuRight, PrintWriter writer)
             {
        try{
            Boolean result =menuRightService.addMenuRight(menuRight);
            writer.write("{\"success\":true}");
                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                    writer.write("{\"success\":false}");
                }
 
    }

2. Page code writing

• ##success: The result in function(result) is The content in writer.write() returned by the background

$.ajax({
        type : 'POST',
        url : WWWROOT + "/menuRight/add",
        data : dat,
        success : function(result) {
            if ($.parseJSON(result).success == true) {
                $(stId).attr("checked", true);
            } else {
                alert("添加授权失败");
                $(stId).attr("checked", false);
            }
        }
    });

ssm framework obtains the parameters passed by the page

Receives the name age through @RequestParam

Parameters, and can be empty

@RequestParam(value = "age",required = false)

Passed @PathVariable

##Passed @RequestBody –Not applicable to Get Request

1.@RequestBody receives a request body, only one @RequestBody can exist, and receives all request parameters - once After receiving
2. If you pass an object or array, it must be converted to Json format\or a pure string first
3.@RequestBody No Suitable for Get requests
Receive date type: @DateTimeFormat\@JsonFormat

• @DateTimeFormat

  Usage scenario: page When the date format is passed directly, use this annotation to receive it directly;

• @JsonFormat

  Usage scenario: When the page passes the date format in Json format, use this annotation to receive it; Special Note: The annotation name may be different when using different Json packages

Usage:

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