如何使用 Spring MVC 为每个对象传递列表参数? [英] How to pass list parameters for each object using Spring MVC?

问题描述

我在这里使用 Spring MVC RequestMapping 作为 GET 参数.下面是我的代码 -

I am using Spring MVC RequestMapping here for GET parameters. Below is my code -

@RequestMapping(value = "index", method = RequestMethod.GET)
public HashMap<String, String> handleRequest(@RequestParam("dc1Servers") String dc1Servers, @RequestParam("dc2Servers") String dc2Servers, @RequestParam("dc3Servers") String dc3Servers) {
    HashMap<String, String> model = new HashMap<String, String>();
    String helloWorld = "Hello World!";
    model.put("greeting", helloWorld);

    System.out.println(dc1Servers);
    System.out.println(dc2Servers);
    System.out.println(dc3Servers);

    return model;
}

我正在点击这个 URL - http://127.0.0.1:8080/dataweb/index?dc1Servers=3&dc2Servers=3&dc3Servers=3 然后它进入上面的代码并打印在控制台上输出 3 以进行所有打印并且工作正常.

I am hitting this URL - http://127.0.0.1:8080/dataweb/index?dc1Servers=3&dc2Servers=3&dc3Servers=3 then it goes into the above code and prints out 3 on the console for all the print and works fine.

现在，如果你看到，我有 dc1、dc2 和 dc3.

Now if you see, I have dc1, dc2 and dc3.

所以对于dc1，我想在URL中将这些作为参数发送-

So for dc1, I would like to send these in the URL as the parameters-

dc1Servers=3

dc1HostA
dc1HostB
dc1HostC

dc1IPAddresssA
dc1IPAddresssB
dc1IPAddresssC

与dc2类似，我想在URL中将这些作为参数发送-

Similarly for dc2, I would like to send these in the URL as the parameters-

dc2Servers=3

dc2HostA
dc2HostB
dc2HostC

dc2IPAddresssA
dc2IPAddresssB
dc2IPAddresssC

与dc3类似，我想在URL中将这些作为参数发送-

Similarly for dc3, I would like to send these in the URL as the parameters-

dc3Servers=3

dc3HostA
dc3HostB
dc3HostC

dc3IPAddresssA
dc3IPAddresssB
dc3IPAddresssC  

现在我不确定我将如何为这个用例构建一个 URL 以及我的方法会是什么样子?我想通过一个 URL 调用发送它们.

Now I am not sure how would I construct an URL for this use case and how would my method will look like? I would like to send them in one single URL call.

这个用例可以使用 Spring MVC 吗?

Is this use case possible to do using Spring MVC?

推荐答案

你可以以任何你认为合适的方式传递参数，一种方法是通过它们的自然分组传递它们，如下所示:http://127.0.0.1:8080/dataweb/index?dc1Server=dc1HostA,dc1IPAddressA&dc1Server=dcHostB,dc1IPAddressB....

You could pass the parameters any way you see fit, one way is to pass them by their natural grouping like this: http://127.0.0.1:8080/dataweb/index?dc1Server=dc1HostA,dc1IPAddressA&dc1Server=dcHostB,dc1IPAddressB....

通过为每个组使用相同的参数名称，您需要使用 MultiValueMap.MultiValueMap 或多或少是一个 Map>，因此具有相同名称(dc1Server、dc2Server 等)的参数将位于相同的列表.您可以使用它来获取您传入的参数的完整列表，如下所示:

By using the same parameter name for each group you'd need to use a MultiValueMap. A MultiValueMap is more or less a Map<String, List<String>>, so parameters with the same name(dc1Server, dc2Server, etc) would be in the same list. You would use this to get a full list of the params you passed in like this:

public HashMap<String, String> handleRequest(@RequestParam MultiValueMap<String,String> allRequestParams) 

那么你有 3 个键，dc1Server 将包含所有 dc1Server 数据，dc2Server 将包含所有dc2Server 等

Then you'd have 3 keys, dc1Server would contain all the dc1Server data, dc2Server all the dc2Server etc

如果你想直接映射到域对象，可以考虑使用 @ModelAttribute:链接

Could look into using @ModelAttribute if you want to do direct mapping to domain objects: Link

编辑

public void testSpringMultiValueMap() {
        MultiValueMap<String, String> map = new LinkedMultiValueMap<String, String>();
        map.add("dc1Server", "dc1HostA,dc1IPAddressA");
        map.add("dc1Server", "dc1HostB,dc1IPAddressB");
        map.add("dc1Server", "dc1HostC,dc1IPAddressC");
        map.add("dc2Server", "dc2HostA,dc2IPAddressA");
        map.add("dc2Server", "dc2HostB,dc2IPAddressB");
        map.add("dc2Server", "dc2HostC,dc2IPAddressC");

        List<String> dc1List = map.get("dc1Server");

        for(String pair: dc1List) {
            String[] tokens = pair.split(",");
            System.out.println("host: " + tokens[0] + " ip: " + tokens[1]);
        }
    }

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