如何使用@RequestParam（value =" foo"）Map< MyEnum，String>在Spring控制器？ [英] How to use @RequestParam(value="foo") Map<MyEnum, String> in Spring Controller?

问题描述

我想在我的Spring控制器中使用一些 Map< MyEnum，String> 作为 @RequestParam 现在我做了以下：

I want to use some Map<MyEnum, String> as @RequestParam in my Spring Controller. For now I did the following:

public enum MyEnum {
    TESTA("TESTA"),
    TESTB("TESTB");

    String tag;

    // constructor MyEnum(String tag) and toString() method omitted
}

@RequestMapping(value = "", method = RequestMethod.POST)
public void x(@RequestParam Map<MyEnum, String> test) {
    System.out.println(test);
    if(test != null) {
        System.out.println(test.size());
        for(Entry<MyEnum, String> e : test.entrySet()) {
            System.out.println(e.getKey() + " : " + e.getValue());
        }
    }
}

获取EVERY参数。因此，如果我调用？FOO = BAR 的URL，它会输出 FOO：BAR 。所以它绝对需要每个String，而不只是在 MyEnum 中定义的字符串。

This acts strange: I just get EVERY Parameter. So if I call the URL with ?FOO=BAR it outputs FOO : BAR. So it definitely takes every String and not just the Strings defined in MyEnum.

所以我想，为什么不命名参数： @RequestParam（value =foo）Map< MyEnum，String> test 。但是我只是不知道如何传递参数，我总是得到 null 。

So I thought about, why not name the param: @RequestParam(value="foo") Map<MyEnum, String> test. But then I just don't know how to pass the parameters, I always get null.

任何其他解决方案为此？

Or is there any other solution for this?

因此，如果你看看这里： http://static.springsource.org/spring/docs /3.2.x/javadoc-api/org/springframework/web/bind/annotation/RequestParam.html

So if you have a look here: http://static.springsource.org/spring/docs/3.2.x/javadoc-api/org/springframework/web/bind/annotation/RequestParam.html

它说：如果方法参数映射< String，String> 或 MultiValueMap< String，String> ..] 。因此，必须可以使用 value =foo，并以某种方式设置值;）

It says: If the method parameter is Map<String, String> or MultiValueMap<String, String> and a parameter name is not specified [...]. So it must be possible to use value="foo" and somehow set the values ;)

em>如果方法参数类型为 Map 并且指定了请求参数名称，则请求参数值将转换为 Map

And: If the method parameter type is Map and a request parameter name is specified, then the request parameter value is converted to a Map assuming an appropriate conversion strategy is available. So where to specify a conversion strategy?

现在，您可以选择适当的转换策略我已经建立了一个自定义的解决方案：

Now I've built a custom solution which works:

@RequestMapping(value = "", method = RequestMethod.POST)
public void x(@RequestParam Map<String, String> all) {
    Map<MyEnum, String> test = new HashMap<MyEnum, String>();
    for(Entry<String, String> e : all.entrySet()) {
        for(MyEnum m : MyEnum.values()) {
            if(m.toString().equals(e.getKey())) {
                test.put(m, e.getValue());
            }
        }
    }

    System.out.println(test);
    if(test != null) {
        System.out.println(test.size());
        for(Entry<MyEnum, String> e : test.entrySet()) {
            System.out.println(e.getKey() + " : " + e.getValue());
        }
    }
}

可以处理此...

推荐答案

@RequestParam(value="foo") Map<MyEnum, String> 

以上工作： -
您必须传递以下格式的值

foo [MyTestA] = bar

foo [MyTestB] = bar2

For Above to work:- You have to pass values in below format
foo[MyTestA]= bar
foo[MyTestB]= bar2

现在绑定String，例如MyTestA，MyTestB 等到你的MyEnum

你必须定义一个转换器。请查看此链接

Now to bind String such as "MyTestA","MyTestB" etc..to your MyEnum
You have to define a converter . Take a look a this link

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