如何为Map<String，String>类型的RequestParam指定默认值？

@RequestMapping("/example")
public String exampleMethod(@RequestParam Map<String, String> requestParams) {
    // Your code here
}

@RequestMapping("/example")
public String exampleMethod(@RequestParam Map<String, String> requestParams) {
    String paramValue = requestParams.containsKey("paramKey") ? requestParams.get("paramKey") : "defaultValue";
    // Your code here
}

@RequestMapping("/example")
public String exampleMethod(@RequestParam Map<String, String> requestParams) {
    String paramValue = requestParams.getOrDefault("paramKey", null);
    // Your code here
}