Spring MVC - How to get all request params in a map in Spring controller?

Under the hood: Born to handle request parameters

Spring MVC gracefully handles request parameters, giving you a smooth ride. Let's get down and dirty with two powerful mechanisms:

Direct access using HttpServletRequest

Stay off @RequestParam but still grab all parameters from the request? Not an issue:

@GetMapping("/your-action")
public String getAllParams(HttpServletRequest request) {
    Map<String, String[]> parameterMap = request.getParameterMap();
    // Here's your map, no '@RequestParam' in sight!
    // (Not that it's a bad thing, it's just you wanted another way)
    return "view-name";
}


This way, your code stays wonderfully flexible, embracing any unexpected parameter.

Model rendition using ModelMap

ModelMap offers smooth interaction between the controller and view layer, making your parameters dance through:

@GetMapping("/your-action")
public String getAllParams(@RequestParam Map<String, String> allRequestParams, ModelMap model) {
    model.addAttribute("params", allRequestParams);
    // Now your views can join the party!
    return "view-name";
}


Bye-bye clumsy parameter passing, hello slick ModelMap magic!

Visualization

Effortlessly turning streams of request parameters into a single, accessible Map:

💧 → param1=value1
💧 → param2=value2
💧 → param3=value3

Bringing all together under @RequestParam in your pond 🗺️:

@RequestParam Map<String, String> allParams
// 🗺️ carves out corners for each 💧: {param1=value1, param2=value2, param3=value3}


Each 💧 has its place, offering a bird's eye view of all parameters at once!

Turbocharged with best practices

Let's not stop here - dive deeper to supercharge your request handling:

Enabling multiple value support

If parameters strike with multiple values, a MultiValueMap is your lifesaver:

@GetMapping("/your-action")
public String getAllParams(@RequestParam MultiValueMap<String, String> params) {
    // params handles multiple values like the champ it is!
    return "view-name";
}


Handle single or multiple values with a smirk, all thanks to MultiValueMap.

Form tackling with POST data

For POST requests, say hello to @ModelAttribute when wrestling with form data:

@PostMapping("/submit-form")
public String submitForm(@ModelAttribute FormData formData) {
    // FormData: "I got this, boss."
    return "result-page";
}


@ModelAttribute bridges the form-to-object gap, making data processing a breeze.

Raw string craving

Should you find yourself craving the raw query string, getQueryString caters to that:

@GetMapping("/your-action")
public String getAllParams(HttpServletRequest request) {
    String rawQueryString = request.getQueryString();
    // Raw and unfiltered, just how you like it.
    return "view-name";
}


Remember, getQueryString is like the sushi of parameters: raw but satisfying.

Navigating Spring upgrades

As Spring keeps blossoming, the way it handles request parameters can change. Stay sharp and stay updated using Spring's documentation.