Spring MVC - @PathVariable Examples

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;

import java.util.logging.Logger;

@Controller
@RequestMapping("trades")
public class TradeController {

    private static final Logger LOGGER = Logger.getLogger(TradeController.class.getName());

    @RequestMapping
    public String handleTradeRequest (Trade trade, Model model) {
        String msg = String.format("trade request. buySell: %s, buyCurrency: %s, sellCurrency: %s",
                                   trade.getBuySell(), trade.getBuyCurrency(),
                                   trade.getSellCurrency());
        LOGGER.info(msg);
        model.addAttribute("msg", msg);
        return "my-page";
    }

    @RequestMapping("{buySell}/{buyCurrency}/{sellCurrency}")
    public String handleTradeRequest2 (Trade trade, Model model) {
        String msg = String.format("trade request. buySell: %s, buyCurrency: %s, sellCurrency: %s",
                                   trade.getBuySell(), trade.getBuyCurrency(),
                                   trade.getSellCurrency());
        LOGGER.info(msg);
        model.addAttribute("msg", msg);
        return "my-page";
    }


    @RequestMapping("paramTest")
    public String handleTradeRequest (@RequestParam("buySell") String buySell,
                                      @RequestParam("buyCurrency") String buyCurrency,
                                      @RequestParam("sellCurrency") String sellCurrency,
                                      Model map) {
        String msg = String.format("trade request. buySell: %s, buyCurrency: %s, sellCurrency: %s",
                                   buySell, buyCurrency, sellCurrency);
        LOGGER.info(msg);
        map.addAttribute("msg", msg);
        return "my-page";
    }

    @RequestMapping("pathTest/{buySell}/{buyCurrency}/{sellCurrency}")
    public String handleTradeRequest3 (@PathVariable("buySell") String buySell,
                                       @PathVariable("buyCurrency") String buyCurrency,
                                       @PathVariable("sellCurrency") String sellCurrency,
                                       Model map) {
        String msg = String.format("trade request. buySell: %s, buyCurrency: %s, sellCurrency: %s",
                                   buySell, buyCurrency, sellCurrency);
        LOGGER.info(msg);
        map.addAttribute("msg", msg);
        return "my-page";
    }
}

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import java.util.Map;

@Controller
@RequestMapping("users")
public class UserController {


    @RequestMapping("{id}")
    public String handleRequest(@PathVariable("id") String userId,
                                Model map) {
        map.addAttribute("msg", "User id " + userId);
        return "my-page";

    }

    //this will fail if code is not compiled with debugging information
    @RequestMapping("profiles/{userName}")
    public String handleRequest2(@PathVariable String userName,
                                 Model model) {
        model.addAttribute("msg", "user profile name : " + userName);
        return "my-page";
    }

    @RequestMapping("{id}/posts/{postId}")
    public String handleRequest3(@PathVariable("id") String userId,
                                 @PathVariable("postId") String postId,
                                 Model model) {
        model.addAttribute("msg",
                           "user id : " + userId + ", post id: " + postId);
        return "my-page";

    }

    @RequestMapping("{id}/messages/{msgId}")
    public String handleRequest4(@PathVariable Map<String, String> varsMap,
                                 Model model) {
        model.addAttribute("msg", varsMap.toString());
        return "my-page";
    }

    @RequestMapping({"/profile", "/profile/{id}"})
    public String getUserProfile(
            @PathVariable(value = "id", required = false) Long userId,
            Model model) {

        if (userId == null) {
            model.addAttribute("msg", "No user id provided");

        } else {
            // ID provided → return that specific user's profile
            model.addAttribute("msg",
                               "user id: " + userId);
        }
        return "my-page";
    }
}