Intro to Spring Boot: Routes

Notes

A route is the mechanism by which a request path gets assigned to a controller within our application. In this video we'll explore routes and how data is transferred from a web page to a specific controller.

We'll look at three different ways handlers can receive data from users:

1. Via a GET request and query parameters
2. Via a POST request and post parameters
3. Via a URL segment and a path variable

Data Transfer by GET

• Add to your controller a parameter that is a request object of the HttpServletRequest class.
• Get data from this request object by using the key of the desired parameter and the method getParameter.
• Use the data in your controller to return a customized greeting.

  @RequestMapping(value = "")
  @ResponseBody
  public String index(HttpServletRequest request){
      String name = request.getParameter("name");
      return "Hello " + name;
  }

Data Transfer by POST

• Display a form that will allow the user to submit data. To do this, create a new request handler that returns a string of HTML.

  @RequestMapping(value = "hello", method = RequestMethod.GET)
  @ResponseBody
  public String helloForm(){
      String html = "<form method='post'>" +
              "<input type='text' name='name' />" +
              "<input type='submit' value='Greet Me!'/>" +
              "</form>";
      return html;
  }

• Create another handler that will handle POST requests and access the request object.

  @RequestMapping(value = "hello", method = RequestMethod.POST)
  @ResponseBody
  public String helloPost(HttpServletRequest request){
      String name = request.getParameter("name");
      return "Hello " + name;
  }

Data Transfer by URL Segment

• Create a new handler that will access data via a URL segment:

  @RequestMapping(value = "hello/{name}")
  @ResponseBody
  public String helloUrlSegment(@PathVariable String name){
      return "Hello " + name;
  }