Make sure you have added dependency for a Web application
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
EXAMPLE 1
Create a class with @Component and @RequestMapping annotations to indicating the path.
Use @GetMapping to serve by HTTP GET request and @ResponseBody to return response body with controller method.
@Component
@RequestMapping("hello")
public class EmpController {
@GetMapping
@ResponseBody
public String hello() {
return "Hello world";
}
}
To access above controller, use : http://localhost:8080/hello
Since there is a single method defined with @GetMapping and @ResponseBody , it will be called.
EXAMPLE 2
@Component
@RequestMapping("hello")
public class EmpController2 {
@GetMapping("rest")
@ResponseBody
public String hello() {
return "hello";
}
}
Here, we provided another path with the method also using @GetMapping("path")
To access above controller method, use http://localhost:8080/hello/rest
EXAMPLE 3
Instead of using @GetMapping, @PostMapping etc., you can use @RequestMapping by specifying path and method attributes.
@Component
@RequestMapping("hello")
public class EmpController2 {
@RequestMapping(path="rest2", method=RequestMethod.GET)
@ResponseBody
public String hello2() {
return "hello 2";
}
}
You can access above method using : http://localhost:8080/hello/rest2
EXAMPLE 4
When you need a HTML page, instead of text from the controller method, DO NOT use @responseBody annotation and return a ModelAndView object.
@Component
@RequestMapping("hello")
public class EmpController2 {
@GetMapping("html")
public ModelAndView helloPg() {
ModelAndView modelAndView = new ModelAndView("hello");
modelAndView.addObject("name", "SHAAN");
return modelAndView;
}
}
You can access above method using : http://localhost:8080/hello/html
It will search and display : /src/main/resources/templates/hello.html
