Merge pull request #4490 from fanatixan/bael-1906

BAEL-1906

spring-mvc-java/src/main/java/com/baeldung/annotations/CustomResponseController.java

@@ -0,0 +1,62 @@
+package com.baeldung.annotations;
+
+import java.io.IOException;
+import java.time.Year;
+
+import javax.servlet.http.HttpServletResponse;
+
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+
+@Controller
+@RequestMapping("/customResponse")
+public class CustomResponseController {
+
+    @GetMapping("/hello")
+    public ResponseEntity<String> hello() {
+        return new ResponseEntity<>("Hello World!", HttpStatus.OK);
+    }
+
+    @GetMapping("/age")
+    public ResponseEntity<String> age(@RequestParam("yearOfBirth") int yearOfBirth) {
+        if (isInFuture(yearOfBirth)) {
+            return new ResponseEntity<>("Year of birth cannot be in the future", HttpStatus.BAD_REQUEST);
+        }
+
+        return new ResponseEntity<>("Your age is " + calculateAge(yearOfBirth), HttpStatus.OK);
+    }
+
+    private int calculateAge(int yearOfBirth) {
+        return currentYear() - yearOfBirth;
+    }
+
+    private boolean isInFuture(int year) {
+        return currentYear() < year;
+    }
+
+    private int currentYear() {
+        return Year.now().getValue();
+    }
+
+    @GetMapping("/customHeader")
+    public ResponseEntity<String> customHeader() {
+        HttpHeaders headers = new HttpHeaders();
+        headers.add("Custom-Header", "foo");
+
+        return new ResponseEntity<>("Custom header set", headers, HttpStatus.OK);
+    }
+
+    @GetMapping("/manual")
+    public void manual(HttpServletResponse response) throws IOException {
+        response.setHeader("Custom-Header", "foo");
+        response.setStatus(200);
+        response.getWriter()
+            .println("Hello World!");
+    }
+
+}