Add request validation and global exception handling for Student API

Spring-Boot-REST-API/src/main/java/com/wasim/rest/api/controller/StudentController.java

@@ -2,6 +2,8 @@
 
 import java.util.List;
 
+import com.wasim.rest.api.request.StudentRequest;
+import jakarta.validation.Valid;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
@@ -25,9 +27,18 @@ public class StudentController {
 	private StudentService studentService;
 
 	@PostMapping("/saveStudent")
-	public ResponseEntity<Student> createStudent(@RequestBody Student student) {
-
-		return new ResponseEntity<Student>(studentService.createStudent(student), HttpStatus.CREATED);
+	public ResponseEntity<Student> createStudent(@Valid @RequestBody StudentRequest request) {
+
+		// Here Converting the Request to Entity.
+		Student student = new Student();
+		student.setName(request.getName());
+		student.setEmail(request.getEmail());
+
+		//called service
+		Student savedStudent = studentService.createStudent(student);
+
+		//returning the response
+		return new ResponseEntity<>(savedStudent, HttpStatus.CREATED);
 	}
 
 	@GetMapping("/getAllStudent")

Spring-Boot-REST-API/src/main/java/com/wasim/rest/api/exception/GlobalExceptionHandler.java

@@ -0,0 +1,31 @@
+package com.wasim.rest.api.exception;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.MethodArgumentNotValidException;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+
+@RestControllerAdvice(basePackages = "com.wasim.rest.api")
+public class GlobalExceptionHandler {
+
+    @ExceptionHandler(MethodArgumentNotValidException.class)
+    public ResponseEntity<Map<String, Object>> handleValidationExceptions(MethodArgumentNotValidException ex) {
+
+        System.out.println("GlobalExceptionHandler hit");
+        Map<String, String> errors = new HashMap<>();
+
+        ex.getBindingResult().getFieldErrors().forEach(error ->
+                errors.put(error.getField(), error.getDefaultMessage())
+        );
+
+        Map<String, Object> response = new HashMap<>();
+        response.put("message", "Validation failed");
+        response.put("errors", errors);
+
+        return new ResponseEntity<>(response, HttpStatus.BAD_REQUEST);
+    }
+}

Spring-Boot-REST-API/src/main/java/com/wasim/rest/api/request/StudentRequest.java

@@ -0,0 +1,30 @@
+package com.wasim.rest.api.request;
+
+import jakarta.validation.constraints.Email;
+import jakarta.validation.constraints.NotBlank;
+
+public class StudentRequest {
+
+    @NotBlank(message = "Name is required")
+    private String name;
+
+    @NotBlank(message = "Email is required")
+    @Email(message = "Invalid email format")
+    private String email;
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    public void setEmail(String email) {
+        this.email = email;
+    }
+}