Springboot请求和响应相关注解及使用场景分析

@RestController
@RequestMapping("/api")
public class MyController {
    @RequestMapping(value = "/hello", method = RequestMethod.GET)
    public String sayHello() {
        return "Hello, World!";
    }
}

@RestController
@RequestMapping("/api")
public class MyController {
    @GetMapping("/hello")
    public String sayHello() {
        return "Hello, World!";
    }
    @PostMapping("/create")
    public String createItem(@RequestBody Item item) {
        return "Item created";
    }
}

@GetMapping("/greet")
public String greet(@RequestParam(name = "name", defaultValue = "World") String name) {
    return "Hello, " + name;
}

@GetMapping("/items/{id}")
public Item getItem(@PathVariable("id") Long id) {
    // Logic to fetch item by id
    return item;
}

@PostMapping("/items")
public Item createItem(@RequestBody Item item) {
    // Logic to create item
    return item;
}

@GetMapping("/user-agent")
public String getUserAgent(@RequestHeader("User-Agent") String userAgent) {
    return "User-Agent: " + userAgent;
}

@GetMapping("/items/{id}")
@ResponseBody
public Item getItem(@PathVariable("id") Long id) {
    // Logic to fetch item by id
    return item;
}

@RestController
@RequestMapping("/api")
public class MyController {
    @GetMapping("/items/{id}")
    public Item getItem(@PathVariable("id") Long id) {
        return item;
    }
}

@PostMapping("/items")
@ResponseStatus(HttpStatus.CREATED)
public Item createItem(@RequestBody Item item) {
    return item;
}

@RestController
@RequestMapping("/api")
public class MyController {
    @GetMapping("/items/{id}")
    public Item getItem(@PathVariable("id") Long id) {
        if (id == null) {
            throw new ItemNotFoundException("Item not found");
        }
        return item;
    }
    @ExceptionHandler(ItemNotFoundException.class)
    @ResponseStatus(HttpStatus.NOT_FOUND)
    public String handleItemNotFoundException(ItemNotFoundException ex) {
        return ex.getMessage();
    }
}

@RestController
@RequestMapping("/api")
@CrossOrigin(origins = "http://example.com")
public class MyController {
    @GetMapping("/items/{id}")
    public Item getItem(@PathVariable("id") Long id) {
        return item;
    }
}

@GetMapping("/attributes")
public String getAttribute(@RequestAttribute("myAttribute") String myAttribute) {
    return "Attribute: " + myAttribute;
}

@PostMapping("/items")
public Item createItem(@Valid @RequestBody Item item) {
    return item;
}