虽然标记的答案是正确的，但有一种方法可以做到这一点，没有例外。服务返回搜索对象的Optional<T>，这被映射到HttpStatus。如果找到OK，如果为空则返回404。

@Controller
public class SomeController {

    @RequestMapping.....
    public ResponseEntity<Object> handleCall(@PathVariable String param) {
        return  service.find(param)
                .map(result -> new ResponseEntity<>(result, HttpStatus.OK))
                .orElse(new ResponseEntity<>(HttpStatus.NOT_FOUND));
    }
}

@Service
public class Service{
  
    public Optional<Object> find(String param){
        if(!found()){
            return Optional.empty();
        }
        ...
        return Optional.of(data); 
    }
    
}

重写你的方法签名，使它接受HttpServletResponse作为参数，这样你就可以对它调用setStatus(int)。

http://static.springsource.org/spring/docs/3.0.x/spring-framework-reference/html/mvc.html#mvc-ann-requestmapping-arguments

因为做同一件事至少有十种方法总是好的:

import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

@Controller
public class Something {
    @RequestMapping("/path")
    public ModelAndView somethingPath() {
        return new ModelAndView("/", HttpStatus.NOT_FOUND);
    }
}

虽然标记的答案是正确的，但有一种方法可以做到这一点，没有例外。服务返回搜索对象的Optional<T>，这被映射到HttpStatus。如果找到OK，如果为空则返回404。

@Controller
public class SomeController {

    @RequestMapping.....
    public ResponseEntity<Object> handleCall(@PathVariable String param) {
        return  service.find(param)
                .map(result -> new ResponseEntity<>(result, HttpStatus.OK))
                .orElse(new ResponseEntity<>(HttpStatus.NOT_FOUND));
    }
}

@Service
public class Service{
  
    public Optional<Object> find(String param){
        if(!found()){
            return Optional.empty();
        }
        ...
        return Optional.of(data); 
    }
    
}

从Spring 3.0.2开始，你可以返回ResponseEntity<T>作为控制器方法的结果:

@RequestMapping.....
public ResponseEntity<Object> handleCall() {
    if (isFound()) {
        // do what you want
        return new ResponseEntity<>(HttpStatus.OK);
    }
    else {
        return new ResponseEntity<>(HttpStatus.NOT_FOUND);
    }
}

(ResponseEntity<T>是一个比@ResponseBody注释更灵活的注释-参见另一个问题)

从Spring 3.0开始，你还可以抛出一个用@ResponseStatus注释声明的Exception:

@ResponseStatus(value = HttpStatus.NOT_FOUND)
public class ResourceNotFoundException extends RuntimeException {
    ...
}

@Controller
public class SomeController {
    @RequestMapping.....
    public void handleCall() {
        if (isFound()) {
            // whatever
        }
        else {
            throw new ResourceNotFoundException(); 
        }
    }
}