我目前正在编写某种框架，该框架将允许其他人为其编写REST控制器。自然，我希望那些“其他”与我的代码中发生的事情尽可能少地互动。
具体来说，我希望并需要访问请求数据（即
RequestEntity，然后由其他控制器处理请求。在控制器处理请求之前先“拦截”请求，然后才让控制器处理请求。
考虑以下代码：
@RestController
@RequestMapping("/")
public class MyController {
@GetMapping("/")
@ResponseBody
public ResponseEntity<String> getSomething(RequestEntity requestEntity) {
MyClass.doStuffWithRequestEntity(requestEntity);
// ...
现在我需要的是调用ExternalClass.doStuffWithRequestEntity(requestEntity);而不需要显式调用它。是否可以在某个类中调用某种方法（将RequestEntity传递给它！）而不必显式调用它？
此外，上述Interceptor类应创建并配置一个对象，然后该对象再次可供其余控制器使用。
我会在想类似的东西
class RestController {
@RestController
@RequestMapping("/")
public class MyController {
@GetMapping("/")
@ResponseBody
public ResponseEntity<String> getSomething() {
MyClass x = MyClass.getInstanceCreatedByInterceptor();
}
}
}
和
class Interceptor {
public void doStuffWithRequestEntity(requestEntity) {
MyClass x = new MyClass();
x.fillObjectWithData();
}
}
之前被执行。
这个想法是，每个（！）传入请求都将被解析，并且其内容将被解码，而其余控制器的程序员完全不必关心这一点。他们应该只通过MyClass实例访问数据。
有没有办法做到这一点？
答案 0 :(得分：2)
Spring-boot允许我们配置自定义拦截器。通常，在Spring Boot应用程序中，所有内容都是自动配置的，在这种情况下，我们可以使用WebMvcConfigurerAdapter 自定义。只需扩展{ {1}}，并提供此类中所需的配置。
请记住添加WebMvcConfigurerAdapter批注，以便在组件扫描期间spring可以拾取此类。
@Configuration这是通常向Spring Boot应用程序添加拦截器的方式。希望这可能有助于回答您的问题。
从spring 5.xx或spring-boot 2起，@Configuration
public class WebMvcConfig extends WebMvcConfigurerAdapter {
@Autowired
HandlerInterceptor customInjectedInterceptor;
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(...)
...
registry.addInterceptor(customInjectedInterceptor).addPathPatterns("/**");
}
}
被标记为已弃用。WebMvcConfigurerAdapter接口（由抽象类{{1 }}）从Spring 5开始，包含其所有方法的默认实现。结果，抽象适配器类被标记为已弃用。您可以按照以下方式采用它：
WebMvcConfigurer答案 1 :(得分：1)
import javax.servlet.http.HttpServletRequest ;
import javax.servlet.http.HttpServletResponse;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
@Configuration
public class AuthenticationHandlerInterceptor implements HandlerInterceptor {
@Override
public void afterCompletion(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, Exception arg3)
throws Exception {
}
@Override
public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, ModelAndView arg3)
throws Exception {
}
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object arg2) throws Exception {
if (validrequest) {
//fill data here add pass to next level
return true;
} else {
// if you opt to not to proceed the request further you can simply return false here
return false;
}
}
}
prehandle （）–在执行实际的处理程序之前调用，但尚未生成视图 postHandle （）–执行处理程序后调用
afterCompletion （）–在完整请求完成并生成视图之后调用
答案 2 :(得分：1)
对于所有在此处遇到相同或相似问题的人，这是一个带有Interceptor的SpringBoot（2.1.4）应用程序的最小工作示例：
Minimal.java：
@SpringBootApplication
public class Minimal
{
public static void main(String[] args)
{
SpringApplication.run(Minimal.class, args);
}
}
MinimalController.java：
@RestController
@RequestMapping("/")
public class Controller
{
@GetMapping("/")
@ResponseBody
public ResponseEntity<String> getMinimal()
{
System.out.println("MINIMAL: GETMINIMAL()");
return new ResponseEntity<String>("returnstring", HttpStatus.OK);
}
}
Config.java：
@Configuration
public class Config implements WebMvcConfigurer
{
//@Autowired
//MinimalInterceptor minimalInterceptor;
@Override
public void addInterceptors(InterceptorRegistry registry)
{
registry.addInterceptor(new MinimalInterceptor());
}
}
MinimalInterceptor.java：
public class MinimalInterceptor extends HandlerInterceptorAdapter
{
@Override
public boolean preHandle(HttpServletRequest requestServlet, HttpServletResponse responseServlet, Object handler) throws Exception
{
System.out.println("MINIMAL: INTERCEPTOR PREHANDLE CALLED");
return true;
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception
{
System.out.println("MINIMAL: INTERCEPTOR POSTHANDLE CALLED");
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception exception) throws Exception
{
System.out.println("MINIMAL: INTERCEPTOR AFTERCOMPLETION CALLED");
}
}
按广告宣传
输出将为您提供以下信息：
> Task :Minimal.main()
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.1.4.RELEASE)
2019-04-29 11:53:47.560 INFO 4593 --- [ main] io.minimal.Minimal : Starting Minimal on y with PID 4593 (/x/y/z/spring-minimal/build/classes/java/main started by x in /x/y/z/spring-minimal)
2019-04-29 11:53:47.563 INFO 4593 --- [ main] io.minimal.Minimal : No active profile set, falling back to default profiles: default
2019-04-29 11:53:48.745 INFO 4593 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
2019-04-29 11:53:48.780 INFO 4593 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2019-04-29 11:53:48.781 INFO 4593 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.17]
2019-04-29 11:53:48.892 INFO 4593 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2019-04-29 11:53:48.893 INFO 4593 --- [ main] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 1269 ms
2019-04-29 11:53:49.130 INFO 4593 --- [ main] o.s.s.concurrent.ThreadPoolTaskExecutor : Initializing ExecutorService 'applicationTaskExecutor'
2019-04-29 11:53:49.375 INFO 4593 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ''
2019-04-29 11:53:49.380 INFO 4593 --- [ main] io.minimal.Minimal : Started Minimal in 2.525 seconds (JVM running for 2.9)
2019-04-29 11:54:01.267 INFO 4593 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring DispatcherServlet 'dispatcherServlet'
2019-04-29 11:54:01.267 INFO 4593 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Initializing Servlet 'dispatcherServlet'
2019-04-29 11:54:01.286 INFO 4593 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Completed initialization in 19 ms
MINIMAL: INTERCEPTOR PREHANDLE CALLED
MINIMAL: GETMINIMAL()
MINIMAL: INTERCEPTOR POSTHANDLE CALLED
MINIMAL: INTERCEPTOR AFTERCOMPLETION CALLED