作者 | 翟永超
来源 | http:// blog.didispace.com/spri ng-boot-learning-21-2-6/
来源平台 | 微信公众号
如果您看过之前的Spring Boot 1.x教程,或者自己原本就对Spring Boot有一些经验,或者对Spring MVC很熟悉。那么对于Spring构建的Web应用在启动的时候,都会输出当前应用创建的HTTP接口列表。
比如下面的这段日志:
2020-02-11 15:32:39.293 INFO 48395 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2020-02-11 15:32:39.482 INFO 48395 --- [ main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@7ff95560: startup date [Tue Feb 11 15:32:37 CST 2020]; root of context hierarchy
2020-02-11 15:32:39.568 INFO 48395 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/users/{id}],methods=[GET]}" onto public com.didispace.chapter26.User com.didispace.chapter26.UserController.getUser(java.lang.Long)
2020-02-11 15:32:39.569 INFO 48395 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/users/{id}],methods=[PUT]}" onto public java.lang.String com.didispace.chapter26.UserController.putUser(java.lang.Long,com.didispace.chapter26.User)
2020-02-11 15:32:39.570 INFO 48395 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/users/],methods=[GET]}" onto public java.util.List com.didispace.chapter26.UserController.getUserList()
2020-02-11 15:32:39.570 INFO 48395 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/users/],methods=[POST]}" onto public java.lang.String com.didispace.chapter26.UserController.postUser(com.didispace.chapter26.User)
2020-02-11 15:32:39.570 INFO 48395 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/users/{id}],methods=[DELETE]}" onto public java.lang.String com.didispace.chapter26.UserController.deleteUser(java.lang.Long)
2020-02-11 15:32:39.573 INFO 48395 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.ResponseEntity> org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
2020-02-11 15:32:39.573 INFO 48395 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
2020-02-11 15:32:39.590 INFO 48395 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2020-02-11 15:32:39.590 INFO 48395 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapp
这些日志接口信息是由org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping
类在启动的时候,通过扫描Spring MVC的@Controller
、@RequestMapping
等注解去发现应用提供的所有接口信息。然后在日志中打印,以方便开发者排查关于接口相关的启动是否正确。
但是,足够仔细的开发者可能已经发现,从Spring Boot 2.1.0版本开始,就不再打印这些信息了,完整的启动日志变的非常少,以Spring Boot 2.x基础教程:构建RESTful API与单元测试一文的例子为例,可以看到输入内容如下:
2020-02-11 15:34:15.280 INFO 48784 --- [main] c.d.chapter26.Chapter26Application : Starting Chapter26Application on zhaiyongchaodeMacBook-Pro.local with PID 48784 (/Users/zhaiyongchao/Documents/git/github/SpringBoot-Learning/2.1.x/chapter2-6/target/classes started by zhaiyongchao in /Users/zhaiyongchao/Documents/git/github/SpringBoot-Learning/2.1.x)
2020-02-11 15:34:15.283 INFO 48784 --- [main] c.d.chapter26.Chapter26Application : No active profile set, falling back to default profiles: default
2020-02-11 15:34:16.556 INFO 48784 --- [main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
2020-02-11 15:34:16.587 INFO 48784 --- [main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2020-02-11 15:34:16.588 INFO 48784 --- [main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.16]
2020-02-11 15:34:16.596 INFO 48784 --- [main] o.a.catalina.core.AprLifecycleListener : The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [/Users/zhaiyongchao/Library/Java/Extensions:/Library/Java/Extensions:/Network/Library/Java/Extensions:/System/Library/Java/Extensions:/usr/lib/java:.]
2020-02-11 15:34:16.702 INFO 48784 --- [main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2020-02-11 15:34:16.702 INFO 48784 --- [main] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 1377 ms
2020-02-11 15:34:16.954 INFO 48784 --- [main] o.s.s.concurrent.ThreadPoolTaskExecutor : Initializing ExecutorService 'applicationTaskExecutor'
2020-02-11 15:34:17.187 INFO 48784 --- [main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ''
2020-02-11 15:34:17.192 INFO 48784 --- [main] c.d.chapter26.Chapter26Application : Sta
为什么在Spring Boot 2.1.x版本中不再打印请求路径列表呢?
主要是由于从该版本开始,将这些日志的打印级别做了调整:从原来的INFO
调整为TRACE
。所以,当我们希望在应用启动的时候打印这些信息的话,只需要在配置文件增增加对RequestMappingHandlerMapping
类的打印级别设置即可,比如在application.properties
中增加下面这行配置:
logging.level.org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping=trace
在增加了上面的配置之后重启应用,便可以看到如下的日志打印:
2020-02-11 15:36:09.787 TRACE 49215 --- [main] s.w.s.m.m.a.RequestMappingHandlerMapping :
c.d.c.UserController:
{
PUT /users/{
id}}: putUser(Long,User)
{
GET /users/{
id}}: getUser(Long)
{
POST /users/}: postUser(User)
{
GET /users/}: getUserList()
{
DELETE /users/{
id}}: deleteUser(Long)
2020-02-11 15:36:09.791 TRACE 49215 --- [main] s.w.s.m.m.a.RequestMappingHandlerMapping :
o.s.b.a.w.s.e.BasicErrorController:
{
/error}: error(HttpServletRequest)
{
/error, produces [text/html]}: errorHtml(HttpServletRequest,HttpServletResponse)
2020-02-11 15:36:09.793 DEBUG 49215 --- [main] s.w.s.m.m.a.RequestMappingHandlerMapping : 7 mappings in 'requestMappingHandlerMapping'
可以看到在2.1.x版本之后,除了调整了日志级别之外,对于打印内容也做了调整。现在的打印内容根据接口创建的Controller类做了分类打印,这样更有助于开发者根据自己编写的Controller来查找初始化了那些HTTP接口。