项目运行时，需要打印更详细的日志信息，不想修改配置文件再重启服务。有没有办法在不直接修改配置重启服务的情况下控制日志级别呢？是的，如果你了解SpringBootAdmin，你应该知道它提供了动态切换日志级别的功能。本文将带你了解不用SpringBootAdmin动态实现日志切换的功能。测试控制器包com.pack.logger.change_level@RestController@RequestMapping("/logger")公共类LoggerLevelChangeController{privatestaticfinalLoggerlogger=LoggerFactory.getLogger(LoggerLevelChangeController.class);@GetMapping("/print")publicObjectprint(){logger.info("ThisisInfologger...");logger.debug("这是调试记录器...");返回“打印”；在配置文件logging中为这个包配置日志级别：level:'[com.pack.logger.change_level]':INFOtest2023-01-1016:29:59.012INFO66436---[nio-8082-exec-5]c.p.l.c.LoggerLevelChangeController：这是信息记录器。..com.pack.logger.change_level包当前配置的日志级别是INFO，所以这里输出info级别的日志信息。当级别调整为DEBUG时，控制台会输出INFO和DEBUG的日志信息，我们这里修改后需要重启服务。接下来我们看看如何在不重启服务的情况下动态调整日志级别。修改日志级别然后我们在上面的Controller中添加如下方法@GetMapping("/level")publicObjectchangeLevel(Stringlevel){LoggingSystemsystem=LoggingSystem.get(LoggingSystem.class.getClassLoader());//第一个参数指定你需要设置的logger的名称//第二个参数将通过接口传入的level转换为LogLevel，然后设置system.setLogLevel("com.pack.logger.change_level",resolveLogLevel（等级））;return"changeloggerlevelsuccess";}privateLogLevelresolveLogLevel(Stringlevel){StringtrimmedLevel=level.trim();returnLogLevel.valueOf(trimmedLevel.toUpperCase(Locale.ENGLISH));}通过LogginSystem对象设置日志级别。测试将日志级别设置为调试，然后方法以上打印界面，控制台输出：2023-01-1016:38:40.490INFO66436---[nio-8082-exec-9]c.p.l.c.LoggerLevelChangeController:ThisisInfologger...2023-01-1016:38:40.490DEBUG66436---[nio-8082-exec-9]c.p.l.c.LoggerLevelChangeController:ThisisDebuglogger...日志级别切换成功，如果你在服务重新启动也将无效。修改整个系统的日志级别上面的例子只是设置了指定logger的名称。如果要调整整个系统的日志级别，可以使用下面的方法：//修改上面的changeLevel方法//要设置的日志记录logger的名称也是通过参数@GetMapping传递的("/level")publicObjectchangeLevel(Stringname,Stringlevel){LoggingSystemsystem=LoggingSystem.get(LoggingSystem.class.getClassLoader());//如果传入的logger名称是root，则将其设置为nullif(name.equalsIgnoreCase("root")){name=null;}//只要把name设置为null，整个系统的level就会一起调整system.setLogLevel(name,resolveLogLevel(level));return"changeloggerlevelsuccess";}测试：将root日志级别更改为debug2023-01-1016:48:15.244DEBUG50544---[nio-8082-exec-6]o.a.coyote.http11.Http11InputBuffer:在fill()之前：parsingHeader:[true],parsingRequestLine:[true],parsingRequestLinePhase:[0],parsingRequestLineStart:[0],byteBuffer.position():[0],byteBuffer.limit()：[0]，结束：[1166]2023-01-1016:48:15.244DEBUG50544---[nio-8082-exec-6]o.a.tomcat.util.net.SocketWrapperBase：套接字：[org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper@619d8bee:org.apache.tomcat.util.net.NioChannel@38066775:java.nio.channels.SocketChannel[已连接本地=/0:0:0:0:0:0:0:1:8082远程=/0:0:0:0:0:0:0:1:59173]]，从缓冲区读取：[0]2023-01-1016:48:15.244DEBUG50544---[nio-8082-exec-6]org.apache.tomcat.util.net.NioEndpoint：套接字：[org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper@619d8bee:org.apache.tomcat.util.net.NioChannel@38066775:java.nio.channels。SocketChannel[connectedlocal=/0:0:0:0:0:0:0:1:8082remote=/0:0:0:0:0:0:0:1:59173]],直接从套接字读取：[1166]2023-01-1016：48：15.244DEBUG50544---[nio-8082-exec-6]o.a.coyote.http11.Http11InputBuffer：收到[GET/logger2/printHTTP/1.1Host：localhost：8082Connection:keep-aliveCache-Control:max-age=0sec-ch-ua:"Not?A_Brand";v="8","Chromium";v="108","GoogleChrome";v="108"sec-ch-ua-mobile:?0sec-ch-ua-platform:"Windows"Upgrade-Insecure-Requests:1User-Agent:Mozilla/5.0(WindowsNT10.0;Win64;x64)AppleWebKit/537.36(KHTML,likeGecko)Chrome/108.0.0.0Safari/537.36Accept:text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9Sec-Fetch-Site:noneSec-Fetch-Mode:navigateSec-Fetch-User:?1Sec-Fetch-Dest:documentAccept-Encoding:gzip,deflate,brAccept-Language:zh-CN,zh;q=0.9Cookie:rememberMe=true;会话=YzQ4NTBkOTQtN2EzYi00YWNjLTk0ZmItZTBmYWVlNGJiNDUx；用户名=管理员；大小=小；侧边栏状态=1；密码=KfhG4ggUsr1BSTaK5EMdiKhM+5GWwmRl9agleoPd4kaDAjpntUNu81ogBYVblALKNf9uqqnY+vEmCpY0ALWuyw==;Admin-Token=eyJhbGciOiJIUzUxMiJ9.eyJsb2dpbl91c2VyX2tleSI6Ijk0MGEwZmVhLWY2NWMtNGRmNy1hMDhhLWMxZDRhMDBkODZmOSJ9.r4syG-ZXBwOre2p6CDpIqaBePZuzPHFjako6oGXUejqxzxAoHA70Ov5bwmqJ9WB-rnwPQx-QSKxLJKDcgfBKdw;JSESSIONID=862D0514B6BDF558E299783289188AB9]2023-01-1016:48:15.245DEBUG50544---[nio-8082-exec-6]o.a.t.util.http.Rfc6265CookieProcessor：Cookies：解析b[]：rememberMe=true；塞西ON=YzQ4NTBkOTQtN2EzYi00YWNjLTk0ZmItZTBmYWVlNGJiNDUx；用户名=管理员；大小=小；侧边栏状态=1；密码=KfhG4ggUsr1BSTaK5EMdiKhM+5GWwmRl9agleoPd4kaDAjpntUNu81ogBYVblALKNf9uqqnY+vEmCpY0ALWuyw==;Admin-Token=eyJhbGciOiJIUzUxMiJ9.eyJsb2dpbl91c2VyX2tleSI6Ijk0MGEwZmVhLWY2NWMtNGRmNy1hMDhhLWMxZDRhMDBkODZmOSJ9.r4syG-ZXBwOre2p6CDpIqaBePZuzPHFjako6oGXUejqxzxAoHA70Ov5bwmqJ9WB-rnwPQx-QSKxLJKDcgfBKdw;JSESSIONID=862D0514B6BDF558E299783289188AB92023-01-1016:48:15.245DEBUG50544---[nio-8082-exec-6]o.a.catalina.connector.CoyoteAdapter:Requestedcookiesessionidis862D0514B6BDF558E299783289188AB92023-01-1016:48:15.245DEBUG50544---[nio-8082-exec-6]o.a.c.authenticator.AuthenticatorBase：安全检查请求GET/logger2/print2023-01-1016:48:15.245DEBUG50544---[nio-8082-exec-6]org。apache.catalina.realm.RealmBase：未定义适用的约束2023-01-1016:48:15.245DEBUG50544---[nio-8082-exec-6]o.a.c.authenticator.AuthenticatorBase：不受任何约束2023-01-1016:48:15.245DEBUG50544---[nio-8082-exec-6]org.apache.tomcat.util.http.Parameters：将编码设置为UTF-82023-01-1016:48:15.245DEBUG50544---[nio-8082-exec-6]o.s.web.servlet.DispatcherServlet：获取“/logger2/print”，参数={}2023-01-1016:48：15.246DEBUG50544---[nio-8082-exec-6]s.w.s.m.m.a.RequestMappingHandlerMapping：映射到com.pack.logger.change_level.LoggerController#print()2023-01-1016:48:15.246INFO50544---[nio-8082-exec-6]c.p.l.change_level.LoggerController：这是信息记录器...2023-01-1016:48:15.246错误50544---[nio-8082-exec-6]c.p.l.change_level.LoggerController：这个是错误记录器...2023-01-1016:48:15.246DEBUG50544---[nio-8082-exec-6]m.m.a.RequestResponseBodyMethodProcessor：使用'text/html'，给定[text/html，application/xhtml+xml,image/avif,image/webp,image/apng,application/xml;q=0.9,application/signed-exchange;v=b3;q=0.9,*/*;q=0.8]并支持[text/plain,*/*,text/plain,*/*,application/json,application/*+json,application/json,application/*+json]2023-01-1016:48:15.247DEBUG50544---[nio-8082-exec-6]m.m.a.RequestResponseBodyMethodProcessor：写入["print"]2023-01-1016:48:15.247DEBUG50544---[nio-8082-exec-6]o.s.web.servlet.DispatcherServlet:Completed200OK2023-01-1016:48:15.247DEBUG50544---[nio-8082-exec-6]o.a.coyote.http11.Http11InputBuffer:在fill()之前：parsingHeader:[true],parsingRequestLine:[true],parsingRequestLinePhase:[0],parsingRequestLineStart:[0],byteBuffer.position():[0],byteBuffer.limit()：[0]，结束：[1166]2023-01-1016：48：15.247DEBUG50544---[nio-8082-exec-6]o.a.tomcat.util.net.SocketWrapperBase：套接字：[org.apache。tomcat.util.net.NioEndpoint$NioSocketWrapper@619d8bee:org.apache.tomcat.util.net.NioChannel@38066775:java.nio.channels.SocketChannel[连接本地=/0:0:0:0:0:0:0:1:8082remote=/0:0:0:0:0:0:0:1:59173]]，从缓冲区读取：[0]2023-01-1016:48：15.247调试50544---[nio-8082-exec-6]org.apache.tomcat.util.net.NioEndpoint：套接字：[org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper@619d8bee:org.apache.tomcat.util.net.NioChannel@38066775:java.nio.channels.SocketChannel[连接本地=/0:0:0:0:0:0:0:1:8082远程=/0:0:0:0:0:0:0:1:59173]]，直接从套接字读取：[0]2023-01-1016:48:15.247DEBUG50544---[nio-8082-exec-6]o.a.coyote.http11。Http11InputBuffer：收到[]2023-01-1016:48:15.247DEBUG50544---[nio-8082-exec-6]o.apache.coyote.http11.Http11Processor：套接字：[org.apache.tomcat.util。net.NioEndpoint$NioSocketWrapper@619d8bee:org.apache.tomcat.util.net.NioChannel@38066775:java.nio.channels.SocketChannel[连接本地=/0:0:0:0:0:0:0:1:8082remote=/0:0:0:0:0:0:0:1:59173]]，状态：[OPEN_READ]，状态输出：[OPEN]2023-01-1016:48:15.247DEBUG50544---[nio-8082-exec-6]org.apache.tomcat.util.net.NioEndpoint：注册阅读兴趣[org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper@619d8bee:org.apache.tomcat.util.net.NioChannel@38066775:java.nio.channels.SocketChannel[已连接本地=/0:0:0:0:0:0:0:1:8082远程=/0:0:0:0:0:0:0:0:1:59173]]2023-01-1016:48:16.258DEBUG50544---[nio-8082-exec-7]o.apache.tomcat.util.threads.LimitLatch：倒计时[http-nio-8082-exec-7]闩锁=22023-01-1016:48:16.258DEBUG50544---[nio-8082-exec-7]org.apache.tomcat.util.net.NioEndpoint：调用[org.apache.tomcat.util.net.NioEndpoint@78b6cb49].closeSocket([org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper@76712a2f:org.apache.tomcat.util.net.NioChannel@724ea039:java.nio.channels.SocketChannel[本地连接=/0:0:0:0:0:0:0:1:8082remote=/0:0:0:0:0:0:0:1:59176]])这次输出了很多信息，所有的整个请求的信息关闭日志修改上面解析日志级别的方法privateLogLevelresolveLogLevel(Stringlevel){StringtrimmedLevel=level.trim();if("false".equalsIgnoreCase(trimmedLevel)){返回LogLevel.OFF;}returnLogLevel.valueOf(trimmedLevel.toUpperCase(Locale.ENGLISH));}只需将级别设置为false
