关于java.io.UncheckedIOException: Cannot delete C:\Users\guo\AppData\Local\Temp\tomcat.8081问题

首先它的报错是这样的，只要遇到这个报错，就是InputStream流使用后未关闭，inputStream.close()一下就可以啦

java.io.UncheckedIOException: Cannot delete C:\Users\guo\AppData\Local\Temp\tomcat.8081.8076585834079724671\work\Tomcat\localhost\ROOT\upload_00daa733_afe5_4d51_a016_0ed308a7e006_00000000.tmpat org.apache.tomcat.util.http.fileupload.disk.DiskFileItem.delete(DiskFileItem.java:431) ~[tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.catalina.core.ApplicationPart.delete(ApplicationPart.java:53) ~[tomcat-embed-core-9.0.79.jar:9.0.79]at org.springframework.web.multipart.support.StandardServletMultipartResolver.cleanupMultipart(StandardServletMultipartResolver.java:134) ~[spring-web-5.3.29.jar:5.3.29]at org.springframework.web.servlet.DispatcherServlet.cleanupMultipart(DispatcherServlet.java:1251) [spring-webmvc-5.3.29.jar:5.3.29]at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1108) [spring-webmvc-5.3.29.jar:5.3.29]at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:965) [spring-webmvc-5.3.29.jar:5.3.29]at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) [spring-webmvc-5.3.29.jar:5.3.29]at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909) [spring-webmvc-5.3.29.jar:5.3.29]at javax.servlet.http.HttpServlet.service(HttpServlet.java:555) [tomcat-embed-core-9.0.79.jar:4.0.FR]at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) [spring-webmvc-5.3.29.jar:5.3.29]at javax.servlet.http.HttpServlet.service(HttpServlet.java:623) [tomcat-embed-core-9.0.79.jar:4.0.FR]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:209) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:153) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51) [tomcat-embed-websocket-9.0.79.jar:9.0.79]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:178) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:153) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) [spring-web-5.3.29.jar:5.3.29]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) [spring-web-5.3.29.jar:5.3.29]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:178) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:153) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) [spring-web-5.3.29.jar:5.3.29]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) [spring-web-5.3.29.jar:5.3.29]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:178) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:153) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) [spring-web-5.3.29.jar:5.3.29]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) [spring-web-5.3.29.jar:5.3.29]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:178) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:153) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:167) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:90) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:481) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:130) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:390) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:926) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1790) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) [tomcat-embed-core-9.0.79.jar:9.0.79]at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.79.jar:9.0.79]at java.lang.Thread.run(Thread.java:750) [na:1.8.0_322]Caused by: java.io.IOException: Cannot delete C:\Users\guo\AppData\Local\Temp\tomcat.8081.8076585834079724671\work\Tomcat\localhost\ROOT\upload_00daa733_afe5_4d51_a016_0ed308a7e006_00000000.tmp... 44 common frames omitted

我当时代码是这样的，以为将流直接赋值就行了，忘记了这是地址啊，一但重新赋值就是指向了新的输入流，原本的那个流就没人指向它了，jvm直接会定期清除。但是我没有关掉那个流，所以就一直报上面的那个bug。怎么说呢，写代码的时候带点脑子。

public static InputStream pictureCompression(InputStream inputStream,String suffix, float scale) throws IOException {File tempFile = File.createTempFile("temp", suffix);try {Thumbnails.of(inputStream).scale(scale).toFile(tempFile);inputStream = new FileInputStream(tempFile);} catch (IOException e) {log.error("[图片压缩失败]");} finally {tempFile.deleteOnExit(); // 删除临时文件}return inputStream;}

就这样关掉就好了

public static InputStream pictureCompression(InputStream inputStream,String suffix, float scale) throws IOException { File tempFile = File.createTempFile("temp", suffix); try { Thumbnails.of(inputStream) .scale(scale) .toFile(tempFile); inputStream.close(); inputStream = new FileInputStream(tempFile); } catch (IOException e) { log.error("[图片压缩失败]"); } finally { tempFile.deleteOnExit(); // 删除临时文件 } return inputStream; }