diff --git a/javaturorial.iml b/javaturorial.iml
deleted file mode 100644
index 4e3316b..0000000
--- a/javaturorial.iml
+++ /dev/null
@@ -1,16 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<module org.jetbrains.idea.maven.project.MavenProjectsManager.isMavenModule="true" type="JAVA_MODULE" version="4">
-  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_8">
-    <output url="file://$MODULE_DIR$/target/classes" />
-    <output-test url="file://$MODULE_DIR$/target/test-classes" />
-    <content url="file://$MODULE_DIR$">
-      <sourceFolder url="file://$MODULE_DIR$/src/main/java" isTestSource="false" />
-      <sourceFolder url="file://$MODULE_DIR$/src/test/java" isTestSource="true" />
-      <excludeFolder url="file://$MODULE_DIR$/target" />
-    </content>
-    <orderEntry type="inheritedJdk" />
-    <orderEntry type="sourceFolder" forTests="false" />
-    <orderEntry type="library" scope="TEST" name="Maven: junit:junit:4.12" level="project" />
-    <orderEntry type="library" scope="TEST" name="Maven: org.hamcrest:hamcrest-core:1.3" level="project" />
-  </component>
-</module>
\ No newline at end of file
diff --git a/src/main/java/cn/byhieg/threadtutorial/char02/ExceptionService.java b/src/main/java/cn/byhieg/threadtutorial/char02/ExceptionService.java
index 4601da7..7fddd82 100644
--- a/src/main/java/cn/byhieg/threadtutorial/char02/ExceptionService.java
+++ b/src/main/java/cn/byhieg/threadtutorial/char02/ExceptionService.java
@@ -18,6 +18,7 @@ synchronized public void getFile(){
             System.out.println("end" + System.currentTimeMillis() + "  " + Thread.currentThread().getName());
 
         } catch (FileNotFoundException | InterruptedException e) {
+            //同步方法出现exception，则会释放锁
             try {
                 Thread.sleep(1000);
             } catch (InterruptedException e1) {