diff --git a/W4/Week4Homework.iml b/W4/Week4Homework.iml
new file mode 100644
index 0000000..9465dd8
--- /dev/null
+++ b/W4/Week4Homework.iml
@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>
\ No newline at end of file
diff --git a/W4/misc.xml b/W4/misc.xml
new file mode 100644
index 0000000..c30fdba
--- /dev/null
+++ b/W4/misc.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectRootManager" version="2" default="true" project-jdk-name="25" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/out" />
+  </component>
+</project>
\ No newline at end of file
diff --git a/W4/modules.xml b/W4/modules.xml
new file mode 100644
index 0000000..1ff5c03
--- /dev/null
+++ b/W4/modules.xml
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/Week4Homework.iml" filepath="$PROJECT_DIR$/Week4Homework.iml" />
+    </modules>
+  </component>
+</project>
\ No newline at end of file
diff --git a/W4/图形面积计算器重构实验报告.docx b/W4/图形面积计算器重构实验报告.docx
new file mode 100644
index 0000000..909be97
Binary files /dev/null and b/W4/图形面积计算器重构实验报告.docx differ
diff --git a/W4/类图.jpg b/W4/类图.jpg
new file mode 100644
index 0000000..7d32b61
Binary files /dev/null and b/W4/类图.jpg differ