diff --git a/代码/workspace_robo4/plugins/dotnet/robocode.dotnet.installer/src/main/java/net/sf/robocode/installer/AutoExtract.java b/代码/workspace_robo4/plugins/dotnet/robocode.dotnet.installer/src/main/java/net/sf/robocode/installer/AutoExtract.java
index 4887396..442ed9b 100644
--- a/代码/workspace_robo4/plugins/dotnet/robocode.dotnet.installer/src/main/java/net/sf/robocode/installer/AutoExtract.java
+++ b/代码/workspace_robo4/plugins/dotnet/robocode.dotnet.installer/src/main/java/net/sf/robocode/installer/AutoExtract.java
@@ -37,11 +37,12 @@ public class AutoExtract implements ActionListener {
 		String licenseText = "";
 
 		InputStream is;
-        JarFile extractJar;
+        
 		try {
-//			extractJar = new JarFile("extract.jar");
+			JarFile extractJar = new JarFile("extract.jar");
 
 			is = extractJar.getInputStream(extractJar.getJarEntry("license/cpl-v10.html"));
+            extractJar.close();
 		} catch (IOException e) {
 			return true;
 		}