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 9ebdb61..96b643c 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
@@ -9,7 +9,6 @@ package net.sf.robocode.installer;
 
 
 import javax.swing.*;
-
 import java.awt.*;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
@@ -34,12 +33,11 @@ public class AutoExtract implements ActionListener {
 	private static File installDir;
 	private static final String javaVersion = System.getProperty("java.version");
 
-	private boolean acceptLicense() throws IOException {
+	private boolean acceptLicense() {
 		String licenseText = "";
 
 		InputStream is;
-
-		JarFile extractJar = null;
+        JarFile extractJar;
 		try {
 			extractJar = new JarFile("extract.jar");
 
@@ -47,8 +45,8 @@ public class AutoExtract implements ActionListener {
 		} catch (IOException e) {
 			return true;
 		} finally{
-			extractJar.close();
-		}
+            extractJar.close();
+        }
 		if (is == null) {
 			return true;
 		}
@@ -229,7 +227,7 @@ public class AutoExtract implements ActionListener {
 		}
 	}
 
-	public static void main(String argv[]) throws HeadlessException, IOException {
+	public static void main(String argv[]) {
 		// Verify that the Java version is version 6 (1.6.0) or newer
 		if (javaVersion.startsWith("1.") && javaVersion.charAt(2) < '5') {
 			final String message = "Robocode requires Java 6 (1.6.0) or newer.\n"