fix history issue

src/main/java/org/springframework/shell/JLineShell.java

@@ -558,9 +558,7 @@ public abstract class JLineShell extends AbstractShell implements CommandMarker,
 	 * 
 	 * @return history file name 
 	 */
-	protected String getHistoryFileName() {
+	abstract protected String getHistoryFileName();
-		return Constant.HISTORY_FILE_NAME;
-	}
 
 	/**
 	 * get prompt text from provider. The provider has highest order 
@@ -568,14 +566,20 @@ public abstract class JLineShell extends AbstractShell implements CommandMarker,
 	 * 
 	 * @return prompt text
 	 */
-	protected String getPromptText() {
+	abstract protected String getPromptText();
-		return Constant.COMMAND_LINE_PROMPT;
-	}
 	
-	protected String getProductName() {
+	/**
-		return Constant.PRODUCT_NAME;
+	 * get product name
-	}
+	 * 
+	 * @return Product Name
+	 */
+	abstract protected String getProductName();
 	
+	/**
+	 * get version information
+	 * 
+	 * @return Version
+	 */
 	protected String getVersion() {
 		return VersionUtils.versionInfo();
 	}

src/main/java/org/springframework/shell/JLineShellComponent.java

@@ -43,7 +43,6 @@ public class JLineShellComponent extends JLineShell implements Lifecycle {
 	private String version;
 	private String welcomeMessage;
 
-	private int historySize;
 
 	// Fields
 	private ExecutionStrategy executionStrategy = new SimpleExecutionStrategy(); //ProcessManagerHostedExecutionStrategy is not what i think we need outside of Roo.		
@@ -206,20 +205,6 @@ public class JLineShellComponent extends JLineShell implements Lifecycle {
 	public void setPrintBanner(boolean printBanner) {
 		this.printBanner = printBanner;
 	}
-
-	/**
-	 * @return the historySize
-	 */
-	public int getHistorySize() {
-		return historySize;
-	}
-
-	/**
-	 * @param historySize the historySize to set
-	 */
-	public void setHistorySize(int historySize) {
-		this.historySize = historySize;
-	}
 	
 	protected String getProductName() {
 		return productName;