Merge pull request julycoding#271 from WangTaoTheTonic/master

Add Java code for Chapter 1.5

ebook/code/java/chapter1/Palindrome.java

@@ -0,0 +1,65 @@
+/**
+ * Check weather a string is a palindrome
+ * @author WangTaoTheTonic
+ */
+public class Palindrome
+{
+	// Solution 1, from sides to middle
+	public static boolean isPalindromeV1(String str)
+	{
+		if(null == str || 0 == str.length())
+		{
+			return false;
+		}
+
+		int length = str.length();
+		if(1 == length)
+		{
+			return true;
+		}
+
+		for(int leftFlag = 0, rightFlag = length - 1 ; leftFlag < rightFlag; leftFlag ++, rightFlag --)
+		{
+			if(str.charAt(leftFlag) != str.charAt(rightFlag))
+				return false;
+		}
+
+		return true;
+	}
+
+	// Solution 2, from middle to sides
+	public static boolean isPalindromeV2(String str)
+	{
+		if(null == str || 0 == str.length())
+		{
+			return false;
+		}
+
+		int length = str.length();
+		if(1 == length)
+		{
+			return true;
+		}
+
+		int leftFlag = 0;
+		int rightFlag = length;
+		leftFlag = length / 2 - 1;
+		if(0 == length % 2)
+		{
+			rightFlag = leftFlag + 1;
+		}
+		else
+		{
+			rightFlag = leftFlag + 2;
+		}
+
+		for( ; leftFlag >= 0; leftFlag --, rightFlag ++)
+		{
+			if(str.charAt(leftFlag) != str.charAt(rightFlag))
+				return false;
+		}
+
+		return true;
+	}
+
+}