JAVA - String 前后pad以及repeat

snippet.java

/**
 * <li>{@code padStart("7", 3, '0')} returns {@code "007"}
 * <li>{@code padStart("2010", 3, '0')} returns {@code "2010"}
 */
public static String padStart(String string, int minLength, char padChar)
{
	checkNotNull(string);
	if(string.length() >= minLength)
	{
		return string;
	}
	StringBuffer sBuf = new StringBuffer(minLength);
	for(int i = string.length(); i < minLength; i++)
	{
		sBuf.append(padChar);
	}
	sBuf.append(string);
	return sBuf.toString();
}

/**
 * <li>{@code padEnd("4.", 5, '0')} returns {@code "4.000"}
 * <li>{@code padEnd("2010", 3, '!')} returns {@code "2010"}
 */
public static String padEnd(String string, int minLength, char padChar)
{
	checkNotNull(string);
	if(string.length() >= minLength)
	{
		return string;
	}
	StringBuffer sBuf = new StringBuffer(minLength);
	sBuf.append(string);
	for(int i = string.length(); i < minLength; i++)
	{
		sBuf.append(padChar);
	}
	return sBuf.toString();
}

/**
 * {@code repeat("hey", 3)} returns the string
 * {@code "heyheyhey"}
 */
public static String repeat(String string, int count)  
{
	checkNotNull(string);
	checkArgument(count >= 0, "invalid count: %s", count);

	StringBuffer sBuf = new StringBuffer(string.length() * count);
	for(int i = 0; i < count; i++)
	{
		sBuf.append(string);
	}
	return sBuf.toString();
}