morestring.java

一个使用的搜索引擎

package ir.utilities;

import java.lang.StringBuffer;
import java.util.*;

/** A place to put some additional string functions 
 *
 * @author Ray Mooney
*/

public class MoreString
{

    /** Pad a string with a specific char on the right to make it the specified length */
    public static String padTo(String string, int length, char ch) {
	if (string.length() >= length)
	    return string;
	StringBuffer stringBuf = new StringBuffer(string);
	stringBuf.setLength(length);
	for(int i = string.length(); i < length; i++) 
	    stringBuf.setCharAt(i, ch);
	return stringBuf.toString();
    }

    /** Pad a string with blanks on the right to make it the specified length */
    public static String padTo(String string, int length) {
	return padTo(string, length, ' ');
    }
	
    /** Pad a string with a specific char on the left to make it the specified length */
    public static String padToLeft(String string, int length, char ch) {
	if (string.length() >= length)
	    return string;
	StringBuffer stringBuf = new StringBuffer(length);
	for(int i = 0; i < (length - string.length()); i++) 
	    stringBuf.append(ch);
	stringBuf.append(string);
	return stringBuf.toString();
    }

    /** Pad a string with blanks on the left to make it the specified length */
    public static String padToLeft(String string, int length) {
	return padToLeft(string, length, ' ');
    }

    /** Convert a double to a string and pad with blanks on the left 
     * to make it the specified length */
    public static String padToLeft(double x, int length) {
	return padToLeft(Double.toString(x), length);
    }

    /** Convert an int to a string and pad with blanks on the left 
     * to make it the specified length */
    public static String padToLeft(int x, int length) {
	return padToLeft(Integer.toString(x), length);
    }

    public static String padWithZeros(int x, int length) {
	return padToLeft(Integer.toString(x), length, '0');
    }

    public static String padWithZeros(double x, int length) {
	return padToLeft(Double.toString(x), length, '0');
    }

    /** Segment a string into substrings by breaking at occurences of the given
     * character and returning a list of segments */
    public static ArrayList segment(String string, char ch) {
	ArrayList result = new ArrayList();
	String segment = null;
	int pos = 0; // The start position of the current segment
	for(int i = 0; i < string.length(); i++) {
	    // If find breaking char at this point
	    if (string.charAt(i) == ch) {
		// Create a segment from pos to this point
		segment = string.substring(pos, i);
		// Unless empty, add to list of segments
		if (! segment.equals(""))
		    result.add(segment);
		// Update start position of next segment
		pos = i+1;
	    }
	}
	// Include last segment for pos to end of string
	if (pos != string.length())
	    result.add(string.substring(pos, string.length()));
	return result;
    }

    public static int indexOfIgnoreCase(String string, String substring, int fromIndex) {
	for(int i = fromIndex; i < string.length(); i++) {
	    if (startsWithIgnoreCase(string, substring, i))
		return i;
	}
	return -1;
    }

    public static int indexOfIgnoreCase(String string, String substring) {
	return indexOfIgnoreCase(string, substring, 0);
    }

    public static boolean startsWithIgnoreCase(String string, String substring, int fromIndex) {
	if ((fromIndex < 0) || ((fromIndex + substring.length()) > string.length()))
	    return false;
	for(int i = 0; i < substring.length(); i++) 
	    if (Character.toUpperCase(string.charAt(fromIndex + i)) != Character.toUpperCase(substring.charAt(i)))
		return false;
	return true;
    }
	
    public static boolean startsWithIgnoreCase(String string, String substring) {
	return startsWithIgnoreCase(string, substring, 0);
    }

    public static String fileExtension(String fileName) {
	int pos = fileName.lastIndexOf(".");
	if (pos == -1)
	    return "";
	else
	    return fileName.substring(pos + 1);
    }
    
    public static void main(String[] args) {
	System.out.println(fileExtension(args[0]));
    }

}