stringutils.java

一个搜索引擎,希望对大家有用

package com.luceneheritrixbook.util;

import java.security.MessageDigest;

public class StringUtils {

	public static String trim(String line) {
		String result = line.trim();
		while (result.startsWith("　")) {
			result = result.substring(1);
		}
		while (result.endsWith("　")) {
			result = result.substring(0, result.length() - 1);
		}

		return result;
	}

	public static String filenameProcess(String name) {
		String result = name.trim();
		result = result.replaceAll("\\\\", "_");
		return result;
	}

	public static void main(String[] args) {
		String a = "190\\180";
		System.out.println(filenameProcess(a));
	}

	/**
	 * Encode a string using algorithm specified in web.xml and return the
	 * resulting encrypted password. If exception, the plain credentials string
	 * is returned
	 * 
	 * @param password
	 *            Password or other credentials to use in authenticating this
	 *            username
	 * @param algorithm
	 *            Algorithm used to do the digest
	 * 
	 * @return encypted password based on the algorithm.
	 */
	public static String encodePassword(String password, String algorithm) {
		byte[] unencodedPassword = password.getBytes();

		MessageDigest md = null;

		try {
			// first create an instance, given the provider
			md = MessageDigest.getInstance(algorithm);
		} catch (Exception e) {
			return password;
		}

		md.reset();

		// call the update method one or more times
		// (useful when you don't know the size of your data, eg. stream)
		md.update(unencodedPassword);

		// now calculate the hash
		byte[] encodedPassword = md.digest();

		StringBuffer buf = new StringBuffer();

		for (int i = 0; i < encodedPassword.length; i++) {
			if ((encodedPassword[i] & 0xff) < 0x10) {
				buf.append("0");
			}

			buf.append(Long.toString(encodedPassword[i] & 0xff, 16));
		}

		return buf.toString();
	}

	public static final String replace(String line, String oldString,
			String newString) {
		if (line == null) {
			return null;
		}
		int i = 0;
		if ((i = line.indexOf(oldString, i)) >= 0) {
			char[] line2 = line.toCharArray();
			char[] newString2 = newString.toCharArray();
			int oLength = oldString.length();
			StringBuffer buf = new StringBuffer(line2.length);
			buf.append(line2, 0, i).append(newString2);
			i += oLength;
			int j = i;
			while ((i = line.indexOf(oldString, i)) > 0) {
				buf.append(line2, j, i - j).append(newString2);
				i += oLength;
				j = i;
			}
			buf.append(line2, j, line2.length - j);
			return buf.toString();
		}
		return line;
	}

}