Strings.java Source code

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Here is the source code for Strings.java

Source

/*
GNU LESSER GENERAL PUBLIC LICENSE
Copyright (C) 2006 The Lobo Project
    
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
    
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.
    
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
    
Contact info: lobochief@users.sourceforge.net
*/

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;

public class Strings {
    private static final MessageDigest MESSAGE_DIGEST;
    public static final String[] EMPTY_ARRAY = new String[0];

    static {
        MessageDigest md;
        try {
            md = MessageDigest.getInstance("MD5");
        } catch (NoSuchAlgorithmException err) {
            throw new IllegalStateException();
        }
        MESSAGE_DIGEST = md;
    }

    public static boolean isBlank(String text) {
        return text == null || "".equals(text);
    }

    public static int countLines(String text) {
        int startIdx = 0;
        int lineCount = 1;
        for (;;) {
            int lbIdx = text.indexOf('\n', startIdx);
            if (lbIdx == -1) {
                break;
            }
            lineCount++;
            startIdx = lbIdx + 1;
        }
        return lineCount;
    }

    public static boolean isJavaIdentifier(String id) {
        if (id == null) {
            return false;
        }
        int len = id.length();
        if (len == 0) {
            return false;
        }
        if (!Character.isJavaIdentifierStart(id.charAt(0))) {
            return false;
        }
        for (int i = 1; i < len; i++) {
            if (!Character.isJavaIdentifierPart(id.charAt(i))) {
                return false;
            }
        }
        return true;
    }

    public static String getJavaStringLiteral(String text) {
        StringBuffer buf = new StringBuffer();
        buf.append('"');
        int len = text.length();
        for (int i = 0; i < len; i++) {
            char ch = text.charAt(i);
            switch (ch) {
            case '\\':
                buf.append("\\\\");
                break;
            case '\n':
                buf.append("\\n");
                break;
            case '\r':
                buf.append("\\r");
                break;
            case '\t':
                buf.append("\\t");
                break;
            case '"':
                buf.append("\\\"");
                break;
            default:
                buf.append(ch);
                break;
            }
        }
        buf.append('"');
        return buf.toString();
    }

    public static String getJavaIdentifier(String candidateID) {
        int len = candidateID.length();
        StringBuffer buf = new StringBuffer();
        for (int i = 0; i < len; i++) {
            char ch = candidateID.charAt(i);
            boolean good = i == 0 ? Character.isJavaIdentifierStart(ch) : Character.isJavaIdentifierPart(ch);
            if (good) {
                buf.append(ch);
            } else {
                buf.append('_');
            }
        }
        return buf.toString();
    }

}