All Downloads are FREE. Search and download functionalities are using the official Maven repository.

org.databene.commons.ParseUtil Maven / Gradle / Ivy

Go to download

'databene commons' is an open source Java library by Volker Bergmann. It provides extensions to the Java core library by utility classes, abstract concepts and concrete implementations.

There is a newer version: 1.0.11
Show newest version
/*
 * Copyright (C) 2004-2014 Volker Bergmann ([email protected]).
 * All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.databene.commons;

import java.io.PushbackReader;
import java.io.IOException;
import java.io.Reader;
import java.io.BufferedReader;
import java.text.ParseException;
import java.text.ParsePosition;
import java.util.List;
import java.util.ArrayList;
import java.math.BigInteger;

/**
 * Provides methods for parsing PushbackReaders and Strings.
 * Created: 20.03.2005 16:32:00
 * @author Volker Bergmann
 */
public final class ParseUtil {

    public static double parseDecimal(PushbackReader reader) throws IOException, ParseException {
        double result = parseInteger(reader);
        double postfix = parseOptionalPostfix(reader);
        if (result >= 0)
            result += postfix;
        else
            result -= postfix;
        return result;
    }

    public static double parseOptionalPostfix(PushbackReader reader) throws IOException {
        int c = reader.read();
        if (c != '.') {
            if (c != -1)
                reader.unread(c);
            return 0.;
        }
        double result = 0;
        double base = 0.1;
        while ((c = reader.read()) != -1 && Character.isDigit((char)c)) {
            result += (c - '0') * base;
            base *= 0.1;
        }
        if (c != -1)
            reader.unread(c);
        return result;
    }

    public static long parseInteger(PushbackReader reader) throws IOException, ParseException {
        boolean negative = parseOptionalSign(reader);
        return parseNonNegativeInteger(reader) * (negative ? -1 : 1);
    }

    public static long parseNonNegativeInteger(String source, ParsePosition pos) throws ParseException {
        int digit;
        if (pos.getIndex() > source.length() || !Character.isDigit(digit = source.charAt(pos.getIndex())))
            throw new ParseException("Number expected", 0);
        pos.setIndex(pos.getIndex() + 1);
        long result = digit - '0';
        while(pos.getIndex() < source.length() && Character.isDigit(digit = source.charAt(pos.getIndex()))) {
            result = result * 10 + digit - '0';
            pos.setIndex(pos.getIndex() + 1);
        }
        return result;
    }

    public static long parseNonNegativeInteger(PushbackReader reader) throws IOException, ParseException {
        int digit;
        if ((digit = reader.read()) == -1 || !Character.isDigit((char)digit))
            throw new ParseException("Long expected", 0);
        long result = digit - '0';
        while((digit = reader.read()) != -1 && Character.isDigit((char)digit))
            result = result * 10 + digit - '0';
        if (digit != -1)
            reader.unread(digit);
        return result;
    }

    public static boolean parseOptionalSign(PushbackReader reader) throws IOException {
        skipWhitespace(reader);
        int optionalSign = reader.read();
        if (optionalSign == '-')
            return true;
        if (optionalSign != -1)
            reader.unread(optionalSign);
        return false;
    }

    public static void skipWhitespace(PushbackReader reader) throws IOException {
        int c;
        do {
            c = reader.read();
        } while (c != -1 && Character.isWhitespace((char)c));
        if (c != -1)
            reader.unread(c);
    }
    
    public static String parseUnit(PushbackReader reader) throws IOException {
        StringBuilder result = new StringBuilder();
        int c;
        while ((c = reader.read()) != -1 && Character.isUpperCase((char)c))
            result.append((char)c);
        if (c != -1)
            reader.unread(c);
        return (result.length() > 0 ? result.toString() : null);
    }
    
    public static boolean parseEstimated(PushbackReader reader) throws IOException {
        int c = reader.read();
        if (c == 'e')
            return true;
        if (c != -1)
            reader.unread(c);
        return false;
    }

    public static boolean isEmpty(Object object) {
        return (object == null || StringUtil.isEmpty((String) object));
    }

    public static int nextNonWhitespaceIndex(String source, int startIndex) {
        int i;
        for (i = startIndex; i < source.length() && Character.isWhitespace(source.charAt(i)); i++) {
        }
        if (i >= source.length())
            i = -1;
        return i;
    }

    public static String[][] parseEmptyLineSeparatedFile(Reader src) throws IOException {
        BufferedReader reader = null;
        List> sections = new ArrayList>();
        List lines = null;
        try {
            reader = new BufferedReader(src);
            String line;
            while ((line = reader.readLine()) != null) {
                if (line.length() > 0) {
                    if (lines == null) {
                        // start a new section
                        lines = new ArrayList();
                        sections.add(lines);
                    }
                    lines.add(line);
                } else {
                    // end of the section
                    if (lines != null) {
                        lines = null;
                    } else {
                        // add empty section
                        sections.add(new ArrayList());
                    }
                }
            }
            return StringUtil.toArrayArray(sections);
        } finally {
            IOUtil.close(reader);
        }
    }

    public static Object[] splitNumbers(String text) {
        List parts = new ArrayList();
        Boolean numMode = null;
        int start = 0;
        for (int i = 0; i < text.length(); i++) {
            char c = text.charAt(i);
            boolean newMode = Character.isDigit(c);
            if (numMode != null && !numMode.equals(newMode)) {
                String partString = text.substring(start, i);
                addPart(partString, parts, numMode);
                start = i;
            }
            numMode = newMode;
        }
        addPart(text.substring(start), parts, numMode);
        return parts.toArray();
    }

    public static boolean isNonNegativeNumber(String text) {
        for (int i = 0; i < text.length(); i++)
            if (!Character.isDigit(text.charAt(i)))
                return false;
        return true;
    }

    public static String from(String s, String separator) {
        return from(s, separator, null);
    }

    public static String from(String s, String separator, String notFoundValue) {
        int separatorIndex = s.indexOf(separator);
        return (separatorIndex >= 0 ? s.substring(separatorIndex) : notFoundValue);
    }

    public static String before(String s, String separator) {
        int separatorIndex = s.indexOf(separator);
        return (separatorIndex >= 0 ? s.substring(0, separatorIndex) : s);
    }

    public static boolean isHex(String s) {
        for (int i = s.length() - 1; i >= 0; i--)
            if (!isHex(s.charAt(i)))
                return false;
        return true;
    }

    public static boolean isHex(char c) {
        return ('0' <= c && c <= '9') || ('a' <= c && c <= 'f') || ('A' <= c && c <= 'F');
    }

    public static String[] parseAssignment(String line, String operator, boolean lhsRequired) {
    	if (line == null)
    		return null;
        int sep = line.indexOf(operator);
        if (sep < 0 || (lhsRequired && sep == 0))
            return null;
        return new String[] {
                line.substring(0, sep).trim(),
                (sep < line.length() - 1 ? line.substring(sep + 1) : null)
        };
    }
    
    public static boolean isNMToken(String testName) {
        if (testName == null || testName.length() == 0)
            return false;
        char c = testName.charAt(0);
        if (!Character.isLetter(c) && c != '_' && c != ':')
            return false;
        for (int i = 1; i < testName.length(); i++) {
            c = testName.charAt(i);
            if (!Character.isLetter(c) && c != '.' && c != '-' && c != '_' && c != ':') 
                return false;
        }
        return true;
    }

	public static void skipWhiteSpace(String text, ParsePosition pos) {
		int i;
		while ((i = pos.getIndex()) < text.length() && Character.isWhitespace(text.charAt(i)))
			pos.setIndex(i + 1);
	}

    public static Boolean parseBoolean(String s) {
    	return parseBoolean(s, false);
    }

    public static Boolean parseBoolean(String s, boolean acceptWhitespace) {
    	if (s == null)
    		return null;
    	if (acceptWhitespace)
    		s = s.trim();
    	if ("true".equalsIgnoreCase(s))
    		return true;
    	else if ("false".equalsIgnoreCase(s))
    		return false;
    	else
    		throw new SyntaxError("Not a boolean value", s);
    }

	// private helpers -------------------------------------------------------------------------------------------------

    private static void addPart(String partString, List parts, Boolean numMode) {
        Object part = (numMode ? new BigInteger(partString) : partString);
        parts.add(part);
    }

}
    

    

    

            

    

            



    
    






    
© 2015 - 2024 Weber Informatics LLC | Privacy Policy