org.eclipse.mylyn.commons.core.CoreUtil.java Source code

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/*******************************************************************************
 * Copyright (c) 2004, 2012 Tasktop Technologies and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Tasktop Technologies - initial API and implementation
 *******************************************************************************/

package org.eclipse.mylyn.commons.core;

import java.util.Map;

import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.osgi.framework.Bundle;
import org.osgi.framework.Version;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;

/**
 * @since 3.0
 * @author Steffen Pingel
 * @author Benjamin Muskalla
 * @noinstantiate This class is not intended to be instantiated by clients.
 */
public class CoreUtil {

    /**
     * @since 3.0
     */
    public static final boolean TEST_MODE;

    static {
        String application = System.getProperty("eclipse.application", ""); //$NON-NLS-1$ //$NON-NLS-2$
        if (application.length() > 0) {
            TEST_MODE = application.endsWith("testapplication") || application.endsWith("uitest"); //$NON-NLS-1$ //$NON-NLS-2$
        } else {
            // eclipse 3.3 does not the eclipse.application property
            String commands = System.getProperty("eclipse.commands", ""); //$NON-NLS-1$ //$NON-NLS-2$
            TEST_MODE = commands.contains("testapplication\n"); //$NON-NLS-1$
        }
    }

    private static final String FRAMEWORK_VERSION = "3.15.0"; //$NON-NLS-1$

    private static final SAXParserFactory saxParserFactory = SAXParserFactory.newInstance();
    static {
        saxParserFactory.setNamespaceAware(true);
    }

    /**
     * Returns a string representation of <code>object</code>. If object is a map or array the returned string will
     * contains a comma separated list of contained elements.
     * 
     * @since 3.4
     */
    public static String toString(Object object) {
        StringBuilder sb = new StringBuilder();
        toString(sb, object);
        return sb.toString();
    }

    private static void toString(StringBuilder sb, Object object) {
        if (object instanceof Object[]) {
            sb.append("["); //$NON-NLS-1$
            Object[] entries = (Object[]) object;
            boolean prependSeparator = false;
            for (Object entry : entries) {
                if (prependSeparator) {
                    sb.append(", "); //$NON-NLS-1$
                }
                toString(sb, entry);
                prependSeparator = true;
            }
            sb.append("]"); //$NON-NLS-1$
        } else if (object instanceof Map<?, ?>) {
            sb.append("{"); //$NON-NLS-1$
            boolean prependSeparator = false;
            for (Map.Entry<?, ?> entry : ((Map<?, ?>) object).entrySet()) {
                if (prependSeparator) {
                    sb.append(", "); //$NON-NLS-1$
                }
                toString(sb, entry.getKey());
                sb.append("="); //$NON-NLS-1$
                toString(sb, entry.getValue());
                prependSeparator = true;
            }
            sb.append("}"); //$NON-NLS-1$
        } else {
            sb.append(object);
        }
    }

    /**
     * Returns the version of the bundle.
     * 
     * @since 3.7
     * @deprecated use {@link Bundle#getVersion()} instead
     */
    @Deprecated
    public static Version getVersion(Bundle bundle) {
        return bundle.getVersion();
    }

    /**
     * Returns true, if <code>o1</code> is equal to <code>o2</code> or <code>o1</code> and <code>o2</code> are
     * <code>null</code>.
     * 
     * @see Object#equals(Object)
     * @since 3.7
     */
    public static boolean areEqual(Object o1, Object o2) {
        if (o1 == null) {
            return (o2 == null);
        } else {
            return o1.equals(o2);
        }
    }

    /**
     * Compares <code>o1</code> and <code>o2</code>.
     * 
     * @since 3.7
     * @return a negative integer, 0, or a positive, if o1 is less than o2, o1 equals o2 or o1 is more than o2; null is
     *         considered less than any value
     */
    public static <T> int compare(Comparable<T> o1, T o2) {
        if (o1 == null) {
            return (o2 != null) ? 1 : 0;
        } else if (o2 == null) {
            return -1;
        }
        return o1.compareTo(o2);
    }

    /**
     * Compares a boolean value.
     * 
     * @since 3.7
     * @see Boolean#equals(Object)
     */
    public static boolean propertyEquals(boolean value, Object expectedValue) {
        return (expectedValue == null) ? value == true : Boolean.valueOf(value).equals(expectedValue);
    }

    /**
     * Disables logging through the Apache commons logging system by default. This can be overridden by specifying the
     * <code>org.apache.commons.logging.Log</code> system property.
     * 
     * @since 3.7
     */
    public static void initializeLoggingSettings() {
        defaultSystemProperty("org.apache.commons.logging.Log", "org.apache.commons.logging.impl.NoOpLog"); //$NON-NLS-1$ //$NON-NLS-2$
    }

    /**
     * Only sets system property if they are not already set to a value.
     */
    private static void defaultSystemProperty(String key, String defaultValue) {
        if (System.getProperty(key) == null) {
            System.setProperty(key, defaultValue);
        }
    }

    /**
     * Returns the version of the Java runtime.
     * 
     * @since 3.7
     * @return {@link Version#emptyVersion} if the version can not be determined
     */
    public static Version getRuntimeVersion() {
        Version result = parseRuntimeVersion(System.getProperty("java.runtime.version")); //$NON-NLS-1$
        if (result == Version.emptyVersion) {
            result = parseRuntimeVersion(System.getProperty("java.version")); //$NON-NLS-1$
        }
        return result;
    }

    private static Version parseRuntimeVersion(String versionString) {
        if (versionString != null) {
            int firstSeparator = versionString.indexOf('.');
            if (firstSeparator != -1) {
                try {
                    int secondSeparator = versionString.indexOf('.', firstSeparator + 1);
                    if (secondSeparator != -1) {
                        int index = findLastNumberIndex(versionString, secondSeparator);
                        String qualifier = versionString.substring(index + 1);
                        if (qualifier.startsWith("_") && qualifier.length() > 1) { //$NON-NLS-1$
                            versionString = versionString.substring(0, index + 1) + "." + qualifier.substring(1); //$NON-NLS-1$
                        } else {
                            versionString = versionString.substring(0, index + 1);
                        }
                        return new Version(versionString);
                    }
                    return new Version(
                            versionString.substring(0, findLastNumberIndex(versionString, firstSeparator) + 1));
                } catch (IllegalArgumentException e) {
                    // ignore
                }
            }
        }
        return Version.emptyVersion;
    }

    private static int findLastNumberIndex(String versionString, int secondSeparator) {
        int lastDigit = secondSeparator;
        for (int i = secondSeparator + 1; i < versionString.length(); i++) {
            if (Character.isDigit(versionString.charAt(i))) {
                lastDigit++;
            } else {
                break;
            }
        }
        if (lastDigit == secondSeparator) {
            return secondSeparator - 1;
        }
        return lastDigit;
    }

    /**
     * Returns the running Mylyn version without the qualifier.
     * 
     * @since 3.7
     */
    public static Version getFrameworkVersion() {
        return new Version(FRAMEWORK_VERSION);
    }

    /**
     * Returns a representation of <code>name</code> that is a valid file name.
     * 
     * @since 3.7
     */
    public static String asFileName(String name) {
        StringBuffer sb = new StringBuffer(name.length());
        char[] chars = name.toCharArray();
        for (char c : chars) {
            if (c >= '0' && c <= '9' || c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z' || c == '.') {
                sb.append(c);
            } else {
                sb.append("%" + Integer.toHexString(c).toUpperCase()); //$NON-NLS-1$
            }
        }
        return sb.toString();
    }

    /**
     * Returns the decoded form of <code>text</code>.
     * 
     * @since 3.8
     * @see #encode(String)
     * @throws IllegalArgumentException
     *             if text is not in a valid form, i.e. it was not encoded using {@link CoreUtil#encode(String)}
     */
    public static String decode(String text) {
        boolean escaped = false;
        StringBuilder sb = new StringBuilder(text.length());
        StringBuilder escapedText = new StringBuilder(4);
        char[] chars = text.toCharArray();
        for (char c : chars) {
            if (c >= '0' && c <= '9' || c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z' || c == '.') {
                if (escaped) {
                    escapedText.append(c);
                } else {
                    sb.append(c);
                }
            } else if (c == '%') {
                if (escaped) {
                    throw new IllegalArgumentException("Unexpected '%' sign in '" + text + "'"); //$NON-NLS-1$ //$NON-NLS-2$
                }
                escaped = !escaped;
            } else if (c == '_') {
                if (!escaped) {
                    throw new IllegalArgumentException("Unexpected '_' sign in '" + text + "'"); //$NON-NLS-1$ //$NON-NLS-2$
                }
                try {
                    sb.append((char) Integer.parseInt(escapedText.toString(), 16));
                    escapedText.setLength(0);
                } catch (NumberFormatException e) {
                    throw new IllegalArgumentException("Invalid escape code in '" + text + "'"); //$NON-NLS-1$ //$NON-NLS-2$
                }
                escaped = !escaped;
            } else {
                throw new IllegalArgumentException("Unexpected character '" + c + "' in '" + text + "'"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
            }
        }
        return sb.toString();
    }

    /**
     * An encoded form of <code>text</code> that is suitable as a filename.
     * 
     * @param text
     *            the string to encode
     * @see #decode(String)
     * @since 3.8
     */
    public static String encode(String text) {
        StringBuilder sb = new StringBuilder(text.length());
        char[] chars = text.toCharArray();
        for (char c : chars) {
            if (c >= '0' && c <= '9' || c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z' || c == '.') {
                sb.append(c);
            } else {
                sb.append("%"); //$NON-NLS-1$
                sb.append(Integer.toHexString(c).toUpperCase());
                sb.append("_"); //$NON-NLS-1$
            }
        }
        return sb.toString();
    }

    /**
     * Returns a new {@link XMLReader} instance using default factories.
     * 
     * @since 3.9
     */
    public static SAXParser newSaxParser() throws SAXException {
        try {
            return saxParserFactory.newSAXParser();
        } catch (ParserConfigurationException e) {
            throw new SAXException(e);
        }
    }

    /**
     * Returns a new {@link XMLReader} instance using default factories.
     * 
     * @since 3.9
     */
    public static XMLReader newXmlReader() throws SAXException {
        return newSaxParser().getXMLReader();
    }

}