util.java

OSGI这是一个中间件,与UPNP齐名,是用于移植到嵌入式平台之上

/*
 * Copyright (c) 2003-2004, KNOPFLERFISH project
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials
 *   provided with the distribution.
 *
 * - Neither the name of the KNOPFLERFISH project nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.knopflerfish.framework;

import java.io.*;
import java.util.List;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Vector;
import java.util.Iterator;

public class Util {
  /**
   * Check for local file storage directory. 
   *
   * @param name local directory name.
   * @return A FileTree object of directory or null if no storage is available.
   */
  public static FileTree getFileStorage(String name) {
    // See if we have a storage directory
    String fwdir = System.getProperty("org.osgi.framework.dir");
    if (fwdir == null) {
      return null;
    }
    FileTree dir = new FileTree(fwdir, name);
    if (dir != null) {
      if (dir.exists()) {
	if (!dir.isDirectory()) {
	  throw new RuntimeException("Not a directory: " + dir);
	}
      } else {
	if (!dir.mkdirs()) {
	  throw new RuntimeException("Cannot create directory: " + dir);
	}
      }
    }
    return dir;
  }


  /**
   * Compare to strings formatted as '<int>[.<int>[.<int>]]'.
   * If string is null, then it counts as ZERO.
   *
   * @param ver1 First version string.
   * @param ver2 Second version string.
   * @return Return 0 if equals, -1 if ver1 < ver2 and 1 if ver1 > ver2.
   * @exception NumberFormatException on syntax error in input.
   */
  public static int compareStringVersion(String ver1, String ver2)
    throws NumberFormatException {
    int i1, i2;
    while (ver1 != null || ver2 != null) {
      if (ver1 != null) {
	int d1 = ver1.indexOf(".");
	if (d1 == -1) {
	  i1 = Integer.parseInt(ver1.trim());
	  ver1 = null;
	} else {
	  i1 = Integer.parseInt(ver1.substring(0, d1).trim());
	  ver1 = ver1.substring(d1 + 1);
	}
      } else {
	i1 = 0;
      }
      if (ver2 != null) {
	int d2 = ver2.indexOf(".");
	if (d2 == -1) {
	  i2 = Integer.parseInt(ver2.trim());
	  ver2 = null;
	} else {
	  i2 = Integer.parseInt(ver2.substring(0, d2).trim());
	  ver2 = ver2.substring(d2 + 1);
	}
      } else {
	i2 = 0;
      }
      if (i1 < i2) {
	return -1;
      }
      if (i1 > i2) {
	return 1;
      }
    }
    return 0;
  }

  /**
   * Parse strings of format:
   *
   *   ENTRY (, ENTRY)*
   *   ENTRY = key (; key)* (; OP)*
   *   OP = param '=' value
   *
   * @param a Attribute being parsed
   * @param s String to parse
   * @param single If true, only allow one key per ENTRY
   *        and only allow unique parmeters for each ENTRY.
   * @return Iterator(Map(param -> value)).
   * @exception IllegalArgumentException If syntax error in input string.
   */
  public static Iterator parseEntries(String a, String s, boolean single) {
    ArrayList result = new ArrayList();
    if (s != null) {
      AttributeTokenizer at = new AttributeTokenizer(s);
      do {
	ArrayList keys = new ArrayList();
	HashMap params = new HashMap();
	boolean doingKeys = true;
	String key = at.getKey();
	if (key == null) {
	  throw new IllegalArgumentException("Attribute, " + a + ", expected key at: " + at.getRest());
	}
	if (!single) {
	  keys.add(key);
	  while ((key = at.getKey()) != null) {
	    keys.add(key);
	  }
	}
	String param;
	while ((param = at.getParam()) != null) {
	  List old = (List)params.get(param);
	  if (old != null && single) {
	    throw new IllegalArgumentException("Attribute, " + a + ", duplicate parameter: " + param);
	  }
	  String value = at.getValue();
	  if (value == null) {
	    throw new IllegalArgumentException("Attribute, " + a + ", expected value at: " + at.getRest());
	  }
	  if (single) {
	    params.put(param, value);
	  } else {
	    if (old == null) {
	      old = new ArrayList();
	      params.put(param, old);
	    }
	    old.add(value);
	  }
	}
	if (at.getEntryEnd()) {
	  if (single) {
	    params.put("key", key);
	  } else {
	    params.put("keys", keys);
	  }
	  result.add(params);
	} else {
	  throw new IllegalArgumentException("Attribute, " + a + ", expected end of entry at: " + at.getRest());
	}
      } while (!at.getEnd());
    }
    return result.iterator();
  }

  /**
   * Read a resource into a byte array.
   *
   * @param name resource name to read
   * @return byte array with contents of resource.
   */
  static byte[] readResource(String name) throws IOException  {
    byte[] buf = new byte[1024];

    InputStream           in = Main.class.getResourceAsStream(name);
    ByteArrayOutputStream bout = new ByteArrayOutputStream();
    int n;
    while ((n = in.read(buf)) > 0) {
      bout.write(buf, 0, n);
    }
    try { in.close(); } catch (Exception ignored) { } 

    return bout.toByteArray();
  }

  /** 
   * Default whitespace string for splitwords().
   * Value is <tt>" \t\n\r"</tt>)
   */
  protected static String  WHITESPACE = " \t\n\r";
  
  /**
   * Default citation char for splitwords().
   * Value is <tt>'"'</tt>
   */
  protected static char   CITCHAR    = '"';
  
  
  /**
   * Utility method to split a string into words separated by whitespace.
   *
   * <p>
   * Equivalent to <tt>splitwords(s, WHITESPACE)</tt>
   * </p>
   */
  public static String [] splitwords(String s) {
    return splitwords(s, WHITESPACE);
  }

  /**
   * Utility method to split a string into words separated by whitespace.
   *
   * <p>
   * Equivalent to <tt>splitwords(s, WHITESPACE, CITCHAR)</tt>
   * </p>
   */
  public static String [] splitwords(String s, String whiteSpace) {
    return splitwords(s, WHITESPACE, CITCHAR);
  }

  
  /**
   * Split a string into words separated by whitespace.
   * <p>
   * Citation chars may be used to group words with embedded
   * whitespace.
   * </p>
   *
   * @param s          String to split.
   * @param whiteSpace whitespace to use for splitting. Any of the
   *                   characters in the whiteSpace string are considered
   *                   whitespace between words and will be removed
   *                   from the result. If no words are found, return an
   *                   array of length zero.
   * @param citChar    Citation character used for grouping words with 
   *                   embedded whitespace. Typically '"'
   */
  public static String [] splitwords(String s, 
				     String whiteSpace,
				     char   citChar) {
    boolean       bCit  = false;        // true when inside citation chars.
    Vector        v     = new Vector(); // (String) individual words after splitting
    StringBuffer  buf   = null; 
    int           i     = 0; 
    
    while(i < s.length()) {
      char c = s.charAt(i);

      if(bCit || whiteSpace.indexOf(c) == -1) {
	// Build up word until we breaks on either a citation char or whitespace
	if(c == citChar) {
	  bCit = !bCit;
	} else {
	  if(buf == null) {
	    buf = new StringBuffer();
	  }
	  buf.append(c);
	}
	i++;
      } else {	
	// found whitespace or end of citation, append word if we have one
	if(buf != null) {
	  v.addElement(buf.toString());
	  buf = null;
	}

	// and skip whitespace so we start clean on a word or citation char
	while((i < s.length()) && (-1 != whiteSpace.indexOf(s.charAt(i)))) {
	  i++;
	}
      }
    }

    // Add possible remaining word
    if(buf != null) {
      v.addElement(buf.toString());
    }
    
    // Copy back into an array
    String [] r = new String[v.size()];
    v.copyInto(r);
    
    return r;
  }

  /**
   * Replace all occurances of a substring with another string.
   *
   * <p>
   * The returned string will shrink or grow as necessary depending on
   * the lengths of <tt>v1</tt> and <tt>v2</tt>.
   * </p>
   *
   * <p>
   * Implementation note: This method avoids using the standard String
   * manipulation methods to increase execution speed. 
   * Using the <tt>replace</tt> method does however
   * include two <tt>new</tt> operations in the case when matches are found.
   * </p>
   *
   *
   * @param s  Source string.
   * @param v1 String to be replaced with <code>v2</code>.
   * @param v2 String replacing <code>v1</code>. 
   * @return Modified string. If any of the input strings are <tt>null</tt>,
   *         the source string <tt>s</tt> will be returned unmodified. 
   *         If <tt>v1.length == 0</tt>, <tt>v1.equals(v2)</tt> or
   *         no occurances of <tt>v1</tt> is found, also 
   *         return <tt>s</tt> unmodified.
   * 
   * @author Erik Wistrand
   */
  public static String replace(final String s, 
			       final String v1, 
			       final String v2) {
    
    // return quick when nothing to do
    if(s == null 
       || v1 == null 
       || v2 == null 
       || v1.length() == 0 
       || v1.equals(v2)) {
      return s;
    }

    int ix       = 0;
    int v1Len    = v1.length(); 
    int n        = 0;

    // count number of occurances to be able to correctly size
    // the resulting output char array
    while(-1 != (ix = s.indexOf(v1, ix))) {
      n++;
      ix += v1Len;
    }

    // No occurances at all, just return source string
    if(n == 0) {
      return s;
    }

    // Set up an output char array of correct size
    int     start  = 0;
    int     v2Len  = v2.length();