repository.java

Mobile 应用程序使用 Java Micro Edition (Java ME) 平台

/*
 * @(#)Repository.java	1.74 05/12/30
 *
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package com.sun.jmx.mbeanserver;

import com.sun.jmx.defaults.ServiceName;
import com.sun.jmx.trace.Trace;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.management.DynamicMBean;
import javax.management.InstanceAlreadyExistsException;
import javax.management.InstanceNotFoundException;
import javax.management.MalformedObjectNameException;
import javax.management.ObjectName;
import javax.management.QueryExp;
import javax.management.RuntimeOperationsException;

/**
 * The RepositorySupport implements the Repository interface.
 * This repository does not support persistency.
 *
 * @since 1.5
 */
public class Repository {

    // Private fields -------------------------------------------->

    /**
     * The structure for storing the objects is very basic.
     * A Hashtable is used for storing the different domains
     * For each domain, a hashtable contains the instances with
     * canonical key property list string as key and named object
     * aggregated from given object name and mbean instance as value.
     */
    private final Map<String,Map<String,NamedObject>> domainTb;

    /**
     * Number of elements contained in the Repository
     */
    private int nbElements = 0;

    /**
     * Domain name of the server the repository is attached to.
     * It is quicker to store the information in the repository rather
     * than querying the framework each time the info is required.
     */
    private final String domain;

    /** The name of this class to be used for tracing */
    private final static String dbgTag = "Repository";

    // Private fields <=============================================

    // Private methods --------------------------------------------->

    // TRACES & DEBUG
    //---------------

    private final static boolean isTraceOn() {
        return Trace.isSelected(Trace.LEVEL_TRACE, Trace.INFO_MBEANSERVER);
    }

    private final static void trace(String clz, String func, String info) {
        Trace.send(Trace.LEVEL_TRACE, Trace.INFO_MBEANSERVER, clz, func,
                   info);
    }

    private final static void trace(String func, String info) {
        trace(dbgTag, func, info);
    }

    private final static boolean isDebugOn() {
        return Trace.isSelected(Trace.LEVEL_DEBUG, Trace.INFO_MBEANSERVER);
    }

    private final static void debug(String clz, String func, String info) {
        Trace.send(Trace.LEVEL_DEBUG, Trace.INFO_MBEANSERVER, clz, func,
                   info);
    }

    private final static void debug(String func, String info) {
        debug(dbgTag, func, info);
    }

    /* This class is used to match an ObjectName against a pattern. */
    private final static class ObjectNamePattern {
        private final char[]   domain;
        private final String[] keys;
        private final String[] values;
        private final String   properties;
        private final boolean  isPropertyListPattern;
        private final boolean  isPropertyValuePattern;

        /**
         * The ObjectName pattern against which ObjectNames are matched.
         **/
        public final ObjectName pattern;

        /**
         * Builds a new ObjectNamePattern object from an ObjectName pattern.
         * @param pattern The ObjectName pattern under examination.
         **/
        public ObjectNamePattern(ObjectName pattern) {
            this(pattern.getDomain(),
                 pattern.isPropertyListPattern(),
                 pattern.isPropertyValuePattern(),
                 pattern.getCanonicalKeyPropertyListString(),
                 pattern.getKeyPropertyList(),
                 pattern);
        }

        /**
         * Builds a new ObjectNamePattern object from an ObjectName pattern
         * constituents.
         * @param domain pattern.getDomain().
         * @param propertyListPattern pattern.isPropertyListPattern().
         * @param propertyValuePattern pattern.isPropertyValuePattern().
         * @param canonicalProps pattern.getCanonicalKeyPropertyListString().
         * @param keyPropertyList pattern.getKeyPropertyList().
         * @param pattern The ObjectName pattern under examination.
         **/
        ObjectNamePattern(String domain,
                          boolean propertyListPattern,
                          boolean propertyValuePattern,
                          String canonicalProps,
                          Map<String,String> keyPropertyList,
                          ObjectName pattern) {
            this.domain = domain.toCharArray();
            this.isPropertyListPattern = propertyListPattern;
            this.isPropertyValuePattern = propertyValuePattern;
            this.properties = canonicalProps;
            final int len = keyPropertyList.size();
            this.keys   = new String[len];
            this.values = new String[len];
            int i = 0;
            for (Map.Entry<String,String> entry : keyPropertyList.entrySet()) {
                keys[i]   = entry.getKey();
                values[i] = entry.getValue();
                i++;
            }
            this.pattern = pattern;
        }

        /**
         * Return true if the given ObjectName matches the ObjectName pattern
         * for which this object has been built.
         * WARNING: domain name is not considered here because it is supposed
         *          not to be wildcard when called. PropertyList is also
         *          supposed not to be zero-length.
         * @param name The ObjectName we want to match against the pattern.
         * @return true if <code>name</code> matches the pattern.
         **/
        public boolean matchKeys(ObjectName name) {
            // If key property value pattern but not key property list
            // pattern, then the number of key properties must be equal
            //
            if (isPropertyValuePattern &&
                !isPropertyListPattern &&
                (name.getKeyPropertyList().size() != keys.length))
                return false;

            // If key property value pattern or key property list pattern,
            // then every property inside pattern should exist in name
            //
            if (isPropertyValuePattern || isPropertyListPattern) {
                for (int i = keys.length - 1; i >= 0 ; i--) {
                    // Find value in given object name for key at current
                    // index in receiver
                    //
                    String v = name.getKeyProperty(keys[i]);
                    // Did we find a value for this key ?
                    //
                    if (v == null) return false;
                    // If this property is ok (same key, same value), go to next
                    //
                    if (isPropertyValuePattern &&
                        pattern.isPropertyValuePattern(keys[i])) {
                        // wildmatch key property values
                        final char[] val_pattern = values[i].toCharArray();
                        final char[] val_string  = v.toCharArray();
                        if (wildmatch(val_string,val_pattern))
                            continue;
                        else
                            return false;
                    }
                    if (v.equals(values[i])) continue;
                    return false;
                }
                return true;
            }

            // If no pattern, then canonical names must be equal
            //
            final String p1 = name.getCanonicalKeyPropertyListString();
            final String p2 = properties;
            return (p1.equals(p2));
        }
    }

    /**
     * Add all the matching objects from the given hashtable in the
     * result set for the given ObjectNamePattern
     * Do not check whether the domains match (only check for matching
     * key property lists - see <i>matchKeys()</i>)
     **/
    private void addAllMatching(final Map<String,NamedObject> moiTb,
                                final Set<NamedObject> result,
                                final ObjectNamePattern pattern) {
        synchronized (moiTb) {
            for (NamedObject no : moiTb.values()) {
                final ObjectName on = no.getName();
                // if all couples (property, value) are contained
                if (pattern.matchKeys(on)) result.add(no);
            }
        }
    }

    private void addNewDomMoi(final DynamicMBean object, final String dom,
                              final ObjectName name) {
        final Map<String,NamedObject> moiTb =
            new HashMap<String,NamedObject>();
        moiTb.put(name.getCanonicalKeyPropertyListString(),
                  new NamedObject(name, object));
        domainTb.put(dom, moiTb);
        nbElements++;
    }

    /** Match a string against a shell-style pattern.  The only pattern
	characters recognised are <code>?</code>, standing for any one
	character, and <code>*</code>, standing for any string of
	characters, including the empty string.

	@param str the string to match, as a character array.
	@param pat the pattern to match the string against, as a
	character array.

	@return true if and only if the string matches the pattern.
    */
    /* The algorithm is a classical one.  We advance pointers in
       parallel through str and pat.  If we encounter a star in pat,
       we remember its position and continue advancing.  If at any
       stage we get a mismatch between str and pat, we look to see if
       there is a remembered star.  If not, we fail.  If so, we
       retreat pat to just past that star and str to the position
       after the last one we tried, and we let the match advance
       again.

       Even though there is only one remembered star position, the
       algorithm works when there are several stars in the pattern.
       When we encounter the second star, we forget the first one.
       This is OK, because if we get to the second star in A*B*C
       (where A etc are arbitrary strings), we have already seen AXB.
       We're therefore setting up a match of *C against the remainder
       of the string, which will match if that remainder looks like
       YC, so the whole string looks like AXBYC.
    */
    public static boolean wildmatch(char[] str, char[] pat) {
	int stri;     // index in str
	int pati;     // index in pat
	int starstri; // index for backtrack if "*" attempt fails
	int starpati; // index for backtrack if "*" attempt fails, +1
	final int strlen = str.length;
	final int patlen = pat.length;

	stri = pati = 0;
	starstri = starpati = -1;
        
	/* On each pass through this loop, we either advance pati,
	   or we backtrack pati and advance starstri.  Since starstri
	   is only ever assigned from pati, the loop must terminate.  */
	while (true) {
	    if (pati < patlen) {
		final char patc = pat[pati];
		switch (patc) {
		case '?':
		    if (stri == strlen)
			break;
		    stri++;
		    pati++;
		    continue;
		case '*':
		    pati++;
		    starpati = pati;
		    starstri = stri;
		    continue;
		default:
		    if (stri < strlen && str[stri] == patc) {
			stri++;
			pati++;
			continue;
		    }
		    break;
		}
	    } else if (stri == strlen)
		return true;

	    // Mismatched, can we backtrack to a "*"?
	    if (starpati < 0 || starstri == strlen)
		return false;

	    // Retry the match one position later in str
	    pati = starpati;
	    starstri++;
	    stri = starstri;
	}
    }

    /**
     * Retrieves the named object contained in repository
     * from the given objectname.
     */
    private NamedObject retrieveNamedObject(ObjectName name) {

        // No patterns inside reposit
        if (name.isPattern()) return null;