StackTraceElementCompositeData.java

/*
 * Copyright 2005 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

package sun.management;

import javax.management.openmbean.CompositeType;
import javax.management.openmbean.CompositeData;
import javax.management.openmbean.CompositeDataSupport;
import javax.management.openmbean.OpenDataException;

/**
 * A CompositeData for StackTraceElement for the local management support.
 * This class avoids the performance penalty paid to the
 * construction of a CompositeData use in the local case.
 */
public class StackTraceElementCompositeData extends LazyCompositeData {
    private final StackTraceElement ste;

    private StackTraceElementCompositeData(StackTraceElement ste) {
        this.ste = ste;
    }

    public StackTraceElement getStackTraceElement() {
        return ste;
    }

    public static StackTraceElement from(CompositeData cd) {
        validateCompositeData(cd);

        return new StackTraceElement(getString(cd, CLASS_NAME),
                                     getString(cd, METHOD_NAME),
                                     getString(cd, FILE_NAME),
                                     getInt(cd, LINE_NUMBER));
    }

    public static CompositeData toCompositeData(StackTraceElement ste) {
        StackTraceElementCompositeData cd = new StackTraceElementCompositeData(ste);
        return cd.getCompositeData();
    }

    protected CompositeData getCompositeData() {
        // CONTENTS OF THIS ARRAY MUST BE SYNCHRONIZED WITH
        // stackTraceElementItemNames!
        final Object[] stackTraceElementItemValues = {
            ste.getClassName(),
            ste.getMethodName(),
            ste.getFileName(),
            new Integer(ste.getLineNumber()),
            new Boolean(ste.isNativeMethod()),
        };
        try {
            return new CompositeDataSupport(stackTraceElementCompositeType,
                                            stackTraceElementItemNames,
                                            stackTraceElementItemValues);
        } catch (OpenDataException e) {
            // Should never reach here
            throw new AssertionError(e);
        }
    }

    private static final CompositeType stackTraceElementCompositeType;
    static {
        try {
            stackTraceElementCompositeType = (CompositeType)
                MappedMXBeanType.toOpenType(StackTraceElement.class);
        } catch (OpenDataException e) {
            // Should never reach here
            throw new AssertionError(e);
        }
    }

    // Attribute names
    private static final String CLASS_NAME      = "className";
    private static final String METHOD_NAME     = "methodName";
    private static final String FILE_NAME       = "fileName";
    private static final String LINE_NUMBER     = "lineNumber";
    private static final String NATIVE_METHOD   = "nativeMethod";

    private static final String[] stackTraceElementItemNames = {
        CLASS_NAME,
        METHOD_NAME,
        FILE_NAME,
        LINE_NUMBER,
        NATIVE_METHOD,
    };

    /** Validate if the input CompositeData has the expected
     * CompositeType (i.e. contain all attributes with expected
     * names and types).
     */
    public static void validateCompositeData(CompositeData cd) {
        if (cd == null) {
            throw new NullPointerException("Null CompositeData");
        }

        if (!isTypeMatched(stackTraceElementCompositeType, cd.getCompositeType())) {
            throw new IllegalArgumentException(
                "Unexpected composite type for StackTraceElement");
        }
    }
}