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MbeansSource.javaAPI DocApache Tomcat 6.0.1413766Fri Jul 20 04:20:34 BST 2007org.apache.tomcat.util.modeler.modules

MbeansSource

public class MbeansSource extends ModelerSource implements MbeansSourceMBean
This will create mbeans based on a config file. The format is an extended version of MLET. Classloading. We don't support any explicit classloader tag. A ClassLoader is just an mbean ( it can be the standard MLetMBean or a custom one ). XXX add a special attribute to reference the loader mbean, XXX figure out how to deal with private loaders

Fields Summary
private static org.apache.juli.logging.Log
log
org.apache.tomcat.util.modeler.Registry
registry
String
type
boolean
loading
List
mbeans
static boolean
loaderLoaded
private Document
document
private HashMap
object2Node
long
lastUpdate
long
updateInterval
Constructors Summary
Methods Summary
public voiddestroy()

        registry.invoke(mbeans, "destroy", false);                
    
public voidexecute()

        if( registry==null ) registry=Registry.getRegistry();
        try {
            InputStream stream=getInputStream();
            long t1=System.currentTimeMillis();
            document = DomUtil.readXml(stream);

            // We don't care what the root node is.
            Node descriptorsN=document.getDocumentElement();

            if( descriptorsN == null ) {
                log.error("No descriptors found");
                return;
            }

            Node firstMbeanN=DomUtil.getChild(descriptorsN, null);

            if( firstMbeanN==null ) {
                // maybe we have a single mlet
                if( log.isDebugEnabled() )
                    log.debug("No child " + descriptorsN);
                firstMbeanN=descriptorsN;
            }

            MBeanServer server=(MBeanServer)Registry.getServer();

            // XXX Not very clean...  Just a workaround
            if( ! loaderLoaded ) {
                // Register a loader that will be find ant classes.
                ObjectName defaultLoader= new ObjectName("modeler",
                        "loader", "modeler");
                MLet mlet=new MLet( new URL[0], this.getClass().getClassLoader());
                server.registerMBean(mlet, defaultLoader);
                loaderLoaded=true;
            }
        
            // Process nodes
            for (Node mbeanN = firstMbeanN; mbeanN != null;
                 mbeanN= DomUtil.getNext(mbeanN, null, Node.ELEMENT_NODE))
            {
                String nodeName=mbeanN.getNodeName();

                // mbean is the "official" name
                if( "mbean".equals(nodeName) || "MLET".equals(nodeName) )
                {
                    String code=DomUtil.getAttribute( mbeanN, "code" );
                    String objectName=DomUtil.getAttribute( mbeanN, "objectName" );
                    if( objectName==null ) {
                        objectName=DomUtil.getAttribute( mbeanN, "name" );
                    }
                    
                    if( log.isDebugEnabled())
                        log.debug( "Processing mbean objectName=" + objectName +
                                " code=" + code);

                    // args can be grouped in constructor or direct childs
                    Node constructorN=DomUtil.getChild(mbeanN, "constructor");
                    if( constructorN == null ) constructorN=mbeanN;

                    processArg(constructorN);

                    try {
                        ObjectName oname=new ObjectName(objectName);
                        if( ! server.isRegistered( oname )) {
                            // We wrap everything in a model mbean.
                            // XXX need to support "StandardMBeanDescriptorsSource"
                            String modelMBean=BaseModelMBean.class.getName();                            
                            server.createMBean(modelMBean, oname,
                                    new Object[] { code, this},
                                    new String[] { String.class.getName(),
                                                  ModelerSource.class.getName() } 
                                    );
                            mbeans.add(oname);
                        }
                        object2Node.put( oname, mbeanN );
                        // XXX Arguments, loader !!!
                    } catch( Exception ex ) {
                        log.error( "Error creating mbean " + objectName, ex);
                    }

                    Node firstAttN=DomUtil.getChild(mbeanN, "attribute");
                    for (Node descN = firstAttN; descN != null;
                         descN = DomUtil.getNext( descN ))
                    {
                        processAttribute(server, descN, objectName);
                    }
                } else if("jmx-operation".equals(nodeName) ) {
                    String name=DomUtil.getAttribute(mbeanN, "objectName");
                    if( name==null )
                        name=DomUtil.getAttribute(mbeanN, "name");

                    String operation=DomUtil.getAttribute(mbeanN, "operation");

                    if( log.isDebugEnabled())
                        log.debug( "Processing invoke objectName=" + name +
                                " code=" + operation);
                    try {
                        ObjectName oname=new ObjectName(name);

                        processArg( mbeanN );
                        server.invoke( oname, operation, null, null);
                    } catch (Exception e) {
                        log.error( "Error in invoke " + name + " " + operation);
                    }
                }

                ManagedBean managed=new ManagedBean();
                DomUtil.setAttributes(managed, mbeanN);
                Node firstN;

                // process attribute info
                firstN=DomUtil.getChild( mbeanN, "attribute");
                for (Node descN = firstN; descN != null;
                     descN = DomUtil.getNext( descN ))
                {
                    AttributeInfo ci=new AttributeInfo();
                    DomUtil.setAttributes(ci, descN);
                    managed.addAttribute( ci );
                }

            }

            long t2=System.currentTimeMillis();
            log.info( "Reading mbeans  " + (t2-t1));
            loading=false;
        } catch( Exception ex ) {
            log.error( "Error reading mbeans ", ex);
        }
    
public java.lang.StringgetLocation()

        return location;
    
public java.util.ListgetMBeans()
Return the list of mbeans created by this source. It can be used to implement runtime services.

        return mbeans;
    
public java.lang.ObjectgetSource()

        return source;
    
public voidinit()

        if( mbeans==null) execute();
        if( registry==null ) registry=Registry.getRegistry();
        
        registry.invoke(mbeans, "init", false);
    
public voidload()

        execute(); // backward compat
    
public java.util.ListloadDescriptors(org.apache.tomcat.util.modeler.Registry registry, java.lang.String location, java.lang.String type, java.lang.Object source)

        setRegistry(registry);
        setLocation(location);
        setType(type);
        setSource(source);
        execute();
        return mbeans;
    
private voidprocessArg(org.w3c.dom.Node mbeanN)

        Node firstArgN=DomUtil.getChild(mbeanN, "arg" );
        // process all args
        for (Node argN = firstArgN; argN != null;
             argN = DomUtil.getNext( argN ))
        {
            String type=DomUtil.getAttribute(argN, "type");
            String value=DomUtil.getAttribute(argN, "value");
            if( value==null ) {
                // The value may be specified as CDATA
                value=DomUtil.getContent(argN);
            }
        }
    
private voidprocessAttribute(javax.management.MBeanServer server, org.w3c.dom.Node descN, java.lang.String objectName)

        String attName=DomUtil.getAttribute(descN, "name");
        String value=DomUtil.getAttribute(descN, "value");
        String type=null; // DomUtil.getAttribute(descN, "type");
        if( value==null ) {
            // The value may be specified as CDATA
            value=DomUtil.getContent(descN);
        }
        try {
            if( log.isDebugEnabled())
                log.debug("Set attribute " + objectName + " " + attName +
                        " " + value);
            ObjectName oname=new ObjectName(objectName);
            // find the type
            if( type==null )
                type=registry.getType(  oname, attName );

            if( type==null ) {
                log.info("Can't find attribute " + objectName + " " + attName );

            } else {
                Object valueO=registry.convertValue( type, value);
                server.setAttribute(oname, new Attribute(attName, valueO));
            }
        } catch( Exception ex) {
            log.error("Error processing attribute " + objectName + " " +
                    attName + " " + value, ex);
        }

    
public voidsave()
Store the mbeans. XXX add a background thread to store it periodically

        // XXX customize no often than ( based on standard descriptor ), etc.
        // It doesn't work very well if we call this on each set att - 
        // the triger will work for the first att, but all others will be delayed
        long time=System.currentTimeMillis();
        if( location!=null &&
                time - lastUpdate > updateInterval ) {
            lastUpdate=time;
            try {
                FileOutputStream fos=new FileOutputStream(location);
                DomUtil.writeXml(document, fos);
            } catch (TransformerException e) {
                log.error( "Error writing");
            } catch (FileNotFoundException e) {
                log.error( "Error writing" ,e );
            }
        }
    
public voidsetLocation(java.lang.String loc)

        this.location=loc;
    
public voidsetRegistry(org.apache.tomcat.util.modeler.Registry reg)

 // 10s

        
        this.registry=reg;
    
public voidsetSource(java.lang.Object source)

        this.source=source;
    
public voidsetType(java.lang.String type)
Used if a single component is loaded

param
type

       this.type=type;
    
public voidstart()

        registry.invoke(mbeans, "start", false);        
    
public voidstop()

        registry.invoke(mbeans, "stop", false);        
    
public voidupdateField(javax.management.ObjectName oname, java.lang.String name, java.lang.Object value)

        if( loading ) return;
        // nothing by default
        //log.info( "XXX UpdateField " + oname + " " + name + " " + value);
        Node n=(Node)object2Node.get( oname );
        if( n == null ) {
            log.info( "Node not found " + oname );
            return;
        }
        Node attNode=DomUtil.findChildWithAtt(n, "attribute", "name", name);
        if( attNode == null ) {
            // found no existing attribute with this name
            attNode=n.getOwnerDocument().createElement("attribute");
            DomUtil.setAttribute(attNode, "name", name);
            n.appendChild(attNode);
        } 
        String oldValue=DomUtil.getAttribute(attNode, "value");
        if( oldValue != null ) {
            // we'll convert all values to text content
            DomUtil.removeAttribute( attNode, "value");
        }
        DomUtil.setText(attNode, value.toString());

        //store();