de.micromata.genome.util.runtime.jndi.SimpleNamingContext.java Source code

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//
// Copyright (C) 2010-2016 Micromata GmbH
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//  http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

package de.micromata.genome.util.runtime.jndi;

import java.util.Collection;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.Map;

import javax.naming.Binding;
import javax.naming.Context;
import javax.naming.Name;
import javax.naming.NameClassPair;
import javax.naming.NameNotFoundException;
import javax.naming.NameParser;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.OperationNotSupportedException;

import org.apache.commons.collections4.CollectionUtils;
import org.apache.commons.lang3.StringUtils;
import org.apache.log4j.Logger;

import de.micromata.genome.util.bean.PrivateBeanUtils;

/**
 * Simple implementation for the naming context.
 * 
 * @author Roger Rene Kommer (r.kommer.extern@micromata.de)
 *
 */
public class SimpleNamingContext implements Context {

    /**
     * The log.
     */
    private final Logger LOG = Logger.getLogger(SimpleNamingContext.class);

    /**
     * The root.
     */
    private final String root;

    /**
     * The bound objects.
     */
    private final Hashtable<String, Object> boundObjects;

    /**
     * The environment.
     */
    private final Hashtable<String, Object> environment = new Hashtable<String, Object>();

    /**
     * Create a new naming context.
     */
    public SimpleNamingContext() {
        this("");
    }

    /**
     * Create a new naming context with the given naming root.
     *
     * @param root the root
     */
    public SimpleNamingContext(String root) {
        this.root = root;
        this.boundObjects = new Hashtable<String, Object>();
    }

    /**
     * Create a new naming context with the given naming root, the given name/object map, and the JNDI environment
     * entries.
     *
     * @param root the root
     * @param boundObjects the bound objects
     * @param env the env
     */
    public SimpleNamingContext(String root, Hashtable<String, Object> boundObjects, Hashtable<String, Object> env) {
        this.root = root;
        this.boundObjects = boundObjects;
        if (env != null) {
            this.environment.putAll(env);
        }
    }

    // Actual implementations of Context methods follow

    @Override
    public NamingEnumeration<NameClassPair> list(String root) throws NamingException {
        if (LOG.isDebugEnabled()) {
            LOG.debug("LsEnv; Listing name/class pairs under [" + root + "]");
        }
        return new NameClassPairEnumeration(this, root);
    }

    @Override
    public NamingEnumeration<Binding> listBindings(String root) throws NamingException {
        if (LOG.isDebugEnabled()) {
            LOG.debug("LsEnv; Listing bindings under [" + root + "]");
        }
        return new BindingEnumeration(this, root);
    }

    private String fixJavaCompName(String name) {
        if (StringUtils.startsWith(name, "java:comp") == false) {
            return name;
        }
        name = "java:" + name.substring("java:".length());
        return name;
    }

    /**
     * Look up the object with the given name.
     * <p>
     * Note: Not intended for direct use by applications. Will be used by any standard InitialContext JNDI lookups.
     *
     * @param lookupName the lookup name
     * @return the object
     * @throws NameNotFoundException the name not found exception
     */
    public Object lookupImpl(String lookupName) throws NameNotFoundException {
        String name = this.root + lookupName;
        name = fixJavaCompName(name);
        if (LOG.isDebugEnabled()) {
            LOG.debug("LsEnv; Static JNDI lookup: [" + name + "]");
        }
        if ("".equals(name)) {
            return new SimpleNamingContext(this.root, this.boundObjects, this.environment);
        }
        Object found = this.boundObjects.get(name);

        if (found == null) {
            String sname = name;
            if (!sname.endsWith("/")) {
                sname = sname + "/";
            }
            for (String boundName : this.boundObjects.keySet()) {
                if (boundName.startsWith(sname)) {
                    return new SimpleNamingContext(sname, this.boundObjects, this.environment);
                }
            }
            throw new NameNotFoundException(
                    "Name [" + this.root + lookupName + "] not bound; " + this.boundObjects.size() + " bindings: ["
                            + collectionToDelimitedString(this.boundObjects.keySet(), ",") + "]");
        }
        return found;
    }

    /**
     * Convert a {@code Collection} into a delimited {@code String} (e.g. CSV).
     * <p>
     * Useful for {@code toString()} implementations.
     * 
     * @param coll the {@code Collection} to convert
     * @param delim the delimiter to use (typically a ",")
     * @return the delimited {@code String}
     */
    public static String collectionToDelimitedString(Collection<?> coll, String delim) {
        return collectionToDelimitedString(coll, delim, "", "");
    }

    /**
     * Convert a {@link Collection} to a delimited {@code String} (e.g. CSV).
     * <p>
     * Useful for {@code toString()} implementations.
     * 
     * @param coll the {@code Collection} to convert
     * @param delim the delimiter to use (typically a ",")
     * @param prefix the {@code String} to start each element with
     * @param suffix the {@code String} to end each element with
     * @return the delimited {@code String}
     */
    public static String collectionToDelimitedString(Collection<?> coll, String delim, String prefix,
            String suffix) {
        if (CollectionUtils.isEmpty(coll)) {
            return "";
        }
        StringBuilder sb = new StringBuilder();
        Iterator<?> it = coll.iterator();
        while (it.hasNext()) {
            sb.append(prefix).append(it.next()).append(suffix);
            if (it.hasNext()) {
                sb.append(delim);
            }
        }
        return sb.toString();
    }

    @Override
    public Object lookupLink(String name) throws NameNotFoundException {
        return lookup(name);
    }

    /**
     * Bind the given object to the given name. Note: Not intended for direct use by applications if setting up a
     * JVM-level JNDI environment. Use SimpleNamingContextBuilder to set up JNDI bindings then.
     * 
     */
    @Override
    public void bind(String name, Object obj) {
        name = fixJavaCompName(name);
        if (LOG.isInfoEnabled()) {
            LOG.info("LsEnv; Static JNDI binding: [" + this.root + name + "] = ["
                    + SimpleNamingContextBuilder.jndiObjectToString(obj) + "]");
        }
        if (obj == null) {
            throw new IllegalArgumentException("Cannot bind null object to JNDI: " + this.root + name);
        }
        this.boundObjects.put(this.root + name, obj);
    }

    @Override
    public void unbind(String name) {
        name = fixJavaCompName(name);
        if (LOG.isInfoEnabled()) {
            LOG.info("LsEnv; Static JNDI remove: [" + this.root + name + "]");
        }
        this.boundObjects.remove(this.root + name);
    }

    @Override
    public void rebind(String name, Object obj) {
        bind(name, obj);
    }

    @Override
    public void rename(String oldName, String newName) throws NameNotFoundException {
        Object obj = lookup(oldName);
        unbind(oldName);
        bind(newName, obj);
    }

    @Override
    public Context createSubcontext(String name) {
        String subcontextName = this.root + name;
        if (!subcontextName.endsWith("/")) {
            subcontextName += "/";
        }
        Context subcontext = new SimpleNamingContext(subcontextName, this.boundObjects, this.environment);
        bind(name, subcontext);
        return subcontext;
    }

    @Override
    public void destroySubcontext(String name) {
        unbind(name);
    }

    @Override
    public String composeName(String name, String prefix) {
        return prefix + name;
    }

    @Override
    public Hashtable<String, Object> getEnvironment() {
        return this.environment;
    }

    @Override
    public Object addToEnvironment(String propName, Object propVal) {
        return this.environment.put(propName, propVal);
    }

    @Override
    public Object removeFromEnvironment(String propName) {
        return this.environment.remove(propName);
    }

    @Override
    public NamingEnumeration<NameClassPair> list(Name name) throws NamingException {
        return list(nameToString(name));
    }

    @Override
    public NamingEnumeration<Binding> listBindings(Name name) throws NamingException {
        return listBindings(nameToString(name));
    }

    @Override
    public Object lookupLink(Name name) throws NamingException {
        return lookupLink(nameToString(name));
    }

    @Override
    public NameParser getNameParser(Name name) throws NamingException {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public String getNameInNamespace() throws NamingException {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public void close() {
    }

    /**
     * Name to string.
     *
     * @param name the name
     * @return the string
     */
    public String nameToString(Name name) {
        StringBuilder sb = new StringBuilder();
        Enumeration<String> en = name.getAll();
        while (en.hasMoreElements()) {
            String part = en.nextElement();
            if (sb.length() > 0) {
                sb.append('/');
            }
            sb.append(part);
        }
        return sb.toString();
    }

    @Override
    public void bind(Name name, Object obj) throws NamingException {
        bind(nameToString(name), obj);
    }

    @Override
    public void unbind(Name name) throws NamingException {
        unbind(nameToString(name));
    }

    @Override
    public void rebind(Name name, Object obj) throws NamingException {
        rebind(nameToString(name), obj);
    }

    @Override
    public void rename(Name oldName, Name newName) throws NamingException {
        rename(nameToString(oldName), nameToString(newName));
    }

    @Override
    public Context createSubcontext(Name name) throws NamingException {
        return createSubcontext(nameToString(name));
    }

    @Override
    public void destroySubcontext(Name name) throws NamingException {
        destroySubcontext(nameToString(name));
    }

    @Override
    public Name composeName(Name name, Name prefix) throws NamingException {
        throw new OperationNotSupportedException("SimpleNamingContext does not support [javax.naming.Name]");
    }

    @Override
    public NameParser getNameParser(String name) throws NamingException {
        return new JndiMockupParser();
    }

    /**
     * To string.
     *
     * @param name the name
     * @return the string
     */
    protected String toString(Name name) {
        return name.toString();
    }

    @Override
    public Object lookup(Name name) throws NamingException {
        return lookup(toString(name));
    }

    protected String getRoot() {
        return PrivateBeanUtils.readField(this, "root", String.class);
    }

    protected Hashtable<String, Object> getBoundObjects() {
        return PrivateBeanUtils.readField(this, "boundObjects", Hashtable.class);
    }

    @Override
    public Object lookup(String lookupName) throws NameNotFoundException {
        try {
            return lookupImpl(lookupName);
        } catch (NameNotFoundException ex) {
            String prefix = "java:comp/env/";
            if (StringUtils.startsWith(lookupName, prefix) == false) {
                return lookupImpl(prefix + lookupName);
            }
            throw ex;
        }
    }

    /**
     * The Class AbstractNamingEnumeration.
     *
     * @param <T> the generic type
     */
    private static abstract class AbstractNamingEnumeration<T> implements NamingEnumeration<T> {

        /**
         * The iterator.
         */
        private Iterator<T> iterator;

        /**
         * Instantiates a new abstract naming enumeration.
         *
         * @param context the context
         * @param proot the proot
         * @throws NamingException the naming exception
         */
        private AbstractNamingEnumeration(SimpleNamingContext context, String proot) throws NamingException {
            if (!"".equals(proot) && !proot.endsWith("/")) {
                proot = proot + "/";
            }
            String root = context.root + proot;
            Map<String, T> contents = new HashMap<String, T>();
            for (String boundName : context.boundObjects.keySet()) {
                if (boundName.startsWith(root)) {
                    int startIndex = root.length();
                    int endIndex = boundName.indexOf('/', startIndex);
                    String strippedName = (endIndex != -1 ? boundName.substring(startIndex, endIndex)
                            : boundName.substring(startIndex));
                    if (!contents.containsKey(strippedName)) {
                        try {
                            contents.put(strippedName,
                                    createObject(strippedName, context.lookup(proot + strippedName)));
                        } catch (NameNotFoundException ex) {
                            // cannot happen
                        }
                    }
                }
            }
            if (contents.size() == 0) {
                throw new NamingException("Invalid root: [" + context.root + proot + "]");
            }
            this.iterator = contents.values().iterator();
        }

        /**
         * Creates the object.
         *
         * @param strippedName the stripped name
         * @param obj the obj
         * @return the t
         */
        protected abstract T createObject(String strippedName, Object obj);

        @Override
        public boolean hasMore() {
            return this.iterator.hasNext();
        }

        @Override
        public T next() {
            return this.iterator.next();
        }

        @Override
        public boolean hasMoreElements() {
            return this.iterator.hasNext();
        }

        @Override
        public T nextElement() {
            return this.iterator.next();
        }

        @Override
        public void close() {
        }
    }

    /**
     * The Class NameClassPairEnumeration.
     */
    private static class NameClassPairEnumeration extends AbstractNamingEnumeration<NameClassPair> {

        /**
         * Instantiates a new name class pair enumeration.
         *
         * @param context the context
         * @param root the root
         * @throws NamingException the naming exception
         */
        private NameClassPairEnumeration(SimpleNamingContext context, String root) throws NamingException {
            super(context, root);
        }

        @Override
        protected NameClassPair createObject(String strippedName, Object obj) {
            return new NameClassPair(strippedName, obj.getClass().getName());
        }
    }

    /**
     * The Class BindingEnumeration.
     */
    private static class BindingEnumeration extends AbstractNamingEnumeration<Binding> {

        /**
         * Instantiates a new binding enumeration.
         *
         * @param context the context
         * @param root the root
         * @throws NamingException the naming exception
         */
        private BindingEnumeration(SimpleNamingContext context, String root) throws NamingException {
            super(context, root);
        }

        @Override
        protected Binding createObject(String strippedName, Object obj) {
            return new Binding(strippedName, obj);
        }
    }

}