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Commons Beanutils example source code file (BasicDynaClass.java)

This example Commons Beanutils source code file (BasicDynaClass.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Commons Beanutils tags/keywords

basicdynaclass, basicdynaclass, class, class, dynabean, dynaproperty, dynaproperty, hashmap, illegalaccessexception, illegalargumentexception, illegalargumentexception, instantiationexception, io, no, reflection, string, util

The Commons Beanutils BasicDynaClass.java source code

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.commons.beanutils;


import java.io.Serializable;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.util.HashMap;


/**
 * <p>Minimal implementation of the DynaClass interface.  Can be
 * used as a convenience base class for more sophisticated implementations.</p> *
 * <p>IMPLEMENTATION NOTE - The DynaBean
 * implementation class supplied to our constructor MUST have a one-argument
 * constructor of its own that accepts a <code>DynaClass.  This is
 * used to associate the DynaBean instance with this DynaClass.</p>
 *
 * @author Craig McClanahan
 * @version $Revision: 926529 $ $Date: 2010-03-23 11:44:24 +0000 (Tue, 23 Mar 2010) $
 */

public class BasicDynaClass implements DynaClass, Serializable {


    // ----------------------------------------------------------- Constructors


    /**
     * Construct a new BasicDynaClass with default parameters.
     */
    public BasicDynaClass() {

        this(null, null, null);

    }


    /**
     * Construct a new BasicDynaClass with the specified parameters.
     *
     * @param name Name of this DynaBean class
     * @param dynaBeanClass The implementation class for new instances
     */
    public BasicDynaClass(String name, Class dynaBeanClass) {

        this(name, dynaBeanClass, null);

    }


    /**
     * Construct a new BasicDynaClass with the specified parameters.
     *
     * @param name Name of this DynaBean class
     * @param dynaBeanClass The implementation class for new intances
     * @param properties Property descriptors for the supported properties
     */
    public BasicDynaClass(String name, Class dynaBeanClass,
                          DynaProperty[] properties) {

        super();
        if (name != null) {
            this.name = name;
        }
        if (dynaBeanClass == null) {
            dynaBeanClass = BasicDynaBean.class;
        }
        setDynaBeanClass(dynaBeanClass);
        if (properties != null) {
            setProperties(properties);
        }

    }


    // ----------------------------------------------------- Instance Variables


    /**
     * The constructor of the <code>dynaBeanClass that we will use
     * for creating new instances.
     */
    protected transient Constructor constructor = null;


    /**
     * The method signature of the constructor we will use to create
     * new DynaBean instances.
     */
    protected static Class[] constructorTypes = { DynaClass.class };


    /**
     * The argument values to be passed to the constructore we will use
     * to create new DynaBean instances.
     */
    protected Object[] constructorValues = { this };


    /**
     * The <code>DynaBean implementation class we will use for
     * creating new instances.
     */
    protected Class dynaBeanClass = BasicDynaBean.class;


    /**
     * The "name" of this DynaBean class.
     */
    protected String name = this.getClass().getName();


    /**
     * The set of dynamic properties that are part of this DynaClass.
     */
    protected DynaProperty[] properties = new DynaProperty[0];


    /**
     * The set of dynamic properties that are part of this DynaClass,
     * keyed by the property name.  Individual descriptor instances will
     * be the same instances as those in the <code>properties list.
     */
    protected HashMap propertiesMap = new HashMap();


    // ------------------------------------------------------ DynaClass Methods


    /**
     * Return the name of this DynaClass (analogous to the
     * <code>getName() method of java.lang.Class implementation class to support
     * different dynamic classes, with different sets of properties.
     *
     * @return the name of the DynaClass
     */
    public String getName() {

        return (this.name);

    }


    /**
     * Return a property descriptor for the specified property, if it exists;
     * otherwise, return <code>null.
     *
     * @param name Name of the dynamic property for which a descriptor
     *  is requested
     * @return The descriptor for the specified property
     *
     * @exception IllegalArgumentException if no property name is specified
     */
    public DynaProperty getDynaProperty(String name) {

        if (name == null) {
            throw new IllegalArgumentException
                    ("No property name specified");
        }
        return ((DynaProperty) propertiesMap.get(name));

    }


    /**
     * <p>Return an array of ProperyDescriptors for the properties
     * currently defined in this DynaClass.  If no properties are defined, a
     * zero-length array will be returned.</p>
     *
     * <p>FIXME - Should we really be implementing
     * <code>getBeanInfo() instead, which returns property descriptors
     * and a bunch of other stuff?</p>
     *
     * @return the set of properties for this DynaClass
     */
    public DynaProperty[] getDynaProperties() {

        return (properties);

    }


    /**
     * Instantiate and return a new DynaBean instance, associated
     * with this DynaClass.
     *
     * @return A new <code>DynaBean instance
     * @exception IllegalAccessException if the Class or the appropriate
     *  constructor is not accessible
     * @exception InstantiationException if this Class represents an abstract
     *  class, an array class, a primitive type, or void; or if instantiation
     *  fails for some other reason
     */
    public DynaBean newInstance()
            throws IllegalAccessException, InstantiationException {

        try {
            // Refind the constructor after a deserialization (if needed)
            if (constructor == null) {
                setDynaBeanClass(this.dynaBeanClass);
            }
            // Invoke the constructor to create a new bean instance
            return ((DynaBean) constructor.newInstance(constructorValues));
        } catch (InvocationTargetException e) {
            throw new InstantiationException
                    (e.getTargetException().getMessage());
        }

    }


    // --------------------------------------------------------- Public Methods


    /**
     * Return the Class object we will use to create new instances in the
     * <code>newInstance() method.  This Class MUST
     * implement the <code>DynaBean interface.
     *
     * @return The class of the {@link DynaBean}
     */
    public Class getDynaBeanClass() {

        return (this.dynaBeanClass);

    }


    // ------------------------------------------------------ Protected Methods


    /**
     * Set the Class object we will use to create new instances in the
     * <code>newInstance() method.  This Class MUST
     * implement the <code>DynaBean interface.
     *
     * @param dynaBeanClass The new Class object
     *
     * @exception IllegalArgumentException if the specified Class does not
     *  implement the <code>DynaBean interface
     */
    protected void setDynaBeanClass(Class dynaBeanClass) {

        // Validate the argument type specified
        if (dynaBeanClass.isInterface()) {
            throw new IllegalArgumentException
                    ("Class " + dynaBeanClass.getName() +
                    " is an interface, not a class");
        }
        if (!DynaBean.class.isAssignableFrom(dynaBeanClass)) {
            throw new IllegalArgumentException
                    ("Class " + dynaBeanClass.getName() +
                    " does not implement DynaBean");
        }

        // Identify the Constructor we will use in newInstance()
        try {
            this.constructor = dynaBeanClass.getConstructor(constructorTypes);
        } catch (NoSuchMethodException e) {
            throw new IllegalArgumentException
                    ("Class " + dynaBeanClass.getName() +
                    " does not have an appropriate constructor");
        }
        this.dynaBeanClass = dynaBeanClass;

    }


    /**
     * Set the list of dynamic properties supported by this DynaClass.
     *
     * @param properties List of dynamic properties to be supported
     */
    protected void setProperties(DynaProperty[] properties) {

        this.properties = properties;
        propertiesMap.clear();
        for (int i = 0; i < properties.length; i++) {
            propertiesMap.put(properties[i].getName(), properties[i]);
        }

    }


}

Other Commons Beanutils examples (source code examples)

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