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Commons Beanutils example source code file (DynaProperty.java)

This example Commons Beanutils source code file (DynaProperty.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

byte_type, char_type, class, class, double_type, dynaproperty, dynaproperty, float_type, int_type, io, ioexception, ioexception, long_type, long_type, string, util

The Commons Beanutils DynaProperty.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.IOException;
import java.io.Serializable;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.StreamCorruptedException;
import java.util.List;
import java.util.Map;


/**
 * <p>The metadata describing an individual property of a DynaBean.

* * <p>The meta contains an optional content type property ({@link #getContentType}) * for use by mapped and iterated properties. * A mapped or iterated property may choose to indicate the type it expects. * The DynaBean implementation may choose to enforce this type on its entries. * Alternatively, an implementatin may choose to ignore this property. * All keys for maps must be of type String so no meta data is needed for map keys.</p> * * @author Craig R. McClanahan * @version $Revision: 926529 $ $Date: 2010-03-23 11:44:24 +0000 (Tue, 23 Mar 2010) $ */ public class DynaProperty implements Serializable { // ----------------------------------------------------------- Constants /* * There are issues with serializing primitive class types on certain JVM versions * (including java 1.3). * This class uses a custom serialization implementation that writes an integer * for these primitive class. * This list of constants are the ones used in serialization. * If these values are changed, then older versions will no longer be read correctly */ private static final int BOOLEAN_TYPE = 1; private static final int BYTE_TYPE = 2; private static final int CHAR_TYPE = 3; private static final int DOUBLE_TYPE = 4; private static final int FLOAT_TYPE = 5; private static final int INT_TYPE = 6; private static final int LONG_TYPE = 7; private static final int SHORT_TYPE = 8; // ----------------------------------------------------------- Constructors /** * Construct a property that accepts any data type. * * @param name Name of the property being described */ public DynaProperty(String name) { this(name, Object.class); } /** * Construct a property of the specified data type. * * @param name Name of the property being described * @param type Java class representing the property data type */ public DynaProperty(String name, Class type) { super(); this.name = name; this.type = type; if (type != null && type.isArray()) { this.contentType = type.getComponentType(); } } /** * Construct an indexed or mapped <code>DynaProperty that supports (pseudo)-introspection * of the content type. * * @param name Name of the property being described * @param type Java class representing the property data type * @param contentType Class that all indexed or mapped elements are instances of */ public DynaProperty(String name, Class type, Class contentType) { super(); this.name = name; this.type = type; this.contentType = contentType; } // ------------------------------------------------------------- Properties /** Property name */ protected String name = null; /** * Get the name of this property. * @return the name of the property */ public String getName() { return (this.name); } /** Property type */ protected transient Class type = null; /** * <p>Gets the Java class representing the data type of the underlying property * values.</p> * * <p>There are issues with serializing primitive class types on certain JVM versions * (including java 1.3). * Therefore, this field <strong>must not be serialized using the standard methods.

* * <p>Please leave this field as transient

* * @return the property type */ public Class getType() { return (this.type); } /** The <em>(optional) type of content elements for indexed DynaProperty */ protected transient Class contentType; /** * Gets the <em>(optional) type of the indexed content for DynaProperty's * that support this feature. * * <p>There are issues with serializing primitive class types on certain JVM versions * (including java 1.3). * Therefore, this field <strong>must not be serialized using the standard methods.

* * @return the Class for the content type if this is an indexed <code>DynaProperty * and this feature is supported. Otherwise null. */ public Class getContentType() { return contentType; } // --------------------------------------------------------- Public Methods /** * Does this property represent an indexed value (ie an array or List)? * * @return <code>true if the property is indexed (i.e. is a List or * array), otherwise <code>false */ public boolean isIndexed() { if (type == null) { return (false); } else if (type.isArray()) { return (true); } else if (List.class.isAssignableFrom(type)) { return (true); } else { return (false); } } /** * Does this property represent a mapped value (ie a Map)? * * @return <code>true if the property is a Map * otherwise <code>false */ public boolean isMapped() { if (type == null) { return (false); } else { return (Map.class.isAssignableFrom(type)); } } /** * Checks this instance against the specified Object for equality. Overrides the * default refererence test for equality provided by {@link java.lang.Object#equals(Object)} * @param obj The object to compare to * @return <code>true if object is a dyna property with the same name * type and content type, otherwise <code>false * @since 1.8.0 */ public boolean equals(final Object obj) { boolean result = false; result = (obj == this); if ((!result) && obj instanceof DynaProperty) { final DynaProperty that = (DynaProperty) obj; result = ((this.name == null) ? (that.name == null) : (this.name.equals(that.name))) && ((this.type == null) ? (that.type == null) : (this.type.equals(that.type))) && ((this.contentType == null) ? (that.contentType == null) : (this.contentType.equals(that.contentType))); } return result; } /** * @return the hashcode for this dyna property * @see java.lang.Object#hashCode * @since 1.8.0 */ public int hashCode() { int result = 1; result = result * 31 + ((name == null) ? 0 : name.hashCode()); result = result * 31 + ((type == null) ? 0 : type.hashCode()); result = result * 31 + ((contentType == null) ? 0 : contentType.hashCode()); return result; } /** * Return a String representation of this Object. * @return a String representation of the dyna property */ public String toString() { StringBuffer sb = new StringBuffer("DynaProperty[name="); sb.append(this.name); sb.append(",type="); sb.append(this.type); if (isMapped() || isIndexed()) { sb.append(" <").append(this.contentType).append(">"); } sb.append("]"); return (sb.toString()); } // --------------------------------------------------------- Serialization helper methods /** * Writes this object safely. * There are issues with serializing primitive class types on certain JVM versions * (including java 1.3). * This method provides a workaround. */ private void writeObject(ObjectOutputStream out) throws IOException { writeAnyClass(this.type,out); if (isMapped() || isIndexed()) { writeAnyClass(this.contentType,out); } // write out other values out.defaultWriteObject(); } /** * Write a class using safe encoding to workaround java 1.3 serialization bug. */ private void writeAnyClass(Class clazz, ObjectOutputStream out) throws IOException { // safely write out any class int primitiveType = 0; if (Boolean.TYPE.equals(clazz)) { primitiveType = BOOLEAN_TYPE; } else if (Byte.TYPE.equals(clazz)) { primitiveType = BYTE_TYPE; } else if (Character.TYPE.equals(clazz)) { primitiveType = CHAR_TYPE; } else if (Double.TYPE.equals(clazz)) { primitiveType = DOUBLE_TYPE; } else if (Float.TYPE.equals(clazz)) { primitiveType = FLOAT_TYPE; } else if (Integer.TYPE.equals(clazz)) { primitiveType = INT_TYPE; } else if (Long.TYPE.equals(clazz)) { primitiveType = LONG_TYPE; } else if (Short.TYPE.equals(clazz)) { primitiveType = SHORT_TYPE; } if (primitiveType == 0) { // then it's not a primitive type out.writeBoolean(false); out.writeObject(clazz); } else { // we'll write out a constant instead out.writeBoolean(true); out.writeInt(primitiveType); } } /** * Reads field values for this object safely. * There are issues with serializing primitive class types on certain JVM versions * (including java 1.3). * This method provides a workaround. * * @throws StreamCorruptedException when the stream data values are outside expected range */ private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException { this.type = readAnyClass(in); if (isMapped() || isIndexed()) { this.contentType = readAnyClass(in); } // read other values in.defaultReadObject(); } /** * Reads a class using safe encoding to workaround java 1.3 serialization bug. */ private Class readAnyClass(ObjectInputStream in) throws IOException, ClassNotFoundException { // read back type class safely if (in.readBoolean()) { // it's a type constant switch (in.readInt()) { case BOOLEAN_TYPE: return Boolean.TYPE; case BYTE_TYPE: return Byte.TYPE; case CHAR_TYPE: return Character.TYPE; case DOUBLE_TYPE: return Double.TYPE; case FLOAT_TYPE: return Float.TYPE; case INT_TYPE: return Integer.TYPE; case LONG_TYPE: return Long.TYPE; case SHORT_TYPE: return Short.TYPE; default: // something's gone wrong throw new StreamCorruptedException( "Invalid primitive type. " + "Check version of beanutils used to serialize is compatible."); } } else { // it's another class return ((Class) in.readObject()); } } }

Other Commons Beanutils examples (source code examples)

Here is a short list of links related to this Commons Beanutils DynaProperty.java source code file:

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