Java tutorial
package org.marketcetera.util.ws.wrappers; import java.io.Externalizable; import java.io.IOException; import java.io.ObjectInput; import java.io.ObjectOutput; import org.apache.commons.lang.ObjectUtils; import org.marketcetera.util.misc.ClassVersion; /** * A remote exception. It wraps any {@link Throwable} in a manner that * enables its marshalling using JAXB in the context of web service * faults, or for use by Java serialization in other contexts; this is * done by serializing the throwable and marshalling it using a {@link * SerWrapper}. On the server side, this class sets the wrapped * throwable as its cause. This also happens on the client side, * provided the client runs in a JVM which is able to deserialize the * throwable (because it has the right resources and classes available * in its classpath). Otherwise, the cause is an instance of {@link * RemoteProxyException}, which encapsulates the throwable's most * important information, as conveyed via a {@link RemoteProperties} * instance. * * <p>Equality and hash code generation rely only on a temporary * {@link RemoteProperties} instance created for comparison purposes * from the receiver's cause; notably, the class of the cause is * ignored.</p> * * @author tlerios@marketcetera.com * @since 1.0.0 * @version $Id$ */ /* $License$ */ @ClassVersion("$Id$") public class RemoteException extends Exception implements Externalizable { // CLASS DATA. private static final long serialVersionUID = 1L; // INSTANCE DATA. private RemoteProperties mProperties; // CONSTRUCTORS. /** * Creates a new exception that wraps the given throwable. * * @param t The throwable, which may be null. */ public RemoteException(Throwable t) { this(); if (t == null) { return; } setProperties(new RemoteProperties(t)); } /** * Creates a new exception. This empty constructor is intended for * use by JAXB and Java serialization. */ public RemoteException() { super(Messages.REMOTE_EXCEPTION.getText()); } // INSTANCE METHODS. /** * Set the receiver's properties to the given ones. This method * can only be called once with a non-null argument because a side * effect is that it sets the receiver's cause based on its * non-null argument. * * @param properties The properties, which may be null. */ public void setProperties(RemoteProperties properties) { mProperties = properties; if (properties == null) { return; } initCause(getProperties().getThrowable()); } /** * Returns the receiver's properties. * * @return The properties, which may be null. */ public RemoteProperties getProperties() { return mProperties; } // Externalizable. @Override public void writeExternal(ObjectOutput out) throws IOException { out.writeObject(getProperties()); } @Override public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException { setProperties((RemoteProperties) in.readObject()); } // Exception. @Override public int hashCode() { if (getCause() == null) { return 0; } return ObjectUtils.hashCode(new RemoteProperties(getCause())); } @Override public boolean equals(Object other) { if (this == other) { return true; } if ((other == null) || !getClass().equals(other.getClass())) { return false; } RemoteException o = (RemoteException) other; if (getCause() == null) { if (o.getCause() == null) { return true; } return false; } else if (o.getCause() == null) { return false; } return ObjectUtils.equals(new RemoteProperties(getCause()), new RemoteProperties(o.getCause())); } }