ExceptionUtils.java

/*
 * Copyright 2012 JBoss Inc
 *
 * 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 org.overlord.dtgov.ui.server.util;

import java.io.PrintWriter;
import java.io.StringWriter;

import org.overlord.dtgov.ui.client.shared.exceptions.DtgovUiException;

/**
 * Provides some util methods for dealing with exceptions.
 *
 * @author eric.wittmann@redhat.com
 */
public class ExceptionUtils {

    /**
     * Gets the root stack trace as a string.
     * @param t
     */
    public static String getRootStackTrace(Throwable t) {
        StringWriter sw = new StringWriter();
        PrintWriter writer = new PrintWriter(sw);
        getRootCause(t).printStackTrace(writer);
        return sw.getBuffer().toString();
    }

    /**
     * Gets the root exception from the given {@link Throwable}.
     * @param t
     */
    public static Throwable getRootCause(Throwable t) {
        Throwable root = t;
        while (root.getCause() != null && root.getCause() != root)
            root = root.getCause();
        return root;
    }

    /**
     * Creates a UI exception that can be thrown to the client.
     * @param message
     * @param root
     */
    public static DtgovUiException createUiException(String message, Throwable root) {
        DtgovUiException re = null;
        if (message != null && root != null) {
            re = new DtgovUiException(message, root);
        } else if (root != null) {
            re = new DtgovUiException(root);
        } else {
            re = new DtgovUiException();
        }
        // TODO also pass the root stack trace
//        if (root != null)
//            re.setRootStackTrace(getRootStackTrace(root));
        return re;
    }

    /**
     * Creates a remote exception that can be thrown to the client.
     * @param root
     */
    public static DtgovUiException createRemoteException(Throwable root) {
        return createUiException(null, root);
    }

}