MultiCauseIOException.java

/*
 * #%L
 * MariaDB4j
 * %%
 * Copyright (C) 2012 - 2014 Michael Vorburger
 * %%
 * 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.
 * #L%
 */
package at.ac.tuwien.dsg.cloud.salsa.pioneer.utils.exec;

import java.io.IOException;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.util.LinkedList;
import java.util.List;

/**
 * IOException with multiple causes.
 * 
 * @author Michael Vorburger
 */
public class MultiCauseIOException extends IOException {

    private static final long serialVersionUID = -2397961845533184622L;

    // Code review comments most welcome; I'm not sure I'm doing this right 100% right?
    // Doesn't something like this (or helpers for it) exist else? Couldn't find in commons-lang or
    // Spring...

    protected List<IOException> causes = new LinkedList<IOException>();

    /**
     * Add a Cause. Must be called at least once! (Otherwise why use this.)
     * 
     * @param message like the constructor argument of a Throwable
     * @param cause like the constructor argument of a Throwable
     */
    public void add(String message, IOException cause) {
        causes.add(new IOException(message, cause));
    }

    // May be safer not to do this - Exceptions from Exception may be more trouble than useful?
    // protected void checkUsage() throws IllegalStateException {
    // if (causes.isEmpty())
    // throw new
    // IllegalStateException("Wrong usage of MultiCauseIOException in code; must call add() at least once before");
    // }

    public List<IOException> getCauses() {
        return causes;
    }

    @Override
    public String getMessage() {
        // checkUsage();
        StringBuilder message = new StringBuilder("MultiCauseIOException, causes: ");
        for (int i = 0; i < causes.size(); i++) {
            message.append(i);
            message.append(". ");
            message.append(causes.get(i).getMessage());
        }
        return message.toString();
    }

    @Override
    public void printStackTrace(PrintStream s) {
        s.println("MultiCauseIOException, stack traces: ");
        for (int i = 0; i < causes.size(); i++) {
            s.print(i);
            s.print(". ");
            causes.get(i).printStackTrace(s);
        }
    }

    @Override
    public void printStackTrace(PrintWriter s) {
        s.println("MultiCauseIOException, stack traces: ");
        for (int i = 0; i < causes.size(); i++) {
            s.print(i);
            s.print(". ");
            causes.get(i).printStackTrace(s);
        }
    }

    // ---

    @Override
    public Throwable getCause() {
        throw new UnsupportedOperationException();
    }

    @Override
    public synchronized Throwable initCause(@SuppressWarnings("unused") Throwable cause) {
        throw new UnsupportedOperationException();
    }

    @Override
    public StackTraceElement[] getStackTrace() {
        throw new UnsupportedOperationException();
    }

    @Override
    public void setStackTrace(@SuppressWarnings("unused") StackTraceElement[] stackTrace) {
        throw new UnsupportedOperationException();
    }

}