filebot/source/net/filebot/util/ExceptionUtilities.java

package net.filebot.util;

import static java.util.Arrays.*;

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

public final class ExceptionUtilities {

	public static <T extends Throwable> T shiftStackTrace(T t, int offset) {
		StackTraceElement[] stackTrace = t.getStackTrace();
		if (offset < stackTrace.length) {
			t.setStackTrace(copyOfRange(stackTrace, offset, stackTrace.length));
		}
		return t;
	}

	public static Throwable getRootCause(Throwable t) {
		while (t.getCause() != null) {
			t = t.getCause();
		}

		return t;
	}

	public static <T extends Throwable> T findCause(Throwable t, Class<T> type) {
		while (t != null) {
			if (type.isInstance(t))
				return type.cast(t);

			t = t.getCause();
		}

		return null;
	}

	public static String getRootCauseMessage(Throwable t) {
		return getMessage(getRootCause(t));
	}

	public static String getMessage(Throwable t) {
		String message = t.getMessage();

		if (message == null || message.isEmpty()) {
			message = t.toString();
		}

		return message;
	}

	public static String getStackTrace(Throwable t) {
		StringWriter buffer = new StringWriter();
		t.printStackTrace(new PrintWriter(buffer, true));
		return buffer.getBuffer().toString();
	}

	public static <T extends Throwable> T wrap(Throwable t, Class<T> type) {
		if (type.isInstance(t)) {
			return type.cast(t);
		}

		try {
			return type.getConstructor(Throwable.class).newInstance(t);
		} catch (Exception e) {
			throw new IllegalArgumentException(e);
		}
	}

	public static RuntimeException asRuntimeException(Throwable t) {
		return wrap(t, RuntimeException.class);
	}

	/**
	 * Dummy constructor to prevent instantiation.
	 */
	private ExceptionUtilities() {
		throw new UnsupportedOperationException();
	}

}