src/java.base/share/classes/java/nio/file/InvalidPathException.java

/*
 * Copyright (c) 2007, 2025, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 */

package java.nio.file;

/**
 * Unchecked exception thrown when path string cannot be converted into a
 * {@link Path} because the path string contains invalid characters, or
 * the path string is invalid for other file system specific reasons.
 *
 * @since 1.7
 */

public class InvalidPathException
    extends IllegalArgumentException
{
    @java.io.Serial
    static final long serialVersionUID = 4355821422286746137L;

    /**
     * @serial The input string.
     */
    private String input;

    /**
     * @serial The index of the input string at which the error occurred or
     * {@code -1} if not known.
     */
    private int index;

    /**
     * Constructs an instance from the given input string, reason, and error
     * index.
     *
     * @param  input   the input string
     * @param  reason  a string explaining why the input was rejected
     * @param  index   the index at which the error occurred,
     *                 or {@code -1} if the index is not known
     *
     * @throws  NullPointerException
     *          if either the input or reason strings are {@code null}
     *
     * @throws  IllegalArgumentException
     *          if the error index is less than {@code -1}
     */
    public InvalidPathException(String input, String reason, int index) {
        super(reason);
        if ((input == null) || (reason == null))
            throw new NullPointerException();
        if (index < -1)
            throw new IllegalArgumentException();
        this.input = input;
        this.index = index;
    }

    /**
     * Constructs an instance from the given input string and reason.  The
     * resulting object will have an error index of {@code -1}.
     *
     * @param  input   the input string
     * @param  reason  a string explaining why the input was rejected
     *
     * @throws  NullPointerException
     *          if either the input or reason strings are {@code null}
     */
    public InvalidPathException(String input, String reason) {
        this(input, reason, -1);
    }

    /**
     * Returns the input string.
     *
     * @return  the input string
     */
    public String getInput() {
        return input;
    }

    /**
     * Returns a string explaining why the input string was rejected.
     *
     * @return  the reason string
     */
    public String getReason() {
        return super.getMessage();
    }

    /**
     * Returns an index into the input string of the position at which the
     * error occurred, or {@code -1} if this position is not known.
     *
     * @return  the error index
     */
    public int getIndex() {
        return index;
    }

    /**
     * Returns a string describing the error.  The resulting string
     * consists of the reason string followed by a colon character
     * ({@code ':'}), a space, and the input string.  If the error index is
     * defined then the string {@code " at index "} followed by the index, in
     * decimal, is inserted after the reason string and before the colon
     * character.
     *
     * @return  a string describing the error
     */
    public String getMessage() {
        StringBuilder sb = new StringBuilder();
        sb.append(getReason());
        if (index > -1) {
            sb.append(" at index ");
            sb.append(index);
        }
        sb.append(": ");
        sb.append(input);
        return sb.toString();
    }
}