001    package org.apache.maven.settings.building;
002    
003    /*
004     * Licensed to the Apache Software Foundation (ASF) under one
005     * or more contributor license agreements.  See the NOTICE file
006     * distributed with this work for additional information
007     * regarding copyright ownership.  The ASF licenses this file
008     * to you under the Apache License, Version 2.0 (the
009     * "License"); you may not use this file except in compliance
010     * with the License.  You may obtain a copy of the License at
011     *
012     *   http://www.apache.org/licenses/LICENSE-2.0
013     *
014     * Unless required by applicable law or agreed to in writing,
015     * software distributed under the License is distributed on an
016     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017     * KIND, either express or implied.  See the License for the
018     * specific language governing permissions and limitations
019     * under the License.
020     */
021    
022    /**
023     * Describes a problem that was encountered during settings building. A problem can either be an exception that was
024     * thrown or a simple string message. In addition, a problem carries a hint about its source, e.g. the settings file
025     * that exhibits the problem.
026     * 
027     * @author Benjamin Bentmann
028     */
029    public interface SettingsProblem
030    {
031    
032        /**
033         * The different severity levels for a problem, in decreasing order.
034         */
035        enum Severity
036        {
037    
038            FATAL, //
039            ERROR, //
040            WARNING; //
041    
042        }
043    
044        /**
045         * Gets the hint about the source of the problem. While the syntax of this hint is unspecified and depends on the
046         * creator of the problem, the general expectation is that the hint provides sufficient information to the user to
047         * track the problem back to its origin. A concrete example for such a source hint can be the file path or URL from
048         * which the settings were read.
049         * 
050         * @return The hint about the source of the problem or an empty string if unknown, never {@code null}.
051         */
052        String getSource();
053    
054        /**
055         * Gets the one-based index of the line containing the problem. The line number should refer to some text file that
056         * is given by {@link #getSource()}.
057         * 
058         * @return The one-based index of the line containing the problem or a non-positive value if unknown.
059         */
060        int getLineNumber();
061    
062        /**
063         * Gets the one-based index of the column containing the problem. The column number should refer to some text file
064         * that is given by {@link #getSource()}.
065         * 
066         * @return The one-based index of the column containing the problem or non-positive value if unknown.
067         */
068        int getColumnNumber();
069    
070        /**
071         * Gets the location of the problem. The location is a user-friendly combination of the values from
072         * {@link #getSource()}, {@link #getLineNumber()} and {@link #getColumnNumber()}. The exact syntax of the returned
073         * value is undefined.
074         * 
075         * @return The location of the problem, never {@code null}.
076         */
077        String getLocation();
078    
079        /**
080         * Gets the exception that caused this problem (if any).
081         * 
082         * @return The exception that caused this problem or {@code null} if not applicable.
083         */
084        Exception getException();
085    
086        /**
087         * Gets the message that describes this problem.
088         * 
089         * @return The message describing this problem, never {@code null}.
090         */
091        String getMessage();
092    
093        /**
094         * Gets the severity level of this problem.
095         * 
096         * @return The severity level of this problem, never {@code null}.
097         */
098        Severity getSeverity();
099    
100    }