    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017
    018package org.apache.commons.jexl3;
    019
    020import org.apache.commons.jexl3.internal.Script;
    021
    022/**
    023 * Helper class to carry information such as a url/file name, line and column for
    024 * debugging information reporting.
    025 */
    026public class JexlInfo {
    027
    028    /**
    029     * Describes errors more precisely.
    030     */
    031    public interface Detail {
    032        /**
    033         * Gets the end column on the line that triggered the error
    034         * @return the end column on the line that triggered the error
    035         */
    036        int end();
    037
    038        /**
    039         * Gets the start column on the line that triggered the error
    040         * @return the start column on the line that triggered the error
    041         */
    042        int start();
    043
    044        /**
    045         * Gets the code that triggered the error
    046         * @return the actual part of code that triggered the error
    047         */
    048        @Override
    049        String toString();
    050    }
    051
    052    /**
    053     * Gets the info from a script.
    054     * @param script the script
    055     * @return the info
    056     */
    057    public static JexlInfo from(final JexlScript script) {
    058        return script instanceof Script? ((Script) script).getInfo() :  null;
    059    }
    060
    061    /** Line number. */
    062    private final int line;
    063
    064    /** Column number. */
    065    private final int column;
    066
    067    /** Name. */
    068    private final String name;
    069
    070    /**
    071     * Create an information structure for dynamic set/get/invoke/new.
    072     * <p>This gathers the class, method and line number of the first calling method
    073     * outside of o.a.c.jexl3.</p>
    074     */
    075    public JexlInfo() {
    076        final StackTraceElement[] stack = new Throwable().getStackTrace();
    077        String cname = getClass().getName();
    078        final String pkgname = getClass().getPackage().getName();
    079        StackTraceElement se = null;
    080        for (int s = 1; s < stack.length; ++s) {
    081            se = stack[s];
    082            final String className = se.getClassName();
    083            if (!className.equals(cname)) {
    084                // go deeper if called from jexl implementation classes
    085                if (!className.startsWith(pkgname + ".internal.") && !className.startsWith(pkgname + ".Jexl")
    086                    && !className.startsWith(pkgname + ".parser")) {
    087                    break;
    088                }
    089                cname = className;
    090            }
    091        }
    092        this.name = se != null ? se.getClassName() + "." + se.getMethodName() + ":" + se.getLineNumber() : "?";
    093        this.line = 1;
    094        this.column = 1;
    095    }
    096
    097    /**
    098     * The copy constructor.
    099     *
    100     * @param copy the instance to copy
    101     */
    102    protected JexlInfo(final JexlInfo copy) {
    103        this(copy.getName(), copy.getLine(), copy.getColumn());
    104    }
    105
    106    /**
    107     * Create info.
    108     *
    109     * @param source source name
    110     * @param l line number
    111     * @param c column number
    112     */
    113    public JexlInfo(final String source, final int l, final int c) {
    114        name = source;
    115        line = l <= 0? 1: l;
    116        column = c <= 0? 1 : c;
    117    }
    118
    119    /**
    120     * Creates info reusing the name.
    121     *
    122     * @param l the line
    123     * @param c the column
    124     * @return a new info instance
    125     */
    126    public JexlInfo at(final int l, final int c) {
    127        return new JexlInfo(name, l, c);
    128    }
    129
    130    /**
    131     * Gets this instance or a copy without any decorations
    132     * @return this instance or a copy without any decorations
    133     */
    134    public JexlInfo detach() {
    135        return this;
    136    }
    137
    138    /**
    139     * Gets the column number.
    140     *
    141     * @return the column.
    142     */
    143    public final int getColumn() {
    144        return column;
    145    }
    146
    147    /**
    148     * Gets error detail
    149     * @return the detailed information in case of an error
    150     */
    151    public Detail getDetail() {
    152        return null;
    153    }
    154
    155    /**
    156     * Gets the line number.
    157     *
    158     * @return line number.
    159     */
    160    public final int getLine() {
    161        return line;
    162    }
    163
    164    /**
    165     * Gets the file/script/url name.
    166     *
    167     * @return template name
    168     */
    169    public final String getName() {
    170        return name;
    171    }
    172
    173    /**
    174     * Formats this info in the form 'name&#064;line:column'.
    175     *
    176     * @return the formatted info
    177     */
    178    @Override
    179    public String toString() {
    180        final StringBuilder sb = new StringBuilder(name != null ? name : "");
    181        sb.append("@");
    182        sb.append(line);
    183        sb.append(":");
    184        sb.append(column);
    185        final JexlInfo.Detail dbg = getDetail();
    186        if (dbg!= null) {
    187            sb.append("![");
    188            sb.append(dbg.start());
    189            sb.append(",");
    190            sb.append(dbg.end());
    191            sb.append("]: '");
    192            sb.append(dbg.toString());
    193            sb.append("'");
    194        }
    195        return sb.toString();
    196    }
    197}
    198