    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         * @return the end column on the line that triggered the error
    034         */
    035        int end();
    036
    037        /**
    038         * @return the start column on the line that triggered the error
    039         */
    040        int start();
    041
    042        /**
    043         * @return the actual part of code that triggered the error
    044         */
    045
    046        @Override
    047        String toString();
    048    }
    049
    050    /**
    051     * Gets the info from a script.
    052     * @param script the script
    053     * @return the info
    054     */
    055    public static JexlInfo from(final JexlScript script) {
    056        return script instanceof Script? ((Script) script).getInfo() :  null;
    057    }
    058
    059    /** Line number. */
    060    private final int line;
    061
    062    /** Column number. */
    063    private final int column;
    064
    065    /** Name. */
    066    private final String name;
    067
    068    /**
    069     * Create an information structure for dynamic set/get/invoke/new.
    070     * <p>This gathers the class, method and line number of the first calling method
    071     * outside of o.a.c.jexl3.</p>
    072     */
    073    public JexlInfo() {
    074        final StackTraceElement[] stack = new Throwable().getStackTrace();
    075        String cname = getClass().getName();
    076        final String pkgname = getClass().getPackage().getName();
    077        StackTraceElement se = null;
    078        for (int s = 1; s < stack.length; ++s) {
    079            se = stack[s];
    080            final String className = se.getClassName();
    081            if (!className.equals(cname)) {
    082                // go deeper if called from jexl implementation classes
    083                if (!className.startsWith(pkgname + ".internal.") && !className.startsWith(pkgname + ".Jexl")
    084                    && !className.startsWith(pkgname + ".parser")) {
    085                    break;
    086                }
    087                cname = className;
    088            }
    089        }
    090        this.name = se != null ? se.getClassName() + "." + se.getMethodName() + ":" + se.getLineNumber() : "?";
    091        this.line = 1;
    092        this.column = 1;
    093    }
    094
    095    /**
    096     * The copy constructor.
    097     *
    098     * @param copy the instance to copy
    099     */
    100    protected JexlInfo(final JexlInfo copy) {
    101        this(copy.getName(), copy.getLine(), copy.getColumn());
    102    }
    103
    104    /**
    105     * Create info.
    106     *
    107     * @param source source name
    108     * @param l line number
    109     * @param c column number
    110     */
    111    public JexlInfo(final String source, final int l, final int c) {
    112        name = source;
    113        line = l <= 0? 1: l;
    114        column = c <= 0? 1 : c;
    115    }
    116
    117    /**
    118     * Creates info reusing the name.
    119     *
    120     * @param l the line
    121     * @param c the column
    122     * @return a new info instance
    123     */
    124    public JexlInfo at(final int l, final int c) {
    125        return new JexlInfo(name, l, c);
    126    }
    127
    128    /**
    129     * @return this instance or a copy without any decorations
    130     */
    131    public JexlInfo detach() {
    132        return this;
    133    }
    134
    135    /**
    136     * Gets the column number.
    137     *
    138     * @return the column.
    139     */
    140    public final int getColumn() {
    141        return column;
    142    }
    143
    144    /**
    145     * @return the detailed information in case of an error
    146     */
    147    public Detail getDetail() {
    148        return null;
    149    }
    150
    151    /**
    152     * Gets the line number.
    153     *
    154     * @return line number.
    155     */
    156    public final int getLine() {
    157        return line;
    158    }
    159
    160    /**
    161     * Gets the file/script/url name.
    162     *
    163     * @return template name
    164     */
    165    public final String getName() {
    166        return name;
    167    }
    168
    169    /**
    170     * Formats this info in the form 'name&#064;line:column'.
    171     *
    172     * @return the formatted info
    173     */
    174    @Override
    175    public String toString() {
    176        final StringBuilder sb = new StringBuilder(name != null ? name : "");
    177        sb.append("@");
    178        sb.append(line);
    179        sb.append(":");
    180        sb.append(column);
    181        final JexlInfo.Detail dbg = getDetail();
    182        if (dbg!= null) {
    183            sb.append("![");
    184            sb.append(dbg.start());
    185            sb.append(",");
    186            sb.append(dbg.end());
    187            sb.append("]: '");
    188            sb.append(dbg.toString());
    189            sb.append("'");
    190        }
    191        return sb.toString();
    192    }
    193}
    194