    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 *      https://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        /**
    034         * Gets the end column on the line that triggered the error
    035         *
    036         * @return the end column on the line that triggered the error
    037         */
    038        int end();
    039
    040        /**
    041         * Gets the start column on the line that triggered the error
    042         *
    043         * @return the start column on the line that triggered the error
    044         */
    045        int start();
    046
    047        /**
    048         * Gets the code that triggered the error
    049         *
    050         * @return the actual part of code that triggered the error
    051         */
    052        @Override
    053        String toString();
    054    }
    055
    056    /**
    057     * Gets the info from a script.
    058     *
    059     * @param script the script
    060     * @return the info
    061     */
    062    public static JexlInfo from(final JexlScript script) {
    063        return script instanceof Script? ((Script) script).getInfo() :  null;
    064    }
    065
    066    /** Line number. */
    067    private final int line;
    068
    069    /** Column number. */
    070    private final int column;
    071
    072    /** Name. */
    073    private final String name;
    074
    075    /**
    076     * Create an information structure for dynamic set/get/invoke/new.
    077     * <p>This gathers the class, method and line number of the first calling method
    078     * outside of o.a.c.jexl3.</p>
    079     */
    080    public JexlInfo() {
    081        final StackTraceElement[] stack = new Throwable().getStackTrace();
    082        String cname = getClass().getName();
    083        final String pkgname = getClass().getPackage().getName();
    084        StackTraceElement se = null;
    085        for (int s = 1; s < stack.length; ++s) {
    086            se = stack[s];
    087            final String className = se.getClassName();
    088            if (!className.equals(cname)) {
    089                // go deeper if called from jexl implementation classes
    090                if (!className.startsWith(pkgname + ".internal.") && !className.startsWith(pkgname + ".Jexl")
    091                    && !className.startsWith(pkgname + ".parser")) {
    092                    break;
    093                }
    094                cname = className;
    095            }
    096        }
    097        this.name = se != null ? se.getClassName() + "." + se.getMethodName() + ":" + se.getLineNumber() : "?";
    098        this.line = 1;
    099        this.column = 1;
    100    }
    101
    102    /**
    103     * The copy constructor.
    104     *
    105     * @param copy the instance to copy
    106     */
    107    protected JexlInfo(final JexlInfo copy) {
    108        this(copy.getName(), copy.getLine(), copy.getColumn());
    109    }
    110
    111    /**
    112     * Create info.
    113     *
    114     * @param source source name
    115     * @param l line number
    116     * @param c column number
    117     */
    118    public JexlInfo(final String source, final int l, final int c) {
    119        name = source;
    120        line = l <= 0? 1: l;
    121        column = c <= 0? 1 : c;
    122    }
    123
    124    /**
    125     * Creates info reusing the name.
    126     *
    127     * @param l the line
    128     * @param c the column
    129     * @return a new info instance
    130     */
    131    public JexlInfo at(final int l, final int c) {
    132        return new JexlInfo(name, l, c);
    133    }
    134
    135    /**
    136     * Gets this instance or a copy without any decorations
    137     *
    138     * @return {@code this} instance or a copy without any decorations
    139     */
    140    public JexlInfo detach() {
    141        return this;
    142    }
    143
    144    /**
    145     * Gets the column number.
    146     *
    147     * @return the column.
    148     */
    149    public final int getColumn() {
    150        return column;
    151    }
    152
    153    /**
    154     * Gets error detail
    155     *
    156     * @return the detailed information in case of an error
    157     */
    158    public Detail getDetail() {
    159        return null;
    160    }
    161
    162    /**
    163     * Gets the line number.
    164     *
    165     * @return line number.
    166     */
    167    public final int getLine() {
    168        return line;
    169    }
    170
    171    /**
    172     * Gets the file/script/url name.
    173     *
    174     * @return template name
    175     */
    176    public final String getName() {
    177        return name;
    178    }
    179
    180    /**
    181     * Formats this info in the form 'name&#064;line:column'.
    182     *
    183     * @return the formatted info
    184     */
    185    @Override
    186    public String toString() {
    187        final StringBuilder sb = new StringBuilder(name != null ? name : "");
    188        sb.append("@");
    189        sb.append(line);
    190        sb.append(":");
    191        sb.append(column);
    192        final JexlInfo.Detail dbg = getDetail();
    193        if (dbg!= null) {
    194            sb.append("![");
    195            sb.append(dbg.start());
    196            sb.append(",");
    197            sb.append(dbg.end());
    198            sb.append("]: '");
    199            sb.append(dbg.toString());
    200            sb.append("'");
    201        }
    202        return sb.toString();
    203    }
    204}
    205