    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    /** line number. */
    029    private final int line;
    030
    031    /** column number. */
    032    private final int column;
    033
    034    /** name. */
    035    private final String name;
    036
    037    /**
    038     * @return the detailed information in case of an error
    039     */
    040    public Detail getDetail() {
    041        return null;
    042    }
    043
    044    /**
    045     * Describes errors more precisely.
    046     */
    047    public interface Detail {
    048        /**
    049         * @return the start column on the line that triggered the error
    050         */
    051        int start();
    052
    053        /**
    054         * @return the end column on the line that triggered the error
    055         */
    056        int end();
    057
    058        /**
    059         * @return the actual part of code that triggered the error
    060         */
    061
    062        @Override
    063        String toString();
    064    }
    065
    066    /**
    067     * Create info.
    068     *
    069     * @param source source name
    070     * @param l line number
    071     * @param c column number
    072     */
    073    public JexlInfo(final String source, final int l, final int c) {
    074        name = source;
    075        line = l;
    076        column = c;
    077    }
    078
    079    /**
    080     * Create an information structure for dynamic set/get/invoke/new.
    081     * <p>This gathers the class, method and line number of the first calling method
    082     * outside of o.a.c.jexl3.</p>
    083     */
    084    public JexlInfo() {
    085        final StackTraceElement[] stack = new Throwable().getStackTrace();
    086        String cname = getClass().getName();
    087        final String pkgname = getClass().getPackage().getName();
    088        StackTraceElement se = null;
    089        for (int s = 1; s < stack.length; ++s) {
    090            se = stack[s];
    091            final String className = se.getClassName();
    092            if (!className.equals(cname)) {
    093                // go deeper if called from jexl implementation classes
    094                if (!className.startsWith(pkgname + ".internal.") && !className.startsWith(pkgname + ".Jexl")
    095                    && !className.startsWith(pkgname + ".parser")) {
    096                    break;
    097                }
    098                cname = className;
    099            }
    100        }
    101        this.name = se != null ? se.getClassName() + "." + se.getMethodName() + ":" + se.getLineNumber() : "?";
    102        this.line = 0;
    103        this.column = 0;
    104    }
    105
    106    /**
    107     * Creates info reusing the name.
    108     *
    109     * @param l the line
    110     * @param c the column
    111     * @return a new info instance
    112     */
    113    public JexlInfo at(final int l, final int c) {
    114        return new JexlInfo(name, l, c);
    115    }
    116
    117    /**
    118     * The copy constructor.
    119     *
    120     * @param copy the instance to copy
    121     */
    122    protected JexlInfo(final JexlInfo copy) {
    123        name = copy.getName();
    124        line = copy.getLine();
    125        column = copy.getColumn();
    126    }
    127
    128    /**
    129     * Formats this info in the form 'name&#064;line:column'.
    130     *
    131     * @return the formatted info
    132     */
    133    @Override
    134    public String toString() {
    135        final StringBuilder sb = new StringBuilder(name != null? name : "");
    136        if (line > 0) {
    137            sb.append("@");
    138            sb.append(line);
    139            if (column > 0) {
    140                sb.append(":");
    141                sb.append(column);
    142            }
    143        }
    144        final JexlInfo.Detail dbg = getDetail();
    145        if (dbg!= null) {
    146            sb.append("![");
    147            sb.append(dbg.start());
    148            sb.append(",");
    149            sb.append(dbg.end());
    150            sb.append("]: '");
    151            sb.append(dbg.toString());
    152            sb.append("'");
    153        }
    154        return sb.toString();
    155    }
    156
    157    /**
    158     * Gets the file/script/url name.
    159     *
    160     * @return template name
    161     */
    162    public final String getName() {
    163        return name;
    164    }
    165
    166    /**
    167     * Gets the line number.
    168     *
    169     * @return line number.
    170     */
    171    public final int getLine() {
    172        return line;
    173    }
    174
    175    /**
    176     * Gets the column number.
    177     *
    178     * @return the column.
    179     */
    180    public final int getColumn() {
    181        return column;
    182    }
    183
    184    /**
    185     * @return this instance or a copy without any decorations
    186     */
    187    public JexlInfo detach() {
    188        return this;
    189    }
    190
    191    /**
    192     * Gets the info from a script.
    193     * @param script the script
    194     * @return the info
    195     */
    196    public static JexlInfo from(final JexlScript script) {
    197        return script instanceof Script? ((Script) script).getInfo() :  null;
    198    }
    199}
    200