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