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      1 /*
      2  * Copyright (C) 2010 Google Inc.
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  * http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.google.clearsilver.jsilver.precompiler;
     18 
     19 import com.google.clearsilver.jsilver.autoescape.EscapeMode;
     20 import com.google.clearsilver.jsilver.exceptions.JSilverAutoEscapingException;
     21 import com.google.common.annotations.VisibleForTesting;
     22 import com.google.common.collect.ImmutableMap;
     23 
     24 import java.io.FileNotFoundException;
     25 import java.io.IOException;
     26 import java.io.InputStream;
     27 import java.io.InputStreamReader;
     28 import java.io.LineNumberReader;
     29 import java.io.Reader;
     30 import java.util.HashMap;
     31 import java.util.Map;
     32 import java.util.StringTokenizer;
     33 
     34 /**
     35  * Utility class that reads in the file output by BatchCompiler that is a list of template names and
     36  * corresponding class names and returns a Map of template filenames to class names which can be fed
     37  * to {@see com.google.clearsilver.jsilver.JSilverOptions#setPrecompiledTemplateMap}
     38  */
     39 public class PrecompiledTemplateMapFileReader {
     40 
     41   private final String mapFileName;
     42   private final String dirPattern;
     43   private final String rootDir;
     44 
     45   private Map<Object, String> templateMap = null;
     46 
     47   /**
     48    * Helper object that reads in the specified resource file and generates a mapping of template
     49    * filenames to corresponding BaseCompiledTemplate class names.
     50    *
     51    * @param filename name of the resource file to read the map from.
     52    * @param dirPattern prefix to remove from read in template names. Used in conjunction with
     53    *        rootDir to update template file paths.
     54    * @param rootDir optional string to prepend to all non-absolute template filenames. Should be set
     55    *        to the location of the templates in production via a flag.
     56    */
     57   public PrecompiledTemplateMapFileReader(String filename, String dirPattern, String rootDir) {
     58     this.mapFileName = filename;
     59     this.dirPattern = dirPattern;
     60     this.rootDir = rootDir;
     61   }
     62 
     63   public Map<Object, String> getTemplateMap() throws IOException {
     64     if (templateMap == null) {
     65       templateMap = makeTemplateMap(mapFileName, rootDir);
     66     }
     67     return templateMap;
     68   }
     69 
     70   private Map<Object, String> makeTemplateMap(String templateMapFile, String rootDir)
     71       throws IOException {
     72     Map<Object, String> templateMap = new HashMap<Object, String>();
     73     LineNumberReader reader = null;
     74     try {
     75       reader = new LineNumberReader(getMapFileReader(templateMapFile));
     76       for (String line = reader.readLine(); line != null; line = reader.readLine()) {
     77         // Process single line from the templateMapFile
     78         // and put found templates into templateMap.
     79         processTemplateMapFileLine(line, reader.getLineNumber(), templateMap, templateMapFile,
     80             rootDir);
     81       }
     82     } finally {
     83       if (reader != null) {
     84         reader.close();
     85       }
     86     }
     87     return ImmutableMap.copyOf(templateMap);
     88   }
     89 
     90   private void processTemplateMapFileLine(String line, int lineNumber,
     91       Map<Object, String> templateMap, String templateMapFile, String rootDir) {
     92 
     93     line = line.trim();
     94     if (line.isEmpty() || line.startsWith("#")) {
     95       // Ignore blank lines and comment lines.
     96       return;
     97     }
     98     StringTokenizer st = new StringTokenizer(line);
     99     if (!st.hasMoreTokens()) {
    100       throw new IllegalArgumentException("No template file name found in " + templateMapFile
    101           + " on line " + lineNumber + ": " + line);
    102     }
    103     String templateName = st.nextToken();
    104     if (dirPattern != null && templateName.startsWith(dirPattern)) {
    105       templateName = templateName.substring(dirPattern.length());
    106     }
    107     if (rootDir != null) {
    108       // If it is not an absolute path and we were given a root directory,
    109       // prepend it.
    110       templateName = rootDir + templateName;
    111     }
    112     if (!st.hasMoreTokens()) {
    113       throw new IllegalArgumentException("No class name found in " + templateMapFile + " on line "
    114           + lineNumber + ": " + line);
    115     }
    116     String className = st.nextToken();
    117     EscapeMode escapeMode;
    118     if (!st.hasMoreTokens()) {
    119       escapeMode = EscapeMode.ESCAPE_NONE;
    120     } else {
    121       String escapeCmd = st.nextToken();
    122       try {
    123         escapeMode = EscapeMode.computeEscapeMode(escapeCmd);
    124       } catch (JSilverAutoEscapingException e) {
    125         throw new IllegalArgumentException("Invalid escape mode found in " + templateMapFile
    126             + " on line " + lineNumber + ": " + escapeCmd);
    127       }
    128     }
    129     PrecompiledTemplateMapKey key = new PrecompiledTemplateMapKey(templateName, escapeMode);
    130     templateMap.put(key, className);
    131   }
    132 
    133   @VisibleForTesting
    134   protected Reader getMapFileReader(String templateMapFile) throws IOException {
    135     ClassLoader classLoader = getClass().getClassLoader();
    136     InputStream in = classLoader.getResourceAsStream(templateMapFile);
    137     if (in == null) {
    138       throw new FileNotFoundException("Unable to locate resource: " + templateMapFile);
    139     }
    140     return new InputStreamReader(in, "UTF-8");
    141   }
    142 
    143 }
    144