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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    * 
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   * 
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.struts2.jasper.compiler;
19  
20  import java.util.ArrayList;
21  import java.util.List;
22  
23  /***
24   * Represents a source map (SMAP), which serves to associate lines
25   * of the input JSP file(s) to lines in the generated servlet in the
26   * final .class file, according to the JSR-045 spec.
27   *
28   * @author Shawn Bayern
29   */
30  public class SmapGenerator {
31  
32      //**********************************************************************
33      // Overview
34  
35      /*
36       * The SMAP syntax is reasonably straightforward.  The purpose of this
37       * class is currently twofold:
38       *  - to provide a simple but low-level Java interface to build
39       *    a logical SMAP
40       *  - to serialize this logical SMAP for eventual inclusion directly
41       *    into a .class file.
42       */
43  
44  
45      //**********************************************************************
46      // Private state
47  
48      private String outputFileName;
49      private String defaultStratum = "Java";
50      private List strata = new ArrayList();
51      private List embedded = new ArrayList();
52      private boolean doEmbedded = true;
53  
54      //*********************************************************************
55      // Methods for adding mapping data
56  
57      /**
58       * Sets the filename (without path information) for the generated
59       * source file.  E.g., "foo$jsp.java".
60       */
61      public synchronized void setOutputFileName(String x) {
62          outputFileName = x;
63      }
64  
65      /***
66       * Adds the given SmapStratum object, representing a Stratum with
67       * logically associated FileSection and LineSection blocks, to
68       * the current SmapGenerator.  If <tt>default</tt> is true, this
69       * stratum is made the default stratum, overriding any previously
70       * set default.
71       *
72       * @param stratum        the SmapStratum object to add
73       * @param defaultStratum if <tt>true</tt>, this SmapStratum is considered
74       *                       to represent the default SMAP stratum unless
75       *                       overwritten
76       */
77      public synchronized void addStratum(SmapStratum stratum,
78                                          boolean defaultStratum) {
79          strata.add(stratum);
80          if (defaultStratum)
81              this.defaultStratum = stratum.getStratumName();
82      }
83  
84      /***
85       * Adds the given string as an embedded SMAP with the given stratum name.
86       *
87       * @param smap        the SMAP to embed
88       * @param stratumName the name of the stratum output by the compilation
89       *                    that produced the <tt>smap</tt> to be embedded
90       */
91      public synchronized void addSmap(String smap, String stratumName) {
92          embedded.add("*O " + stratumName + "\n"
93                  + smap
94                  + "*C " + stratumName + "\n");
95      }
96  
97      /***
98       * Instructs the SmapGenerator whether to actually print any embedded
99       * SMAPs or not.  Intended for situations without an SMAP resolver.
100      *
101      * @param status If <tt>false</tt>, ignore any embedded SMAPs.
102      */
103     public void setDoEmbedded(boolean status) {
104         doEmbedded = status;
105     }
106 
107     //**********************************************************************
108     // Methods for serializing the logical SMAP
109 
110     public synchronized String getString() {
111         // check state and initialize buffer
112         if (outputFileName == null)
113             throw new IllegalStateException();
114         StringBuffer out = new StringBuffer();
115 
116         // start the SMAP
117         out.append("SMAP\n");
118         out.append(outputFileName + '\n');
119         out.append(defaultStratum + '\n');
120 
121         // include embedded SMAPs
122         if (doEmbedded) {
123             int nEmbedded = embedded.size();
124             for (int i = 0; i < nEmbedded; i++) {
125                 out.append(embedded.get(i));
126             }
127         }
128 
129         // print our StratumSections, FileSections, and LineSections
130         int nStrata = strata.size();
131         for (int i = 0; i < nStrata; i++) {
132             SmapStratum s = (SmapStratum) strata.get(i);
133             out.append(s.getString());
134         }
135 
136         // end the SMAP
137         out.append("*E\n");
138 
139         return out.toString();
140     }
141 
142     public String toString() {
143         return getString();
144     }
145 
146     //*********************************************************************
147     // For testing (and as an example of use)...
148 
149     public static void main(String args[]) {
150         SmapGenerator g = new SmapGenerator();
151         g.setOutputFileName("foo.java");
152         SmapStratum s = new SmapStratum("JSP");
153         s.addFile("foo.jsp");
154         s.addFile("bar.jsp", "/foo/foo/bar.jsp");
155         s.addLineData(1, "foo.jsp", 1, 1, 1);
156         s.addLineData(2, "foo.jsp", 1, 6, 1);
157         s.addLineData(3, "foo.jsp", 2, 10, 5);
158         s.addLineData(20, "bar.jsp", 1, 30, 1);
159         g.addStratum(s, true);
160         System.out.print(g);
161 
162         System.out.println("---");
163 
164         SmapGenerator embedded = new SmapGenerator();
165         embedded.setOutputFileName("blargh.tier2");
166         s = new SmapStratum("Tier2");
167         s.addFile("1.tier2");
168         s.addLineData(1, "1.tier2", 1, 1, 1);
169         embedded.addStratum(s, true);
170         g.addSmap(embedded.toString(), "JSP");
171         System.out.println(g);
172     }
173 }