XMLWriter


1   /* XMLWriter.java                                                  NanoXML/Java
2    *
3    * $Revision: 1421 $
4    * $Date: 2006-03-12 17:32:32 +0100 (Sun, 12 Mar 2006) $
5    * $Name$
6    *
7    * This file is part of NanoXML 2 for Java.
8    * Copyright (C) 2001 Marc De Scheemaecker, All Rights Reserved.
9    *
10   * This software is provided 'as-is', without any express or implied warranty.
11   * In no event will the authors be held liable for any damages arising from the
12   * use of this software.
13   *
14   * Permission is granted to anyone to use this software for any purpose,
15   * including commercial applications, and to alter it and redistribute it
16   * freely, subject to the following restrictions:
17   *
18   *  1. The origin of this software must not be misrepresented; you must not
19   *     claim that you wrote the original software. If you use this software in
20   *     a product, an acknowledgment in the product documentation would be
21   *     appreciated but is not required.
22   *
23   *  2. Altered source versions must be plainly marked as such, and must not be
24   *     misrepresented as being the original software.
25   *
26   *  3. This notice may not be removed or altered from any source distribution.
27   */
28  
29  package net.n3.nanoxml;
30  
31  import java.io.IOException  ;
32  import java.io.OutputStream  ;
33  import java.io.PrintWriter  ;
34  import java.io.Writer  ;
35  import java.util.Enumeration  ;
36  
37  /**
38   * An XMLWriter writes XML data to a stream.
39   * 
40   * @see net.n3.nanoxml.XMLElement
41   * @see java.io.Writer
42   * 
43   * @author Marc De Scheemaecker
44   * @version $Name$, $Revision: 1421 $
45   */
46  public class XMLWriter
47  {
48  
49      /**
50       * Where to write the output to.
51       */
52      private PrintWriter   writer;
53  
54      /**
55       * Creates a new XML writer.
56       * 
57       * @param writer where to write the output to.
58       */
59      public XMLWriter(Writer   writer)
60      {
61          if (writer instanceof PrintWriter  )
62          {
63              this.writer = (PrintWriter  ) writer;
64          }
65          else
66          {
67              this.writer = new PrintWriter  (writer);
68          }
69      }
70  
71      /**
72       * Creates a new XML writer.
73       * 
74       * @param stream where to write the output to.
75       */
76      public XMLWriter(OutputStream   stream)
77      {
78          this.writer = new PrintWriter  (stream);
79      }
80  
81      /**
82       * Cleans up the object when it's destroyed.
83       */
84      protected void finalize() throws Throwable  
85      {
86          this.writer = null;
87          super.finalize();
88      }
89  
90      /**
91       * Writes an XML element.
92       * 
93       * @param xml the non-null XML element to write.
94       */
95      public void write(XMLElement xml) throws IOException  
96      {
97          this.write(xml, true, 0);
98      }
99  
100     /**
101      * Writes an XML element.
102      * 
103      * @param xml the non-null XML element to write.
104      * @param prettyPrint if spaces need to be inserted to make the output more readable
105      */
106     public void write(XMLElement xml, boolean prettyPrint) throws IOException  
107     {
108         this.write(xml, prettyPrint, 0);
109     }
110 
111     /**
112      * Writes an XML element.
113      * 
114      * @param xml the non-null XML element to write.
115      * @param prettyPrint if spaces need to be inserted to make the output more readable
116      * @param indent how many spaces to indent the element.
117      */
118     public void write(XMLElement xml, boolean prettyPrint, int indent) throws IOException  
119     {
120         if (prettyPrint)
121         {
122             for (int i = 0; i < indent; i++)
123             {
124                 this.writer.print(' ');
125             }
126         }
127 
128         if (xml.getName() == null)
129         {
130             if (xml.getContent() != null)
131             {
132                 if (prettyPrint)
133                 {
134                     this.writeEncoded(xml.getContent().trim());
135                     writer.println();
136                 }
137                 else
138                 {
139                     this.writeEncoded(xml.getContent());
140                 }
141             }
142         }
143         else
144         {
145             this.writer.print('<');
146             this.writer.print(xml.getName());
147             Enumeration   enumeration = xml.enumerateAttributeNames();
148 
149             while (enumeration.hasMoreElements())
150             {
151                 String   key = (String  ) enumeration.nextElement();
152                 String   value = xml.getAttribute(key);
153                 this.writer.print(" " + key + "=\"");
154                 this.writeEncoded(value);
155                 this.writer.print('"');
156             }
157 
158             if ((xml.getContent() != null) && (xml.getContent().length() > 0))
159             {
160                 writer.print('>');
161                 this.writeEncoded(xml.getContent());
162                 writer.print("</" + xml.getName() + '>');
163 
164                 if (prettyPrint)
165                 {
166                     writer.println();
167                 }
168             }
169             else if (xml.hasChildren())
170             {
171                 writer.print('>');
172 
173                 if (prettyPrint)
174                 {
175                     writer.println();
176                 }
177 
178                 enumeration = xml.enumerateChildren();
179 
180                 while (enumeration.hasMoreElements())
181                 {
182                     XMLElement child = (XMLElement) enumeration.nextElement();
183                     this.write(child, prettyPrint, indent + 4);
184                 }
185 
186                 if (prettyPrint)
187                 {
188                     for (int i = 0; i < indent; i++)
189                     {
190                         this.writer.print(' ');
191                     }
192                 }
193 
194                 this.writer.print("</" + xml.getName() + ">");
195 
196                 if (prettyPrint)
197                 {
198                     writer.println();
199                 }
200             }
201             else
202             {
203                 this.writer.print("/>");
204 
205                 if (prettyPrint)
206                 {
207                     writer.println();
208                 }
209             }
210         }
211 
212         this.writer.flush();
213     }
214 
215     /**
216      * Writes a string encoding reserved characters.
217      * 
218      * @param str the string to write.
219      */
220     private void writeEncoded(String   str)
221     {
222         for (int i = 0; i < str.length(); i++)
223         {
224             char c = str.charAt(i);
225 
226             switch (c)
227             {
228             case 0x0D:
229             case 0x0A:
230                 this.writer.print(c);
231                 break;
232 
233             case '<':
234                 this.writer.print("&lt;");
235                 break;
236 
237             case '>':
238                 this.writer.print("&gt;");
239                 break;
240 
241             case '&':
242                 this.writer.print("&amp;");
243                 break;
244 
245             case '\'':
246                 this.writer.print("&apos;");
247                 break;
248 
249             case '"':
250                 this.writer.print("&quot;");
251                 break;
252 
253             default:
254                 if ((c < ' ') || (c > 0x7E))
255                 {
256                     this.writer.print("&#x");
257                     this.writer.print(Integer.toString(c, 16));
258                     this.writer.print(';');
259                 }
260                 else
261                 {
262                     this.writer.print(c);
263                 }
264             }
265         }
266     }
267 
268 }
269
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