Merge branch 'feature/JAL-3690_callback-based-web-services' into alpha/JAL-3066_Jalvi...

[jalview.git] / unused / xml / sax / demo / EntityDemo.java

diff --git a/unused/xml/sax/demo/EntityDemo.java b/unused/xml/sax/demo/EntityDemo.java
new file mode 100644 (file)
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+++ b/unused/xml/sax/demo/EntityDemo.java
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+package org.xml.sax.demo;
+// SAX demonstration for custom entity resolution.
+// No warranty; no copyright -- use this as you will.
+// $Id: EntityDemo.java,v 1.2 1998/05/01 20:52:16 david Exp $
+
+import org.xml.sax.InputSource;
+import org.xml.sax.Parser;
+import org.xml.sax.SAXException;
+
+import org.xml.sax.helpers.ParserFactory;
+
+import java.io.StringReader;
+import java.net.URL;
+
+
+/**
+  * Demonstrate custom entity resolution.
+  *
+  * <p>Usage: java -Dorg.xml.sax.parser=<var>classname</var> EntityDemo
+  * <var>systemId</var></p>
+  *
+  * <p>If you create an XML document which references an 
+  * external text entity with the public identifier
+  * "-//megginson//TEXT Sample Entity//EN", this application will
+  * substitute the string "Entity resolution works!" for the
+  * entity's contents:</p>
+  *
+  * <pre>
+  * &lt;!DOCTYPE doc [
+  *   &lt;!ENTITY ent 
+  *     PUBLIC "-//megginson//TEXT Sample Entity//EN" "ent.xml">
+  * ]>
+  * &lt;doc>
+  * &lt;para>&ent;&lt;/para>
+  * &lt;/doc>
+  * </pre>
+  *
+  * <p>The SAX parser will open a connection to the URI itself.</p>
+  *
+  * @see DemoHandler
+  */
+public class EntityDemo extends DemoHandler {
+
+                               // This is the Reader that will be
+                               // substituted for the entity contents.
+  StringReader reader =
+    new StringReader("Entity resolution works!");
+
+  /**
+    * Main entry point.
+    */
+  public static void main (String args[])
+    throws Exception
+  {
+    Parser parser;
+    EntityDemo handler;
+
+                               // Check the command-line usage.
+    if (args.length != 1) {
+      System.err.println("Usage: java -Dorg.xml.sax.parser=<classname> " +
+                        "EntityDemo <document>");
+      System.exit(2);
+    }
+
+                               // Make the parser, using the value
+                               // provided in the org.xml.sax.parser property.
+    parser = ParserFactory.makeParser();
+
+                               // Create an event handler, and register
+                               // it with the SAX parser.
+    handler = new EntityDemo();
+    parser.setEntityResolver(handler);
+    parser.setDTDHandler(handler);
+    parser.setDocumentHandler(handler);
+    parser.setErrorHandler(handler);
+
+                               // Parse the document.
+    parser.parse(makeAbsoluteURL(args[0]));
+  }
+
+
+  /**
+    * Override resolveEntity().
+    *
+    * <p>If the public identifier is "-//megginson//TEXT Sample
+    * //Entity//EN", instruct the parser to read the entity's
+    * contents from the StringReader rather than from the 
+    * system identifier.</p>
+    *
+    * <p>The public identifier is safer than the system identifier,
+    * since the parser may have resolved the system identifier to
+    * an absolute URL.</p>
+    *
+    * @see org.xml.sax.EntityResolver#resolveEntity
+    */
+  @Override
+       public InputSource resolveEntity (String publicId, String systemId)
+  {
+    if (publicId != null &&
+       publicId.equals("-//megginson//TEXT Sample Entity//EN")) {
+      return new InputSource(reader);
+    } else {
+      return null;
+    }
+  }
+
+
+  /**
+    * If a URL is relative, make it absolute against the current directory.
+    */
+  private static String makeAbsoluteURL (String url)
+    throws java.net.MalformedURLException
+  {
+    URL baseURL;
+
+    String currentDirectory = System.getProperty("user.dir");
+    String fileSep = System.getProperty("file.separator");
+    String file = currentDirectory.replace(fileSep.charAt(0), '/') + '/';
+
+    if (file.charAt(0) != '/') {
+      file = "/" + file;
+    }
+    baseURL = new URL("file", null, file);
+
+    return new URL(baseURL, url).toString();
+  }
+
+}