Version 16.3, July 2014

[GpsPrune.git] / tim / prune / save / xml / XmlUtils.java

diff --git a/tim/prune/save/xml/XmlUtils.java b/tim/prune/save/xml/XmlUtils.java
index a4f9caec11704a46dcd56fe3d22bde4922a49f09..dc8284c30ea90d4586b0cdec70c72c6102346225 100644 (file)
--- a/tim/prune/save/xml/XmlUtils.java
+++ b/tim/prune/save/xml/XmlUtils.java
@@ -1,5 +1,11 @@
 package tim.prune.save.xml;
 
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.OutputStreamWriter;
+import java.nio.charset.Charset;
+
 /**
  * Collection of utility functions for handling XML
  */
@@ -9,6 +15,8 @@ public abstract class XmlUtils
        private static final String CDATA_START = "<![CDATA[";
        /** End of Cdata sequence */
        private static final String CDATA_END = "]]>";
+       /** Cached copy of system encoding string */
+       private static String _systemEncoding = null;
 
        /**
         * Fix the CDATA blocks in the given String to give valid xml
@@ -34,4 +42,68 @@ public abstract class XmlUtils
                }
                return CDATA_START + result + CDATA_END;
        }
+
+
+       /**
+        * @return true if system uses UTF-8 by default
+        */
+       public static boolean isSystemUtf8()
+       {
+               String systemEncoding = getSystemEncoding();
+               return (systemEncoding != null && systemEncoding.toUpperCase().equals("UTF-8"));
+       }
+
+       /**
+        * @return name of the system's character encoding
+        */
+       public static String getSystemEncoding()
+       {
+               if (_systemEncoding == null) {
+                       _systemEncoding = determineSystemEncoding();
+               }
+               return _systemEncoding;
+       }
+
+       /**
+        * Use a temporary file to obtain the name of the default system encoding
+        * @return name of default system encoding, or null if write failed
+        */
+       private static String determineSystemEncoding()
+       {
+               File tempFile = null;
+               String encoding = null;
+               try
+               {
+                       tempFile = File.createTempFile("gpsprune", null);
+                       OutputStreamWriter writer = new OutputStreamWriter(new FileOutputStream(tempFile));
+                       encoding = getEncoding(writer);
+                       writer.close();
+               }
+               catch (IOException e) {} // value stays null
+               // Delete temp file
+               if (tempFile != null && tempFile.exists()) {
+                       if (!tempFile.delete()) {
+                               System.err.println("Cannot delete temp file: " + tempFile.getAbsolutePath());
+                       }
+               }
+               // If writing failed (eg permissions) then just ask system for default
+               if (encoding == null) encoding = Charset.defaultCharset().name();
+               return encoding;
+       }
+
+
+       /**
+        * Get the default system encoding using a writer
+        * @param inWriter writer object
+        * @return string defining encoding
+        */
+       public static String getEncoding(OutputStreamWriter inWriter)
+       {
+               String encoding = inWriter.getEncoding();
+               try {
+                       encoding =  Charset.forName(encoding).name();
+               }
+               catch (Exception e) {} // ignore failure to find encoding
+               return encoding;
+       }
 }