X-Git-Url: https://gitweb.fperrin.net/?p=GpsPrune.git;a=blobdiff_plain;f=tim%2Fprune%2Fsave%2Fxml%2FXmlUtils.java;h=dc8284c30ea90d4586b0cdec70c72c6102346225;hp=a4f9caec11704a46dcd56fe3d22bde4922a49f09;hb=88f2c3647ed9e055090484f01a959d4581f85e7d;hpb=326f489e36aa7f235bc19409a57bf4955cd50f24

diff --git a/tim/prune/save/xml/XmlUtils.java b/tim/prune/save/xml/XmlUtils.java
index a4f9cae..dc8284c 100644
--- 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;
+	}
 }