source: josm/trunk/src/org/openstreetmap/josm/io/XmlWriter.java@ 1023

// License: GPL. Copyright 2007 by Immanuel Scholz and others
package org.openstreetmap.josm.io;

import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.util.HashMap;

/**
 * Helper class to use for xml outputting classes.
 * 
 * @author imi
 */
public class XmlWriter {

        /**
         * The interface to write the data into an Osm stream
         * @author immanuel.scholz
         */
        public static interface OsmWriterInterface {
                void header(PrintWriter out);
                void write(PrintWriter out);
                void footer(PrintWriter out);
        }


        protected XmlWriter(PrintWriter out) {
                this.out = out;
        }

        /**
         * Encode the given string in XML1.0 format.
         * Optimized to fast pass strings that don't need encoding (normal case).
         */
        public static String encode(String unencoded) {
                StringBuilder buffer = null;
                for (int i = 0; i < unencoded.length(); ++i) {
                        String encS = XmlWriter.encoding.get(unencoded.charAt(i));
                        if (encS != null) {
                                if (buffer == null)
                                        buffer = new StringBuilder(unencoded.substring(0,i));
                                buffer.append(encS);
                        } else if (buffer != null)
                                buffer.append(unencoded.charAt(i));
                }
                return (buffer == null) ? unencoded : buffer.toString();
        }

        /**
         * Write the header and start tag, then call the runnable to add all real tags and finally
         * "closes" the xml by writing the footer.
         */
        public static void output(OutputStream outStream, OsmWriterInterface outputWriter) {
                PrintWriter out;
                try {
                        out = new PrintWriter(new OutputStreamWriter(outStream, "UTF-8"));
                } catch (UnsupportedEncodingException e) {
                        throw new RuntimeException(e);
                }
                out.println("<?xml version='1.0' encoding='UTF-8'?>");
                outputWriter.header(out);
                outputWriter.write(out);
                outputWriter.footer(out);
                out.flush();
                out.close();
        }

        /**
         * The output writer to save the values to.
         */
        protected final PrintWriter out;
        final private static HashMap<Character, String> encoding = new HashMap<Character, String>();
        static {
                encoding.put('<', "&lt;");
                encoding.put('>', "&gt;");
                encoding.put('"', "&quot;");
                encoding.put('\'', "&apos;");
                encoding.put('&', "&amp;");
                encoding.put('\n', "&#xA;");
                encoding.put('\r', "&#xD;");
                encoding.put('\t', "&#x9;");
        }
}