001 /*
002 * (c) Copyright 2009 University of Bristol
003 * All rights reserved.
004 * [See end of file]
005 */
006
007 package net.rootdev.javardfa.output;
008
009 import java.io.OutputStream;
010 import java.io.OutputStreamWriter;
011 import java.io.PrintWriter;
012 import java.io.UnsupportedEncodingException;
013 import java.io.Writer;
014 import java.util.regex.Pattern;
015 import net.rootdev.javardfa.StatementSink;
016
017
018 /**
019 * A pretty ropey NTriple serialiser.
020 * Advantages: streams, no dependencies.
021 *
022 * @author pldms
023 */
024 public class NTripleSink implements StatementSink {
025 protected final PrintWriter out;
026 protected final String[] comments;
027
028 public NTripleSink(OutputStream os, String... comments) throws UnsupportedEncodingException {
029 this(new OutputStreamWriter(os, "US-ASCII"), comments); // N-Triples is 7-bit ascii
030 }
031
032 public NTripleSink(Writer writer, String... comments) {
033 this.out = new PrintWriter(writer);
034 this.comments = comments;
035 }
036
037 public void start() {
038 for (String line: comments) {
039 out.print("# ");
040 out.println(line);
041 }
042 }
043
044 public void end() {
045 out.flush();
046 }
047
048 public void addObject(String subject, String predicate, String object) {
049 out.print(toNode(subject));
050 out.print(toNode(predicate));
051 out.print(toNode(object));
052 out.println(".");
053 }
054
055 public void addLiteral(String subject, String predicate, String lex, String lang, String datatype) {
056 out.print(toNode(subject));
057 out.print(toNode(predicate));
058 out.print(toLiteral(lex, lang, datatype));
059 out.println(".");
060 }
061
062 public void addPrefix(String prefix, String uri) {}
063
064 protected final String toNode(String node) {
065 if (node.startsWith("_:") || node.startsWith("?"))
066 return node + " ";
067 return "<" + node + "> ";
068 }
069
070 protected final String toLiteral(String lex, String lang, String datatype) {
071 if (lang != null && lang.length() != 0)
072 return quote(lex) + "@" + lang + " ";
073 if (datatype != null)
074 return quote(lex) + "^^<" + datatype + "> ";
075 return quote(lex) + " ";
076 }
077
078 private Pattern quotePattern = Pattern.compile("\"");
079 protected final String quote(String lex) {
080 return "\"" + encode(lex) + "\"";
081 }
082
083 protected final String encode(String s) {
084 StringBuilder b = new StringBuilder();
085 for (int i = 0; i < s.length(); i++) {
086 int c = s.codePointAt(i);
087 if (c <= 8) b.append(enc(c));
088 else if (c == '\t') b.append("\\t");
089 else if (c == '\n') b.append("\\n");
090 else if (c == '\r') b.append("\\r");
091 else if (c == '"') b.append("\\\"");
092 else if (c == '\\') b.append("\\\\");
093 else if (c <= 127) b.appendCodePoint(c);
094 else if (c <= 0xFFFF) b.append(enc(c));
095 else b.append(longenc(c));
096 }
097 return b.toString();
098 }
099
100 protected String enc(int codepoint) {
101 return String.format("\\u%04x", codepoint);
102 }
103
104 protected String longenc(int codepoint) {
105 return String.format("\\U%08x", codepoint);
106 }
107
108 public void setBase(String base) {}
109 }
110
111 /*
112 * (c) Copyright 2009 University of Bristol
113 * All rights reserved.
114 *
115 * Redistribution and use in source and binary forms, with or without
116 * modification, are permitted provided that the following conditions
117 * are met:
118 * 1. Redistributions of source code must retain the above copyright
119 * notice, this list of conditions and the following disclaimer.
120 * 2. Redistributions in binary form must reproduce the above copyright
121 * notice, this list of conditions and the following disclaimer in the
122 * documentation and/or other materials provided with the distribution.
123 * 3. The name of the author may not be used to endorse or promote products
124 * derived from this software without specific prior written permission.
125 *
126 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
127 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
128 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
129 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
130 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
131 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
132 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
133 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
134 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
135 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
136 */