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1
29
30 package com.hp.hpl.jena.rdf.model.impl;
31
32 import com.hp.hpl.jena.rdf.model.*;
33 import com.hp.hpl.jena.util.FileUtils;
34 import com.hp.hpl.jena.shared.*;
35
36 import java.io.*;
37
38 import org.apache.commons.logging.Log;
39 import org.apache.commons.logging.LogFactory;
40
41
46 public class NTripleWriter extends Object  implements RDFWriter {
47
48 RDFErrorHandler errorHandler = new RDFDefaultErrorHandler();
49
50 protected static Log logger = LogFactory.getLog( NTripleWriter.class );
51
52 public NTripleWriter() {
53 }
54 public void write(Model model, OutputStream out, String base)
55 {
56 try {
57 Writer w;
58 try {
59 w = new OutputStreamWriter(out, "ascii");
60 } catch (UnsupportedEncodingException e) {
61 logger.warn( "ASCII is not supported: in NTripleWriter.write", e );
62 w = FileUtils.asUTF8(out);
63 }
64 write(model, w, base);
65 w.flush();
66
67 } catch (Exception ioe) {
68 errorHandler.error(ioe);
69 }
70 }
71 public void write(Model baseModel, Writer writer, String base)
72 {
73 try {
74 Model model = ModelFactory.withHiddenStatements(baseModel);
75 PrintWriter pw;
76 if (writer instanceof PrintWriter) {
77 pw = (PrintWriter) writer;
78 } else {
79 pw = new PrintWriter(writer);
80 }
81
82 StmtIterator iter = model.listStatements();
83 Statement stmt = null;
84
85 while (iter.hasNext()) {
86 stmt = iter.nextStatement();
87 writeResource(stmt.getSubject(), pw);
88 pw.print(" ");
89 writeResource(stmt.getPredicate(), pw);
90 pw.print(" ");
91 writeNode(stmt.getObject(), pw);
92 pw.println(" .");
93 }
94 pw.flush();
95 } catch (Exception e) {
96 errorHandler.error(e);
97 }
98 }
99
100
109 public Object setProperty(String propName, Object propValue) {
110 throw new UnknownPropertyException( propName );
111 }
112
113 public void setNsPrefix(String prefix, String ns) {
114 }
115
116 public String getPrefixFor( String uri )
117 { return null; }
118
119 public RDFErrorHandler setErrorHandler(RDFErrorHandler errHandler) {
120 RDFErrorHandler old = this.errorHandler;
121 this.errorHandler = errHandler;
122 return old;
123 }
124
125 public static void write(Model model, PrintWriter writer)
126 throws java.io.IOException {
127 StmtIterator iter = model.listStatements();
128 Statement stmt = null;
129
130 while (iter.hasNext()) {
131 stmt = iter.nextStatement();
132 writeResource(stmt.getSubject(), writer);
133 writer.print(" ");
134 writeResource(stmt.getPredicate(), writer);
135 writer.print(" ");
136 writeNode(stmt.getObject(), writer);
137 writer.println(" .");
138 }
139 }
140
141 protected static void writeResource(Resource r, PrintWriter writer)
142 {
143 if (r.isAnon()) {
144 writer.print(anonName(r.getId()));
145 } else {
146 writer.print("<");
147 writeURIString(r.getURI(), writer);
148 writer.print(">");
149 }
150 }
151 static private boolean okURIChars[] = new boolean[128];
152 static {
153 for (int i = 32; i < 127; i++)
154 okURIChars[i] = true;
155 okURIChars['<'] = false;
156 okURIChars['>'] = false;
157 okURIChars['\\'] = false;
158
159 }
160 private static void writeURIString(String s, PrintWriter writer) {
161
162 for (int i = 0; i < s.length(); i++) {
163 char c = s.charAt(i);
164 if (c < okURIChars.length && okURIChars[c]) {
165 writer.print(c);
166 } else {
167 String hexstr = Integer.toHexString(c).toUpperCase();
168 int pad = 4 - hexstr.length();
169 writer.print("\\u");
170 for (; pad > 0; pad--)
171 writer.print("0");
172 writer.print(hexstr);
173 }
174 }
175 }
176 private static void writeString(String s, PrintWriter writer) {
177
178 for (int i = 0; i < s.length(); i++) {
179 char c = s.charAt(i);
180 if (c == '\\' || c == '"') {
181 writer.print('\\');
182 writer.print(c);
183 } else if (c == '\n') {
184 writer.print("\\n");
185 } else if (c == '\r') {
186 writer.print("\\r");
187 } else if (c == '\t') {
188 writer.print("\\t");
189 } else if (c >= 32 && c < 127) {
190 writer.print(c);
191 } else {
192 String hexstr = Integer.toHexString(c).toUpperCase();
193 int pad = 4 - hexstr.length();
194 writer.print("\\u");
195 for (; pad > 0; pad--)
196 writer.print("0");
197 writer.print(hexstr);
198 }
199 }
200 }
201 protected static void writeLiteral(Literal l, PrintWriter writer) {
202 String s = l.getString();
203
207 writer.print('"');
208 writeString(s, writer);
209 writer.print('"');
210 String lang = l.getLanguage();
211 if (lang != null && !lang.equals(""))
212 writer.print("@" + lang);
213 String dt = l.getDatatypeURI();
214 if (dt != null && !dt.equals(""))
215 writer.print("^^<" + dt + ">");
216 }
217
218 protected static void writeNode(RDFNode n, PrintWriter writer)
219 {
220 if (n instanceof Literal) {
221 writeLiteral((Literal) n, writer);
222 } else {
223 writeResource((Resource) n, writer);
224 }
225 }
226
227 protected static String anonName(AnonId id) {
228 String name = "_:A";
229 String sid = id.toString();
230 for (int i = 0; i < sid.length(); i++) {
231 char c = sid.charAt(i);
232 if (c == 'X') {
233 name = name + "XX";
234 } else if (Character.isLetterOrDigit(c)) {
235 name = name + c;
236 } else {
237 name = name + "X" + Integer.toHexString((int) c) + "X";
238 }
239 }
240 return name;
241 }
242 }
243 |
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