1 /*
2 * $Id$
3 *
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21 package org.apache.struts.util;
22
23 import jakarta.servlet.ServletContext;
24
25 import java.io.PrintWriter;
26 import java.io.StringWriter;
27
28 /**
29 * A PrintWriter implementation that uses the logging facilities of a
30 * <code>jakarta.servlet.ServletContext</code> to output its results. Output
31 * will be buffered until a newline character is output, <code>flush()</code>
32 * is called, or until one of the <code>println()</code> methods is called.
33 * Along the way, carriage return characters are skipped.
34 *
35 * @version $Rev$ $Date: 2005-05-07 12:11:38 -0400 (Sat, 07 May 2005)
36 * $
37 */
38 public class ServletContextWriter extends PrintWriter {
39 // ------------------------------------------------------------- Properties
40
41 /**
42 * The buffer into which we accumulate lines to be logged.
43 */
44 protected StringBuffer buffer = new StringBuffer();
45
46 /**
47 * The servlet context with which we are associated.
48 */
49 protected ServletContext context = null;
50
51 /**
52 * The error state for this stream.
53 */
54 protected boolean error = false;
55
56 // ----------------------------------------------------------- Constructors
57
58 /**
59 * Construct a ServletContextWriter associated with the specified
60 * ServletContext instance.
61 *
62 * @param context The associated servlet context
63 */
64 public ServletContextWriter(ServletContext context) {
65 super(new StringWriter());
66 this.context = context;
67 }
68
69 // --------------------------------------------------------- Public Methods
70
71 /**
72 * Flush the stream and check for its error state. <strong>IMPLEMENTATION
73 * NOTE</strong> - our associated servlet context gives no indication of
74 * problems with logging, so the only way this method will return
75 * <code>true</code> is if <code>setError()</code> is called.
76 */
77 public boolean checkError() {
78 flush();
79
80 return (error);
81 }
82
83 /**
84 * Close the stream.
85 */
86 public void close() {
87 flush();
88 }
89
90 /**
91 * Flush the stream.
92 */
93 public void flush() {
94 if (buffer.length() > 0) {
95 context.log(buffer.toString());
96 buffer.setLength(0);
97 }
98 }
99
100 /**
101 * Print a boolean value.
102 *
103 * @param b The value to be printed
104 */
105 public void print(boolean b) {
106 write(String.valueOf(b));
107 }
108
109 /**
110 * Print a character value.
111 *
112 * @param c The value to be printed
113 */
114 public void print(char c) {
115 write(c);
116 }
117
118 /**
119 * Print a character array.
120 *
121 * @param c The character array to be printed
122 */
123 public void print(char[] c) {
124 for (int i = 0; i < c.length; i++) {
125 write(c[i]);
126 }
127 }
128
129 /**
130 * Print a double value.
131 *
132 * @param d The value to be printed
133 */
134 public void print(double d) {
135 write(String.valueOf(d));
136 }
137
138 /**
139 * Print a float value.
140 *
141 * @param f The value to be printed
142 */
143 public void print(float f) {
144 write(String.valueOf(f));
145 }
146
147 /**
148 * Print an integer value.
149 *
150 * @param i The value to be printed
151 */
152 public void print(int i) {
153 write(String.valueOf(i));
154 }
155
156 /**
157 * Print a long value.
158 *
159 * @param l The value to be printed
160 */
161 public void print(long l) {
162 write(String.valueOf(l));
163 }
164
165 /**
166 * Print an object.
167 *
168 * @param o The value to be printed
169 */
170 public void print(Object o) {
171 write(o.toString());
172 }
173
174 /**
175 * Print a String value.
176 *
177 * @param s The value to be printed
178 */
179 public void print(String s) {
180 int len = s.length();
181
182 for (int i = 0; i < len; i++) {
183 write(s.charAt(i));
184 }
185 }
186
187 /**
188 * Terminate the current line and flush the buffer.
189 */
190 public void println() {
191 flush();
192 }
193
194 /**
195 * Print a boolean value and terminate the line.
196 *
197 * @param b The value to be printed
198 */
199 public void println(boolean b) {
200 println(String.valueOf(b));
201 }
202
203 /**
204 * Print a character value and terminate the line.
205 *
206 * @param c The value to be printed
207 */
208 public void println(char c) {
209 write(c);
210 println();
211 }
212
213 /**
214 * Print a character array and terminate the line.
215 *
216 * @param c The character array to be printed
217 */
218 public void println(char[] c) {
219 for (int i = 0; i < c.length; i++) {
220 print(c[i]);
221 }
222
223 println();
224 }
225
226 /**
227 * Print a double value and terminate the line.
228 *
229 * @param d The value to be printed
230 */
231 public void println(double d) {
232 println(String.valueOf(d));
233 }
234
235 /**
236 * Print a float value and terminate the line.
237 *
238 * @param f The value to be printed
239 */
240 public void println(float f) {
241 println(String.valueOf(f));
242 }
243
244 /**
245 * Print an integer value and terminate the line.
246 *
247 * @param i The value to be printed
248 */
249 public void println(int i) {
250 println(String.valueOf(i));
251 }
252
253 /**
254 * Print a long value and terminate the line.
255 *
256 * @param l The value to be printed
257 */
258 public void println(long l) {
259 println(String.valueOf(l));
260 }
261
262 /**
263 * Print an object and terminate the line.
264 *
265 * @param o The value to be printed
266 */
267 public void println(Object o) {
268 println(o.toString());
269 }
270
271 /**
272 * Print a String value and terminate the line.
273 *
274 * @param s The value to be printed
275 */
276 public void println(String s) {
277 int len = s.length();
278
279 for (int i = 0; i < len; i++) {
280 print(s.charAt(i));
281 }
282
283 println();
284 }
285
286 /**
287 * Set the error state for this stream.
288 */
289 public void setError() {
290 this.error = true;
291 }
292
293 /**
294 * Write a single character to this stream.
295 *
296 * @param c The character to be written
297 */
298 public void write(char c) {
299 if (c == '\n') {
300 flush();
301 } else if (c != '\r') {
302 buffer.append(c);
303 }
304 }
305
306 /**
307 * Write a single character to this stream.
308 *
309 * @param c The character to be written
310 */
311 public void write(int c) {
312 write((char) c);
313 }
314
315 /**
316 * Write an array of charaters to this stream.
317 *
318 * @param buf The character array to be written
319 */
320 public void write(char[] buf) {
321 for (int i = 0; i < buf.length; i++) {
322 write(buf[i]);
323 }
324 }
325
326 /**
327 * Write the specified subset of an array of characters to this stream.
328 *
329 * @param buf The character array from which to write
330 * @param off The zero-relative starting offset to write
331 * @param len The number of characters to write
332 */
333 public void write(char[] buf, int off, int len) {
334 for (int i = off; i < len; i++) {
335 write(buf[i]);
336 }
337 }
338
339 /**
340 * Write a String to this stream.
341 *
342 * @param s The string to be written
343 */
344 public void write(String s) {
345 int len = s.length();
346
347 for (int i = 0; i < len; i++) {
348 write(s.charAt(i));
349 }
350 }
351
352 /**
353 * Write the specified portion of a String to this stream.
354 *
355 * @param s The String from which to write
356 * @param off The zero-relative starting offset to write
357 * @param len The number of characters to write
358 */
359 public void write(String s, int off, int len) {
360 for (int i = off; i < len; i++) {
361 write(s.charAt(i));
362 }
363 }
364 }