1.
1 package algorithms.util;
2
3 /******************************************************************************
4 * Compilation: javac Out.java
5 * Execution: java Out
6 * Dependencies: none
7 *
8 * Writes data of various types to: stdout, file, or socket.
9 *
10 ******************************************************************************/
11
12
13 import java.io.FileOutputStream;
14 import java.io.IOException;
15 import java.io.OutputStream;
16 import java.io.OutputStreamWriter;
17 import java.io.PrintWriter;
18 import java.net.Socket;
19 import java.util.Locale;
20
21 /**
22 * This class provides methods for writing strings and numbers to
23 * various output streams, including standard output, file, and sockets.
24 * <p>
25 * For additional documentation, see
26 * <a href="http://introcs.cs.princeton.edu/31datatype">Section 3.1</a> of
27 * <i>Introduction to Programming in Java: An Interdisciplinary Approach</i>
28 * by Robert Sedgewick and Kevin Wayne.
29 *
30 * @author Robert Sedgewick
31 * @author Kevin Wayne
32 */
33 public class Out {
34
35 // force Unicode UTF-8 encoding; otherwise it‘s system dependent
36 private static final String CHARSET_NAME = "UTF-8";
37
38 // assume language = English, country = US for consistency with In
39 private static final Locale LOCALE = Locale.US;
40
41 private PrintWriter out;
42
43 /**
44 * Initializes an output stream from a {@link OutputStream}.
45 *
46 * @param os the <tt>OutputStream</tt>
47 */
48 public Out(OutputStream os) {
49 try {
50 OutputStreamWriter osw = new OutputStreamWriter(os, CHARSET_NAME);
51 out = new PrintWriter(osw, true);
52 }
53 catch (IOException e) {
54 e.printStackTrace();
55 }
56 }
57
58 /**
59 * Initializes an output stream from standard output.
60 */
61 public Out() {
62 this(System.out);
63 }
64
65 /**
66 * Initializes an output stream from a socket.
67 *
68 * @param socket the socket
69 */
70 public Out(Socket socket) {
71 try {
72 OutputStream os = socket.getOutputStream();
73 OutputStreamWriter osw = new OutputStreamWriter(os, CHARSET_NAME);
74 out = new PrintWriter(osw, true);
75 }
76 catch (IOException e) {
77 e.printStackTrace();
78 }
79 }
80
81 /**
82 * Initializes an output stream from a file.
83 *
84 * @param filename the name of the file
85 */
86 public Out(String filename) {
87 try {
88 OutputStream os = new FileOutputStream(filename);
89 OutputStreamWriter osw = new OutputStreamWriter(os, CHARSET_NAME);
90 out = new PrintWriter(osw, true);
91 }
92 catch (IOException e) {
93 e.printStackTrace();
94 }
95 }
96
97 /**
98 * Closes the output stream.
99 */
100 public void close() {
101 out.close();
102 }
103
104 /**
105 * Terminates the current line by printing the line-separator string.
106 */
107 public void println() {
108 out.println();
109 }
110
111 /**
112 * Prints an object to this output stream and then terminates the line.
113 *
114 * @param x the object to print
115 */
116 public void println(Object x) {
117 out.println(x);
118 }
119
120 /**
121 * Prints a boolean to this output stream and then terminates the line.
122 *
123 * @param x the boolean to print
124 */
125 public void println(boolean x) {
126 out.println(x);
127 }
128
129 /**
130 * Prints a character to this output stream and then terminates the line.
131 *
132 * @param x the character to print
133 */
134 public void println(char x) {
135 out.println(x);
136 }
137
138 /**
139 * Prints a double to this output stream and then terminates the line.
140 *
141 * @param x the double to print
142 */
143 public void println(double x) {
144 out.println(x);
145 }
146
147 /**
148 * Prints a float to this output stream and then terminates the line.
149 *
150 * @param x the float to print
151 */
152 public void println(float x) {
153 out.println(x);
154 }
155
156 /**
157 * Prints an integer to this output stream and then terminates the line.
158 *
159 * @param x the integer to print
160 */
161 public void println(int x) {
162 out.println(x);
163 }
164
165 /**
166 * Prints a long to this output stream and then terminates the line.
167 *
168 * @param x the long to print
169 */
170 public void println(long x) {
171 out.println(x);
172 }
173
174 /**
175 * Prints a byte to this output stream and then terminates the line.
176 * <p>
177 * To write binary data, see {@link BinaryOut}.
178 *
179 * @param x the byte to print
180 */
181 public void println(byte x) {
182 out.println(x);
183 }
184
185
186
187 /**
188 * Flushes this output stream.
189 */
190 public void print() {
191 out.flush();
192 }
193
194 /**
195 * Prints an object to this output stream and flushes this output stream.
196 *
197 * @param x the object to print
198 */
199 public void print(Object x) {
200 out.print(x);
201 out.flush();
202 }
203
204 /**
205 * Prints a boolean to this output stream and flushes this output stream.
206 *
207 * @param x the boolean to print
208 */
209 public void print(boolean x) {
210 out.print(x);
211 out.flush();
212 }
213
214 /**
215 * Prints a character to this output stream and flushes this output stream.
216 *
217 * @param x the character to print
218 */
219 public void print(char x) {
220 out.print(x);
221 out.flush();
222 }
223
224 /**
225 * Prints a double to this output stream and flushes this output stream.
226 *
227 * @param x the double to print
228 */
229 public void print(double x) {
230 out.print(x);
231 out.flush();
232 }
233
234 /**
235 * Prints a float to this output stream and flushes this output stream.
236 *
237 * @param x the float to print
238 */
239 public void print(float x) {
240 out.print(x);
241 out.flush();
242 }
243
244 /**
245 * Prints an integer to this output stream and flushes this output stream.
246 *
247 * @param x the integer to print
248 */
249 public void print(int x) {
250 out.print(x);
251 out.flush();
252 }
253
254 /**
255 * Prints a long integer to this output stream and flushes this output stream.
256 *
257 * @param x the long integer to print
258 */
259 public void print(long x) {
260 out.print(x);
261 out.flush();
262 }
263
264 /**
265 * Prints a byte to this output stream and flushes this output stream.
266 *
267 * @param x the byte to print
268 */
269 public void print(byte x) {
270 out.print(x);
271 out.flush();
272 }
273
274 /**
275 * Prints a formatted string to this output stream, using the specified format
276 * string and arguments, and then flushes this output stream.
277 *
278 * @param format the format string
279 * @param args the arguments accompanying the format string
280 */
281 public void printf(String format, Object... args) {
282 out.printf(LOCALE, format, args);
283 out.flush();
284 }
285
286 /**
287 * Prints a formatted string to this output stream, using the specified
288 * locale, format string, and arguments, and then flushes this output stream.
289 *
290 * @param locale the locale
291 * @param format the format string
292 * @param args the arguments accompanying the format string
293 */
294 public void printf(Locale locale, String format, Object... args) {
295 out.printf(locale, format, args);
296 out.flush();
297 }
298
299
300 /**
301 * A test client.
302 */
303 public static void main(String[] args) {
304 Out out;
305
306 // write to stdout
307 out = new Out();
308 out.println("Test 1");
309 out.close();
310
311 // write to a file
312 out = new Out("test.txt");
313 out.println("Test 2");
314 out.close();
315 }
316
317 }
时间： 2024-10-27 17:38:39