[Java学习] Java文件处理类，

[Java学习] Java文件处理类，

1. 包含一些对文件的基本操作。
3. import java.io.*;
4. import java.util.ArrayList;
5. import java.util.List;
7. public class fileTest {
9. static int countFiles=0;
10. static int countFolders=0;
11. http://www.kmnk01.com/hxpfk/2015/bdf_1219/312.html
12. public static void createFile(String filepath)
13. {
14. File file=new File(filepath);
15. if(file.exists())
16. {
17. System.out.println("目标文件已经存在!");
18. return;
19. }
20. if(filepath.endsWith(File.separator))
21. {
22. System.out.println("目标文件不能为目录!");
23. return;
24. }
25. try {
26. if(file.createNewFile())
27. System.out.println("文件创建成功!");
28. else
29. {
30. System.out.println("文件创建失败!");
31. return;
32. }
33. } catch (IOException e) {
34. // TODO Auto-generated catch block
35. e.printStackTrace();
36. http://www.kmnk01.com/hxpfk/2015/xmz_1219/320.html
    
37. }
39. public static void createDir(String dirname)
40. {
41. if(!dirname.endsWith(File.separator))
42. dirname=dirname+File.separator;
43. File dir=new File(dirname);
44. if(dir.exists())
45. {
46. System.out.println("目录已存在!");
47. return;
48. http://www.kmnk01.com/hxpfk/2015/gm_1219/314.html
49. if(dir.mkdirs())
50. System.out.println("目录创建成功!");
51. else
52. {
53. System.out.println("目录创建失败!");
54. return;
55. }
56. }
58. public static boolean checkDirExist(String dirname)
59. {
60. File file=new File(dirname);
61. if(file.exists())
62. {
63. if(file.isDirectory())
64. return true;
65. }
66. return false;
67. http://www.kmnk01.com/hxpfk/2015/mny_1219/315.html
69. public static File[] getDirFiles(String dirname)
70. {
71. File[] result=null;
72. File fileDir = new File(dirname);
73. if (!fileDir.exists())
74. {
75. System.out.println("文件夹不存在");
76. return null;
77. }
78. else
79. {
80. if (!fileDir.isDirectory())
81. {
82. fileDir = new File(fileDir.getParent());
83. }
84. result = fileDir.listFiles();
85. http://www.kmnk01.com/hxpfk/2015/qcd_1219/318.html
86. return result;
87. }
89. public static void deleteFiles(String filename)
90. {
91. File file=new File(filename);
92. if(!file.exists())
93. {
94. System.out.println("文件不存在!");
95. return;
96. }
97. if(file.delete())
98. {
99. System.out.println(filename+"文件删除成功!");
100. http://www.kmnk01.com/hxpfk/2015/py_1219/321.html
101. }
103. public static void deleteDirs(String dirname)
104. {
105. if(!dirname.endsWith(File.separator))
106. dirname=dirname+File.separator;
107. File dirn=new File(dirname);
108. if(!dirn.exists())
109. {
110. System.out.println("文件目录不存在!");
111. return;
112. }
113. File[] files=dirn.listFiles();
114. for(int i=0;i<files.length;i++)
115. {
116. if(files[i].isFile())
117. {
118. deleteFiles(files[i].getAbsolutePath());
119. }
120. else
121. deleteDirs(files[i].getAbsolutePath());
122. }
123. if(dirn.delete())
124. {
125. System.out.println("目录删除成功!");
126. }
127. }
129. public static void searchFiles(String dirname,String filename)
130. http://www.kmnk01.com/hxpfk/2015/sz_1219/313.html
131. if(!dirname.endsWith(File.separator))
132. dirname=dirname+File.separator;
133. File dir=new File(dirname);
134. if(!dir.exists())
135. {
136. System.out.println("该文件夹不存在");
137. return;
138. }
139. File[] files=dir.listFiles();
140. for(int i=0;i<files.length;i++)
141. {
142. if(files[i].isFile())
143. {
144. if(files[i].getName().equals(filename))
145. System.out.println("文件路径为:"+files[i].getAbsolutePath());
146. http://www.kmnk01.com/hxpfk/2015/py_1219/316.html
147. else
148. {
149. searchFiles(files[i].getAbsolutePath(),filename);
150. }
151. }
152. }
154. public static File[] searchFile(File folder,final String keyWord)
155. {
156. File[] subFolders=folder.listFiles(new FileFilter()
157. {
158. public boolean accept(File pathname)
159. http://www.kmnk01.com/hxpfk/2015/sz_1219/317.html
160. if(pathname.isFile())
161. countFiles++;
162. else
163. countFolders++;
164. if(pathname.isDirectory()||(pathname.isFile()&&pathname.getName().contains(keyWord)))
165. return true;
166. return false;
167. }
169. });
170. List<File> result=new ArrayList<File>();
171. for(int i=0;i<subFolders.length;i++)
172. {
173. if(subFolders[i].isFile())
174. result.add(subFolders[i]);
175. else
176. {
177. File[] foldResult=searchFile(subFolders[i],keyWord);
178. for(int j=0;j<foldResult.length;j++)
179. result.add(foldResult[j]);
180. }
181. }
182. File files[]=new File[result.size()];
183. result.toArray(files);
184. return files;
185. }
187. public static void copyFileToFile(File tofile,File fromfile)
188. {
189. if(tofile.exists())
190. http://www.kmnk01.com/hxpfk/2015/ylb_1219/319.html
191. System.out.println("文件已经存在!");
192. return;
193. }
194. else
195. {
196. try {
197. tofile.createNewFile();
198. } catch (IOException e) {
199. // TODO Auto-generated catch block
200. e.printStackTrace();
201. }
202. }
203. System.out.println("复制文件从"+fromfile.getAbsolutePath()+"到"+tofile.getAbsolutePath());
204. try {
205. InputStream is=new FileInputStream(fromfile);
206. FileOutputStream fos=new FileOutputStream(tofile);
207. byte []buffer=new byte[1024];
208. try {
209. while(is.read(buffer)!=-1)
210. fos.write(buffer);
211. is.close();
212. fos.close();
213. } catch (IOException e) {
214. // TODO Auto-generated catch block
215. e.printStackTrace();
216. }
217. } catch (FileNotFoundException e) {
218. // TODO Auto-generated catch block
219. e.printStackTrace();
220. }
221. }
223. /**
224. * @param file 要复制的文件
225. * @param dirname 文件复制到目标目录
226. */
227. public static void copyFileToDir(File file,String dirname)
228. {
229. createDir(dirname);
230. String filename=dirname+"/"+file.getName();
231. File nfile=new File(filename);
232. copyFileToFile(nfile,file);
233. }
235. public static void copyDirToDir(String todir,String fromdir)
236. {
237. File []f=getDirFiles(fromdir);
238. for(int i=0;i<f.length;i++)
239. {
240. if(f[i].isFile())
241. copyFileToDir(f[i],todir);
242. else
243. copyDirToDir(todir+"/"+f[i].getName(),fromdir+"/"+f[i].getName());
244. }
245. System.out.println(fromdir+"复制到文件夹"+todir+"复制完成!");
246. }
250. /**
251. * @param args
252. * @throws IOException
253. */
254. public static byte[] readFilebyByte(String filename) throws IOException
255. {
256. byte[] result = null;
257. File file = new File(filename);
258. if (file.exists() && file.isFile() && file.length() > 0)
259. {
260. result = new byte[(int) file.length()];
261. FileInputStream inStream = new FileInputStream(filename);
262. inStream.read(result);
263. inStream.close();
264. }
265. return result;
266. }
268. public static void readFilebyLine(String filename) throws IOException
269. {
270. File file=new File(filename);
271. BufferedReader reader=null;
272. System.out.println("以行为单位读取数据,一次读取一行:");
273. try {
274. reader=new BufferedReader(new FileReader(file));
275. String temp=null;
276. int line=1;
277. while((temp=reader.readLine())!=null)
278. {
279. System.out.println("line"+line+":"+temp);
280. line++;
281. }
282. reader.close();
283. } catch (FileNotFoundException e) {
284. // TODO Auto-generated catch block
285. e.printStackTrace();
286. }
287. }
290. public static void writeFilebyByte(String filename) throws IOException
291. {
292. String content="fsfni ds dw wod";
293. File file=new File(filename);
294. OutputStream out=null;
295. System.out.println("以字节为单位写入文件:"+content);
296. out=new FileOutputStream(file);
297. byte []bytes=content.getBytes();
298. out.write(bytes);
299. out.close();
300. }
302. public static void writeFilebyChar(String filename) throws IOException
303. {
304. String content="fsfni ds dw wod";
305. File file=new File(filename);
306. Writer writer=null;
307. System.out.println("以字符为单位写入文件:"+content);
308. writer=new OutputStreamWriter(new FileOutputStream(file));
309. writer.write(content);
310. writer.close();
311. }
313. public static void writeFilebyLine(String filename) throws IOException
314. {
315. String content="fsfni ds dw wod";
316. File file=new File(filename);
317. PrintWriter writer=null;
318. System.out.println("以行为单位写入文件:"+content);
319. writer=new PrintWriter(new FileOutputStream(file));
320. writer.println(content);
321. writer.print(2355);
322. writer.flush();
323. writer.close();
324. }
326. public static void addContent1(String filename) throws IOException
327. {
328. FileWriter writer=new FileWriter(filename,true);
329. String content="this is a nice man,so you should get it";
330. writer.write(content);
331. writer.close();
332. }
334. public static void addContent2(String filename) throws IOException
335. {
336. RandomAccessFile rfile=new RandomAccessFile(filename, "rw");
337. long filelength=rfile.length();
338. rfile.seek(filelength);
339. String content="hello world";
340. rfile.write(content.getBytes("gb2312"));
341. rfile.close();
343. }
344. /**
345. * @param args
346. * @throws IOException
347. */
348. public static void main(String[] args) throws IOException {
349. // TODO Auto-generated method stub
352. String dirname="c:/cc/";
353. String todir="c:/dd/";
354. String tdir="c:/ee/";
355. String fn="c:/cc/c.txt";
356. String filename="ww.txt";
357. File folder=new File("c:/cc/");
358. String keyword="ww";
359. //readFilebyLine(fn);
360. writeFilebyLine(fn);
361. addContent1(fn);
362. addContent2(fn);
363. //File fromfile=new File("c:/cc/c.txt");
364. //File tofile=new File("e:/ccc.txt");
365. //byte[] fb=readFilebyByte(fn);
366. //for(int i=0;i<fb.length;i++)
367. // System.out.println((char)fb[i]);
368. //System.out.println(fb.toString());
369. //copyFile(tofile,fromfile);
370. //copyFileToDir(fromfile,todir);
371. //copyDirToDir(tdir,dirname);
372. //File[] f=searchFile(folder,keyword);
373. //createDir(dirname);
374. //deleteDirs(dirname);
375. //searchFiles(dirname, filename);
376. //File[] f=getDirFiles(dirname);
377. //for(int i=0;i<f.length;i++)
378. {
379. // System.out.println(f[i].getAbsolutePath());
380. }
381. }
384. }