java创建文件和目录

[java] view plaincopy

1. 创建文件和目录的关键技术点如下：  

[java] view plaincopy

1. <pre name="code" class="java">    1、File类的createNewFile根据抽象路径创建一个新的空文件，当抽象路径制定的文件存在时，创建失败  
2.     2、File类的mkdir方法根据抽象路径创建目录  
3.     3、File类的mkdirs方法根据抽象路径创建目录，包括创建必需但不存在的父目录  
4.     4、File类的createTempFile方法创建临时文件，可以制定临时文件的文件名前缀、后缀及文件所在的目录，如果不指定目录，则存放在系统的临时文件夹下。  
5.     5、除mkdirs方法外，以上方法在创建文件和目录时，必须保证目标文件不存在，而且父目录存在，否则会创建失败  
6.      
7. 实例演示</pre><br>  
8. <pre></pre>  
9. <pre name="code" class="java">package book.io;  
10.   
11. import java.io.File;  
12. import java.io.IOException;  
13.   
14. public class CreateFileUtil {  
15.      
16.     public static boolean createFile(String destFileName) {  
17.         File file = new File(destFileName);  
18.         if(file.exists()) {  
19.             System.out.println("创建单个文件" + destFileName + "失败，目标文件已存在！");  
20.             return false;  
21.         }  
22.         if (destFileName.endsWith(File.separator)) {  
23.             System.out.println("创建单个文件" + destFileName + "失败，目标文件不能为目录！");  
24.             return false;  
25.         }  
26.         //判断目标文件所在的目录是否存在  
27.         if(!file.getParentFile().exists()) {  
28.             //如果目标文件所在的目录不存在，则创建父目录  
29.             System.out.println("目标文件所在目录不存在，准备创建它！");  
30.             if(!file.getParentFile().mkdirs()) {  
31.                 System.out.println("创建目标文件所在目录失败！");  
32.                 return false;  
33.             }  
34.         }  
35.         //创建目标文件  
36.         try {  
37.             if (file.createNewFile()) {  
38.                 System.out.println("创建单个文件" + destFileName + "成功！");  
39.                 return true;  
40.             } else {  
41.                 System.out.println("创建单个文件" + destFileName + "失败！");  
42.                 return false;  
43.             }  
44.         } catch (IOException e) {  
45.             e.printStackTrace();  
46.             System.out.println("创建单个文件" + destFileName + "失败！" + e.getMessage());  
47.             return false;  
48.         }  
49.     }  
50.      
51.      
52.     public static boolean createDir(String destDirName) {  
53.         File dir = new File(destDirName);  
54.         if (dir.exists()) {  
55.             System.out.println("创建目录" + destDirName + "失败，目标目录已经存在");  
56.             return false;  
57.         }  
58.         if (!destDirName.endsWith(File.separator)) {  
59.             destDirName = destDirName + File.separator;  
60.         }  
61.         //创建目录  
62.         if (dir.mkdirs()) {  
63.             System.out.println("创建目录" + destDirName + "成功！");  
64.             return true;  
65.         } else {  
66.             System.out.println("创建目录" + destDirName + "失败！");  
67.             return false;  
68.         }  
69.     }  
70.      
71.      
72.     public static String createTempFile(String prefix, String suffix, String dirName) {  
73.         File tempFile = null;  
74.         if (dirName == null) {  
75.             try{  
76.                 //在默认文件夹下创建临时文件  
77.                 tempFile = File.createTempFile(prefix, suffix);  
78.                 //返回临时文件的路径  
79.                 return tempFile.getCanonicalPath();  
80.             } catch (IOException e) {  
81.                 e.printStackTrace();  
82.                 System.out.println("创建临时文件失败！" + e.getMessage());  
83.                 return null;  
84.             }  
85.         } else {  
86.             File dir = new File(dirName);  
87.             //如果临时文件所在目录不存在，首先创建  
88.             if (!dir.exists()) {  
89.                 if (!CreateFileUtil.createDir(dirName)) {  
90.                     System.out.println("创建临时文件失败，不能创建临时文件所在的目录！");  
91.                     return null;  
92.                 }  
93.             }  
94.             try {  
95.                 //在指定目录下创建临时文件  
96.                 tempFile = File.createTempFile(prefix, suffix, dir);  
97.                 return tempFile.getCanonicalPath();  
98.             } catch (IOException e) {  
99.                 e.printStackTrace();  
100.                 System.out.println("创建临时文件失败！" + e.getMessage());  
101.                 return null;  
102.             }  
103.         }  
104.     }  
105.      
106.     public static void main(String[] args) {  
107.         //创建目录  
108.         String dirName = "D:/work/temp/temp0/temp1";  
109.         CreateFileUtil.createDir(dirName);  
110.         //创建文件  
111.         String fileName = dirName + "/temp2/tempFile.txt";  
112.         CreateFileUtil.createFile(fileName);  
113.         //创建临时文件  
114.         String prefix = "temp";  
115.         String suffix = ".txt";  
116.         for (int i = 0; i < 10; i++) {  
117.             System.out.println("创建了临时文件："  
118.                     + CreateFileUtil.createTempFile(prefix, suffix, dirName));  
119.         }  
120.         //在默认目录下创建临时文件  
121.         for (int i = 0; i < 10; i++) {  
122.             System.out.println("在默认目录下创建了临时文件："  
123.                     + CreateFileUtil.createTempFile(prefix, suffix, null));  
124.         }  
125.     }  
126.   
127. }  
128. 输出结果：  
129.   
130.   
131. 创建目录D:/work/temp/temp0/temp1成功！  
132. 目标文件所在目录不存在，准备创建它！  
133. 创建单个文件D:/work/temp/temp0/temp1/temp2/tempFile.txt成功！  
134. 创建了临时文件：D:work emp emp0 emp1 emp5171.txt  
135. 创建了临时文件：D:work emp emp0 emp1 emp5172.txt  
136. 创建了临时文件：D:work emp emp0 emp1 emp5173.txt  
137. 创建了临时文件：D:work emp emp0 emp1 emp5174.txt  
138. 创建了临时文件：D:work emp emp0 emp1 emp5175.txt  
139. 创建了临时文件：D:work emp emp0 emp1 emp5176.txt  
140. 创建了临时文件：D:work emp emp0 emp1 emp5177.txt  
141. 创建了临时文件：D:work emp emp0 emp1 emp5178.txt  
142. 创建了临时文件：D:work emp emp0 emp1 emp5179.txt  
143. 创建了临时文件：D:work emp emp0 emp1 emp5180.txt  
144. 在默认目录下创建了临时文件：C:Documents and SettingsAdministratorLocal SettingsTemp emp5181.txt  
145. 在默认目录下创建了临时文件：C:Documents and SettingsAdministratorLocal SettingsTemp emp5182.txt  
146. 在默认目录下创建了临时文件：C:Documents and SettingsAdministratorLocal SettingsTemp emp5183.txt  
147. 在默认目录下创建了临时文件：C:Documents and SettingsAdministratorLocal SettingsTemp emp5184.txt  
148. 在默认目录下创建了临时文件：C:Documents and SettingsAdministratorLocal SettingsTemp emp5185.txt  
149. 在默认目录下创建了临时文件：C:Documents and SettingsAdministratorLocal SettingsTemp emp5186.txt  
150. 在默认目录下创建了临时文件：C:Documents and SettingsAdministratorLocal SettingsTemp emp5187.txt  
151. 在默认目录下创建了临时文件：C:Documents and SettingsAdministratorLocal SettingsTemp emp5188.txt  
152. 在默认目录下创建了临时文件：C:Documents and SettingsAdministratorLocal SettingsTemp emp5189.txt  
153. 在默认目录下创建了临时文件：C:Documents and SettingsAdministratorLocal SettingsTemp emp5190.txt  
154.   
155. </pre><br>  
156. http://www.zhihu.com/collection/25873857
     http://www.zhihu.com/collection/25873973
     http://www.zhihu.com/collection/25874894
     http://www.zhihu.com/collection/25875057
     http://www.zhihu.com/collection/25875292
     http://www.zhihu.com/collection/25875441
     http://www.zhihu.com/collection/25875724
     http://www.zhihu.com/collection/25876004
     http://www.zhihu.com/collection/25876195
     http://www.zhihu.com/collection/25876399
     http://www.zhihu.com/collection/25876800
     http://www.zhihu.com/collection/25876958
     http://www.zhihu.com/collection/25877184
     http://www.zhihu.com/collection/25877589
     http://www.zhihu.com/collection/25877672
     http://www.zhihu.com/collection/25878094
     http://www.zhihu.com/collection/25878835
     http://www.zhihu.com/collection/25879155
     http://www.zhihu.com/collection/25879518
     http://www.zhihu.com/collection/25879828
     http://www.zhihu.com/collection/25882215
     http://www.zhihu.com/collection/25882427
     http://www.zhihu.com/collection/25882792
     http://www.zhihu.com/collection/25883083
     http://www.zhihu.com/collection/25883285
     http://www.zhihu.com/collection/25890851
     http://www.zhihu.com/collection/25890925
     http://www.zhihu.com/collection/25891014
     http://www.zhihu.com/collection/25891089
     http://www.zhihu.com/collection/25891157
     http://www.zhihu.com/collection/25893431
     http://www.zhihu.com/collection/25893548
     http://www.zhihu.com/collection/25893627
     http://www.zhihu.com/collection/25893736
     http://www.zhihu.com/collection/25893766
     http://www.zhihu.com/collection/25893803
     http://www.zhihu.com/collection/25893887
     http://www.zhihu.com/collection/25893927
     http://www.zhihu.com/collection/25893951
     http://www.zhihu.com/collection/25894031
     http://www.zhihu.com/collection/25894098
     http://www.zhihu.com/collection/25894130
     http://www.zhihu.com/collection/25894229
     http://www.zhihu.com/collection/25894335
     http://www.zhihu.com/collection/25894487
     http://www.zhihu.com/collection/25952664
     http://www.zhihu.com/collection/25952927
     http://www.zhihu.com/collection/25953157
     http://www.zhihu.com/collection/25953294
     http://www.zhihu.com/collection/25953594
     http://www.zhihu.com/collection/25953832
     http://www.zhihu.com/collection/25954116
     http://www.zhihu.com/collection/25954402
     http://www.zhihu.com/collection/25954354
     http://www.zhihu.com/collection/25954612
     http://www.zhihu.com/collection/25954672
     http://www.zhihu.com/collection/25954904
     http://www.zhihu.com/collection/25954729
     http://www.zhihu.com/collection/25954889
     http://www.zhihu.com/collection/25954959
     http://www.zhihu.com/collection/25955219
     http://www.zhihu.com/collection/25955469
     http://www.zhihu.com/collection/25955307
     http://www.zhihu.com/collection/25955528
     http://www.zhihu.com/collection/25955707
     http://www.zhihu.com/collection/25955781
     http://www.zhihu.com/collection/25955993
     http://www.zhihu.com/collection/25957047
     http://www.zhihu.com/collection/25957087
     http://www.zhihu.com/collection/25956572
     http://www.zhihu.com/collection/25956238
     http://www.zhihu.com/collection/25956794
     http://www.zhihu.com/collection/25957995
     http://www.zhihu.com/collection/25958231
     http://www.zhihu.com/collection/25958197
     http://www.zhihu.com/collection/25958484
     http://www.zhihu.com/collection/25958267
     http://www.zhihu.com/collection/25958534
     http://www.zhihu.com/collection/25958531
     http://www.zhihu.com/collection/25958784
     http://www.zhihu.com/collection/25959296
     http://www.zhihu.com/collection/25959529
     http://www.zhihu.com/collection/25959730
     http://www.zhihu.com/collection/25961124
     http://www.zhihu.com/collection/25961313
     http://www.zhihu.com/collection/25961372
     http://www.zhihu.com/collection/25961621
     http://www.zhihu.com/collection/25961817
     http://www.zhihu.com/collection/25961910
     http://www.zhihu.com/collection/25962050
     http://www.zhihu.com/collection/25962228
     http://www.zhihu.com/collection/25962740
     http://www.zhihu.com/collection/25962921
     http://www.zhihu.com/collection/25962905
     http://www.zhihu.com/collection/25962988
     http://500px.com/photo/45156486
     http://500px.com/photo/45156624
     http://500px.com/photo/45156692
     http://500px.com/photo/45156746
     http://500px.com/photo/45157808
     http://500px.com/photo/45157862
     http://500px.com/photo/45157892
     http://500px.com/photo/45158216
     http://500px.com/photo/45158224
     http://500px.com/photo/45158358
     http://500px.com/photo/45158390
     http://500px.com/photo/45158978
     http://500px.com/photo/45159382
     http://500px.com/photo/45159406
     http://500px.com/photo/45159538
     http://500px.com/photo/45040488
     http://500px.com/photo/45040620
     http://500px.com/photo/45134550
     http://500px.com/photo/45134644
     http://500px.com/photo/45134700
     http://500px.com/photo/45134856
     http://500px.com/photo/45134926
     http://500px.com/photo/45135300
     http://500px.com/photo/45135400
     http://500px.com/photo/45135450
     http://500px.com/photo/45135464
     http://500px.com/photo/45135500
     http://500px.com/photo/45135536
     http://500px.com/photo/45135550
     http://500px.com/photo/45135754