File文件操作

1.  

   //1.创建文件夹
2.  
   //import java.io.*;
3.  
   File myFolderPath = new File(str1);
4.  
   try {
5.  
   if (!myFolderPath.exists()) {
6.  
   myFolderPath.mkdir();
7.  
   }
8.  
   }
9.  
   catch (Exception e) {
10.  
    System.out.println("新建目录操作出错");
11.  
    e.printStackTrace();
12.  
    }
13.  
     
14.  
    //2.创建文件
15.  
    //import java.io.*;
16.  
    File myFilePath = new File(str1);
17.  
    try {
18.  
    if (!myFilePath.exists()) {
19.  
    myFilePath.createNewFile();
20.  
    }
21.  
    FileWriter resultFile = new FileWriter(myFilePath);
22.  
    PrintWriter myFile = new PrintWriter(resultFile);
23.  
    myFile.println(str2);
24.  
    resultFile.close();
25.  
    }
26.  
    catch (Exception e) {
27.  
    System.out.println("新建文件操作出错");
28.  
    e.printStackTrace();
29.  
    }
30.  
     
31.  
    //3.删除文件
32.  
    //import java.io.*;
33.  
    File myDelFile = new File(str1);
34.  
    try {
35.  
    myDelFile.delete();
36.  
    }
37.  
    catch (Exception e) {
38.  
    System.out.println("删除文件操作出错");
39.  
    e.printStackTrace();
40.  
    }
41.  
     
42.  
    //4.删除文件夹
43.  
    //import java.io.*;
44.  
    File delFolderPath = new File(str1);
45.  
    try {
46.  
    delFolderPath.delete(); //删除空文件夹
47.  
    }
48.  
    catch (Exception e) {
49.  
    System.out.println("删除文件夹操作出错");
50.  
    e.printStackTrace();
51.  
    }
52.  
     
53.  
    //5.删除一个文件下夹所有的文件夹
54.  
    //import java.io.*;
55.  
    File delfile=new File(str1);
56.  
    File[] files=delfile.listFiles();
57.  
    for(int i=0;i<files.length;i++){
58.  
    if(files[i].isDirectory()){
59.  
    files[i].delete();
60.  
    }
61.  
    }
62.  
     
63.  
    //6.清空文件夹
64.  
    //import java.io.*;
65.  
    File delfilefolder=new File(str1);
66.  
    try {
67.  
    if (!delfilefolder.exists()) {
68.  
    delfilefolder.delete();
69.  
    }
70.  
    delfilefolder.mkdir();
71.  
    }
72.  
    catch (Exception e) {
73.  
    System.out.println("清空目录操作出错");
74.  
    e.printStackTrace();
75.  
    }
76.  
     
77.  
    //7.读取文件
78.  
    //import java.io.*;
79.  
    // 逐行读取数据
80.  
    FileReader fr = new FileReader(str1);
81.  
    BufferedReader br = new BufferedReader(fr);
82.  
    String str2 = br.readLine();
83.  
    while (str2 != null) {
84.  
     
85.  
    str2 = br.readLine();
86.  
    }
87.  
    br.close();
88.  
    fr.close();
89.  
     
90.  
    //8.写入文件
91.  
    //import java.io.*;
92.  
    // 将数据写入文件
93.  
    try {
94.  
    FileWriter fw = new FileWriter(str1);
95.  
    fw.write(str2);
96.  
    fw.flush();
97.  
    fw.close();
98.  
    } catch (IOException e) {
99.  
    e.printStackTrace();
100.  
     }
101.  
      
102.  
     //9.写入随机文件
103.  
     //import java.io.*;
104.  
     try {
105.  
     RandomAcessFile logFile=new RandomAcessFile(str1,"rw");
106.  
     long lg=logFile.length();
107.  
     logFile.seek(str2);
108.  
     logFile.writeByte(str3);
109.  
     }catch(IOException ioe){
110.  
     System.out.println("无法写入文件："+ioe.getMessage());
111.  
     }
112.  
      
113.  
     //10.读取文件属性
114.  
     //import java.io.*;
115.  
     // 文件属性的取得
116.  
     File f = new File(str1);
117.  
     if (af.exists()) {
118.  
     System.out.println(f.getName() + "的属性如下： 文件长度为：" + f.length());
119.  
     System.out.println(f.isFile() ? "是文件" : "不是文件");
120.  
     System.out.println(f.isDirectory() ? "是目录" : "不是目录");
121.  
     System.out.println(f.canRead() ? "可读取" : "不");
122.  
     System.out.println(f.canWrite() ? "是隐藏文件" : "");
123.  
     System.out.println("文件夹的最后修改日期为：" + new Date(f.lastModified()));
124.  
     } else {
125.  
     System.out.println(f.getName() + "的属性如下：");
126.  
     System.out.println(f.isFile() ? "是文件" : "不是文件");
127.  
     System.out.println(f.isDirectory() ? "是目录" : "不是目录");
128.  
     System.out.println(f.canRead() ? "可读取" : "不");
129.  
     System.out.println(f.canWrite() ? "是隐藏文件" : "");
130.  
     System.out.println("文件的最后修改日期为：" + new Date(f.lastModified()));
131.  
     }
132.  
     if(f.canRead()){
133.  
     str2
134.  
     }
135.  
     if(f.canWrite()){
136.  
     str3
137.  
     }
138.  
      
139.  
     //11.写入属性
140.  
     //import java.io.*;
141.  
     File filereadonly=new File(str1);
142.  
     try {
143.  
     boolean b=filereadonly.setReadOnly();
144.  
     }
145.  
     catch (Exception e) {
146.  
     System.out.println("拒绝写访问："+e.printStackTrace());
147.  
     }
148.  
      
149.  
     //12.枚举一个文件夹中的所有文件
150.  
     //import java.io.*;
151.  
     //import java.util.*;
152.  
     LinkedList<String> folderList = new LinkedList<String>();
153.  
     folderList.add(str1);
154.  
     while (folderList.size() > 0) {
155.  
     File file = new File(folderList.peek());
156.  
     folderList.removeLast();
157.  
     File[] files = file.listFiles();
158.  
     ArrayList<File> fileList = new ArrayList<File>();
159.  
     for (int i = 0; i < files.length; i++) {
160.  
     if (files[i].isDirectory()) {
161.  
     folderList.add(files[i].getPath());
162.  
     } else {
163.  
     fileList.add(files[i]);
164.  
     }
165.  
     }
166.  
     for (File f : fileList) {
167.  
     str2=f.getAbsoluteFile();
168.  
     str3
169.  
     }
170.  
     }
171.  
      
172.  
     //13.复制文件夹
173.  
     //import java.io.*;
174.  
     //import java.util.*;
175.  
     LinkedList<String> folderList = new LinkedList<String>();
176.  
     folderList.add(str1);
177.  
     LinkedList<String> folderList2 = new LinkedList<String>();
178.  
     folderList2.add(str2+ str1.substring(str1.lastIndexOf("\\")));
179.  
     while (folderList.size() > 0) {
180.  
     (new File(folderList2.peek())).mkdirs(); // 如果文件夹不存在 则建立新文件夹
181.  
     File folders = new File(folderList.peek());
182.  
     String[] file = folders.list();
183.  
     File temp = null;
184.  
     try {
185.  
     for (int i = 0; i < file.length; i++) {
186.  
     if (folderList.peek().endsWith(File.separator)) {
187.  
     temp = new File(folderList.peek() + File.separator
188.  
     + file[i]);
189.  
     } else {
190.  
     temp = new File(folderList.peek() + File.separator + file[i]);
191.  
     }
192.  
     if (temp.isFile()) {
193.  
     FileInputStream input = new FileInputStream(temp);
194.  
     FileOutputStream output = new FileOutputStream(
195.  
     folderList2.peek() + File.separator + (temp.getName()).toString());
196.  
     byte[] b = new byte[5120];
197.  
     int len;
198.  
     while ((len = input.read(b)) != -1) {
199.  
     output.write(b, 0, len);
200.  
     }
201.  
     output.flush();
202.  
     output.close();
203.  
     input.close();
204.  
     }
205.  
     if (temp.isDirectory()) {// 如果是子文件夹
206.  
     for (File f : temp.listFiles()) {
207.  
     if (f.isDirectory()) {
208.  
     folderList.add(f.getPath());
209.  
     folderList2.add(folderList2.peek()
210.  
     + File.separator + f.getName());
211.  
     }
212.  
     }
213.  
     }
214.  
     }
215.  
     } catch (Exception e) {
216.  
     //System.out.println("复制整个文件夹内容操作出错");
217.  
     e.printStackTrace();
218.  
     }
219.  
     folderList.removeFirst();
220.  
     folderList2.removeFirst();
221.  
     }
222.  
      
223.  
     //14.复制一个文件夹下所有的文件夹到另一个文件夹下
224.  
     //import java.io.*;
225.  
     //import java.util.*;
226.  
     File copyfolders=new File(str1);
227.  
     File[] copyfoldersList=copyfolders.listFiles();
228.  
     for(int k=0;k<copyfoldersList.length;k++){
229.  
     if(copyfoldersList[k].isDirectory()){
230.  
     ArrayList<String>folderList=new ArrayList<String>();
231.  
     folderList.add(copyfoldersList[k].getPath());
232.  
     ArrayList<String>folderList2=new ArrayList<String>();
233.  
     folderList2.add(str2+"/"+copyfoldersList[k].getName());
234.  
     for(int j=0;j<folderList.length;j++){
235.  
     (new File(folderList2.get(j))).mkdirs(); //如果文件夹不存在 则建立新文件夹
236.  
     File folders=new File(folderList.get(j));
237.  
     String[] file=folders.list();
238.  
     File temp=null;
239.  
     try {
240.  
     for (int i = 0; i < file.length; i++) {
241.  
     if(folderList.get(j).endsWith(File.separator)){
242.  
     temp=new File(folderList.get(j)+"/"+file[i]);
243.  
     } else {
244.  
     temp=new File(folderList.get(j)+"/"+File.separator+file[i]);
245.  
     }
246.  
     FileInputStream input = new FileInputStream(temp);
247.  
     if(temp.isFile()){
248.  
     FileInputStream input = new FileInputStream(temp);
249.  
     FileOutputStream output = new FileOutputStream(folderList2.get(j) + "/" + (temp.getName()).toString());
250.  
     byte[] b = new byte[5120];
251.  
     int len;
252.  
     while ( (len = input.read(b)) != -1) {
253.  
     output.write(b, 0, len);
254.  
     }
255.  
     output.flush();
256.  
     output.close();
257.  
     input.close();
258.  
     }
259.  
     if(temp.isDirectory()){//如果是子文件夹
260.  
     folderList.add(folderList.get(j)+"/"+file[i]);
261.  
     folderList2.add(folderList2.get(j)+"/"+file[i]);
262.  
     }
263.  
     }
264.  
     }
265.  
     catch (Exception e) {
266.  
     System.out.println("复制整个文件夹内容操作出错");
267.  
     e.printStackTrace();
268.  
     }
269.  
     }
270.  
     }
271.  
     }
272.  
      
273.  
     //15.移动文件夹
274.  
     //import java.io.*;
275.  
     //import java.util.*;
276.  
     LinkedList<String> folderList = new LinkedList<String>();
277.  
     folderList.add(str1);
278.  
     LinkedList<String> folderList2 = new LinkedList<String>();
279.  
     folderList2.add(str2 + str1.substring(str1.lastIndexOf("\\")));
280.  
     while (folderList.size() > 0) {
281.  
     (new File(folderList2.peek())).mkdirs(); // 如果文件夹不存在 则建立新文件夹
282.  
     File folders = new File(folderList.peek());
283.  
     String[] file = folders.list();
284.  
     File temp = null;
285.  
     try {
286.  
     for (int i = 0; i < file.length; i++) {
287.  
     if (folderList.peek().endsWith(File.separator)) {
288.  
     temp = new File(folderList.peek() + File.separator + file[i]);
289.  
     } else {
290.  
     temp = new File(folderList.peek() + File.separator + file[i]);
291.  
     }
292.  
     if (temp.isFile()) {
293.  
     FileInputStream input = new FileInputStream(temp);
294.  
     FileOutputStream output = new FileOutputStream(
295.  
     folderList2.peek() + File.separator + (temp.getName()).toString());
296.  
     byte[] b = new byte[5120];
297.  
     int len;
298.  
     while ((len = input.read(b)) != -1) {
299.  
     output.write(b, 0, len);
300.  
     }
301.  
     output.flush();
302.  
     output.close();
303.  
     input.close();
304.  
     if (!temp.delete())
305.  
     System.out.println("删除单个文件操作出错!");
306.  
     }
307.  
     if (temp.isDirectory()) {// 如果是子文件夹
308.  
     for (File f : temp.listFiles()) {
309.  
     if (f.isDirectory()) {
310.  
     folderList.add(f.getPath());
311.  
     folderList2.add(folderList2.peek() + File.separator + f.getName());
312.  
     }
313.  
     }
314.  
     }
315.  
     }
316.  
     } catch (Exception e) {
317.  
     // System.out.println("复制整个文件夹内容操作出错");
318.  
     e.printStackTrace();
319.  
     }
320.  
     folderList.removeFirst();
321.  
     folderList2.removeFirst();
322.  
     }
323.  
     File f = new File(str1);
324.  
     if (!f.delete()) {
325.  
     for (File file : f.listFiles()) {
326.  
     if (file.list().length == 0) {
327.  
     System.out.println(file.getPath());
328.  
     file.delete();
329.  
     }
330.  
     }
331.  
     }
332.  
     //16.移动一个文件夹下所有的文件夹到另一个目录下
333.  
     //import java.io.*;
334.  
     //import java.util.*;
335.  
     File movefolders=new File(str1);
336.  
     File[] movefoldersList=movefolders.listFiles();
337.  
     for(int k=0;k<movefoldersList.length;k++){
338.  
     if(movefoldersList[k].isDirectory()){
339.  
     ArrayList<String>folderList=new ArrayList<String>();
340.  
     folderList.add(movefoldersList[k].getPath());
341.  
     ArrayList<String>folderList2=new ArrayList<String>();
342.  
     folderList2.add(str2+"/"+movefoldersList[k].getName());
343.  
     for(int j=0;j<folderList.length;j++){
344.  
     (new File(folderList2.get(j))).mkdirs(); //如果文件夹不存在 则建立新文件夹
345.  
     File folders=new File(folderList.get(j));
346.  
     String[] file=folders.list();
347.  
     File temp=null;
348.  
     try {
349.  
     for (int i = 0; i < file.length; i++) {
350.  
     if(folderList.get(j).endsWith(File.separator)){
351.  
     temp=new File(folderList.get(j)+"/"+file[i]);
352.  
     }
353.  
     else{
354.  
     temp=new File(folderList.get(j)+"/"+File.separator+file[i]);
355.  
     }
356.  
     FileInputStream input = new FileInputStream(temp);
357.  
     if(temp.isFile()){
358.  
     FileInputStream input = new FileInputStream(temp);
359.  
     FileOutputStream output = new FileOutputStream(folderList2.get(j) + "/" + (temp.getName()).toString());
360.  
     byte[] b = new byte[5120];
361.  
     int len;
362.  
     while ( (len = input.read(b)) != -1) {
363.  
     output.write(b, 0, len);
364.  
     }
365.  
     output.flush();
366.  
     output.close();
367.  
     input.close();
368.  
     temp.delete();
369.  
     }
370.  
     if(temp.isDirectory()){//如果是子文件夹
371.  
     folderList.add(folderList.get(j)+"/"+file[i]);
372.  
     folderList2.add(folderList2.get(j)+"/"+file[i]);
373.  
     }
374.  
     }
375.  
     }
376.  
     catch (Exception e) {
377.  
     System.out.println("复制整个文件夹内容操作出错");
378.  
     e.printStackTrace();
379.  
     }
380.  
     }
381.  
     movefoldersList[k].delete();
382.  
     }
383.  
     }
384.  
      
385.  
     //17.以一个文件夹的框架在另一个目录创建文件夹和空文件
386.  
     //import java.io.*;
387.  
     //import java.util.*;
388.  
     boolean b=false;//不创建空文件
389.  
     ArrayList<String>folderList=new ArrayList<String>();
390.  
     folderList.add(str1);
391.  
     ArrayList<String>folderList2=new ArrayList<String>();
392.  
     folderList2.add(str2);
393.  
     for(int j=0;j<folderList.length;j++){
394.  
     (new File(folderList2.get(j))).mkdirs(); //如果文件夹不存在 则建立新文件夹
395.  
     File folders=new File(folderList.get(j));
396.  
     String[] file=folders.list();
397.  
     File temp=null;
398.  
     try {
399.  
     for (int i = 0; i < file.length; i++) {
400.  
     if(folderList.get(j).endsWith(File.separator)){
401.  
     temp=new File(folderList.get(j)+"/"+file[i]);
402.  
     }
403.  
     else{
404.  
     temp=new File(folderList.get(j)+"/"+File.separator+file[i]);
405.  
     }
406.  
     FileInputStream input = new FileInputStream(temp);
407.  
     if(temp.isFile()){
408.  
     if (b) temp.createNewFile();
409.  
     }
410.  
     if(temp.isDirectory()){//如果是子文件夹
411.  
     folderList.add(folderList.get(j)+"/"+file[i]);
412.  
     folderList2.add(folderList2.get(j)+"/"+file[i]);
413.  
     }
414.  
     }
415.  
     }
416.  
     catch (Exception e) {
417.  
     System.out.println("复制整个文件夹内容操作出错");
418.  
     e.printStackTrace();
419.  
     }
420.  
     }
421.  
      
422.  
     //18.复制文件
423.  
     //import java.io.*;
424.  
     int bytesum = 0;
425.  
     int byteread = 0;
426.  
     File oldfile = new File(str1);
427.  
     try {
428.  
     if (oldfile.exists()) { //文件存在时
429.  
     FileInputStream inStream = new FileInputStream(oldfile); //读入原文件
430.  
     FileOutputStream fs = new FileOutputStream(new File(str2,oldfile.getName()));
431.  
     byte[] buffer = new byte[5120];
432.  
     int length;
433.  
     while ( (byteread = inStream.read(buffer)) != -1) {
434.  
     bytesum += byteread; //字节数 文件大小
435.  
     System.out.println(bytesum);
436.  
     fs.write(buffer, 0, byteread);
437.  
     }
438.  
     inStream.close();
439.  
     }
440.  
     }
441.  
     catch (Exception e) {
442.  
     System.out.println("复制单个文件操作出错");
443.  
     e.printStackTrace();
444.  
     }
445.  
      
446.  
     //19.复制一个文件夹下所有的文件到另一个目录
447.  
     //import java.io.*;
448.  
     File copyfiles=new File(str1);
449.  
     File[] files=copyfiles.listFiles();
450.  
     for(int i=0;i<files.length;i++){
451.  
     if(!files[i].isDirectory()){
452.  
     int bytesum = 0;
453.  
     int byteread = 0;
454.  
     try {
455.  
     InputStream inStream = new FileInputStream(files[i]); //读入原文件
456.  
     FileOutputStream fs = new FileOutputStream(new File(str2,files[i].getName());
457.  
     byte[] buffer = new byte[5120];
458.  
     int length;
459.  
     while ( (byteread = inStream.read(buffer)) != -1) {
460.  
     bytesum += byteread; //字节数 文件大小
461.  
     System.out.println(bytesum);
462.  
     fs.write(buffer, 0, byteread);
463.  
     }
464.  
     inStream.close();
465.  
     } catch (Exception e) {
466.  
     System.out.println("复制单个文件操作出错");
467.  
     e.printStackTrace();
468.  
     }
469.  
     }
470.  
     }
471.  
      
472.  
     //20.提取扩展名
473.  
     String str2=str1.substring(str1.lastIndexOf(".")+1);