文件操作（IO）

JAVA 文件操作

java IO最基本操作总结~~~

1 文件写入

2 读取文件内容

3 删除文件

4 复制文件内容到另一文件

5 向文件中追加数据

6 创建临时文件

7 修改文件最后修改日期

8 获取文件大小

9 文件重命名

10 设置文件为只读模式

11 检测文件是否存在

12 在指定目录创建文件

13 获取文件需改时间

14 创建文件

15 文件路径比较

  1 import java.io.*;
  2 import java.util.*;
  3 
  4 public class FileControl {
  5     public static void main(String[] args) throws Exception{
  6         FileWrite();
  7         FileRead();
  8         FileDel();
  9         FileCopy();
 10         FileAddData();
 11         FileCreatTemporary();
 12         FileLastDate();
 13         FileGetSize();
 14         FileRename();
 15         FileOnlyRead();
 16         FileIfExist();
 17         FileCreatFile();
 18         FileGetChangeDate();
 19         FileCreat();
 20         FilePathCompare();
 21     }
 22 
 23     // 文件写入
 24     private static void FileWrite(){
 25         try {
 26             BufferedWriter out = new BufferedWriter(new FileWriter("outfilename"));
 27             out.write("w3cSchool");
 28             out.close();
 29             System.out.println("文件创建成功!");
 30         }catch (IOException e){
 31             e.printStackTrace();
 32         }
 33     }
 34     // 读取文件内容
 35     private static void FileRead(){
 36         try {
 37             BufferedReader in = new BufferedReader(new FileReader("test.log"));
 38             String str;
 39             while ((str = in.readLine()) != null){
 40                 System.out.println(str);
 41             }
 42         }catch (IOException e){
 43             e.printStackTrace();
 44         }
 45     }
 46     // 删除文件
 47     private static void FileDel(){
 48         try {
 49             File file = new File("text.txt");
 50             if (file.delete()){
 51                 System.out.println(file.getName() + "文件已被删除!");
 52             }else {
 53                 System.out.println("文件删除失败!");
 54             }
 55         }catch (Exception e){
 56             e.printStackTrace();
 57         }
 58     }
 59     // 将文件内容复制到另一个文件
 60     private static void FileCopy() throws Exception{
 61         BufferedWriter out1 = new BufferedWriter(new FileWriter("srcFile"));
 62         out1.write("String to be copied\n");
 63         out1.close();
 64         InputStream in = new FileInputStream(new File("srcFile"));
 65         OutputStream out = new FileOutputStream(new File("destnfile"));
 66         byte[] buf = new byte[1024];
 67         int len;
 68         while ((len = in.read(buf)) > 0){
 69             out.write(buf, 0, len);
 70         }
 71         in.close();
 72         out1.close();
 73         BufferedReader in1 = new BufferedReader(new FileReader("destnfile"));
 74         String str;
 75         while ((str = in1.readLine()) != null){
 76             System.out.println(str);
 77         }
 78         in1.close();
 79     }
 80     // 向文件中追加数据
 81     private static void FileAddData(){
 82         try {
 83             BufferedWriter out = new BufferedWriter(new FileWriter("filename"));
 84             out.write("aString1\n");
 85             out.close();
 86             out = new BufferedWriter(new FileWriter("filename", true));
 87             out.write("aString2");
 88             out.close();
 89             BufferedReader in = new BufferedReader(new FileReader("filename"));
 90             String str;
 91             while ((str = in.readLine()) != null){
 92                 System.out.println(str);
 93             }
 94             in.close();
 95         }catch (IOException e){
 96             System.out.println("Exception occoured" + e);
 97         }
 98     }
 99     // 创建临时文件
100     private static void FileCreatTemporary() throws Exception{
101         File temp = File.createTempFile("pattern", ".suffix");
102         temp.deleteOnExit();
103         BufferedWriter out = new BufferedWriter(new FileWriter(temp));
104         out.write("aString");
105         System.out.println("临时文件已创建");
106         out.close();
107     }
108     // 修改文件最后日期
109     private static void FileLastDate() throws Exception{
110         File fileToChange = new File("myJava.txt");
111         fileToChange.createNewFile();
112         Date filetime = new Date(fileToChange.lastModified());
113         System.out.println(filetime.toString());
114         System.out.println(fileToChange.setLastModified(System.currentTimeMillis()));
115         filetime = new Date(fileToChange.lastModified());
116         System.out.println(filetime.toString());
117     }
118     // 获取文件大小
119     public static long getFileSize(String filename){
120         File file = new File(filename);
121         if (!file.exists() || !file.isFile()){
122             System.out.println("文件不存在");
123             return -1;
124         }
125         return file.length();
126     }
127     private static void FileGetSize(){
128         long size = getFileSize("java.txt");
129         System.out.println("java文件的大小为:" + size);
130     }
131     // 文件重命名
132     private static void FileRename(){
133         File oldName = new File("program.txt");
134         File newName = new File("java.txt");
135         if (oldName.renameTo(newName)){
136             System.out.println("已经重命名");
137         }else {
138             System.out.println("Error");
139         }
140     }
141     // 设置文件只读模式
142     private static void FileOnlyRead(){
143         File file = new File("java.txt");
144         System.out.println(file.setReadOnly());
145         System.out.println(file.canWrite());
146     }
147     // 检测文件是否存在
148     private static void FileIfExist(){
149         File file = new File("java.txt");
150         System.out.println(file.exists());
151     }
152     // 在指定文件中创建文件
153     private static void FileCreatFile() throws Exception{
154         File file = null;
155         File dir = new File("E:/JAVA_CODE/");
156         file = File.createTempFile("JavaTemp", ".javatemp", dir);
157         System.out.println(file.getPath());
158     }
159     // 获取文件修改时间
160     private static void FileGetChangeDate(){
161         File file = new File("MAIN.java");
162         Long lastModified = file.lastModified();
163         Date date = new Date(lastModified);
164         System.out.println(date);
165     }
166     // 创建文件
167     private static void FileCreat(){
168         try {
169             File file = new File("E:/JAVA_CODE/myfile.txt");
170             if (file.createNewFile())
171                 System.out.println("文件创建成功!");
172             else System.out.println("创建文件出错!");
173         }catch (IOException io){
174             io.printStackTrace();
175         }
176     }
177     // 文件路径比较
178     private static void FilePathCompare(){
179         File file1 = new File("E:/demo1/demo.txt");
180         File file2 = new File("E:/demo2/demo.txt");
181         if (file1.compareTo(file2) == 0){
182             System.out.println("文件路径一致!");
183         }else {
184             System.out.println("文件路径不同!");
185         }
186     }
187 }

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