Java对txt文件内容的增删该查操作
时间: 2024-01-19 20:03:50 浏览: 29
Java可以通过以下方式对txt文件内容进行增删改查操作:
1. 读取txt文件内容:使用Java的FileReader和BufferedReader类,可以读取txt文件的内容。例如:
```
File file = new File("file.txt");
try {
BufferedReader reader = new BufferedReader(new FileReader(file));
String line = reader.readLine();
while (line != null) {
System.out.println(line);
line = reader.readLine();
}
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
```
2. 写入txt文件内容:使用Java的FileWriter和BufferedWriter类,可以向txt文件中写入内容。例如:
```
File file = new File("file.txt");
try {
FileWriter writer = new FileWriter(file);
BufferedWriter out = new BufferedWriter(writer);
out.write("Hello World");
out.close();
} catch (IOException e) {
e.printStackTrace();
}
```
3. 修改txt文件内容:读取txt文件内容,修改后再写入。例如:
```
File file = new File("file.txt");
try {
BufferedReader reader = new BufferedReader(new FileReader(file));
List<String> list = new ArrayList<String>();
String line = reader.readLine();
while (line != null) {
list.add(line);
line = reader.readLine();
}
reader.close();
list.set(0, "Hello World");
FileWriter writer = new FileWriter(file);
BufferedWriter out = new BufferedWriter(writer);
for (String s : list) {
out.write(s + "\n");
}
out.close();
} catch (IOException e) {
e.printStackTrace();
}
```
4. 删除txt文件内容:使用Java的File类的delete方法可以删除txt文件。例如:
```
File file = new File("file.txt");
if (file.delete()) {
System.out.println("File deleted successfully");
} else {
System.out.println("Failed to delete the file");
}
```