Java IO流：文件读写、打印和输入的基本示例

原创 ╰半橙微兮° 2024-12-08 19:39 24阅读 0赞

在Java中，IO流用于进行文件读写操作。以下是一些基本的示例：

1. **文件读取**：
```java
import java.io.*;

public class FileReaderExample {
    public static void main(String[] args) {
        String fileName = "example.txt"; // 文件名

try (FileReader fr = new FileReader(fileName)) {
            BufferedReader br = new BufferedReader(fr);
            
            System.out.println("Reading from file...");
            String line;
            while ((line = br.readLine()) != null) {
                System.out.println(line);
            }
            
            System.out.println("Closing file.");
            br.close();
        } catch (IOException e) {
            e.printStackTrace();
            System.out.println("Error occurred while reading the file.");
        }
    }
}
```
2. **文件写入**：
```java
import java.io.*;

public class FileWriterExample {
    public static void main(String[] args) {
        String fileName = "example.txt"; // 文件名
        String content = "This is an example written to a file."; // 内容

try (FileWriter fw = new FileWriter(fileName)) {
            System.out.println("Writing to file...");
            fw.write(content);
            
            System.out.println("Closing file.");
            fw.close();
        } catch (IOException e) {
            e.printStackTrace();
            System.out.println("Error occurred while writing the content to the file.");
        }
    }
}
```
3. **打印到控制台**：
```java
import java.io.*;

public class PrintExample {
    public static void main(String[] args) {
        String message = "Hello, World!"; // 要打印的消息

try (PrintWriter writer = new PrintWriter(System.out)) {
            System.out.println("Writing to console...");
            writer.print(message);
            
            System.out.println("Closing the writer.");
            writer.close();
        } catch (IOException e) {
            e.printStackTrace();
            System.out.println("Error occurred while printing to the console.");
        }
    }
}
```
以上示例展示了Java中文件读写、打印和输入的基本操作。