如何使用BufferedReader和BufferedWriter等缓冲流？

以下是Java中使用BufferedReader和BufferedWriter等缓冲流的示例：

1. 使用BufferedReader从文件中读取数据并打印出来：

import java.io.*;

public class ReadFromFile {
    public static void main(String[] args) {
        try {
            BufferedReader reader = new BufferedReader(new FileReader("file.txt"));
            String line = reader.readLine();
            while (line != null) {
                System.out.println(line);
                line = reader.readLine();
            }
            reader.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

2. 使用BufferedWriter向文件中写入数据：

import java.io.*;

public class WriteToFile {
    public static void main(String[] args) {
        try {
            BufferedWriter writer = new BufferedWriter(new FileWriter("file.txt"));
            writer.write("Hello World!");
            writer.newLine();
            writer.write("This is a test.");
            writer.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

3. 使用BufferedReader从控制台读取数据并打印出来：

import java.io.*;

public class ReadFromConsole {
    public static void main(String[] args) {
        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
            String line = reader.readLine();
            while (!line.equals("exit")) {
                System.out.println(line);
                line = reader.readLine();
            }
            reader.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

4. 使用BufferedWriter向控制台写入数据：

import java.io.*;

public class WriteToConsole {
    public static void main(String[] args) {
        try {
            BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(System.out));
            writer.write("Hello World!");
            writer.newLine();
            writer.write("This is a test.");
            writer.flush();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}