Java IO - BufferedReader & BufferedWriter

java.io 包提供丰富的 IO 读写功能，封装在不同的类里面。其中，使用 BufferedReader 和 BufferedWriter 可以方便地进行读、写文件的操作。

使用例子如下：

import static java.lang.System.out;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;

public class FileReaderExample {

    public final static String PATH_IN = "src/resources/data_input.txt";
    public final static String PATH_OUT = "src/resources/data_output.txt";

    /**
     * example of BufferedReader and BufferedWriter
     *
     * @throws Exception
     */
    public void BufferedReader_Writer() throws Exception {

        FileReader fr = new FileReader(PATH_IN);
        BufferedReader br = new BufferedReader(fr);

        FileWriter fw = new FileWriter(PATH_OUT);
        BufferedWriter bw = new BufferedWriter(fw);

        String line;
        while ((line = br.readLine()) != null) {
            out.println(line);
            bw.write(line + "\n");
        }

        String endStr = " - End of BufferedReader ";
        out.print(endStr);
        bw.write(endStr + "\n");

        br.close();
        bw.close();
    }
}

参考资料：

Java IO BufferedReader, tutorialspoint

Java Files and IO, tutorialspint