java使用追加的形式将26个小写字母写入到一个txt文件中

发布网友发布时间：2024-10-06 07:04

共2个回答

热心网友时间：2024-10-06 10:52

import java.io.File;
import java.io.RandomAccessFile;

/**
*
* @author sie1501
*
*/
public class AddCharacter {

    private static RandomAccessFile accessFile;// 定义RandomAccessFile对象对文件进行操作
    private static String dir = "D:\\char.txt";// 文件路径

    /**
     * 往文件追加新的字符
     *
     * @param newChar
     *            字符
     * @return 追加成功返回true,否则返回false
     */
    public static boolean addChar(char newChar) {
        try {
            File file = new File(dir);

            accessFile = new RandomAccessFile(file, "rw");

            long length = file.length();// 获取文件长度
            accessFile.seek(length);// 末尾处添加内容

            accessFile.writeChars(String.valueOf(newChar));// 写入操作

            accessFile.close();
            return true;

        } catch (Exception e) {// 异常捕获
            // TODO: handle exception
            e.printStackTrace();
        }
        return false;
    }

    public static void main(String[] args) {
        for (char charIndex = 'a'; charIndex <= 'z'; charIndex++) {
            if (!addChar(charIndex)) {// 错误提示
                System.out.println("Add character: " + charIndex + "  was failure");
            }
        }
        System.out.println("--------------  End ---------------");
    }

}

热心网友时间：2024-10-06 10:53

FileOutputStream 的构造中，有参数

FileOutputStream(String name,
boolean append)
Creates an output file stream to write to the file with the specified
name.

FileOutputStream(File file,
boolean append)
Creates a file output stream to write to the file represented by
the specified File object.