求求大学JAVA问题，如何做

replaceAll函数

给你个例子作为参考

public static void main(String[] args) throws IOException {
    String text = "asda sdfl 132dfg #!FA三是6点饭稍等".replaceAll(" ", "@");
    stringToFile(text, new File("D:/test.txt"));

}

public static void stringToFile(String text, File file) throws IOException {
    BufferedReader br = null;
    BufferedWriter bw = null;
    br = new BufferedReader(new StringReader(text));
    bw = new BufferedWriter(new FileWriter(file));
    char[] buf = new char[1024 * 64];          //字符缓冲区
    int len;
    while ((len = br.read(buf)) != -1) {
        bw.write(buf, 0, len);
    }
    bw.flush();
    br.close();
    bw.close();
}