将字符串写入文件并把其内容读出

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class FileOperation {
public static void main(String[] args) throws IOException {
System.out.println("请输入要写入的字符串");
BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
String s = new String();
s = bf.readLine();
System.out.println(s);
File myfile = new File("D:\\test.txt");
BufferedWriter out = new BufferedWriter(new FileWriter(myfile));
out.write(s);
out.close();
System.out.println("文件已经写入"+myfile.getName());
System.out.println("现在读取文件内容......");

BufferedReader in = new BufferedReader(new FileReader("D:\\test.txt"));
StringBuffer txt = new StringBuffer("");
System.out.println("文件内容是......");
while(in.ready()){
txt.append(in.readLine());
}
//     StringTokenizer st =new StringTokenizer(txt.toString());
//           while(st.hasMoreTokens()){
//            System.out.println(st.nextToken("\n"));
//           }
String[] result = txt.toString().split("");
for (int i=0; i<result.length; i++){
System.out.println(result[i]);
}
in.close();

}
}//end FileOperation

BufferedWriter buff = new BufferedWriter(new FileWriter(this.getClass().getResource("/").getPath()+"test.txt"));
String str = "test string";
for (int i = 0; i < str.length(); i++) {
buff.write(str.charAt(i));
}