filewriter为啥就是没有写到文件中

package dadeo;

import java.io.FileWriter;
import java.io.IOException;

public class filewriter {
    public static void main(String[] args) {
        String filepath="d:\\hello.txt";
        FileWriter fileWriter=null;
        char [] buf={'a','b'};
        try {
            FileWriter fileWriter1 = new FileWriter(filepath);
            fileWriter1.write(buf);
            System.out.println("成功");
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {

                    fileWriter.flush();
                fileWriter.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

代码看着没问题，运行有报错吗？