取得文件中的字符数

import java.io.File;
import java.io.FileOutputStream;

public class Demo {

  /**
    * 取得文件中的字符数
    */
  public static void main(String[] args) throws Exception{
    // TODO Auto-generated method stub
    File file = new File("e:"+File.separator+"yanjun.txt");
    FileOutputStream fileOutputStream = new FileOutputStream(file);
    String str1 = "111111111111";
    char b [] = str1.toCharArray();
    for (int i = 0; i < b.length; i++) {
        
      fileOutputStream.write(b[i]);
    }
    fileOutputStream.close();
    byte[] b1 = str1.getBytes();
    System.out.println(b1.length);
  }
}