Java二维数组存储一位数组的问题

从一个txt文件中读出字符串，每一行输出一个record，但我想把所有record中的字符串存放到一个字符数组中，便于我下一步单个字符分析，该怎么改啊

class test2 {
    public static void main(String[] args) {
        test2 t = new test2();
        t.readMyFile();
    }

    void readMyFile() {
        String record;
        int recCount = 0;
        char[] a;
        char[][] b=new char[10][];
        int i=0;
        int j=0;
        try {
            FileReader fr = new FileReader("D:\\data.txt");
            BufferedReader br = new BufferedReader(fr);
            while ((record = br.readLine()) != null) {
                recCount++;
                a=record.toCharArray();
                System.out.println(recCount + ": " + record);
                System.out.println(a[j]);
                for(;j<a.length;j++)
                {   
                    b[i][j]=a[j];
                }
                i++;
                //System.out.println(b[i][j]);
            }
            br.close();
            fr.close();
        } catch (IOException e) {
            System.out.println("Uh oh, got an IOException error!");
            e.printStackTrace();
        }
    }

}