JAVA里怎样读取一个文件的最后两行！用Bufferdread

public static void main(String args){
/*
* 读文件名
*/
File file = new File("请输文件名");
FileReader filereader1;

try {
filereader1 = new FileReader(file);
BufferedReader bufferreader1 = new BufferedReader(filereader1);
String str1 = null;

/*
* 用于记录数量的指标
*/
StringBuffer sb=new StringBuffer();
ArrayList al=new ArrayList();
while ((str1 = bufferreader1.readLine()) != null)
{
al.add(str1);

}
bufferreader1.close();
filereader1.close();
//最后两行嘛。就是指针最后的两行喽
int len=al.size();
System.out.println("最后两行为"+al.get(len)+al.get(len-1));

} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOE