java分割txt全量文件

public class Ja {
   public static void main (String args[])throws IOException{
  File files=new File("D:/all_2012-03-28.txt");
      FileReader readfile=new FileReader(files);
      BufferedReader buffer=new BufferedReader(readfile);
      String s;
      System.out.println(DateUtil.getStandardTime());
      int i=0;
      int m=0;//全量文件行数
         int ge=0;//新生成文件个数
         StringBuffer fileContent  =   new  StringBuffer();
      while((s=buffer.readLine())!=null){
     
    File file=null;
//     for( int i=0;i<tlist.size();i++){
    if(ge==0){
           file = new File("D://logs//all_2012-03-28_"+ge+".txt");  //生成第一个分段全量新文件
                 if(!file.getParentFile().exists()){  
                     file.mkdir();  
                 }
                 ge++;
           }
    fileContent.append(s.toString());
                 fileContent.append(System.getProperty("line.separator")); //System.getProperty("line.separator")获取行分隔符（如“/n”）
               write(fileContent.toString(), "D://logs//all_2012-03-28_"+(ge-1)+".txt","UTF-8");//写入分段全量新文件
               if(m==20000){
               m=0;
               file = new File("D://logs//gall_2012-03-28_"+ge+".txt");  //生成分段全量新文件
              
               if(!file.getParentFile().exists()){  
               file.mkdir();  
               }
               ge++;
                fileContent=null;
                fileContent=   new  StringBuffer();
               }
               m++;
            

   
   
      }
    System.out.println("ok"+i);
   
    System.out.println(DateUtil.getStandardTime());
       }
/**
* 以utf-8格式写文件
* @param fileContent
* @param fileName
* @param encoding
*/

public   static   void  write(String fileContent, String fileName, String encoding) {
         try  {
            FileOutputStream fos  =   new  FileOutputStream(fileName);
            OutputStreamWriter osw  =   new  OutputStreamWriter(fos, encoding);
            osw.write(fileContent);
            osw.flush();
        }  catch  (Exception e) {
            e.printStackTrace();
        }
    }
}