使用java applet编写文件

Question

public class filewrite {



public static void main(String ar[]){
  try{
     BufferedReader br=new BufferedReader(new FileReader(new File("database.txt")));
     BufferedWriter br2=new BufferedWriter(new FileWriter(new File("database1.txt")));

     String st;
     while((st=br.readLine())!=null){

       br2.write(st+"\n");
      }
    }
   catch(IOException e){}        
   }
  } 

没有错误或警告，但它仍然无法从＆＃34; database.txt＆＃34;复制数据。 to＆＃34; database1.txt＆＃34;

请帮忙。 提前致谢

Answer 1

您需要告诉它允许特权操作。使用AccessController。试试这个：

public void start() {
    AccessController.doPrivileged(new PrivilegedAction<Object>(){
        @Override
        public Object run() {
            try{
              BufferedReader br=new BufferedReader(new FileReader(new File("database.txt")));
              BufferedWriter br2=new BufferedWriter(new FileWriter(new File("database1.txt")));

              String st;
              while((st=br.readLine())!=null){
                String []str=st.split(";");
                br2.write(st+"\n");
              }
            }
            catch(IOException e){}        
                //catch your exceptions
            }
        }               
    });
}