import java.io.*;

public class ck{
public static void main(String[] args){
try{

File read = new File("d:\\jjjj.txt");
File write = new File("d:\\ck.txt");

BufferedReader br = new BufferedReader(
new FileReader(read));
BufferedWriter bw = new BufferedWriter(
new FileWriter(write));
String temp = null;
temp = br.readLine();
while(temp != null){
//写文件
if(temp.indexOf("JGDM") >0){
bw.write(temp + "\r\n"); //只适用Windows系统

}
//继续读文件
temp = br.readLine();
}

bw.close();
br.close();

}catch(FileNotFoundException e){ //文件未找到
System.out.println (e);
}catch(IOException e){
System.out.println (e);
}
}
}