import java.io.BufferedReader;
import java.io.FileReader;


public class ReadCSV {

    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new   FileReader("c:/2009.csv"));
        String line ;
        while((line = br.readLine())!=null){
            System.out.println(line.split(",")[0]);
        }
        br.close();
    }

}

------解决方案--------------------
改成line.split(",.*")[0] 效率更高点