import java.io.*; public class BigDataTest { public static void main(String[] args) throws IOException { File sourceFile = new File("train.dat"); FileWriter fileWriter = new FileWriter(sourceFile, true); PrintWriter pw = new PrintWriter(fileWriter); for (int i = 2; i <= 7000000; ++i) { if (i == 2) pw.print("\n"); pw.println("3 qid:" + i + " 1:1 2:1 3:0 4:0.2 5:0"); for (int j = 1; j <= 9; ++j) { pw.println("1 qid:" + i + " 1:2 2:3 3:1 4:0.1 5:1"); } } pw.flush(); fileWriter.flush(); pw.close(); fileWriter.close(); } }