java写入大量数据

package performanceproblem; import java.io.*; public class PerformanceProblem { { public static void main(String[] args) throws Exception { StringBuffer sb = new StringBuffer(); BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter("./performace.txt")); long start = System.currentTimeMillis() ; for(int i = 0; i < 100; ++i) { for(int j = 0; j < 1024; ++j) { for(int k = 0; k < 1024; ++k) { sb.append("a"); } sb.append("\n"); } bufferedWriter.write(sb.toString()); // 积累1M数据，才写一次 sb = sb.delete(0, sb.length()); } bufferedWriter.flush(); bufferedWriter.close(); long end = System.currentTimeMillis() ; System.out.println((end - start) + "ms elapsed."); } }