java写文件方法之比较

    import java.io.BufferedOutputStream;         import java.io.File;         import java.io.FileOutputStream;         import java.io.FileWriter;         import java.nio.ByteBuffer;         import java.nio.channels.FileChannel;                 /**         * 测试各种写文件的方法性能。         *          *          */        public class T {                   public static void main(String[] args) {             FileOutputStream out = null;             FileOutputStream outSTr = null;             BufferedOutputStream Buff = null;             FileWriter fw = null;             int count = 1000000;// 写文件行数             try {               byte[] bs = "测试java 文件操作/r/n".getBytes();               out = new FileOutputStream(new File("C:/add.txt"));               long begin = System.currentTimeMillis();               for (int i = 0; i < count; i++) {                 out.write(bs);               }               out.close();               long end = System.currentTimeMillis();               System.out.println("FileOutputStream执行耗时:" + (end - begin) + " 豪秒");                       outSTr = new FileOutputStream(new File("C:/add0.txt"));               Buff = new BufferedOutputStream(outSTr);               long begin0 = System.currentTimeMillis();               for (int i = 0; i < count; i++) {                 Buff.write(bs);               }               Buff.flush();               Buff.close();               long end0 = System.currentTimeMillis();               System.out.println("BufferedOutputStream执行耗时:" + (end0 - begin0) + " 豪秒");                       fw = new FileWriter("C:/add2.txt");               long begin3 = System.currentTimeMillis();               for (int i = 0; i < count; i++) {                 fw.write("测试java 文件操作/r/n");               }               fw.flush();               fw.close();               long end3 = System.currentTimeMillis();               System.out.println("FileWriter执行耗时:" + (end3 - begin3) + " 豪秒");                       long begin4 = System.currentTimeMillis();               String path = "C:/add3.txt";               ByteBuffer bb = ByteBuffer.wrap(bs);               FileChannel out2 = new FileOutputStream(path).getChannel();               for (int i = 0; i < count; i++) {                 out2.write(bb);                 bb.rewind();               }                       out2.close();               long end4 = System.currentTimeMillis();               System.out.println("FileChannel执行耗时:" + (end4 - begin4) + " 豪秒");             } catch (Exception e) {               e.printStackTrace();             } finally {               try {                 fw.close();                 Buff.close();                 outSTr.close();                 out.close();               } catch (Exception e) {                 e.printStackTrace();               }             }           }         }  

FileOutputStream执行耗时:4891 豪秒

BufferedOutputStream执行耗时:78 豪秒

FileWriter执行耗时:438 豪秒

FileChannel执行耗时:2812 豪秒

当然最终生成的文件都是正确的

总结：

BufferedOutputStream 由于有缓冲，性能明显好

FileOutputStream 性能最差，因为其每次都写入字节。

FileWriter 性能很一般

FileChannel使用了nio,但如果没有缓冲，必能太指望性能了