[置顶] 数据写入文件的几种方法速度比较

import java.io.File;
import java.io.FileOutputStream;
import java.io.*;
public class FileTest {
public FileTest() {
}
public static void main(String[] args) {
FileOutputStream out = null;
FileOutputStream outSTr = null;
BufferedOutputStream Buff=null;
FileWriter fw = null;
PrintWriter pw = null;
PrintWriter pw1 = null;
int count=100000;//写文件行数
try {
out = new FileOutputStream(new File(“d:/add.txt”));
long begin = System.currentTimeMillis();
for (int i = 0; i < count; i++) {
out.write(“测试java 文件操作\r\n”.getBytes());
}
out.close();
long end = System.currentTimeMillis();
System.out.println(“FileOutputStream执行耗时:” + (end - begin) + ” 豪秒”);
outSTr = new FileOutputStream(new File(“d:/add0.txt”));
Buff=new BufferedOutputStream(outSTr);
long begin0 = System.currentTimeMillis();
for (int i = 0; i < count; i++) {
Buff.write(“测试java 文件操作\r\n”.getBytes());
}
Buff.flush();
Buff.close();
long end0 = System.currentTimeMillis();
System.out.println(“BufferedOutputStream执行耗时:” + (end0 - begin0) + ” 豪秒”);
fw = new FileWriter(“d:/add1.txt”);
long begin3 = System.currentTimeMillis();
for (int i = 0; i < count; i++) {
fw.write(“测试java 文件操作\r\n”);
}
fw.close();
long end3 = System.currentTimeMillis();
System.out.println(“FileWriter执行耗时:” + (end3 - begin3) + ” 豪秒”);
pw = new PrintWriter(“d:/add2.txt”);
long begin4= System.currentTimeMillis();
for (int i = 0; i < count; i++) {
pw.write(“测试java 文件操作\r\n”);
}
pw.close();
long end4 = System.currentTimeMillis();
System.out.println(“PrintWriter执行耗时:” + (end4 - begin4) + ” 豪秒”);
pw1 = new PrintWriter(new FileWriter(“d:/add3.txt”));
long begin5= System.currentTimeMillis();
for (int i = 0; i < count; i++) {
pw1.write(“测试java 文件操作\r\n”);
}
pw1.close();
long end5 = System.currentTimeMillis();
System.out.println(“PrintWriter FileWriter执行耗时:” + (end5 - begin5) + ” 豪秒”);
} catch (Exception e) {
e.printStackTrace();
}
finally {
try {
fw.close();
Buff.close();
outSTr.close();
out.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
}

这是count=100000的结果，字节流是最慢的，缓冲Buffer速度比较稳定，PrintWriter直接加载文件比先用FileWriter加载然后再用PrintWriter输出速度快。

PrintWriter以字符为单位，支持汉字，
OutputStreamWriter以字节为单位，不支持汉字

写文件最佳组合
PrintWriter out = new PrintWriter(
new BufferedWriter(
new FileWriter(filename)));
PrintWriter 提供println()方法可以写不同平台的换行符
BufferedWriter 可以任意设定缓冲大小。提供缓冲，用以加速
FileWriter 用于写文件