各类写入方法
/***1 按字节写入 FileOutputStream
*
*@paramcount 写入循环次数
*@paramstr 写入字符串*/publicvoidoutputStreamTest(intcount, String str) {
File f=newFile("f:test1.txt");
OutputStream os=null;try{
os=newFileOutputStream(f);for(inti = 0; i < count; i++) {
os.write(str.getBytes());
}
os.flush();
System.out.PRintln("file's long:" +f.length());
}catch(FileNotFoundException e) {
e.printStackTrace();
}catch(IOException e) {
e.printStackTrace();
}finally{try{
os.close();
}catch(IOException e) {
e.printStackTrace();
}
}
}/***2 按字节缓冲写入 BufferedOutputStream
*
*@paramcount 写入循环次数
*@paramstr 写入字符串*/publicvoidbufferedOutputTest(intcount, String str) {
File f=newFile("f:test2.txt");
BufferedOutputStream bos=null;try{
OutputStream os=newFileOutputStream(f);
bos=newBufferedOutputStream(os);for(inti = 0; i < count; i++) {
bos.write(str.getBytes());
}
bos.flush();
}catch(FileNotFoundException e) {
e.printStackTrace();
}catch(IOException e) {
e.printStackTrace();
}finally{try{
bos.close();
}catch(IOException e) {
e.printStackTrace();
}
}
}/***3 按字符写入 FileWriter
*
*@paramcount 写入循环次数
*@paramstr 写入字符串*/publicvoidfileWriteTest(intcount, String str) {
File f=newFile("f:test.txt");
Writer writer=null;try{
writer=newFileWriter(f);for(inti = 0; i < count; i++) {
writer.write(str);
}
writer.flush();
}catch(IOException e) {
e.printStackTrace();
}finally{try{
writer.close();
}catch(Exception e) {
e.printStackTrace();
}
}
}/***4 按字符缓冲写入 BufferedWriter
*
*@paramcount 写入循环次数
*@paramstr 写入字符串*/publicvoidbufferedWriteTest(intcount, String str) {
File f=newFile("f:test3.txt");
OutputStreamWriter writer=null;
BufferedWriter bw=null;try{
OutputStream os=newFileOutputStream(f);
writer=newOutputStreamWriter(os);
bw=newBufferedWriter(writer);for(inti = 0; i < count; i++) {
bw.write(str);
}
bw.flush();if(f.exists()){
f.delete();
}
}catch(FileNotFoundException e) {
e.printStackTrace();
}catch(IOException e) {
e.printStackTrace();
}finally{try{
bw.close();
}catch(IOException e) {
e.printStackTrace();
}
}
}/***5 按字符缓冲写入 BufferedWriter and BufferedOutputStream
*
*@paramcount 写入循环次数
*@paramstr 写入字符串*/publicvoidbufferedWriteAndBufferedOutputStreamTest(intcount, String str) {
File f=newFile("f:test4.txt");
BufferedOutputStream bos=null;
OutputStreamWriter writer=null;
BufferedWriter bw=null;try{
OutputStream os=newFileOutputStream(f);
bos=newBufferedOutputStream(os);
writer=newOutputStreamWriter(bos);
bw=newBufferedWriter(writer);for(inti = 0; i < count; i++) {
bw.write(str);
}
bw.flush();if(f.exists()){
f.delete();
System.out.println("delete---");
}
}catch(FileNotFoundException e) {
e.printStackTrace();
}catch(IOException e) {
e.printStackTrace();
}finally{try{
bw.close();
}catch(IOException e) {
e.printStackTrace();
}
}
}/***6 按字符缓冲写入 BufferedWriter and FileWriter
*
*@paramcount 写入循环次数
*@paramstr 写入字符串*/publicvoidbufferedWriteAndFileWriterTest(intcount, String str) {
File f=newFile("f:test5.txt");
FileWriter fw=null;
BufferedWriter bw=null;try{
fw=newFileWriter(f);
bw=newBufferedWriter(fw);for(inti = 0; i < count; i++) {
bw.write(str);
}
bw.flush();
}catch(FileNotFoundException e) {
e.printStackTrace();
}catch(IOException e) {
e.printStackTrace();
}finally{try{
bw.close();if(f.exists()){
f.delete();
}
}catch(IOException e) {
e.printStackTrace();
}
}
}
测试写入类
publicstaticvoidmain(String[] args) {
String str= "abcdefghiJKLMN！";intcount = 1000000;
TestOutputStream t=newTestOutputStream();//1.fileWrite's timelongstart =System.currentTimeMillis();
t.fileWriteTest(count, str);longend =System.currentTimeMillis();
System.out.println("fileWrite's time---------" + (start -end));//2.outputStreamTest's timestart =System.currentTimeMillis();
t.outputStreamTest(count, str);
end=System.currentTimeMillis();
System.out.println("outputStreamTest's time---------" + (start -end));//3.bufferedOutputTest's timestart =System.currentTimeMillis();
t.bufferedOutputTest(count, str);
end=System.currentTimeMillis();
System.out.println("bufferedOutputTest's time---------" + (start -end));//4.bufferedWriteTest's timestart =System.currentTimeMillis();
t.bufferedWriteTest(count, str);
end=System.currentTimeMillis();
System.out.println("bufferedWriteTest's time---------" + (start -end));//5.bufferedWrite And FileWriterTest's timestart =System.currentTimeMillis();
t.bufferedWriteAndFileWriterTest(count, str);
end=System.currentTimeMillis();
System.out.println("bufferedWrite And FileWriterTest's time---------" + (start -end));//6.bufferedWrite And BufferedOutputStreamTest's timestart =System.currentTimeMillis();
t.bufferedWriteAndBufferedOutputStreamTest(count, str);
end=System.currentTimeMillis();
System.out.println("bufferedWrite And BufferedOutputStreamTest's time---------" + (start -end));
}
测试结果
/*** 测试结果
*
* 1.file's long:16kb
*
fileWrite's time----------36
outputStreamTest's time----------167
bufferedOutputTest's time----------17
bufferedWriteTest's time----------14
bufferedWrite And FileWriterTest's time----------9
bufferedWrite And BufferedOutputStreamTest's time----------12
*
* 2.file's long:1600kb
*
fileWrite's time----------69
outputStreamTest's time----------1282
bufferedOutputTest's time----------68
bufferedWriteTest's time----------40
bufferedWrite And FileWriterTest's time----------52
bufferedWrite And BufferedOutputStreamTest's time----------37
*
* 3.file's long:16000kb
*
fileWrite's time----------555
outputStreamTest's time----------12448
bufferedOutputTest's time----------599
bufferedWriteTest's time----------346
bufferedWrite And FileWriterTest's time----------316
bufferedWrite And BufferedOutputStreamTest's time----------358
*
*4.file's long:160000kb
*
fileWrite's time----------5203
outputStreamTest's time----------127182
bufferedOutputTest's time----------5972
bufferedWriteTest's time----------3445 最优
bufferedWrite And FileWriterTest's time----------5904
bufferedWrite And BufferedOutputStreamTest's time----------5353
*
*5.file's long:1600000kb
*
fileWrite's time----------50416
outputStreamTest's time----------1303242
bufferedOutputTest's time----------60931
bufferedWriteTest's time----------46697
bufferedWrite And FileWriterTest's time----------48710
bufferedWrite And BufferedOutputStreamTest's time----------64354*/
总结：
如果按字符和字节来分类，除方法1和2，其余都是按字符写入文件，字符写入一般比字节快；看javaAPI可知，FileWriter的父类就是OutputStreamWriter，他俩都是实现Writer类，从这点上来说，方法4和6几乎没区别，时间有些微的差别，但内部机制是一样的。