Comparison of several methods JAVA text input and output streams

测试写入类


 


/**
  * 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
  */


 public static void main(String[] args) {


  String str = "abcdefghiJKLMN！";
  int count = 1000000;
  TestOutputStream t = new TestOutputStream();
  long start = System.currentTimeMillis();
  t.fileWriteTest(count, str);
  long end = System.currentTimeMillis();
  System.out.println("fileWrite's time---------" + (start - end));


  start = System.currentTimeMillis();
  t.outputStreamTest(count, str);
  end = System.currentTimeMillis();
  System.out.println("outputStreamTest's time---------" + (start - end));


  start = System.currentTimeMillis();
  t.bufferedOutputTest(count, str);
  end = System.currentTimeMillis();
  System.out
    .println("bufferedOutputTest's time---------" + (start - end));
  
  start = System.currentTimeMillis();
  t.bufferedWriteTest(count, str);
  end = System.currentTimeMillis();
  System.out.println("bufferedWriteTest's time---------" + (start - end));
  
  start = System.currentTimeMillis();
  t.bufferedWriteAndFileWriterTest(count, str);
  end = System.currentTimeMillis();
  System.out.println("bufferedWrite And FileWriterTest's time---------" + (start - end));
  
  start = System.currentTimeMillis();
  t.bufferedWriteAndBufferedOutputStreamTest(count, str);
  end = System.currentTimeMillis();
  System.out.println("bufferedWrite And BufferedOutputStreamTest's time---------" + (start - end));   * /   * @param str write the string   * @param COUNT write cycles   *    * 1 byte write FileOutputStream  / **
  
  
  
 }
 










 public void outputStreamTest(int count, String str) {
  File f = new File("f:test1.txt");
  OutputStream os = null;
  try {
   os = new FileOutputStream(f);
   for (int i = 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
  * 
  * @param count 写入循环次数
  * @param str 写入字符串
  */
 public void bufferedOutputTest(int count, String str) {
  File f = new File("f:test2.txt");
  BufferedOutputStream bos = null;
  try {
   OutputStream os = new FileOutputStream(f);
   bos = new BufferedOutputStream(os);
   for (int i = 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
  * 
  * @param count 写入循环次数
  * @param str 写入字符串
  */
 public void fileWriteTest(int count, String str) {
  File f = new File("f:test.txt");
  Writer writer = null;
  try {
   writer = new FileWriter(f);
   for (int i = 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
  * 
  * @param count 写入循环次数
  * @param str 写入字符串
  */
 public void bufferedWriteTest(int count, String str) {
  File f = new File("f:test3.txt");
  OutputStreamWriter writer = null;
  BufferedWriter bw = null;
  try {
   OutputStream os = new FileOutputStream(f);
   writer = new OutputStreamWriter(os);
   bw = new BufferedWriter(writer);
   for (int i = 0; i < count; i++) {
    bw.write (STR);
   }
   bw.flush ();
   IF (f.exists ()) {
    f.delete ();
   }
  } the catch (a FileNotFoundException E) {
   e.printStackTrace ();
  } the catch (IOException E) {
   e.printStackTrace ();
  } {the finally
   the try {
    bw.close ();
   } the catch (IOException E) {
    e.printStackTrace ();
   }
  }
 }
 
 / **
  * written in the character buffer. 5 and BufferedOutputStream The BufferedWriter,
  * 
  * @param count the number of write cycles
  * @param str write the string
  * /
 public void bufferedWriteAndBufferedOutputStreamTest(int count, String str) {
  File f = new File("f:test4.txt");
  BufferedOutputStream bos=null;
  OutputStreamWriter writer = null;
  BufferedWriter bw = null;
  try {
   OutputStream os = new FileOutputStream(f);
   bos=new BufferedOutputStream(os);
   writer = new OutputStreamWriter(bos);
   bw = new BufferedWriter(writer);
   for (int i = 0; i < count; i++) {
    bw.write(str);
   }
   bw.flush();
   if(f.exists()){
    f.delete();
    System.out.println("delete---");
   }
  } catch (FileNotFoundException e) {
   e.printStackTrace ();
  } the catch (IOException E) {
   e.printStackTrace ();
  } {the finally
   the try {
    bw.close ();
   } the catch (IOException E) {
    e.printStackTrace ();
   }
  }
 }
 
 / **
  * 6 is written by character buffer and FileWriter BufferedWriter,
  * 
  * @param COUNT write cycles
  * @param str write the string
  * /
 public void bufferedWriteAndFileWriterTest (int COUNT, string STR) {
  File File new new F = ( "F: Test5. TXT ");
  FileWriter FW = null;
  BufferedWriter, BW = null;
  the try {
   FW = new new FileWriter (F); 
   bw = new BufferedWriter(fw);
   for (int i = 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();
   }
  }
 }


 


总结：


If classified by character bytes and, in addition to 1 and 2, the rest are written to the file by character, the character is typically faster than the write byte; see java API understood, that the OutputStreamWriter FileWriter parent class, they are both implemented Writer class, from this point on, the method is almost no difference between 4 and 6, there is a slight time difference, but the internal mechanism is the same, but the method is relatively simple 6, the definition of variables a little, I used to use method 4, it seems that after too under the change.