package org.cholwich.binvstxt;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.EOFException;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
public class BinVsTxt {
public void writeTextFile(String fname, int N) {
try {
Random r = new Random();
r.setSeed(10241024);
PrintWriter out = new PrintWriter(new FileWriter(fname));
for(int i=0; i<N; i++) {
out.println(r.nextDouble());
}
out.close();
} catch (IOException e) {
e.printStackTrace();
}
}
public void writeBinaryFile(String fname, int N) {
try {
Random r = new Random();
r.setSeed(10241024);
DataOutputStream out = new DataOutputStream(
new BufferedOutputStream(
new FileOutputStream(fname)));
for(int i=0; i<N; i++) {
out.writeDouble(r.nextDouble());
}
out.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public List<Double> readTextFile(String fname) {
List<Double> l = new ArrayList<Double>();
try {
BufferedReader in = new BufferedReader(
new FileReader(fname));
double d;
String buf;
while((buf = in.readLine()) != null) {
d = Double.parseDouble(buf);
l.add(d);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (NumberFormatException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return l;
}
public List<Double> readBinaryFile(String fname) {
List<Double> l = new ArrayList<Double>();
DataInputStream in = null;
try {
in = new DataInputStream(
new BufferedInputStream(
new FileInputStream(fname)));
double d;
while(true) {
d = in.readDouble();
l.add(d);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (EOFException e) {
try {
in.close();
} catch (IOException e1) {
e1.printStackTrace();
}
} catch (IOException e) {
e.printStackTrace();
}
return l;
}
public static void main(String[] args) {
boolean read = true;
boolean bin = true;
final int N = 10000000;
for(String s : args) {
if (s.equals("write")) {
read = false;
}
else if (s.equals("text")) {
bin = false;
}
}
BinVsTxt m = new BinVsTxt();
long start = System.currentTimeMillis();
if (read) {
if (bin) {
List<Double> l = m.readBinaryFile("out"+N+".dat");
System.out.println(l.get(N-1));
}
else {
List<Double> l = m.readTextFile("out"+N+".txt");
System.out.println(l.get(N-1));
}
}
else {
if (bin) {
m.writeBinaryFile("out"+N+".dat", N);
}
else {
m.writeTextFile("out"+N+".txt", N);
}
}
long stop = System.currentTimeMillis();
long len = stop - start;
System.out.println("Required time = " + len);
}
}
เมื่อลองรันทั้งสี่แบบดูแล้ว ปรากฎว่าความเร็วที่ได้คือ
- เขียน text file ใช้เวลา 6.109 วินาที
- อ่าน text file ใช้เวลา 11.666 วินาที
- เขียน binary file ใช้เวลา 0.583 วินาที
- อ่าน binary file ใช้เวลา 3.698 วินาที
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