public class IOTest {
public static void main(String[] args) throws IOException {
dataReady();
File data = new File("C:/Mu/data.txt");
File a = new File("C:/Mu/a.txt");
File b = new File("C:/Mu/b.txt");
File c = new File("C:/Mu/c.txt");
long start = System.currentTimeMillis();
copy(data, a);
long end = System.currentTimeMillis();
long start2 = System.currentTimeMillis();
copyChars(data, b);
long end2 = System.currentTimeMillis();
long start3 = System.currentTimeMillis();
bufferedCopy(data, c);
long end3 = System.currentTimeMillis();
System.out.println("普通字节流1耗时：" + (end - start) + " ms,文件大小：" + a.length() / 1024 + " kb");
System.out.println("普通字节流2耗时：" + (end2 - start2) + " ms,文件大小：" + b.length() / 1024 + " kb");
System.out.println("缓冲字节流耗时：" + (end3 - start3) + " ms,文件大小：" + c.length() / 1024 + " kb");
}
public static void copy(File in, File out) throws IOException {
Reader reader = new FileReader(in);
Writer writer = new FileWriter(out);
int ch = 0;
while ((ch = reader.read()) != -1) {
writer.write((char) ch);
}
reader.close();
writer.close();
}
public static void copyChars(File in, File out) throws IOException {
Reader reader = new FileReader(in);
Writer writer = new FileWriter(out);
char[] chs = new char[1024];
while ((reader.read(chs)) != -1) {
writer.write(chs);
}
reader.close();
writer.close();
}
public static void bufferedCopy(File in, File out) throws IOException {
BufferedReader br = new BufferedReader(new FileReader(in));
BufferedWriter bw = new BufferedWriter(new FileWriter(out));
String line = null;
while ((line = br.readLine()) != null) {
bw.write(line);
bw.newLine();
bw.flush();
}
bw.close();
br.close();
}
public static void dataReady() throws IOException {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < 600000; i++) {
sb.append("abcdefghijklmnopqrstuvwxyz");
}
OutputStream os = new FileOutputStream(new File("C:/Mu/data.txt"));
os.write(sb.toString().getBytes());
os.close();
System.out.println("完毕");
}
}
