10/31/2011 - Java I/O

对于Java I/O， 虽然JDK提控了大量的API， 但实际当中我们可能用到的并不多。 下面简单说说：
1. FileReader - 按照字符读取
2. FileInputStream - 按照字节读取
3. BufferedReader
4. BufferedInputStream / BufferedOutputStream

FileReader

private static void fileReader(String filePath) throws IOException {
	char[] c = new char[1];
	FileReader fr = new FileReader(filePath);

	while (fr.read(c) != -1) {
		System.out.print(new String(c));
	}

	fr.close();
}

FileInputStream

private static void fileInputStream(String filePath) throws IOException {
	byte[] data = new byte[1];
	FileInputStream fis = new FileInputStream(new File(filePath));
	while (fis.read(data) != -1) {
		System.out.print(new String(data));
	}

	fis.close();
}

BufferedReader

private static void bufferedReader(String filePath) throws IOException {
	FileReader fr = new FileReader(new File(filePath));
	BufferedReader br = new BufferedReader(fr);

	String output = null;
	while ((output = br.readLine()) != null) {
		System.out.println(output);
	}

	br.close();
	fr.close();
}

private static void readConsole() throws IOException {
	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	String output = null;
	while ((output = br.readLine()) != null) {
		System.out.println("Response: " + output);
		if ("exit".equals(output))
			System.exit(0);
	}

	br.close();
}

BufferedInputStream/BufferedOutputStream

byte[] data = new byte[1];

File srcFile = new File(".../Source.java");
File desFile = new File(".../Des.txt");

BufferedInputStream bufferedInputStream = new BufferedInputStream(new FileInputStream(srcFile));
BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(new FileOutputStream(desFile));

while (bufferedInputStream.read(data) != -1) {
	bufferedOutputStream.write(data);
}

bufferedOutputStream.flush();

// Print to TXT file
bufferedInputStream = new BufferedInputStream(new FileInputStream(desFile));

while (bufferedInputStream.read(data) != -1) {
	System.out.print(new String(data));
}

bufferedInputStream.close();
bufferedOutputStream.close();