Java IO实战操作(三)

/** * IO管道处理集合 */ public void OutFile() throws FileNotFoundException { /** * 使用PrintStream进行输出 */ PrintStream print = new PrintStream(new FileOutputStream(new File("d:" + File.separator + "hello.txt"))); print.println(true); print.println("Rollen"); print.close(); /** *****格式化输出******** */ String name = "Rollen"; int age = 20; print.printf("姓名：%s. 年龄：%d.", name, age); print.close(); /** * 使用OutputStream向屏幕上输出内容 * */ OutputStream out = System.out; try { out.write("hello".getBytes()); } catch (Exception e) { e.printStackTrace(); } try { out.close(); } catch (Exception e) { e.printStackTrace(); } /** * 为System.out.println()重定向输出 * */ // 此刻直接输出到屏幕 System.out.println("hello"); File file = new File("d:" + File.separator + "hello.txt"); try { System.setOut(new PrintStream(new FileOutputStream(file))); } catch (FileNotFoundException e) { e.printStackTrace(); } System.out.println("这些内容在文件中才能看到哦！"); /** * System.err重定向 这个例子也提示我们可以使用这种方法保存错误信息 * */ System.err.println("这些在控制台输出"); try { System.setErr(new PrintStream(new FileOutputStream(file))); } catch (FileNotFoundException e) { e.printStackTrace(); } System.err.println("这些在文件中才能看到哦！"); /** * System.in重定向 前提是文件中提前要有值* */ if (!file.exists()) { return; } else { try { System.setIn(new FileInputStream(file)); } catch (FileNotFoundException e) { e.printStackTrace(); } byte[] bytes = new byte[1024]; int len = 0; try { len = System.in.read(bytes); } catch (IOException e) { e.printStackTrace(); } System.out.println("读入的内容为：" + new String(bytes, 0, len)); } /** * 使用缓冲区从键盘上读入内容 * */ BufferedReader buf = new BufferedReader( new InputStreamReader(System.in)); String str = null; System.out.println("请输入内容"); try { str = buf.readLine(); } catch (IOException e) { e.printStackTrace(); } System.out.println("你输入的内容是：" + str); } /** * 消息发送类 */ class Send implements Runnable { private PipedOutputStream out = null; public Send() { out = new PipedOutputStream(); } public PipedOutputStream getOut() { return this.out; } public void run() { String message = "hello , Rollen"; try { out.write(message.getBytes()); } catch (Exception e) { e.printStackTrace(); } try { out.close(); } catch (Exception e) { e.printStackTrace(); } } } /** * 接受消息类 * */ class Recive implements Runnable { private PipedInputStream input = null; public Recive() { this.input = new PipedInputStream(); } public PipedInputStream getInput() { return this.input; } public void run() { byte[] b = new byte[1000]; int len = 0; try { len = this.input.read(b); } catch (Exception e) { e.printStackTrace(); } try { input.close(); } catch (Exception e) { e.printStackTrace(); } System.out.println("接受的内容为 " + (new String(b, 0, len))); } /** Scanner读取数据 */ public void OutFile() { File file = new File("d:" + File.separator + "hello.txt"); Scanner sca = null; try { sca = new Scanner(file); } catch (FileNotFoundException e) { e.printStackTrace(); } String str = sca.next(); System.out.println("从文件中读取的内容是：" + str); } /** * 数据操作流DataOutputStream、DataInputStream类 * @throws IOException */ public void DataOutFile() throws IOException { File file = new File("d:" + File.separator + "hello.txt"); char[] ch = { 'A', 'B', 'C' }; DataOutputStream out = null; out = new DataOutputStream(new FileOutputStream(file)); for (char temp : ch) { out.writeChar(temp); } out.close(); } /** * DataInputStream读取数据 * @throws IOException */ public void DataInputStreamFile() throws IOException { File file = new File("d:" + File.separator + "hello.txt"); DataInputStream input = new DataInputStream(new FileInputStream(file)); char[] ch = new char[10]; int count = 0; char temp; while ((temp = input.readChar()) != 'C') { ch[count++] = temp; } System.out.println(ch); } /** * 合并流 SequenceInputStream合并文件 合并hello1/hello2到hello中 * @throws IOException */ public void SequenceInputStreamFile() throws IOException { File file1 = new File("d:" + File.separator + "hello1.txt"); File file2 = new File("d:" + File.separator + "hello2.txt"); File file3 = new File("d:" + File.separator + "hello.txt"); InputStream input1 = new FileInputStream(file1); InputStream input2 = new FileInputStream(file2); OutputStream output = new FileOutputStream(file3); // 合并流 SequenceInputStream sis = new SequenceInputStream(input1, input2); int temp = 0; while ((temp = sis.read()) != -1) { output.write(temp); } input1.close(); input2.close(); output.close(); sis.close(); }