摘要：包幾乎包含了所有操作輸入輸出需要的類。所有這些流類代表了輸入源和輸出目標(biāo)。輸入流表示從一個源讀取數(shù)據(jù)，輸出流表示向一個目標(biāo)寫數(shù)據(jù)。但本節(jié)講述最基本的和流與相關(guān)的功能。讀取控制臺輸入的控制臺輸入由完成。有多種構(gòu)造方法可用來創(chuàng)建對象。

package com.learn;

import org.omg.CORBA.PUBLIC_MEMBER;

import java.io.*;


/**
 * Created by fiz on 7/10/17.
 * 

 * Java.io 包幾乎包含了所有操作輸入、輸出需要的類。所有這些流類代表了輸入源和輸出目標(biāo)。
 * Java.io 包中的流支持很多種格式，比如：基本類型、對象、本地化字符集等等。
 * 一個流可以理解為一個數(shù)據(jù)的序列。輸入流表示從一個源讀取數(shù)據(jù)，輸出流表示向一個目標(biāo)寫數(shù)據(jù)。
 * Java 為 I/O 提供了強大的而靈活的支持，使其更廣泛地應(yīng)用到文件傳輸和網(wǎng)絡(luò)編程中。
 * 但本節(jié)講述最基本的和流與 I/O 相關(guān)的功能。我們將通過一個個例子來學(xué)習(xí)這些功能。
 * 

 * 

 * 

 * 讀取控制臺輸入:
 * 

 * Java 的控制臺輸入由 System.in 完成。
 * 為了獲得一個綁定到控制臺的字符流，你可以把 System.in 包裝在一個 BufferedReader 對象中來創(chuàng)建一個字符流。
 * 下面是創(chuàng)建 BufferedReader 的基本語法：
 */


public class FileStreamTest {


    public static void readDir(String dir) {
        /**
         *   讀取指定目錄下的文件夾，并只返回文件，
         */
        File file = new File(dir);
        if (file.isDirectory()) {
            System.out.println("這個是個文件夾");
        } else {
            System.out.println();
        }

    }

    public static void main(String[] args) throws IOException {

        BufferedReader bufferedReader = new BufferedReader(new
                InputStreamReader(System.in));

        System.out.println("請輸入你的要輸入的內(nèi)容");
        String input = bufferedReader.readLine();
        System.out.println(input);


        /**
         * FileInputStream
         *該流用于從文件讀取數(shù)據(jù)，它的對象可以用關(guān)鍵字 new 來創(chuàng)建。
         *有多種構(gòu)造方法可用來創(chuàng)建對象。
         *可以使用字符串類型的文件名來創(chuàng)建一個輸入流對象來讀取文件
         */
        InputStream inputStream = new FileInputStream("/Users/fiz/Documents/JavaProject/JavaProject.iml");
        byte[] buffer = new byte[1000];
        while (inputStream.read(buffer) > 0) {
            System.out.println(inputStream.read(buffer));
        }


        /**
         *  輸出文件
         */


        File f = new File("/Users/fiz/Documents/JavaProject/demo.txt");
        FileOutputStream fop = new FileOutputStream(f);
        // 構(gòu)建FileOutputStream對象,文件不存在會自動新建
        OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fop);
        outputStreamWriter.write("demo");
        outputStreamWriter.close();


        /**
         * PipedOutputStream/PipedInputStream
         * 不能用于同一個線程中，主要是要去不同線程獲取
         */

        final PipedOutputStream pipedOutputStream = new PipedOutputStream();
        final PipedInputStream pipedInputStream = new PipedInputStream(pipedOutputStream);


        Thread thread1 = new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    pipedOutputStream.write("Hello world, pipe!".getBytes());
                } catch (IOException e) {
                }
            }
        });

        Thread thread2 = new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    int data = pipedInputStream.read();
                    while (data != -1) {
                        System.out.print((char) data);
                        data = pipedInputStream.read();
                    }

                } catch (IOException e) {

                }
            }
        });
        thread1.start();
        thread2.start();


        /**
         * InputStream
         */
        InputStream inputStream1 = new FileInputStream("/Users/fiz/Documents/JavaProject/JavaProject.iml");
        byte[] bytesRead = new byte[1024];
        int data = inputStream1.read(bytesRead);
        while (data != -1) {
            //do something with data...
            System.out.println((char) data);
            data = inputStream1.read();
        }
        inputStream1.close();


        /**
         * FileOutputStream
         */
        File file = new File("demo.txt");
        FileOutputStream fileOutputStream = new FileOutputStream(file);
        int num = 10;
        while (num > 0) {
            fileOutputStream.write("deno+
".getBytes());
            num = num - 1;
        }
        fileOutputStream.close();


        /**
         *FileInputStream 讀取文件
         */


        FileInputStream fileInputStream = new FileInputStream(file);
        int read = fileInputStream.read();
        while (read != -1) {

            System.out.println((char) fileInputStream.read());
            read = fileInputStream.read();
        }


        /**
         * inputStreamReader
         */


        InputStream inputStream2 = new FileInputStream("demo.txt");
        Reader inputStreamReader = new InputStreamReader(inputStream2);

        int data2 = inputStreamReader.read();
        while (data2 != -1) {
            char theChar = (char) data2;
            System.out.println("inputStreamReader");
            System.out.println(theChar);
            data2 = inputStreamReader.read();
        }


        /**
         *
         */
        OutputStream outputStream = new FileOutputStream("demo.txt");
        Writer outputStreamWriter1 = new OutputStreamWriter(outputStream);

        outputStreamWriter1.write("Hello World");

        outputStreamWriter1.close();


        /**
         * FileWriter
         */

        FileWriter fileWriter = new FileWriter(file);
        fileWriter.write("This
 is
 an
 example
");
        fileWriter.flush();// 刷掉緩沖區(qū)的內(nèi)容
        fileWriter.close();


        /**
         * FileReader
         */
        FileReader fileReader = new FileReader(file);
        int fileReader_data = fileReader.read();
        while (fileReader_data != -1) {
            fileReader_data = fileReader.read();
            System.out.println((char) fileReader_data);
        }


        /**
         *BufferedReader
         */

        BufferedReader bufferedReader1 = new BufferedReader(new FileReader(file));
        String line = bufferedReader1.readLine();
        System.out.println("BufferedReader" + line);
        bufferedReader1.close();

        // 循環(huán)讀取
//        while (line != null) {
//            // process line
//        }


        /**
         *BufferedWriter
         */
        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter("demo.txt", true));
        bufferedWriter.write("this is a demo process");
        int count = 10;
        while (count > 0) {
            bufferedWriter.write("this is a demo process
");
            count = count - 1;
        }
        bufferedWriter.close();

        File file1 = new File("test.txt");
        FileWriter fw = new FileWriter(file1);
        BufferedWriter bw = new BufferedWriter(fw);
        bw.write("demo");
        System.out.println("File written Successfully");


        /**
         *FilterWriter  虛擬類
         */


        /**
         *
         */
        LineNumberReader lineNumberReader = new LineNumberReader(new FileReader(file1));
        String line1 = lineNumberReader.readLine();
        while (line != null) {


            line = lineNumberReader.readLine();
            System.out.println(line + lineNumberReader.getLineNumber());
        }

    }


}

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