考研后的Java温习之I/O

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package test;
import java.io.*;
import java.util.Date;

public class LearnIo {
    // InputStream-- OutputStream-- Reader-- Writer
    public void read1() {
        FileInputStream in = null;
        try {
            in = new FileInputStream("D:\note.txt");

        } catch (FileNotFoundException e) {
            System.out.println("Can't find relevent files!");
            System.exit(-1);
        }

        try {
            long num = 0;
            int b = 0;
            while ((b = in.read()) != -1) {
                System.out.print((char) b);
                num++;
            }
            in.close();
            System.out.println();
            System.out.println("一共读取了" + num + "个字符");

        } catch (IOException ee) {
            System.out.println("file can't read correct!");
            System.exit(-1);
        }

    }// 这样写的话中文出现乱码问题！

    // +++++++++++++++++++++++++++++++++++++++++++++
    public void read2() {

        FileReader fr = null;
        try {
            fr = new FileReader("D:\note.txt");

        } catch (FileNotFoundException e) {
            System.out.println("Can't find relevent files!");
            System.exit(-1);
        }

        try {
            long ln = 0;
            int c = 0;
            while ((c = fr.read()) != -1) {
                System.out.print((char) c);
                ln++;
            }
            fr.close();
            System.out.println();
            System.out.println("一共读取了" + ln + "行");

        } catch (IOException ee) {
            System.out.println("file can't read correct!");
            System.exit(-1);
        }

    }//
    // 下面使用缓冲流 BufferedReader/Writer BufferedInputStream/OutputStream
    public void testbufferStream1() {
        try {
            BufferedInputStream bis = new BufferedInputStream(
                    new FileInputStream("D:\note.txt"));
            int d = 0;
            System.out.println(bis.read());
            System.out.println(bis.read());
            bis.mark(30);// 用的比较少！
            for (int i = 0; i <= 10 && (d = bis.read()) != -1; i++) {
                System.out.print((char) d + " ");
            }
            System.out.println();
            bis.reset();// 用的比较少！
            for (int i = 0; i <= 10 && (d = bis.read()) != -1; i++) {
                System.out.print((char) d + " ");
            }
            bis.close();

        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public void testBufferedStream2() {
        try {
            BufferedReader br = new BufferedReader(new FileReader(
                    "/home/yourname/javacode/note.txt"));// D:\note.txt
            // BufferedWriter bw = new BufferedWriter(new FileWriter(
            // "/home/zsx/javacode/note.txt"));
            String es = null;
            while ((es = br.readLine()) != null) {

                String ess = new String(es.getBytes("utf-8"));
                System.out.println(ess);
                // bw.write(e);
            }
            // 读取txt文件乱码问题解决！
            // notice!IO里面涉及了设计模式，BufferedReader经常使用readLine方法，Input/OutputStream
            // 才有设置字符编码参数的方法，BufferedReader br=new BufferedReader(new
            // InputStreamReader(new
            // FileInputStream("path+"/"+title"),"UTF-8"));

        } catch (IOException ee) {
            ee.printStackTrace();
        }
    }

    // 字节数据和字符数据之间的转换InputStreamReader and InputStream OutputStreamWriter and
    // OutputStream

    public void testTransform1() {
        try {
            OutputStreamWriter osw = new OutputStreamWriter(
                    new FileOutputStream("/home/yourname/javacode/note_1.txt"));
            osw.write("qwertyuiop");
            System.out.println(osw.getEncoding());
            osw.close();
            osw = new OutputStreamWriter(new FileOutputStream(
                    "/home/yourname/javacode/note_1.txt", true));
            osw.write("qwertyuiop学徒学徒学徒");
            osw.flush();
            osw.close();// 流一定要关闭！关闭前一定要flush！
            System.out.println("done!");

        } catch (IOException ex1) {
            ex1.printStackTrace();
        }
    }

    // ctrl+shift+b 设置断点 ，F5是跳进，F6是执行下一步，F7是跳出

    public void testTransform2() {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));// System.in是InputStream
        String s = null;
        try {
            s = br.readLine();
            while (null != s) {
                if (s.equalsIgnoreCase("exit")) {
                    System.out
                            .println("program has exited! don't call it again");
                    break;
                }
                System.out.println(s.toUpperCase());
                s = br.readLine();
            }
            br.close();
        } catch (IOException ex2) {
            ex2.printStackTrace();
        }
    }

    // DataInputStream,DataOutputStream 提供处理与机器无关的java 原始类型数据eg.:int float ...
    public void testDataStream() {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        DataOutputStream dos = new DataOutputStream(baos);
        try {
            dos.writeDouble(Math.random());
            dos.writeBoolean(true);

            DataInputStream dis = new DataInputStream(new ByteArrayInputStream(
                    baos.toByteArray()));
            System.out.println(dis.readDouble());
            System.out.println(dis.readBoolean());
            dos.close();
            dis.close();
        } catch (IOException et) {
            et.printStackTrace();
        }
    }

    // Print流
    public void testPrintStream1() {
        PrintStream ps = null;
        try {
            FileOutputStream fos = new FileOutputStream(
                    "/home/yourname/javacode/testPrintStream1.txt");
            ps = new PrintStream(fos);
        } catch (IOException e) {
            e.printStackTrace();
        }
        if (null != ps) {
            System.out.println(ps);
        }
        int line = 0;
        for (char c = 0; c <= 2000; c++) {
            System.out.println(c + " ");
            if (line++ >= 100) {
                System.out.println();
                line = 0;
            }
        }
    }

    public void testPrintStream2(String f, PrintStream fs) {
        try {
            BufferedReader br = new BufferedReader(new FileReader(f));
            String s = null;
            while ((s = br.readLine()) != null) {
                fs.print(s);
            }
            br.close();
        } catch (IOException exx) {
            fs.println("无法读取文件");
        }
    }

    public void testPrintStream3() {
        String s = null;
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        try {
            FileWriter fw = new FileWriter(
                    "/home/yourname/javacode/testPrintStream.log", true);
            PrintWriter log = new PrintWriter(fw);
            while ((s = br.readLine()) != null) {
                if (s.equalsIgnoreCase("exit"))
                    break;
                System.out.println(s.toUpperCase());
                log.println("-----------");
                log.println(s.toUpperCase());
                log.flush();
            }
            log.println("======" + new Date() + "=====");
            log.flush();
            log.close();

        } catch (IOException exxx) {
            exxx.printStackTrace();
        }
    }

    public void testObjectIo() {
        TestClass ts = new TestClass();
        ts.tall = 8;
        try {
            ObjectOutputStream oos = new ObjectOutputStream(
                    new FileOutputStream("/home/yourname/javacode/testObjectIo.dat"));
            oos.writeObject(ts);
            oos.flush();
            oos.close();
            // ~~~~~~~~~~~~~
            ObjectInputStream ois = new ObjectInputStream(new FileInputStream(
                    "/home/yourname/javacode/testObjectIo.dat"));
            TestClass tts;

            tts = (TestClass) ois.readObject();

            System.out.println(tts.tall + " " + tts.name);

        } catch (IOException e8) {
            System.out.println("处理出现问题!");
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    // 为了便于测试方法:使用成员内部类
    class TestClass {
        int tall;
        String name;
    }

    public static void main(String[] args) {
        LearnIo learnIo = new LearnIo();
        // learnIo.read1();
        // learnIo.read2();
        // learnIo.testbufferStream1();
        // learnIo.testBufferedStream2();
        // learnIo.testTransform1();
        // learnIo.testTransform2();
        // learnIo.testDataStream();
        // learnIo.testPrintStream1();
        // learnIo.testPrintStream2("/home/yourname/javacode/note.txt", System.out);
        // learnIo.testPrintStream3();
        learnIo.testObjectIo();

    }
}