摘要：字節(jié)流和字符流和和兩個抽象類是所有輸入流的基類本身并不能創(chuàng)建實例來執(zhí)行輸入但它們將成為所有輸入流的模板他們的方法是所有輸入流都可用的方法中包含如下三個方法從輸入流中讀取單個字節(jié)返回所讀取的字節(jié)數(shù)據(jù)字節(jié)數(shù)據(jù)可直接轉(zhuǎn)換為類型從輸入流中讀取最多個

InputStream和Reader兩個抽象類是所有輸入流的基類,本身并不能創(chuàng)建實例來執(zhí)行輸入,但它們將成為所有輸入流的模板.他們的方法是所有輸入流都可用的方法.

int read() 從輸入流中讀取單個字節(jié),返回所讀取的字節(jié)數(shù)據(jù)(字節(jié)數(shù)據(jù)可直接轉(zhuǎn) 換為int類型).

int read(byte[] b) 從輸入流中讀取最多b.lenght個字節(jié)數(shù)據(jù),并將其存貯在數(shù)組b中,返回實際讀取的字節(jié)數(shù).

int read(byte[] b,int off,int len) 從輸入流中讀取最多的len個字符的數(shù)據(jù),并存在數(shù)組b中,放入數(shù)組b中時,從off的位置開始,返回實際讀取的字節(jié)數(shù).

int read() 從輸入流中讀取單個字符,返回所讀取的字符數(shù)據(jù)(字符數(shù)可以直接轉(zhuǎn)換為int類型)

int read(char[] cbuf) 從輸入流中讀取最多的cbuf.length個字符數(shù)據(jù),并將其存儲在字符數(shù)組cbuf中,返回實際讀取的字符數(shù).

int read(char cbuf,int off,int len) 從輸入流中讀取最多l(xiāng)en個字符的數(shù)據(jù),并將其存在cbuf中,從off位置開始,返回實際的讀取的字符數(shù).

使用FileInputStream讀取自身

javapublic void readFile() throws IOException {
    //創(chuàng)建字節(jié)輸入流
    FileInputStream fis = new FileInputStram("FileInputTest.java");
    //創(chuàng)建一個長度為1024的緩沖數(shù)組
    byte[] bbuf = new byte[1024];
    //保存實際讀取的字節(jié)數(shù)
    int hasRead = 0;
    //循環(huán)讀取文件內(nèi)容
    while ((hasRead = fis.read(bbuf)) > 0) {
       System.out.println(new String(bbuf,0,hasRead));
    }
    //文件IO資源不屬于內(nèi)存資源
    //垃圾回收無法回收該資源
    //必須顯式關(guān)閉
    fis.close();
}

public void readFile() throws IOException {
    FileReader fr = new FileReader("FileReaderTest.java");
    char[] cbuf = new char[32];
    int hasRead = 0;
    while ((hasRead = fr.read(cbuf)) > 0) {
        System.out.println(new String(cbuf,0,hasRead));
    }
    fr.clse();
}

javapublic void copyFile() throws IOException {
    FileInputStream fis = null;
    FileOutputStream fos = null;

    try {
        fis = new FileInputStream("outfile.txt");
        fos = new FileOutputStream("newfile.txt");

        byte[] bbuf = new byte[32];
        int hasRead = 0;
        while ((hasRead =fis.read(bbuf)) > 0) {
            fos.write(bbuf,0,hasRead);
        }
    } catch(IOException ioe) {
        ioe.printStatckTrance();
    } finally {
        if (fis != null) {
            fis.close();
        }
        if(fos != null) {
            fos.close();
        }
    }
}

javapublic void out() {
    FileWriter fw = null;
    try {
        fw = new FileWrite("file.txt");
        fw.write("但我不能放歌，
");
        fw.write("悄悄是別離的笙簫；
");
        fw.write("夏蟲也為我沉默，
");
        fw.write("沉默是今晚的康橋！
");
    } catch (IOException ioe) {

    } finally {
        if(null != fw) {
            fw.close();
        }
    }
}

javapublic void StringNodeTest() {

    String src = "軟泥上的青荇，
"
                +"油油的在水底招搖;
"
                +"在康河的柔波里，
"
                +"我甘心做一條水草。";

    StringReader sr = new StringReader(src);
    char[] cbuf = new char[32];
    int hasRead = 0;
    try {
        while((hasRead =sr.read(cbuf)) > 0) {
            System.out.println(new String(cbuf,0,hasRead));
        }
    } catch (IOException ioe) {
        ioe.
    } finally {
        if (null != sr){
            sr.close();
        }
    }
}

javapublic void convInput() {
    BufferedReader br = null;

    try {
        //System.in轉(zhuǎn)換成Reader對象
        InputStreamReader reader = new InputStreamReader(System.in);
        //將Reader包裝成BufferedReader
        br = new BufferedReader(reader);
        String buffer = null;
        While((buffer = br.readLine()) != null) {
            if("exit".equals(buffer)) {
                System.exit(1);
            }
            System.out.println("輸入內(nèi)容為:" + buffer);
        }
    } catach (IOException ioe) {

    } finally {
        try {
            if (null != br) {
                br.close();
            }
        } catach (IOException ioe) {

        }
    }
}

java/**省略無數(shù)代碼**/

PushbackReader pr = null;

        try {
            pr = new PushbackReader(new FileReader("E:workplace1
eviewsrcioPushbackReaderTest.java"), 64);
            char[] buf = new char[32];
            //保存上次讀取的字符串內(nèi)容
            String lastContent = "";
            int hasRead = 0;
            while ((hasRead = pr.read(buf)) > 0) {
                //讀取到內(nèi)容轉(zhuǎn)換成字符串
                String content = new String(buf,0,hasRead);
                int targetIndex = 0;
                //將上一次內(nèi)容和本次內(nèi)容拼起來 檢查是否包含目標(biāo)字符串
                //如果包含目標(biāo)字符串
                if ((targetIndex = (lastContent + content).indexOf("new PushbackReader")) > 0) {
                    //將本次內(nèi)容上次內(nèi)容一起退回到推回緩沖區(qū)
                    pr.unread((lastContent + content).toCharArray());
                    //再次讀取指定程度的內(nèi)容(目標(biāo)字符串之前的內(nèi)容)
                    pr.read(buf,0,targetIndex);
                    //打印讀取內(nèi)容
                    System.out.println(new String(buf,0,targetIndex));
                    System.exit(0);
                } else {
                    System.out.println(lastContent);
                    lastContent = content;
                }
            }

/**省略無數(shù)代碼**/

java/**省略無數(shù)代碼**/
        PrintStream ps = null;

        try {
            //創(chuàng)建重定向需要的輸出流
            ps = new PrintStream(new FileOutputStream("out.txt"));
            //將標(biāo)準(zhǔn)輸出流重定向到ps輸出流
            System.setOut(ps);
            //測試輸出
            System.out.println("普通字符串");
            System.out.println(new RedirectOut());
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            if (null != ps) {
                ps.close();
            }
        }
/**省略無數(shù)代碼**/

java/**省略無數(shù)代碼**/
        FileInputStream fis = null;

        try {
            fis = new FileInputStream("E:workplace1
eviewsrcioRedirectIn.java");
            //將標(biāo)準(zhǔn)輸入重定向到fis輸入流
            System.setIn(fis);
            //獲取標(biāo)準(zhǔn)輸入
            Scanner sc = new Scanner(System.in);
            //設(shè)置只把回車作為分隔符
            sc.useDelimiter("
");
            while (sc.hasNext()) {
                System.out.println("鍵盤輸入內(nèi)容為:" + sc.next());
            }
/**省略無數(shù)代碼**/