java缓冲流

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//创建缓冲流，用低级流构建
File file = new File(); //文件路径
FileInputStream fileinputstream = new FileInputStream(file); //字节型
BufferedInputStream bufferedinputstream = new BufferedInputStream(fileinputstream);//字节型缓冲
//BufferedInputStream 的使用方法和FileInputStream的方法一致
//在BufferedOutputStream写入的时候最好写flush()这个方法，在1.8版本前是需要写的，新版本做了优化可以不写

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		File file = new File("D:\java_work\TestFile\abc.txt");
        FileInputStream fileInputStream = null;
        BufferedInputStream bufferedInputStream = null;
        FileOutputStream fileOutputStream = null;
        BufferedOutputStream bufferedOutputStream = null;
        try {
            fileInputStream = new FileInputStream(file);
            bufferedInputStream = new BufferedInputStream(fileInputStream);
            int buffers = bufferedInputStream.available();
            System.out.println("大小:" + buffers);
            byte[] bytes = new byte[10];
            int code = bufferedInputStream.read(bytes);
            while (code != -1) {
                String value = new String(bytes, 0, code);
                System.out.println(value);
                code = bufferedInputStream.read(bytes);
            }
            System.out.println("----------------------------------------");
            fileOutputStream = new FileOutputStream(file, true);
            bufferedOutputStream = new BufferedOutputStream(fileOutputStream);
            bufferedOutputStream.write('2');
            bufferedOutputStream.flush();
            int leg = bufferedInputStream.available();
            byte[] b = new byte[leg];
            int codes = bufferedInputStream.read(b);
            String values = new String(b, 0, codes);
            System.out.println("写入完成" + values);

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (fileInputStream != null) {
                    fileInputStream.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                if (bufferedInputStream != null) {
                    bufferedInputStream.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                if (fileOutputStream != null) {
                    fileOutputStream.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                if (bufferedOutputStream != null) {
                    bufferedOutputStream.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        System.out.println("-------------------------------------------------------------------------");
        File file1 = new File("D:\java_work\TestFile\abc.txt");
        FileReader fileReader = null;
        BufferedReader bufferedReader = null;
        FileWriter fileWriter = null;
        BufferedWriter bufferedWriter = null;
        try {
            fileReader = new FileReader(file1);
            bufferedReader = new BufferedReader(fileReader);
            fileWriter = new FileWriter(file1);
            bufferedWriter = new BufferedWriter(fileWriter);
            bufferedWriter.write("静夜思-李白n");
            bufferedWriter.write(
                    "床前明月光,n" +
                    "疑是地上霜,n" +
                    "举头望明月,n" +
                    "低头思故乡。");
            bufferedWriter.flush();

            char[] chars = new char[5];
            int count = bufferedReader.read(chars);
            while (count != -1) {
                String value = new String(chars, 0, count);
                System.out.print(value);
                count = bufferedReader.read(chars);
            }

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (fileReader != null) {
                    fileReader.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                if (bufferedReader != null) {
                    bufferedReader.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                if (fileWriter != null) {
                    fileWriter.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                if (bufferedWriter != null) {
                    bufferedWriter.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }