public class ReadFromFile {    /**     * 以字节为单位读取文件，常用于读二进制文件，如图片、声音、影像等文件。     */    public static void readFileByBytes(String fileName) {        File file = new File(fileName);        InputStream in = null;        try {            System.out.println("以字节为单位读取文件内容，一次读一个字节：");            // 一次读一个字节            in = new FileInputStream(file);            int tempbyte;            while ((tempbyte = in.read()) != -1) {                System.out.write(tempbyte);            }            in.close();        } catch (IOException e) {            e.printStackTrace();            return;        }        try {            System.out.println("以字节为单位读取文件内容，一次读多个字节：");            // 一次读多个字节            byte[] tempbytes = new byte[100];            int byteread = 0;            in = new FileInputStream(fileName);            ReadFromFile.showAvailableBytes(in);            // 读入多个字节到字节数组中，byteread为一次读入的字节数            while ((byteread = in.read(tempbytes)) != -1) {                System.out.write(tempbytes, 0, byteread);            }        } catch (Exception e1) {            e1.printStackTrace();        } finally {            if (in != null) {                try {                    in.close();                } catch (IOException e1) {                }            }        }    }    /**     * 以字符为单位读取文件，常用于读文本，数字等类型的文件     */    public static void readFileByChars(String fileName) {        File file = new File(fileName);        Reader reader = null;        try {            System.out.println("以字符为单位读取文件内容，一次读一个字节：");            // 一次读一个字符            reader = new InputStreamReader(new FileInputStream(file));            int tempchar;            while ((tempchar = reader.read()) != -1) {                // 对于windows下，\r\n这两个字符在一起时，表示一个换行。                // 但如果这两个字符分开显示时，会换两次行。                // 因此，屏蔽掉\r，或者屏蔽\n。否则，将会多出很多空行。                if (((char) tempchar) != ‘\r‘) {                    System.out.print((char) tempchar);                }            }            reader.close();        } catch (Exception e) {            e.printStackTrace();        }        try {            System.out.println("以字符为单位读取文件内容，一次读多个字节：");            // 一次读多个字符            char[] tempchars = new char[30];            int charread = 0;            reader = new InputStreamReader(new FileInputStream(fileName));            // 读入多个字符到字符数组中，charread为一次读取字符数            while ((charread = reader.read(tempchars)) != -1) {                // 同样屏蔽掉\r不显示                if ((charread == tempchars.length)                        && (tempchars[tempchars.length - 1] != ‘\r‘)) {                    System.out.print(tempchars);                } else {                    for (int i = 0; i < charread; i++) {                        if (tempchars[i] == ‘\r‘) {                            continue;                        } else {                            System.out.print(tempchars[i]);                        }                    }                }            }        } catch (Exception e1) {            e1.printStackTrace();        } finally {            if (reader != null) {                try {                    reader.close();                } catch (IOException e1) {                }            }        }    }    /**     * 以行为单位读取文件，常用于读面向行的格式化文件     */    public static void readFileByLines(String fileName) {        File file = new File(fileName);        BufferedReader reader = null;        try {            System.out.println("以行为单位读取文件内容，一次读一整行：");            reader = new BufferedReader(new FileReader(file));            String tempString = null;            int line = 1;            // 一次读入一行，直到读入null为文件结束            while ((tempString = reader.readLine()) != null) {                // 显示行号                System.out.println("line " + line + ": " + tempString);                line++;            }            reader.close();        } catch (IOException e) {            e.printStackTrace();        } finally {            if (reader != null) {                try {                    reader.close();                } catch (IOException e1) {                }            }        }    }    /**     * 随机读取文件内容     */    public static void readFileByRandomAccess(String fileName) {        RandomAccessFile randomFile = null;        try {            System.out.println("随机读取一段文件内容：");            // 打开一个随机访问文件流，按只读方式            randomFile = new RandomAccessFile(fileName, "r");            // 文件长度，字节数            long fileLength = randomFile.length();            // 读文件的起始位置            int beginIndex = (fileLength > 4) ? 4 : 0;            // 将读文件的开始位置移到beginIndex位置。            randomFile.seek(beginIndex);            byte[] bytes = new byte[10];            int byteread = 0;            // 一次读10个字节，如果文件内容不足10个字节，则读剩下的字节。            // 将一次读取的字节数赋给byteread            while ((byteread = randomFile.read(bytes)) != -1) {                System.out.write(bytes, 0, byteread);            }        } catch (IOException e) {            e.printStackTrace();        } finally {            if (randomFile != null) {                try {                    randomFile.close();                } catch (IOException e1) {                }            }        }    }    /**     * 显示输入流中还剩的字节数     */    private static void showAvailableBytes(InputStream in) {        try {            System.out.println("当前字节输入流中的字节数为:" + in.available());        } catch (IOException e) {            e.printStackTrace();        }    }    public static void main(String[] args) {        String fileName = "C:/temp/newTemp.txt";        ReadFromFile.readFileByBytes(fileName);        ReadFromFile.readFileByChars(fileName);        ReadFromFile.readFileByLines(fileName);        ReadFromFile.readFileByRandomAccess(fileName);    }}

package mergesql;import java.awt.BorderLayout;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.io.BufferedInputStream;import java.io.BufferedOutputStream;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.nio.ByteBuffer;import java.nio.channels.FileChannel;import java.text.SimpleDateFormat;import java.util.Arrays;import java.util.Collections;import java.util.Comparator;import java.util.Date;import java.util.List;import java.util.Scanner;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JOptionPane;import javax.swing.JPanel;import javax.swing.JTextField;/** * 合并sql脚本文件工具类 *  * @author webapp *  */public class MergeSqlFileUtil extends JFrame implements ActionListener {    /**     *      */    private static final long serialVersionUID = 1L;    private final static String fileName = ".sql";    /**     * 获取当前路径下的所有文件中     *      * @time 2014年8月25日     * @auther yuxu.feng     * @param filepath     * @return     */    private static List<File> getFiles(String filepath) {        File file = new File(filepath);        if (!file.exists() | file.listFiles(new MyFileFileter()) == null)            return null;        List<File> fileList = Arrays                .asList(file.listFiles(new MyFileFileter()));        // 最好在这里把 文件过滤掉 只获取文件夹        return sortFolder(fileList);    }    /**     * 按照文件夹按照文件名进行升序 或按着文件名的名字进行升序     *      * @time 2014年8月25日     * @auther yuxu.feng     * @param files     * @return     */    private static List<File> sortFolder(List<File> files) {        if (files.size() == 0)            return null;        Collections.sort(files, new Comparator<File>() {            @Override            public int compare(File o1, File o2) {                if (o1.isDirectory() && o2.isFile())                    return -1;                if (o1.isFile() && o2.isDirectory())                    return 1;                if (o1.isDirectory() && o2.isDirectory())                    return sortFolderName(o1.getName(), o2.getName());                else                    return 0;            }        });        return files;    }    /**     * 根据文件夹名称排序     *      * @time 2014年8月25日     * @auther yuxu.feng     * @param startName     * @param endName     * @return     */    private static int sortFolderName(String startName, String endName) {        if ((parseFloderName(startName) - parseFloderName(endName)) >= 0)            return 1;        else            return -1;    }    /**     * 将文件夹的名字(格式为 A.B.C.D) 转换为long型的数字     *      * @time 2014年8月25日     * @auther yuxu.feng     * @param floderName     * @return     */    private static long parseFloderName(String floderName) {        Scanner sc = new Scanner(floderName).useDelimiter("\\.");        return (sc.nextLong() << 24) + (sc.nextLong() << 16)                + (sc.nextLong() << 8) + (sc.nextLong());    }    /**     * 使用NIO进行文件合并     *      * @time 2014年8月25日     * @auther yuxu.feng     * @param filepath     */    public static void mergerNIO(String filepath) {        SimpleDateFormat fd = new SimpleDateFormat("yyyyMMddHHmmss");        String nowTime = fd.format(new Date());        List<File> fileList = getFiles(filepath);        if (fileList == null)            return;        File fout = new File(filepath + File.separator + nowTime + fileName);        try {            @SuppressWarnings("resource")            FileChannel mFileChannel = new FileOutputStream(fout).getChannel();            FileChannel inFileChannel;            List<File> files = null;            for (File folder : fileList) {                if (folder.isDirectory()) {                    files = Arrays.asList(folder.listFiles());                    // sortFolder(files);                    for (File fin : files) {                        // if (fin.getName().endsWith(fileName)) {                        // inFileChannel = new FileInputStream(fin)                        // .getChannel();                        // inFileChannel.transferTo(0, inFileChannel.size(),                        // mFileChannel);                        //                        // inFileChannel.close();                        // }                        if (fin.getName().endsWith(fileName)) {                            inFileChannel = new FileInputStream(fin)                                    .getChannel();                            inFileChannel.transferTo(0, inFileChannel.size(),                                    mFileChannel);                            inFileChannel.close();                            mFileChannel.write(ByteBuffer.wrap("\r\n"                                    .getBytes()));                        }                    }                }            }            mFileChannel.close();        } catch (IOException e) {            e.printStackTrace();        }    }    /**     * 使用普通IO进行拷贝文件     *      * @time 2014年8月27日     * @auther yuxu.feng     * @param filepath     */    public static void mergerIO(String filepath) {        SimpleDateFormat fd = new SimpleDateFormat("yyyyMMddHHmmss");        String nowTime = fd.format(new Date());        List<File> fileList = getFiles(filepath);        if (fileList == null)            return;        File fout = new File(filepath + File.separator + nowTime + fileName);        BufferedInputStream inBuff = null;        BufferedOutputStream outBuff = null;        try {            outBuff = new BufferedOutputStream(new FileOutputStream(fout));            List<File> files = null;            FileInputStream finput = null;            for (File folder : fileList) {                if (folder.isDirectory()) {                    files = Arrays.asList(folder.listFiles());                    for (File fin : files) {                        finput = new FileInputStream(fin);                        inBuff = new BufferedInputStream(finput);                        byte[] b = new byte[finput.available()];                        int len;                        while ((len = inBuff.read(b)) != -1) {                            outBuff.write(b, 0, len);                        }                        inBuff.close();                        outBuff.flush();                    }                }            }            outBuff.close();        } catch (IOException e) {            e.printStackTrace();        }    }    /**     *      * @time 2014年8月27日     * @auther yuxu.feng     * @param filepath     */    public static void mergeByBuffWriter(String filepath) {        SimpleDateFormat fd = new SimpleDateFormat("yyyyMMddHHmmss");        String nowTime = fd.format(new Date());        List<File> fileList = getFiles(filepath);        if (fileList == null)            return;        try {            File fout = new File(filepath + File.separator + nowTime + fileName);// 输出文件位置            List<File> files = null;            BufferedReader br = null;            BufferedWriter bw = null;            FileOutputStream fops = new FileOutputStream(fout);            bw = new BufferedWriter(new OutputStreamWriter(                    fops, "UTF-8"));//            bw.write(‘\ufeff‘); 带有bom格式的utf-8//            fops.write(new byte[]{(byte)0xEF, (byte)0xBB, (byte)0xBF}); 带有bom格式的utf-8            for (File folder : fileList) {                if (folder.isDirectory()) {                    files = Arrays.asList(folder.listFiles());                    for (File fin : files) {                        FileInputStream finput = new FileInputStream(fin);                        br = new BufferedReader(new InputStreamReader(finput,                                "UTF-8"));                        char[] cbuf = new char[finput.available()];                        int len = cbuf.length;                        int off = 0;                        int ret = 0;                        while ((ret = br.read(cbuf, off, len)) > 0) {                            off += ret;                            len -= ret;                        }                        br.close();                        bw.write(cbuf, 0, off);                                                bw.newLine();                        bw.flush();                    }                }            }            bw.close();        } catch (IOException e) {            e.printStackTrace();        }    }    // /////////////////swing界面////////////////////////    private JLabel lblUsername;    private JTextField tfUsername;    private JButton btnOK;    private JButton btnExit;    public MergeSqlFileUtil() {        JPanel p1 = new JPanel();        p1.setLayout(new BorderLayout());        lblUsername = new JLabel("合并的文件目录:");        tfUsername = new JTextField(20);        p1.add(lblUsername, BorderLayout.WEST);        p1.add(tfUsername, BorderLayout.EAST);        JPanel p2 = new JPanel();        p2.setLayout(new BorderLayout());        JPanel p3 = new JPanel();        btnOK = new JButton("确定");        btnOK.addActionListener(this);        btnExit = new JButton("取消");        btnExit.addActionListener(this);        p3.add(btnOK);        p3.add(btnExit);        this.add(p1, BorderLayout.NORTH);        this.add(p2, BorderLayout.CENTER);        this.add(p3, BorderLayout.SOUTH);        this.setLocation(400, 300);        this.setSize(350, 110);        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        this.setVisible(true);    }    @Override    public void actionPerformed(ActionEvent e) {        if (e.getActionCommand().equals("确定")) {            String path = tfUsername.getText();            Long endIo = System.currentTimeMillis();            MergeSqlFileUtil.mergerIO(path);//            MergeSqlFileUtil.mergeByBuffWriter(path);            Long endNio = System.currentTimeMillis();            JOptionPane.showMessageDialog(this, "运行时间为:" + (endNio - endIo));        } else if (e.getActionCommand().equals("取消")) {            System.exit(0);        }    }    public static void main(String[] args) {        new MergeSqlFileUtil();    }}

package mergesql;import java.io.File;import java.io.FileFilter;public class MyFileFileter implements FileFilter{    @Override    public boolean accept(File pathname) {        if(pathname.isDirectory()){            return true;        }        return false;    }}