nio实现文件读取写入数据库或文件

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1.nio实现读取大文件，之后分批读取写入数据库
2.nio实现读取大文件，之后分批写入指定文件
package com.ally;import java.io.File;import java.io.RandomAccessFile;import java.nio.ByteBuffer;import java.nio.channels.FileChannel;import java.sql.*;/** * Created by admin on 2016/6/28. * 1.nio分批读取sql文件并执行插入数据库 * 2.读取一个文件写入另外文件 */public class TestNio {    public static void main(String args[]) throws Exception {        System.err.println("begin");        long start = System.currentTimeMillis();        int _5M = 1024 * 1024 * 5;        File fin = new File("D:\\drug_general_info.sql");        FileChannel fcin = new RandomAccessFile(fin, "r").getChannel();        ByteBuffer rBuffer = ByteBuffer.allocate(_5M);        //将文件读取执行到数据库        readFileByLine(_5M, fcin, rBuffer);        //将文件读取并写入另外文件        File fout = new File("D:\\mm.sql");        FileChannel fcout = new RandomAccessFile(fout, "rws").getChannel();        ByteBuffer wBuffer = ByteBuffer.allocateDirect(_5M);        saveOtherFile( _5M,  fcin, rBuffer,  fcout,  wBuffer);        System.err.print((System.currentTimeMillis() - start) / 1000);    }    /**     * 将一个文件内容写入另外一个     * @param bufSize     * @param fcin     * @param rBuffer     * @param fcout     * @param wBuffer     */    public static void saveOtherFile(int bufSize, FileChannel fcin,                                     ByteBuffer rBuffer, FileChannel fcout, ByteBuffer wBuffer){            Statement pst = null;            String enterStr = "\n";            try {                byte[] bs = new byte[bufSize];                StringBuilder strBuf = new StringBuilder("");                String tempString = null;                while (fcin.read(rBuffer) != -1) {                    int rSize = rBuffer.position();                    rBuffer.rewind();                    rBuffer.get(bs);                    rBuffer.clear();                    tempString = new String(bs, 0, rSize);                    int fromIndex = 0;                    int endIndex = 0;                    int i = 0;                    while ((endIndex = tempString.indexOf(enterStr, fromIndex)) != -1) {                        String line = tempString.substring(fromIndex, endIndex);                        line = strBuf.toString() + line;                        writeFileByLine(fcout, wBuffer, line);                        strBuf.delete(0, strBuf.length());                        fromIndex = endIndex + 1;                    }                }            } catch (Exception e) {                e.printStackTrace();            }    }    /**     * 读文件写入数据库     * @param bufSize     * @param fcin     * @param rBuffer     */    public static void readFileByLine(int bufSize, FileChannel fcin,                                      ByteBuffer rBuffer) {        Connection conn = null;        Statement pst = null;        String enterStr = "\n";        try {            byte[] bs = new byte[bufSize];            StringBuilder strBuf = new StringBuilder("");            String tempString = null;            Class.forName("com.mysql.jdbc.Driver");            conn = DriverManager.getConnection(                    "jdbc:mysql://localhost:3306/doctor?useUnicode=true&characterEncoding=utf-8", "root", "root");            pst = conn.createStatement();            while (fcin.read(rBuffer) != -1) {                int rSize = rBuffer.position();                rBuffer.rewind();                rBuffer.get(bs);                rBuffer.clear();                tempString = new String(bs, 0, rSize);                int fromIndex = 0;                int endIndex = 0;                int i = 0;                while ((endIndex = tempString.indexOf(enterStr, fromIndex)) != -1) {                    String line = tempString.substring(fromIndex, endIndex);                    line = strBuf.toString() + line;                    strBuf.delete(0, strBuf.length());                    fromIndex = endIndex + 1;                    pst.addBatch(line);                  /*  System.out.println("-----------------------");                    System.out.println(line);                    System.out.println("-----------------------");*/                    if (i % 100 == 0) {                        System.out.println("执行了：" + i);                        if (i == 2700) {                            System.out.println("导了：" + i);                        }                        int[] flag = pst.executeBatch();                        System.out.println("结果：" + flag[0]);                    }                    i += 1;                }                // 执行批量更新                pst.executeBatch();                if (rSize > tempString.length()) {                    strBuf.append(tempString.substring(fromIndex,                            tempString.length()));                } else {                    strBuf.append(tempString.substring(fromIndex, rSize));                }                //  System.out.println(strBuf.toString());            }        } catch (Exception e) {            e.printStackTrace();        } finally {            try {                if (pst != null) {                    pst.close();                }                if (conn != null) {                    conn.close();                }            } catch (SQLException e) {                e.printStackTrace();            }        }    }    public static void writeFileByLine(FileChannel fcout, ByteBuffer wBuffer,                                       String line) {        try {            fcout.write(wBuffer.wrap(line.getBytes()), fcout.size());        } catch (Exception e) {            e.printStackTrace();        }    }}
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