读取大文件,分割成每次读取5兆

1
2
3
4
5
6
7
8
9
10
11
12
13
14
public static void main(String[] args) throws IOException {
        //大文件读取
        String filepath="C:\\Users\\doume\\Desktop\\spring cloud系列教程第一篇-介绍_files\\test1.txt";
        File file = new File(filepath);  
        BufferedInputStream fis = new BufferedInputStream(new FileInputStream(file));   
        BufferedReader reader = new BufferedReader(new InputStreamReader(fis,"utf-8"),5*1024*1024);// 用5M的缓冲读取文本文件 
           
        String line = "";
        while((line = reader.readLine()) != null){
           //TODO: write your business
            String name=reader.readLine();
            System.out.println(name);
        }
    }<br><br><br><br><br><br><br>

package test;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.math.BigDecimal;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.UUID;


public class DZTZ {

public static void readFileByBytes(String fileName) {
InputStream in = null;
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[200000000];
int byteread = 0;
in = new FileInputStream(fileName);
// 读入多个字节到字节数组中,byteread为一次读入的字节数
int i=0;
while ((byteread = in.read(tempbytes)) != -1) {
String name="E:\\邮储\\文档\\河南项目\\新中评\\文档\\新乡存量房\\新乡存量房\\20220418\\"+i++ +"caoni.txt";
File file=new File(name);
if(!file.exists())
try{
file.createNewFile();
}catch(Exception e){
e.printStackTrace();
}
try{
FileOutputStream out=new FileOutputStream(file);
out.write(tempbytes);
out.close();
}catch(Exception e){
e.printStackTrace();
}
}
System.out.println("结束");
} catch (Exception e1) {
e1.printStackTrace();
} finally {
if (in != null) {
try {
in.close();
} catch (IOException e1) {
}
}
}
}

public static void write(String path) {
File file=new File(path);
if(!file.exists())
try{
file.createNewFile();
}catch(Exception e){
e.printStackTrace();
}
try{
FileOutputStream out=new FileOutputStream(file);
byte bt[]="i eat apple".getBytes();
out.write(bt);
out.close();
}catch(Exception e){
e.printStackTrace();
}
}

public static void main(String[] args) {
readFileByBytes("E:\\文档\\20220418\\btp-trace.log\\btp-trace.log");
}

}

  

posted @   王短腿  阅读(37)  评论(0编辑  收藏  举报
相关博文:
阅读排行:
· Manus重磅发布:全球首款通用AI代理技术深度解析与实战指南
· 被坑几百块钱后,我竟然真的恢复了删除的微信聊天记录!
· 没有Manus邀请码?试试免邀请码的MGX或者开源的OpenManus吧
· 【自荐】一款简洁、开源的在线白板工具 Drawnix
· 园子的第一款AI主题卫衣上架——"HELLO! HOW CAN I ASSIST YOU TODAY
点击右上角即可分享
微信分享提示