java对.txt文件进行读取方法实战---室友是网络安全方向，帮他提取文件里的特定ip

需求：类似如下的txt文件，现在需要把每一小段包含open的ip地址输出，这样他就可以去攻击有用ip了，这孩子真坏，哈哈。

Nmap scan report for 123.59.68.48
Host is up (0.044s latency).
PORT   STATE SERVICE
22/tcp open  ssh


Nmap scan report for 123.59.68.49
Host is up (0.00023s latency).
PORT   STATE    SERVICE
22/tcp filtered ssh


Nmap scan report for 123.59.68.50
Host is up (0.027s latency).
PORT   STATE SERVICE
22/tcp open  ssh


Nmap scan report for 123.59.68.51
Host is up (0.00029s latency).
PORT   STATE    SERVICE
22/tcp filtered ssh


Nmap scan report for 123.59.68.52
Host is up (0.036s latency).
PORT   STATE SERVICE
22/tcp open  ssh


Nmap scan report for 123.59.68.53
Host is up (0.058s latency).
PORT   STATE SERVICE
22/tcp open  ssh


Nmap scan report for 123.59.68.54
Host is up (0.060s latency).
PORT   STATE    SERVICE
22/tcp filtered ssh


Nmap scan report for 123.59.68.55
Host is up (0.00028s latency).
PORT   STATE    SERVICE
22/tcp filtered ssh


Nmap scan report for 123.59.68.56
Host is up (0.030s latency).
PORT   STATE SERVICE
22/tcp open  ssh


Nmap scan report for 123.59.68.57
Host is up (0.19s latency).
PORT   STATE  SERVICE
22/tcp closed ssh


Nmap scan report for 123.59.68.58
Host is up (0.059s latency).
PORT   STATE    SERVICE
22/tcp filtered ssh


Nmap scan report for 123.59.68.59
Host is up (0.00037s latency).
PORT   STATE    SERVICE
22/tcp filtered ssh


Nmap scan report for 123.59.68.60
Host is up (0.00018s latency).
PORT   STATE    SERVICE
22/tcp filtered ssh


Nmap scan report for 123.59.68.61
Host is up (0.19s latency).
PORT   STATE  SERVICE
22/tcp closed ssh


Nmap scan report for 123.59.68.62
Host is up (0.18s latency).
PORT   STATE  SERVICE
22/tcp closed ssh


Nmap scan report for 123.59.68.63
Host is up (0.038s latency).
PORT   STATE    SERVICE
22/tcp filtered ssh


Nmap scan report for 123.59.68.64
Host is up (0.026s latency).
PORT   STATE    SERVICE
22/tcp filtered ssh


Nmap scan report for 123.59.68.65
Host is up (0.00023s latency).
PORT   STATE    SERVICE
22/tcp filtered ssh


Nmap scan report for 123.59.68.66
Host is up (0.00022s latency).
PORT   STATE    SERVICE
22/tcp filtered ssh


Nmap scan report for 123.59.68.67
Host is up (0.00011s latency).
PORT   STATE    SERVICE
22/tcp filtered ssh

......未完

实现方法：用java的BufferedReader类，一次只读一行来操作，不多说了，直接上代码

package com.hbut.test;


import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.Scanner;


import com.hbut.basetest.SingleTon;


@SuppressWarnings("unused")
public class Main {

@SuppressWarnings("resource")
public static void main(String[] args) throws IOException {


File file = new File("D:/host.txt");//Text文件

BufferedReader br = new BufferedReader(new FileReader(file));//构造一个BufferedReader类来读取文件


String s = null;
String temp=null;

while((s = br.readLine())!=null){//使用readLine方法，一次读一行
    if(s.contains("123")){
    temp=s;
    }
    
    if(s.contains("open")){
    System.out.println(temp);
     temp=null;
    }

}


}
     
}

读取结果：

Nmap scan report for 123.59.68.48
Nmap scan report for 123.59.68.50
Nmap scan report for 123.59.68.52
Nmap scan report for 123.59.68.53
Nmap scan report for 123.59.68.56
Nmap scan report for 123.59.68.72
Nmap scan report for 123.59.68.76
Nmap scan report for 123.59.68.78
Nmap scan report for 123.59.68.79
Nmap scan report for 123.59.68.82
Nmap scan report for 123.59.68.89
Nmap scan report for 123.59.68.92
Nmap scan report for 123.59.68.93
Nmap scan report for 123.59.68.94
Nmap scan report for 123.59.68.95
Nmap scan report for 123.59.68.96
Nmap scan report for 123.59.68.98
Nmap scan report for 123.59.68.99
Nmap scan report for 123.59.68.101
Nmap scan report for 123.59.68.102
Nmap scan report for 123.59.68.103
Nmap scan report for 123.59.68.109
Nmap scan report for 123.59.68.110
Nmap scan report for 123.59.68.113
Nmap scan report for 123.59.68.124
Nmap scan report for 123.59.68.131
Nmap scan report for 123.59.68.132
Nmap scan report for 123.59.68.135
Nmap scan report for 123.59.68.136
Nmap scan report for 123.59.68.137
Nmap scan report for 123.59.68.139
Nmap scan report for 123.59.68.140
Nmap scan report for 123.59.68.142
Nmap scan report for 123.59.68.145
Nmap scan report for 123.59.68.146
Nmap scan report for 123.59.68.152
Nmap scan report for 123.59.68.153
Nmap scan report for 123.59.68.155
Nmap scan report for 123.59.68.156
Nmap scan report for 123.59.68.157
Nmap scan report for 123.59.68.158
Nmap scan report for 123.59.68.159
Nmap scan report for 123.59.68.163

.....