求问大神怎么提取txt中的指定内容到一个新的txt

求问大神怎么提取txt中的指定内容到一个新的txt

1. 使用语言java，maven依赖

           <dependency>
               <groupId>cn.hutool</groupId>
               <artifactId>hutool-all</artifactId>
               <version>5.2.4</version>
           </dependency>

    

2. 类似下面的txt，需要提取1-4行到新的txt 

 

1. 代码

       public static void main(String[] args) {
           List<String> readLines = FileUtil.readLines("D:\\test.txt", "UTF-8");
           List<String> stringList = readLines.subList(0, 4);
           StringBuilder sb = new StringBuilder();
           for (String str : stringList) {
               sb.append(str).append("\n");
           }
           FileUtil.writeBytes(sb.toString().getBytes(), "D:\\test3.txt");
       }

    

 

这里用c++给个例子，题目应该说清楚txt什么内容，编程语言是什么。
https://www.imooc.com/wenda/detail/532759
A文件中，内容是这样的：

[fullText]abcd[rating]
[fullText]efg[rating]

抽取[fullText][rating]之间的内容，并将其保存到B文件中

#include <fstream>
using std::ifstream; using std::ofstream;
#include <string>
using std::string;
#include <vector>
using std::vector;
#include <iostream>


vector<string> &split( const string &str, const string &delimiters, vector<string> &elems, bool skip_empty = true ) {
string::size_type pos, prev = 0;
while ( ( pos = str.find_first_of(delimiters, prev) ) != string::npos ) {
if ( pos > prev ) {
if ( skip_empty && 1 == pos - prev ) break;
elems.emplace_back( str, prev, pos - prev );
}
prev = pos + 1;
}
if ( prev < str.size() ) elems.emplace_back( str, prev, str.size() - prev );
return elems;
}


bool pickup(const string &source, const string &dest, const string &label_front, const string &label_back) {
ifstream ifs( source );
if ( ifs.fail() ) return false;


ofstream ofs( dest );
if ( ofs.fail() ) return false;


for ( string line; std::getline(ifs, line); ) {
vector<string> content;
if ( 3 == split( line, "[]", content ).size() && content[0] == label_front && content[2] == label_back )
ofs << content[1] << " ";
}


return true;
}


int main()
{
if ( pickup("A.txt", "B.txt", "fullText", "rating") )
std::cout << "pickup success!" << std::endl;
}