在数据末尾找到参数时如何删除选定的行？

Question

我的文本文件如下：

a~a~a~a~a~a~a~a~a~a~a~a~a~a~a~a~a~a~a~a~a~a~a~a ~1 b~b~b~b~b~b~b~b~b~b~b~b~b~b~b~b~b~b~b~b~b~b~b~b~2 c~c~c~c~c~c~c~c~c~c~c~c~c~c~c~c~c~c~c~c~c~c~c~c~3

我的计划是找到行尾的数字，然后 删除该行。

我已经使用 Delimeter 找到了该数字。 但我不知道如何删除整行。

例如我搜索 No.2，我希望我的输出如下：

a~a~a~a~a~a~a~a~a~a~a~a~a~a~a~a~a~a~a~a~a~a~a~a ~1 c~c~c~c~c~c~c~c~c~c~c~c~c~c~c~c~c~c~c~c~c~c~c~c~3

这是我最后一次编辑代码，我卡在这里..

public class test {

    static Scanner x;

    public static void main(String [] args) {
        String filepath = "input.txt";
        String removeterm = "1";

        removeRecord(filepath,removeterm);

    }

    private static void removeRecord(String filepath, String removeterm) {

        String tempFile = "temp.txt";
        File oldfile = new File(filepath);
        File newfile = new File(tempFile);

        String ID1  = ""; String ID2  = ""; String ID3  = "";
        String ID4  = ""; String ID5  = ""; String ID6  = "";
        String ID7  = ""; String ID8  = ""; String ID9  = "";
        String ID10 = ""; String ID11 = ""; String ID12 = "";
        String ID13 = ""; String ID14 = ""; String ID15 = "";
        String ID16 = ""; String ID17 = ""; String ID18 = "";
        String ID19 = ""; String ID20 = ""; String ID21 = "";
        String ID22 = ""; String ID23 = ""; String ID24 = "";
        String ID25 = "";

        try
        {
            FileWriter fw = new FileWriter(tempFile,true);
            BufferedWriter bw = new BufferedWriter(fw);
            PrintWriter pw = new PrintWriter(bw);
            x = new Scanner(new File(filepath));
            x.useDelimiter("[~\n]");

            while(x.hasNext())
            {
                ID1  = x.next(); ID2  = x.next(); ID3  = x.next();
                ID4  = x.next(); ID5  = x.next(); ID6  = x.next();
                ID7  = x.next(); ID8  = x.next(); ID9  = x.next();
                ID10 = x.next(); ID11 = x.next(); ID12 = x.next();
                ID13 = x.next(); ID14 = x.next(); ID15 = x.next();
                ID16 = x.next(); ID17 = x.next(); ID18 = x.next();
                ID19 = x.next(); ID20 = x.next(); ID21 = x.next();
                ID22 = x.next(); ID23 = x.next(); ID24 = x.next();
                ID25 = x.next();

                if(!ID1.equals(removeterm)) { 
                    pw.println(ID1  + "~" + ID2 + "~" + ID3  + "~" + ID4  + "~" + ID5  + "~" + ID6  + "~" + ID7  + "~" + ID8  + "~" + ID9  + "~" + ID10 + "~" + ID11 + "~" + ID12 + "~" + ID13 + "~" + ID14 + "~" + ID15 + "~" + ID16 + "~" + ID17 + "~" + ID18 + "~" + ID19 + "~" + ID20 + "~" + ID21 + "~" + ID22 + "~" + ID23 + "~" + ID24 + "~" + ID25);
                    JOptionPane.showMessageDialog(null, "Done !");
                }
            }
            x.close();
            pw.flush();
            pw.close();
            oldfile.delete();
            File dump = new File(filepath);
            newfile.renameTo(dump);
        }
        catch (NoSuchElementException exception) {
            // Output expected NoSuchElementExceptions.
        }
        catch(Exception e)
        {
            JOptionPane.showMessageDialog(null, "Error !" + e);
        }
    }
}

Answer 1

可能会有所帮助！
第 1 步：将文件读入列表（推荐使用 LinkedList），其中元素为一行“a~a~a~a~a~a~a~a~a~a~a~a~a~a~a~ a~a~a~a~a~a~a~a~a~1" 例如。 Refer

第 2 步：尝试删除 list[i].endWiths("yournumber") 的元素，然后重写文件或对列表执行一些操作。 Refer

Answer 2

使用 Java8 特性和 NIO（从 Java7 开始），解决方案将非常简单：

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.List;
import java.util.stream.Collectors;

public class Test {

    public static void main(String[] args) {
        String filepath = "./input.txt";
        String removeterm = "1";

        removeRecord(filepath, removeterm);

    }

    private static void removeRecord(String filepath, String removeterm) {
        try {
            List<String> filtered = Files.readAllLines(Paths.get(filepath)).stream().filter(s -> !s.endsWith(removeterm)).collect(Collectors.toList());
            Files.write(Paths.get("./temp.txt"), filtered);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}