Question

我有一个带有一组IP地址的文本文件，我用BufferedReader读取它想将它存储在一个二维字符串数组中。

这是我的文字档案：

102.168.212.226, 104.170.214.228, 0 57.68.58.212, 59.70.60.214, 1 10.42.12.22, 12.44.14.24, 2 78.16.22.234, 80.18.24.236, 3 123.168.2.2, 125.170.4.4, 4

这是我的代码：

import java.io.;
import java.util.;
public class IPAddressLookup
    {
        IPAddressLookup()   //Constructor
        {
            int Width = 0, Height = 0;

            try
            {
                File fileA = new File("ClassA.txt");
                BufferedReader bra = new BufferedReader(new FileReader(fileA));

                String line = "";
                String[] str;

                while((line = bra.readLine()) != null )
                {
                    str = line.trim().split(", ");
                    Width = str.length;
                    Height++;
                }

                String [][] ClassATable = new String[Height][Width];

                for(int i = 0; i < Height; i++)
                {
                    if((line = bra.readLine()) != null )
                    {
                        str = line.trim().split(", ");
                        for(int j = 0; j < Width; j++)
                            ClassATable[i][j] = str[j];
                    }
                }

                for(int i = 0; i < Height; i++)
                    for(int j = 0; j < Width; j++)
                        System.out.println(ClassATable[i][j]);

                System.out.println("The text file contains:");
                System.out.println("Row : " +Height);
                System.out.println("Column : " +Width);
            }
            catch(IOException e)
            {
                System.out.println("Error: File not found.");
            }
        }

        public static void main(String args[])
        {
            IPAddressLookup acnl1 = new IPAddressLookup();
        }
    }

问题是当我尝试打印String数组时，它显示＆＃34; null＆＃34;在输出中。还有什么方法可以从文件中读取字符串IP地址并将它们存储在整数2D数组中吗？

我在Java方面有点新鲜。任何人都可以帮我这个吗？

Answer 1

您似乎正在阅读该文件两次，但您没有重置阅读器，因此在第二个循环中，您将从顶部重新开始。

您需要在循环之间添加如下内容：LastRow1 =.Cells(Rows.Count, 1).End(xlUp).Row Cells(lastRow1 + 1, 1).Value = "Your value here" LastRow2 =.Cells(Rows.Count, 2).End(xlUp).Row Range("A" & LastRow1 & ".AutoFill Destination:=Range("A" & LastRow1 & ":A" & LastRow2 & "), Type:=xlFillDefault（在此之后：bra.getChannel().position(0)）。这将重置您的阅读器，以便它可以从顶部再次启动。

Answer 2

试试这段代码：

public class IPAddressLookup {
ArrayList<String[]> ip = new ArrayList<>();
IPAddressLookup()   //Constructor
{
    int Width = 0, Height = 0;

    try
    {
        File fileA = new File("ClassA.txt");
        BufferedReader bra = new BufferedReader(new FileReader(fileA));

        String line = "";
        String[] str;

        while((line = bra.readLine()) != null )
        {
            str = line.trim().split(", ");
            ip.add(str);
            Width = str.length;
            Height++;
        }

        String [][] ClassATable = new String[Height][Width];

        for(int i=0 ; i<ip.size();i++){
            String[] temp = ip.get(i);
            for(int j=0;j<temp.length;j++){
                ClassATable[i][j] = temp[j];
            }
        }


        for(int i = 0; i < Height; i++)
            for(int j = 0; j < Width; j++)
                System.out.println(ClassATable[i][j]);

        System.out.println("The text file contains:");
        System.out.println("Row : " +Height);
        System.out.println("Column : " +Width);
    }
    catch(IOException e)
    {
        System.out.println("Error: File not found.");
    }
}

public static void main(String args[])
{
    IPAddressLookup acnl1 = new IPAddressLookup();
}

}

结果：

102.168.212.226 104.170.214.228 0 57.68.58.212 59.70.60.214 1 10.42.12.22 12.44.14.24 2 78.16.22.234 80.18.24.236 3 123.168.2.2 125.170.4.4 4 The text file contains: Row : 5 Column : 3

读取字符串IP地址以存储在二维字符串数组

2 个答案: