Java的StringTokenizer的只读第一行

Question

我的问题是StringTokenizer似乎只能读的第一线ip.txt

我试图做的是加载IP列表从“ip.txt”的地址和将其保存到阵列中以自动ping我的网络上的设备以查看它们是否在线。无论我尝试什么，我都无法获得比“ip.txt”中阵列中的第一行更多的内容。我的分隔符是“//”，并且IP地址的名称也存储在txt文件中。我包含了代码和一个文本文件的样本。

在此先感谢！

public class IP { 
    public static IP[] ips = new IP[100]; 
    public static int total_ips=0; 

    String name; 
    String ip1; 
    String ip2; 
    String ip3; 
    String ip4; 
    String fullIP; 

    public static void read_ips() throws FileNotFoundException{ 

     FileInputStream fstream1 = new FileInputStream("ip.txt"); 

     String line; 
     String delimiter = "//"; 

     StringTokenizer tokenizer; 
     BufferedReader input = null;  
     try { 
      int i = 0; 
      int totalIps = 0; 

      input = new BufferedReader(new InputStreamReader(fstream1)); 
      line = input.readLine(); 

      //outer while 
      while(line != null) { 
      tokenizer = new StringTokenizer(line, delimiter); 

      while(tokenizer.hasMoreElements()) {//process tokens in line 
       ips[i] = new IP(); 
       ips[i].name = tokenizer.nextToken(); 
       ips[i].ip1 = tokenizer.nextToken(); 
       ips[i].ip2 = tokenizer.nextToken(); 
       ips[i].ip3 = tokenizer.nextToken(); 
       ips[i].ip4 = tokenizer.nextToken(); 
       ips[i].fullIP = ips[i].ip1+"."+ips[i].ip2+"."+ips[i].ip3+"."+ips[i].ip4; 
       i++; 
       totalIps = i; 

       System.out.println(line); 
      } 
      line = input.readLine(); //next line 
      }//close outer while 
      total_ips = totalIps; // count of total cars 
      System.out.println("total_ips after i++ "+total_ips); 
      }catch (FileNotFoundException e) { 
       System.out.println("Unable to open file " + fstream1); 
      } catch (IOException e) { 
       System.out.println("Unable to read from file " + fstream1); 
      }finally { 
       // Close the file 
       try { 
      if (input != null) 
       input.close(); 
       } catch (IOException e) { 
        System.out.println("Unable to close file " + fstream1); 
       } 
      } 
    } 
} 

这里是ip.txt

Desktop1//192//168//1//127// 
Desktop2//192//168//1//128// 
Desktop3//192//168//1//129// 

Answer 1

你的代码应该做工精细的例子。更经典的方法来遍历在时间的BufferedReader一条线是通过使用类似的表达式：

while ((line = input.readLine()) != null) {. 

这是对我做你的代码的唯一重构和它工作。您可能需要打印完整的IP以检查您是否正确地检索它。

下面是代码：

import java.io.BufferedReader; 
import java.io.FileInputStream; 
import java.io.FileNotFoundException; 
import java.io.IOException; 
import java.io.InputStreamReader; 
import java.util.StringTokenizer; 

public class IP { 
    public static IP[] ips = new IP[100]; 
    public static int total_ips=0; 

    String name; 
    String ip1; 
    String ip2; 
    String ip3; 
    String ip4; 
    String fullIP; 

    public static void main(String[] args) throws IOException { 
     read_ips(); 
    } 
    public static void read_ips() throws FileNotFoundException{ 

     FileInputStream fstream1 = new FileInputStream("c:\\ips\\ip.txt"); 

     String line; 
     String delimiter = "//"; 

     StringTokenizer tokenizer; 
     BufferedReader input = null;  
     try { 
      int i = 0; 
      int totalIps = 0; 

      input = new BufferedReader(new InputStreamReader(fstream1)); 
      while ((line = input.readLine()) != null) { 
       tokenizer = new StringTokenizer(line, delimiter); 

       while(tokenizer.hasMoreElements()) {//process tokens in line 
        ips[i] = new IP(); 
        ips[i].name = tokenizer.nextToken(); 
        ips[i].ip1 = tokenizer.nextToken(); 
        ips[i].ip2 = tokenizer.nextToken(); 
        ips[i].ip3 = tokenizer.nextToken(); 
        ips[i].ip4 = tokenizer.nextToken(); 
        ips[i].fullIP = ips[i].ip1+"."+ips[i].ip2+"."+ips[i].ip3+"."+ips[i].ip4; 
        System.out.println(ips[i].fullIP); 
        i++; 
        totalIps = i; 

        System.out.println(line); 
       } 
      } 


      total_ips = totalIps; // count of total cars 
      System.out.println("total_ips after i++ "+total_ips); 
      }catch (FileNotFoundException e) { 
       System.out.println("Unable to open file " + fstream1); 
      } catch (IOException e) { 
       System.out.println("Unable to read from file " + fstream1); 
      }finally { 
       // Close the file 
       try { 
      if (input != null) 
       input.close(); 
       } catch (IOException e) { 
        System.out.println("Unable to close file " + fstream1); 
       } 
      } 
    } 
} 

而一个例证：