如何从csv文件中删除垃圾值？

Question

我有一些数据的CSV文件，它也有很多无效的数据。我如何才能打印有效数据并保留其余部分？

我的数据是这样的： -

1,Ron,1234,XYZ 
2,Harry,214,SDA 
3,Kent,1786,GHI 
SAMNE:MANNS;ndndo 
kdbg;obmgdf;brhj 

我只想打印头三行并删除最后两行无效。我在Eclipse中这样做。

Answer 1

你可以尝试这样的事情。

BufferedReader reader = new BufferedReader(new FileReader(new File("~/input.csv"))); 
    String line; 
    while((line = reader.readLine())!= null){ 
     try{ 

      int sno = Integer.parseInt(line.split(",")[0]); 
      System.out.println("Valid "+ line); 
      //Continue doing more checks or other operations 

     }catch(NumberFormatException e){ 
      //Skip invalid line 
      System.out.println("Invalid row "+ line); 
     } 
    } 

Answer 2

你应该通过正则表达式检查是否有效，抛出异常是一个坏主意。

BufferedReader reader = new BufferedReader(new FileReader(new File("~/input.csv"))); 
String line; 
while((line = reader.readLine())!= null){ 
    if(line.matches("(\\d+,\\w+,\\d+,\\w+)"){ 
     print line; 
    } 
} 

Answer 3

事情是这样的：

import java.io.BufferedReader; 
import java.io.FileNotFoundException; 
import java.io.FileReader; 
import java.io.IOException; 

public class JavaApplication1 { 

    public static void main(String[] args) throws FileNotFoundException, IOException { 
     try (BufferedReader reader = new BufferedReader(new FileReader("file.txt"))) { 
      StringBuilder sb = new StringBuilder(); 
      String line = reader.readLine(); 
      while (line != null) { 
       String[] part = line.split(","); 
       try { 
        Integer.parseInt(part[0]); 
        System.out.println(line); 
       } catch (NumberFormatException nfe) { 
        // This is not a valid line 
       } 
       line = reader.readLine(); 
      } 
     } 
    } 
}