如何通过java中的内容删除excel文件

Question

我有一些excel文件，我想通过内容删除它。 举例来说，有一个文件崩溃并且没有内容。如何使用byte[]用java删除该文件？

Answer 1

CSV解析器将pase文件。

package com.epox.cmc.core.util; 

import java.util.*; 


/** 
* @author SMehta 
* 
*/ 
public class CSVParser { 


    public static final char DEFAULT_SEP = ','; 

    /** Construct a CSV parser, with the default separator (`,'). */ 
    public CSVParser() { 
     this(DEFAULT_SEP); 
    } 

    /** 
    * Construct a CSV parser with a given separator. 
    * 
    * @param sep 
    *   The single char for the separator (not a list of separator 
    *   characters) 
    */ 
    public CSVParser(char sep) { 
     fieldSep = sep; 
    } 

    /** The fields in the current String */ 
    protected List list = new ArrayList(); 

    /** the separator char for this parser */ 
    protected char fieldSep; 

    /** 
    * parse: break the input String into fields 
    * 
    * @return java.util.Iterator containing each field from the original as a 
    *   String, in order. 
    */ 
    public List parse(String line) { 
     StringBuffer sb = new StringBuffer(); 
     list.clear(); // recycle to initial state 
     int i = 0; 

     if (line.length() == 0) { 
      list.add(line); 
      return list; 
     } 

     do { 
      sb.setLength(0); 
      if (i < line.length() && line.charAt(i) == '"') 
       i = advQuoted(line, sb, ++i); // skip quote 
      else 
       i = advPlain(line, sb, i); 
      list.add(sb.toString());   
      i++; 
     } while (i < line.length()); 

     return list; 
    } 

    /** advQuoted: quoted field; return index of next separator */ 
    protected int advQuoted(String s, StringBuffer sb, int i) { 
     int j; 
     int len = s.length(); 
     for (j = i; j < len; j++) { 
      if (s.charAt(j) == '"' && j + 1 < len) { 
       if (s.charAt(j + 1) == '"') { 
        j++; // skip escape char 
       } else if (s.charAt(j + 1) == fieldSep) { //next delimeter 
        j++; // skip end quotes 
        break; 
       } 
      } else if (s.charAt(j) == '"' && j + 1 == len) { // end quotes at 
                  // end of line 
       break; //done 
      } 
      sb.append(s.charAt(j)); // regular character. 
     } 
     return j; 
    } 

    /** advPlain: unquoted field; return index of next separator */ 
    protected int advPlain(String s, StringBuffer sb, int i) { 
     int j; 

     j = s.indexOf(fieldSep, i); // look for separator 

     if (j == -1) { // none found 
      sb.append(s.substring(i)); 
      return s.length(); 
     } else { 
      sb.append(s.substring(i, j)); 
      return j; 
     } 
    } 

} 

将byte []转换为List>。

private List<List<String>> parseFile(byte[] csvFileData) throws Exception { 

     List<List<String>> data; 
     Reader targetReader = null; 
     CSVParser csvParser = null; 

     try { 
      CSVFormat csvFormat = CSVFormat.DEFAULT; 
      targetReader = new InputStreamReader(new ByteArrayInputStream(csvFileData)); 
      csvParser = new CSVParser(new BufferedReader(targetReader),csvFormat); 

      List<CSVRecord> records = csvParser.getRecords(); 
      data = new ArrayList<List<String>>(); 

      for (CSVRecord csvRecord : records) { 
       Iterator<String> iterator = csvRecord.iterator(); 
       List<String> row = new ArrayList<String>(); 
       while (iterator.hasNext()) { 
        String column = iterator.next(); 
        row.add(column); 
       } 
       data.add(row); 
      } 
     } catch (Exception e) { 
      throw e; 
     } finally { 

      if(targetReader != null) 
       targetReader.close(); 

      if(csvParser != null) 
       csvParser.close(); 
     } 


     return data; 
    } 

现在检查列表的大小，并根据大小删除文件