CSV file parsing

CSV (Comma separated value file format)

Comma-separated values (comma-separated values,csv, sometimes referred to as character-delimited values, because delimited characters can also be not commas), whose files store tabular data (numbers and text) in plain text. Plain text means that the file is a sequence of characters and does not contain data that must be interpreted like a binary number. A CSV file consists of any number of records separated by a newline character, each record consists of a field, and the delimiter between the fields is another character or string, most commonly a comma or tab. Typically, all records have exactly the same sequence of fields. The common criteria for the CSV file format do not exist, but there is a basic description in RFC 4180.      The character encoding used is also not specified, but 7-BITASCII is the most basic generic encoding. Java parsing csv file common method: Other Auxiliary Group class referencehttp://www.cnblogs.com/wshsdlau/p/5643862.html

import java.io.bufferedreader;import java.io.filereader;import java.io.ioexception;import java.util.ArrayList; Import Java.util.list;import Java.util.regex.matcher;import Java.util.regex.pattern;import Com.boguan.bte.service.common.IExcelRowReader;/** Name: csvparser.java<br> * Description: <br> * Type: java<br> * Last modified: July 6, 2016 morning 10:22:34<br> * * @s Ince July 6, 2016 * @author*/ Public classCsvreader {/** * Space mark,;: etc. */    PrivateString Spacemark =","; /** * CSV fixed only sheet_num=0*/    PrivateFinalStatic intSheet_num =0; /** * contructor * * @param inputcsvfile*/     PublicCsvreader () {}/** * Line read*/    PrivateIexcelrowreader Rowreader;  Public voidSetrowreader (Iexcelrowreader rowreader) { This. Rowreader =Rowreader; }    /** * get the array from the CSV file * * @return * @throws IOException*/     Public voidprocess (String inputcsvfile) throws IOException {BufferedReaderinch=NULL; Try {            inch=NewBufferedReader (NewFileReader (inputcsvfile)); List<List<String>> retval =NewArraylist<list<string>>(); String RegExp=Getregexp ();            String StrLine; String Str=""; intRowNum =0; List<String> listtemp =NULL;  while((StrLine =inch. ReadLine ())! =NULL) {pattern pattern=Pattern.compile (REGEXP); Matcher Matcher=Pattern.matcher (StrLine); Listtemp=NewArraylist<string>();  while(Matcher.find ()) {str=Matcher.group (); STR=Str.trim (); if(Str.endswith (Spacemark)) {str= Str.substring (0, Str.length ()-1); STR=Str.trim (); }                    if(Str.startswith ("\"") && Str.endswith ("\"") ) {str= Str.substring (1, Str.length ()-1); if(Csvreader.isexisted ("\"\"", str)) {STR= Str.replaceall ("\"\"","\""); }                    }                    if(!"". Equals (str))                    {Listtemp.add (str); }Else{Listtemp.add (" ");                }} retval.add (Listtemp);                Rowreader.getrows (Sheet_num, RowNum, listtemp); RowNum++; }        } finally {            if(inch!=NULL) {                inch. Close (); }        }    }    /** * Regular Expression for CSV parse * * @return*/    PrivateString Getregexp () {final String special_char_a="[^\ ", \\n]"; Final String Special_char_b="[^\""+ Spacemark +"\\n]"; StringBuffer Strregexps=NewStringBuffer (); Strregexps.append ("\"((");        Strregexps.append (special_char_a); Strregexps.append ("*["+ Spacemark +"\\n]) *(");        Strregexps.append (special_char_a); Strregexps.append ("*\ "{2}) *) *");        Strregexps.append (special_char_a); Strregexps.append ("*\ "[]*"+ Spacemark +"[]*"); Strregexps.append ("|");        Strregexps.append (Special_char_b); Strregexps.append ("*[]*"+ Spacemark +"[]*"); Strregexps.append ("|\"((");        Strregexps.append (special_char_a); Strregexps.append ("*["+ Spacemark +"\\n]) *(");        Strregexps.append (special_char_a); Strregexps.append ("*\ "{2}) *) *");        Strregexps.append (special_char_a); Strregexps.append ("*\ "[]*"); Strregexps.append ("|");        Strregexps.append (Special_char_b); Strregexps.append ("*[]*"); returnstrregexps.tostring (); }    /** * If Argchar is exist in ARGSTR * * @param argchar * @param argstr * @return*/    Private Staticboolean isexisted (String Argchar, String argstr) {Boolean blnreturnvalue=false; if((Argstr.indexof (Argchar) >=0) && (Argstr.indexof (Argchar) <=argstr.length ())) {Blnreturnvalue=true; }        returnBlnreturnvalue; }}

CSV file parsing