java - Reading from a CSV file -

try {     bufferedreader br = new bufferedreader(new inputstreamreader(item.getinputstream()));     string strline = "";     stringtokenizer st = null;     while ((strline = br.readline()) != null) {         st = new stringtokenizer(strline, "\t");         while (st.hasmoretokens()) {             urlcnt = st.nexttoken();             srccnt = st.nexttoken();             contenttype = st.nexttoken();             verticle = st.nexttoken();             timeframe = st.nexttoken();         }         if (con == null) {             sqlconnection.seturl("jdbc:sqlserver://192.168.2.53\\sql2005;user=sa;password=365media;databasename=ln_adweek");             con = sqlconnection.getnewconnection();             stmt = con.createstatement();         }         try {             resultset rs;             boolean hasrows = false;             rs = stmt.executequery("select url urls_temp url='"+urlcnt+"'");             while (rs.next()) {                 hasrows=true;                 i++;             }             if (!hasrows) {                 j++;                 preparedstatement inserturlstatement = con.preparestatement("insert urls_temp(url, source_name, is_active, is_periodic, link_type, new_entry, verticle, periodic_timeframe) values(?, ?, ?, ?, ?, ?, ?, ?)");                 if (timeframe.equalsignorecase("daily")) {                     inserturlstatement.setstring(1, urlcnt);                     inserturlstatement.setstring(2, srccnt);                     inserturlstatement.setint(3, 1);                     inserturlstatement.setint(4, 0);                     inserturlstatement.setstring(5, contenttype);                     inserturlstatement.setint(6, 1);                     inserturlstatement.setstring(7, verticle);                     inserturlstatement.setstring(8, timeframe);                     inserturlstatement.executeupdate();                     inserturlstatement.close();                 } else {                     inserturlstatement.setstring(1, urlcnt);                     inserturlstatement.setstring(2, srccnt);                     inserturlstatement.setint(3, 1);                     inserturlstatement.setint(4, 1);                     inserturlstatement.setstring(5, contenttype);                     inserturlstatement.setint(6, 1);                     inserturlstatement.setstring(7, verticle);                     inserturlstatement.setstring(8, timeframe);                     inserturlstatement.executeupdate();                 }             }         }     } } 

the above code used uploading details database given tab separated in csv file.

sample format of csv file follows , works fine:

http://avb.com(tab space)asdf(tab space)asdf(tab space)asdd(tab space)asdf

http://anything.com(tab space)asdf(tab space)asdf(tab space)asdfasd(tab space)asdfsadf

sometimes may need null values inserted database csv file follows:

http://asdf.com(tab space)(tab space)aasddf(tab space)(tab space)asdfsad

but not working, nothing getting inserted database.

what modification has done above program inserting null values in second , fourth (srccnt & verticle) columns of table?

stringtokenizer treats consecutive delimiters single delimiter. input contains [tab space] delimiters, rest of code doesn't seem expecting spaces so, without more information, i'm going guess input delimited tabs (not [tab space]), , adjacent delimiters being ignored, last nexttoken() throws exception ignoring.

the answer here rewrite using split(), recommended in javadoc

stringtokenizer legacy class retained compatibility reasons although use discouraged in new code. recommended seeking functionality use split method of string or java.util.regex package instead.

that said, should @ of existing csv libraries out there (google java csv).