Start Free Trial

asked on

StringTokenizer working on plain String text but not on String from MS Access (text = rs.getString(1);)

Hey,

I have a problem using a string, that I have read from a MS Access-database, in a StringTokenizer. I have to user the StringTokenizer to recognize \n so that I can put all separate lines into an array that I will later paint with a drawString()

Below is an working example where I get the text from a simple String text:

(I have declared "String text;" in my class far up in the code)

text = "this is row 1\nthis is row 2\nthis is row 3";

StringTokenizer st = new StringTokenizer(text,"\n");
num_lines = st.countTokens();
lines = new String[num_lines];
line_widths = new int[num_lines];
for (int i = 0; i < num_lines; i++){
lines[i] = st.nextToken();

This works like a charm and I have an array with the length of 3.

Below is the example I want to get working and that just wont work:

try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); // Calling the JDBC:ODBC bridge to be able to connect to our MS Access database
String filename = "c:/jollydb.mdb"; // declaring and setting the database-file variable
String database = "jdbc:odbc:Driver={Microsoft Access Driver (*.mdb)};DBQ="; // declaring and assigning the database driver variable
database+= filename.trim() + ";DriverID=22;READONLY=true}";
Connection con = DriverManager.getConnection( database ,"",""); // creating a connection object to communicate with the database via DriverManager
Statement s = con.createStatement(); // creating a java.sql.Statement
s.execute("SELECT news_text FROM JT_content"); // getting the our text from the database
ResultSet rs = s.getResultSet(); // get any ResultSet that came from our query
while ( rs.next() ) { // stepping through our data row-by-row
text = rs.getString(1); // setting the text to be scrolled
}
s.close(); // closing the Statement
con.close(); // closing the Connection
}
catch (Exception e) {
System.out.println("Error: " + e);
}

StringTokenizer st = new StringTokenizer(text,"\n");
num_lines = st.countTokens();
lines = new String[num_lines];
line_widths = new int[num_lines];
for (int i = 0; i < num_lines; i++){
lines[i] = st.nextToken();

The output of this will be "this is row 1\nthis is row 2\nthis is row 3", meaning that it doesn't do **** with my "text"-string.
What am I doing wrong? I have tried to do text.toString(); on it but it doesn't help.

Would love a quick solution.

Maybe try

StringTokenizer st = new StringTokenizer(text,"[\n|\r|\n\r|\r\n]");

ASKER

zzynx

Thanks for your quick reply, but no it had no effect.

Hey, think that should be:

StringTokenizer st = new StringTokenizer(text,"\\n");

And if that doesn't work:

StringTokenizer st = new StringTokenizer(text,"[\\n|\\r|\\n\\r|\\r\\n]");

I read for the StringTokenizer constructor with only one parameter:

Constructs a string tokenizer for the specified string.
The tokenizer uses the default delimiter set, which is " \t\n\r\f": the space character, the tab character, the newline character, the carriage-return character, and the form-feed character. Delimiter characters themselves will not be treated as tokens.

So also try:

StringTokenizer st = new StringTokenizer(text);

mindweaver, sorry the StringTokenizer doesn't take regular expression.
It's the String.split() that does.
So if the previous doesn't work

Try:

String lines[] = text.split("\\n");
or
String lines[] = text.split(""[\\n|\\r|\\n\\r|\\r\\n]");

ASKER

Thanks alot!

StringTokenizer st = new StringTokenizer(text,"\\n");

worked like a charm!

Thanks

So, with

StringTokenizer st = new StringTokenizer(text,"\n");

you were searching for a sequence of
1) a back slash followed by
2) the character 'n'

instead of a newline.

I would really try
String lines[] = text.split("\\n");

That one line of code replaces all these

StringTokenizer st = new StringTokenizer(text,"\\n");
num_lines = st.countTokens();
lines = new String[num_lines];
line_widths = new int[num_lines];
for (int i = 0; i < num_lines; i++)
lines[i] = st.nextToken();

ASKER

Yeah I was looking for a backslash followed by the character n. I had manually put those \n into the text in the database field.

ASKER

too bad I can't use that oneliner you gave me, would be nice to get rid of all that code I put in and replace it with yours.

>>too bad I can't use that oneliner you gave me
Why nt?

ASKER

I tried it, I got no output. and isn't it looking for a "real" new line? There are no real line breaks in the db field (don't think it's possible in ms access) it's only a text string "this is row 1\nthis is row 2\nthis is row 3" in the db field.

>> There are no real line breaks in the db field
Oh, I see. Then you should try:

String lines[] = text.split("\n");

ASKER

Nope, tried it, gave me no output.

Code:

try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); // Calling the JDBC:ODBC bridge to be able to connect to our MS Access database
String filename = "c:/jollydb.mdb"; // declaring and setting the database-file variable
String database = "jdbc:odbc:Driver={Microsoft Access Driver (*.mdb)};DBQ="; // declaring and assigning the database driver variable
database+= filename.trim() + ";DriverID=22;READONLY=true}";
Connection con = DriverManager.getConnection( database ,"",""); // creating a connection object to communicate with the database via DriverManager
Statement s = con.createStatement(); // creating a java.sql.Statement
s.execute("SELECT news_text FROM JT_content"); // getting the our text from the database
ResultSet rs = s.getResultSet(); // get any ResultSet that came from our query
while ( rs.next() ) { // stepping through our data row-by-row
text = rs.getString(1); // setting the text to be scrolled
}
s.close(); // closing the Statement
con.close(); // closing the Connection
}
catch (Exception e) {
System.out.println("Error: " + e);
}

String lines[] = text.split("\n");
Font f = getFont(); // getting our font context
FontMetrics fm = getFontMetrics(f); // gettomg out FontMetrics
line_height = fm.getHeight(); // setting the line_height variable to the our font lineheight

for (int i=0; i<num_lines; i++){ // creating a loop for drawing all of our lines
g.drawString(lines[i], x, flexibleHeight + (i * line_height)); // drawing one line from the lines-array
}

Shouldn't

for (int i=0; i<num_lines; i++){

be

for (int i=0; i<lines.length; i++){

?

ASKER

Yeah :) damn have been looking at this code for 6 hours..

Thanks, still having problems though. Now I get an output but it gives the the whole string on one row :

"this is row 1\nthis is row 2\nthis is row 3"

tried both

String lines[] = text.split("\n");

and

String lines[] = text.split("\\n");

Damn, I wish I could give you more points for helping me.

Well, for me it works:

String inputString = "this is row 1\nthis is row 2\nthis is row 3";
String lines[] = inputString.split("\n");
System.out.println(lines.length); // <<<<<< this nicely prints "3"

Could you insert that line

System.out.println(lines.length);

in your code and tell the result?

>>Damn, I wish I could give you more points for helping me.
You're allowed to give 500 points per question.
Ask for reopening this one, incrementing the points and reaccept is an option.
;°)

ASKER

Yeah well that's the problem :) We are back at square one.

String inputString = "this is row 1\nthis is row 2\nthis is row 3";

You got it from a nice little text-string you made static in the code.
when I do that it works for me aswell, it is when I get the exact same
string from my database that it won't recognize my "\n"'s
I have no idea why and it is really frustrating:

text = rs.getString(1); // setting the text to be scrolled

__

String inputString = "this is row 1\nthis is row 2\nthis is row 3"; (lines.length = 3)

same string but in:

text = rs.getString(1); // setting the text to be scrolled (lines.length = 1)

Well, I would print out that "text" variable character by character (print out the ascii code) to see what Access made from that '\'+'n'
Once you know that you can pass it in split()

ASKER

Me too if I knew how to do it :)

String inputString = "A\nB\nC";
for (int i=0; i<inputString.length(); i++)
System.out.println(""+ inputString.charAt(i) + " - " +(int)inputString.charAt(i));

Prints out:

A - 65
// <<<<<< here the newline is printed out
- 10 // <<<<<< ASCII is indeed 10 (LineFeed)
B - 66

- 10
C - 67

Try it with putting "A\nB" in the database

ASKER

it gave me

A - 65

\ - 92

n - 110

B - 66

Have tried to read up on how to put it into the split()-thingie but can't figure it out.

ASKER CERTIFIED SOLUTION

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

At last ;°)

If you want to reopen this question, post a zero-point question in https://www.experts-exchange.com/Community_Support/

Subject: Moderator Please Reopen
Body: Please reopen this question:
https://www.experts-exchange.com/questions/21159428/StringTokenizer-working-on-plain-String-text-but-not-on-String-from-MS-Access-text-rs-getString-1.html

ASKER

awesome :) it worked!

thanks ALOT! :)

:)

Hi mindweaver,

ee_ai_construct tells us that this Q has been reopened.
But I didn't receive a new "Good Answer" mail, so I think it wasn't really reopened, right?
Or did I miss that mail and have you forgotten to increment the points before re-accepting?

Hi mindweaver,

Could you please make sure you
- *first* increment the points
- *then* re-accept the comment

(See the EE help pages if you don't know how to increment the points. Or ask here)

Thanks mindweaver