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how to write String values to csv file in java

I have situation where i need to write the values from database to csv file.I am putting all the values in a String.My String out put looks like [event1=0,event2=4,event3=5.............]
Event equal value is count.Now i need to write those values in to csv file as below

event count

event1 0

event2 4

event3 5

and so on.can anyone help me how to do that
I tried to use supercsv but i am not able write the data in to the file

for_yan

import java.io.FileOutputStream;
import java.io.PrintStream;
import java.util.StringTokenizer;

public class ParseEventString {
    public static void main(String[] args) {
        try{
            PrintStream psout = new PrintStream(new FileOutputStream("out.csv"));
            String s=    "event1=0,event2=4,event3=5";
            StringTokenizer t = new StringTokenizer(s,"=,");
            psout.println("Event,Count");
                  while(true){
                      if(t.hasMoreTokens()){
                          psout.println(t.nextToken()+","+t.nextToken());
                      } else break;
                  }

             psout.close();


        }   catch(Exception ex){
            ex.printStackTrace();
        }

    }

}

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Contents of out.csv:

Event,Count
event1,0
event2,4
event3,5

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ASKER CERTIFIED SOLUTION

for_yan

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for_yan

Another option is to use split(regex) method of class String:

import java.io.FileOutputStream;
import java.io.PrintStream;
import java.util.StringTokenizer;

public class ParseEventString {
    public static void main(String[] args) {
        try{
            PrintStream psout = new PrintStream(new FileOutputStream("out.csv"));
            String s1=    "[event1=0,event2=4,event3=5]";
               String s = s1.substring(1,s1.indexOf("]"));
                     psout.println("Event,Count");
                      

            String [] array = s.split("[=,]");
            for(int i=0; i<array.length; i=i+2) {
                psout.println(array[i] + "," + array[i+1]);
            }
          
             psout.close();


        }   catch(Exception ex){
            ex.printStackTrace();
        }

    }

}

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Contents of output file:

Event,Count
event1,0
event2,4
event3,5

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for_yan

And one more solution:

import java.io.FileOutputStream;
import java.io.PrintStream;
import java.util.StringTokenizer;

public class ParseEventString {
    public static void main(String[] args) {
        try{
            PrintStream psout = new PrintStream(new FileOutputStream("out.csv"));
            String s1=    "[event1=0,event2=4,event3=5]";

            psout.println("Event,Count");


            String [] array = s1.split("[=,\\[\\]]");
            for(int i=1; i<array.length-1; i=i+2) {
                psout.println(array[i] + "," + array[i+1]);
            }
           
             psout.close();


        }   catch(Exception ex){
            ex.printStackTrace();
        }

    }

}

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Output is of course the same:

Event,Count
event1,0
event2,4
event3,5

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CEHJ

Write the csv directly from the ResultSet or it's inefficient. Try something like

public static void resultSetToCsv(ResultSet rs, Writer out) {
		try {
			final String LINEFEED = System.getProperty("line.separator");
			ResultSetMetaData metaData = rs.getMetaData();
			int numberOfColumns = metaData.getColumnCount();

			// Get the column names
			String sep = "";

			for (int column = 0; column < numberOfColumns; column++) {
				System.out.print(sep);
				System.out.print(metaData.getColumnLabel(column + 1));
				sep = ",";
			}

			out.write(LINEFEED);

			// Get all rows.
			while (rs.next()) {
				sep = "";

				for (int i = 1; i <= numberOfColumns; i++) {
					System.out.print(sep);
					System.out.print("" + rs.getObject(i));
					sep = ",";
				}

				out.write(LINEFEED);
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			try {
				out.close();
			} catch (IOException e) { /* ignore */
			}
		}
	}

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googleart

ASKER

Thanks for the prompt suggestions.I tried both ways.they are working good for me.

Output is like this in csv
event count

event1 0
event2 3

is there anyway that i could color the first two columns in the first row.I mean how to color in csv for particular rows and columns

for_yan

I don't think you can color in the csv file.
For that you may want to go to Excel file say using POI - which will take much more work, but it can use
many finctions of Excel.
CSV is just plain text format - so I'm really not sure about the color - you can probably have some sophisticated editor which can read csv and color the headers,
but csv by itself is not concerned with formatting etc - it is just plain text

googleart

ASKER

Thank You Yan for the suggestions

googleart

ASKER

Yan I need to manipulate the Csv i get to xml .How can i do with the Xstream?

for_yan

Create an object with fields say EventName Eventvalue
and each time you get to two values - when youy are redy to write the line
in CSV in the code above create new instance of such object
EventObject eo = new EventObject(evetntname, eventvalue);
String xml = xstream.toXML(eo);
like in this example:

http://xstream.codehaus.org/tutorial.html

(section serializing object to XML)

Something of this sort should work

googleart

ASKER

I have got the xml ouptut as attached.
out.txt

googleart

ASKER

              XStream xstream = new XStream();
              String xml = xstream.toXML(map3);
              System.out.println("xml..."+xml);
the above code gives the xml as attached file

I am trying to change the elements name .is there anyway to do it?Thanks in advance

googleart

ASKER

i am getting the event and count values as hash map

for_yan

Don't understand what you mean by "attached file" ?
What is map3 and how do you create it?

googleart

ASKER

     while(resultSet.next()){
                        String event = resultSet.getString("EVENTTYPE");
                        int countEvent = resultSet.getInt("COUNTS");
                        map1.put(event,countEvent );
                  }

                  map3.putAll(map1);

this is how i created map3.attached file is the xml output,i have put in a txt file and attached it.sorry for confusion

for_yan

Which elemen names you want to change - "string" and "int" ?

googleart

ASKER

i want to change both the elements as String--EventType and int --Count

for_yan

look at that example more closely:
http://xstream.codehaus.org/tutorial.html

I am guessing the if you come up with some class
like EventInfo and it would have two fields String EventType and
int count and you will make ArrayList made up of the objects of
such class XStream will produce something similar with what you see in example
in the above link and your elements will be named EventType and count

googleart

ASKER

Thanks Yan it worked out.I have a small concern that is there anyway to convert print stream to string?

for_yan

Check here in the solution:
http://stackoverflow.com/questions/1760654/java-printstream-to-string

googleart

ASKER

I tried that but not sure how to get it as string.I need to send as to another method as String

for_yan

I think this is how you get String from PrintStream:

ByteArrayOutputStream baos = new ByteArrayOutputStream();
PrintStream ps = new PrintStream(baos);
ps.println(//do your printing here);

String content = baos.toString(charsetName);

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googleart

ASKER

it worked out previously i am giving wrong encoding.Thanks once again

ByteArrayOutputStream baos = new ByteArrayOutputStream();
PrintStream ps = new PrintStream(baos);
ps.println(//do your printing here);

String content = baos.toString("UTF-8");

for_yan

Great!