Write records into text file from database using java

Question

I want to store database records to text file. for that I used the ResultSet, I have selected the whole table using sql select query and store the data in the ArrayList. But this code doesn't work properly. my database name is test and table is employee. what should I do? this is what I have tried.

import java.io.*;
import java.sql.*;
import java.util.*;
public class ResultSetWriteInToTextFile {
    public static void main(String[] args) {
            List data = new ArrayList();
            try {
                    Connection con = null;
                    Class.forName("com.mysql.jdbc.Driver");
                    con = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "root");
                    Statement st = con.createStatement();
                    ResultSet rs = st.executeQuery("Select * from employee");

                    while (rs.next()) {
                            String id = rs.getString("emp_id");
                            String name = rs.getString("emp_name");
                            String address = rs.getString("emp_address");
                            String contactNo = rs.getString("contactNo");
                            data.add(id + " " + name + " " + address + " " + contactNo);

                    }
                    writeToFile(data, "Employee.txt");
                    rs.close();
                    st.close();
            } catch (Exception e) {
                    System.out.println(e);
            }
    }

    private static void writeToFile(java.util.List list, String path) {
            BufferedWriter out = null;
            try {
                    File file = new File(path);
                    out = new BufferedWriter(new FileWriter(file, true));
                    for (String s : list) {
                            out.write(s);
                            out.newLine();

                    }
                    out.close();
            } catch (IOException e) {
            }
    }

}

Why are you using a [raw type](http://stackoverflow.com/questions/2770321/what-is-a-raw-type-and-why-shouldnt-we-use-it)? Also, what part doesn't work properly? Is there an Exception? Do you get the wrong output? — Elliott Frisch, Jun 10 '14 at 13:42
@JProgrammer Is it on `(String s : list)`? Because that's a raw type. — Elliott Frisch, Jun 10 '14 at 13:51

score 3 · Accepted Answer · answered Jun 10 '14 at 13:56

3

Change this line:

for (String s : list) {

to

for (Object s : list) {

answered Jun 10 '14 at 13:56

fajarkoe

1,543
10
12

I have don. but now error at out.write(s); – JProgrammer Jun 10 '14 at 14:01
Great. Change out.write(s) to out.write((String) s) – fajarkoe Jun 10 '14 at 14:03

Dinal · Answer 2 · 2014-06-10T13:56:17.630

1

You cannot use for (String s : data) {}. You have no where mentioned that data is a List of Strings. Declare it as List<String> data = new ArrayList<String>();. Hope you are using Java 1.5 or higher.

Also you need to give an absolute file path.

String path = "D:/Sample/Employee.txt" //whatever path you are using
File file = new File(path);
File parent_directory = file.getParentFile();
if (parent_directory != null) {
   parent_directory.mkdirs();
}

edited Jun 10 '14 at 13:56

answered Jun 10 '14 at 13:46

Dinal

661
4
9

are u sure???? I have tried this way. not running – JProgrammer Jun 10 '14 at 13:48
Have you included the code for creating parent folders? Also make sure that you have write access to the path that you provide. – Dinal Jun 10 '14 at 13:50
@JProgrammer, Have updated the answer, pointing out one more issue. – Dinal Jun 10 '14 at 13:57

score 1 · Answer 3 · answered Jun 10 '14 at 14:04

1

Don't use raw types! Change List data = new ArrayList(); to

List<String> data = new ArrayList<String>();

and change writeToFile(java.util.List list, String path) { to

writeToFile(java.util.List<String> list, String path) {

answered Jun 10 '14 at 14:04

Elliott Frisch

198,278
20
158
249

score 0 · Answer 4 · answered Jun 10 '14 at 13:52

First make sure that your file path is correct, and that all of the directories exist.

Also, you have a try-catch statement in writeToFile. That method is called inside another try-catch statement. In the function declaration for writeToFile, try something like this:

private static void writeToFile(java.util.List list, String path) throws IOException`

You can then remove the try-catch statement in writeToFile, as if that exception is thrown, it is handled by the try-catch in the main method.

If that doesn't work, make sure that your code is connecting to the database properly.

Write records into text file from database using java

4 Answers4