Working with DML to Develop SQL Server based Java Applications using NetBeans IDE
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This article introduces you to a step-by-step process for developing Java (or JFC) based applications with Microsoft SQL Server as database, using NetBeans IDE. The third in a series, this article introduces you to working with DML statements such as SELECT, INSERT, UPDATE and DELETE.
A downloadable file for this article is available
here.
I already introduced about NetBeans IDE in my previous article "Developing Java Applications using NetBeans." Even though, that article is fairly an introductory article, the next two articles are concentrated on basics of JFC. You can find the next two articles here and here.
If you are new to NetBeans IDE, I strongly suggest you go through the existing articles first, before proceeding with this one. If you are new to developing Microsoft SQL Server based Java applications, I request you go through another article of mine here.
How to write the output of a SELECT statement to a text file using Java with NetBeans IDE: creating the application
We shall develop a small application with a button, ScrollPane and TextArea. When the button is hit, it needs to write out all the rows given by the SELECT statement to a text file. For the purpose of this series, I created a simple table named "emp" in the "Northwind" database of SQL Server 2000. The structure and rows available in the "emp" table will be as follows:
Empno Ename Sal Deptno
-------- -------------- ------------- ------
1001 Jag 4200.0 10
1002 Chat 5000.0 20
1003 Win 3500.0 10
1004 Dhan 4600.0 20
Currently, I named the project "SampleJavaApplication1" and the form (or JFrame) "DBSample03" in the package "MyDBPack."
When the form (or JFrame) is created with "DBSample03," the code behind it (only the constructor) would look something like the following:
public class DBSample03 extends javax.swing.JFrame {
/** Creates new form DBSample03 */
public DBSample03() {
initComponents();
}
Make changes to the above code fragment in such a way that it looks similar to the following:
public class DBSample03 extends javax.swing.JFrame {
/** Creates new form DBSample03 */
public DBSample03() {
initComponents();
this.setSize(300,200);
}
In the above code, I explicitly defined the initial size of the frame. Before dropping all the controls on the form, set the layout to "null layout" (fig 01) to ease our development for this article. When you complete your form design, it should look something like the first figure below, and the "inspector" view should look something like the second one.
Fig 1
Fig 2
For the convenience of writing understandable code, I named those controls as follows:
btnConnect
jScrollPane1
txtMsg
I also gave a value to the Frame property "title" (using the property window), namely "Writing SELECT output to file using Java: Demo."
You are also required to import the necessary packages as shown below:
import java.sql.*;
import java.util.*;
import java.io.*;
"java.io" is necessary to work with "streams" in java.
Next: How to write the output of a SELECT statement to a text file using Java with NetBeans IDE: source code >>
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