Using the Insert statement in a Java program without hardcoding the data
hello.
this is james mcfadden. i have developed a program called Demo.java, which is used with another program called QueryTableModel.java (a program that allows data to be viewed in a JTable). The Demo.java program displays a menu, connects to a database, allows the user to add data into the database and allows the user to view data that is already in the database. I have a problem with the Demo.java program. I have hardcoded the Insert statement in it. How do you use the Insert statement to put data into a database without hardcoding the data?
import java.awt.*;//Contains all of the classes for creating user interfaces and for painting graphics and images
import java.awt.event.*;//Provides interfaces and classes for dealing with different types of events fired by AWT components
import javax.swing.*;//Provides a set of lightweight components that, to the maximum degree possible, work the same on all platforms
import javax.swing.table.*;//Provides classes and interfaces for dealing with javax.swing.JTable
import javax.swing.JOptionPane;//provides a class that makes it easy to pop up a standard dialog box that prompts users for a value or informs them of something
import java.sql.*;//Provides the API for accessing and processing data stored in a data source using the Java programming language
publicclass Demoextends JFrame{
static String url ="jdbc:odbc:VideoLibrary";//a static variable that allows a connection to be made to a database called VideoLibrary
static Statement stmt;//a static variable that allows a statement to be made once a connection is set up
static Connection con;//a static interface that allows a connection to be made to a database
//global variables
JTextField hostField;//a class that allows a line of text to be changed
JTextField queryField;//a class that allows a line of text to be changed
QueryTableModel qtm;//a class that shows and changes regular two-dimensional tables of cells
JComboBox comboBox;//a class that puts a button or editable field and a drop-down list together
publicstaticvoid main(String args[]){
int choice=-1;//a variable of type int that is set to -1
do{
choice=getChoice();//invokes the method getChoice()
if(choice!=0){
getSelected(choice);//invokes the method getSelected(choice)
}//end if
//if the user chooses 5, it will cause him or her to exit the system
}while(choice!=5);//end do-while
System.exit(0);//closes down the menu screen
}//end main
publicstaticint getChoice(){
String choice;//a variable of type string
int ch;//a variable of type int
choice = JOptionPane.showInputDialog(null,"1. Maintain product details\n"+"2. Maintain member details\n"+"3. Maintain rental details\n"+"4. View product, member and rental details\n"+"5. Log Off\n\n"+"Enter your choice");//asks the user for some input
ch = Integer.parseInt(choice);//a class that wraps a value of the primitive type int in an object
return ch;//a method that returns an integer value
}//end getChoice
publicstaticvoid getSelected(int choice){
if(choice==1){
maintainProductDetails();//invokes the method maintainProductDetails()
}//end if
if(choice==2){
maintainMemberDetails();//invokes the method maintainMemberDetails()
}//end if
if(choice==3){
maintainRentalDetails();//invokes the method maintainRentalDetails()
}//end if
if(choice==4){
Demo test =new Demo();//invokes the constructor Demo()
test.setVisible(true);//shows the JTable component by marking it as visible
}//end if
}//end getSelected
publicstatic Connection getConnection(){
try{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");//used to create a JDBC connection using a database
}//end try
catch(java.lang.ClassNotFoundException e){//causes an exception to be thrown when an application tries to load in a class through its string name
System.err.print("ClassNotFoundException: ");//displays an error message
System.err.println(e.getMessage());//returns the exception that was raised if an error occurred while attempting to load the ClassNotFoundException class
}//end catch
try{
con=DriverManager.getConnection(url,"","");//tries to create a connection with the database using the DriverManager class
}//end try
catch(SQLException ex){
System.err.println("SQLException: " + ex.getMessage());//returns an SQL error message
}//end catch
return con;
}//end getConnection
publicstaticvoid maintainProductDetails(){
Connection con = getConnection();//creates a connection with the database
String addProduct1, addProduct2, addProduct3, addProduct4, addProduct5, addProduct6, addProduct7, addProduct8, addProduct9, addProduct10;//string variables that represent information about the different types of product data that will be stored in the database
addProduct1 ="insert into Product values (110001, 'The Killers - Sams Town', 5.00, 'G', 'CD', 2006)";
addProduct2 ="insert into Product values (110002, 'Robbie Williams - Rudebox', 5.00, 'G', 'CD', 2006)";
addProduct3 ="insert into Product values (110003, 'Razorlight - Razorlight', 5.00, 'G', 'CD', 2006)";
addProduct4 ="insert into Product values (110004, 'My Chemical Romance - The Black Parade', 5.00, 'G', 'CD', 2006)";
addProduct5 ="insert into Product values (110005, 'Snow Patrol - Eyes Open', 5.00, 'G', 'CD', 2006)";
addProduct6 ="insert into Product values (110006, 'Scissor Sisters - Ta-Dah!', 5.00, 'G', 'CD', 2006)";
addProduct7 ="insert into Product values (110007, 'Lovesounds - Justin Timberlake', 5.00, 'G', 'CD', 2006)";
addProduct8 ="insert into Product values (110008, 'Director - We thrive on big cities', 5.00, 'G', 'CD', 2006)";
addProduct9 ="insert into Product values (110009, 'Roxette - Roxette hits', 5.00, 'G', 'CD', 2006)";
addProduct10 ="insert into Product values (110010, 'Pussy Cat Dolls - PCD', 5.00, 'G', 'CD', 2006)";
try{
stmt = con.createStatement();//Creates a Statement object for sending SQL statements to the database
//statements are allowed to be made once a connection is set up
stmt.executeUpdate(addProduct1);
stmt.executeUpdate(addProduct2);
stmt.executeUpdate(addProduct3);
stmt.executeUpdate(addProduct4);
stmt.executeUpdate(addProduct5);
stmt.executeUpdate(addProduct6);
stmt.executeUpdate(addProduct7);
stmt.executeUpdate(addProduct8);
stmt.executeUpdate(addProduct9);
stmt.executeUpdate(addProduct10);
stmt.close();//closes the Statement object
con.close();//terminates the connection with the database
}//end try
catch(SQLException ex){
System.err.println("SQLException: " + ex.getMessage());//returns an SQL error message
}//end catch
}//end maintainProductDetails
publicstaticvoid maintainMemberDetails(){
Connection con = getConnection();//creates a connection with the database
String addMember1, addMember2, addMember3, addMember4, addMember5, addMember6, addMember7, addMember8, addMember9, addMember10;//string variables that represent information about the member data that will be stored in the database
addMember1 ="insert into Member values (1234, 'Ann', 'Smyth', 'Upper Killult, Falcarragh, Co. Donegal', '(074)-9135210', '(087)-2030172', #5/11/85#, #5/12/06#)";
addMember2 ="insert into Member values (2345, 'John', 'Murphy', 'Lower Killult, Falcarragh, Co. Donegal', '(074)-9135211', '(087)-2030173', #4/12/85#, #6/13/06#)";
addMember3 ="insert into Member values (1324, 'James', 'McFadden', 'Lower Ardsbeg, Gortahork, Co. Donegal', '(074)-9165314', '(087)-2030171', #4/11/85#, #6/14/06#)";
addMember4 ="insert into Member values (1235, 'Frankie', 'Ferry', 'Ardsmore, Gortahork, Co. Donegal', '(074)-9165325', '(087)-2031234', #6/13/60#, #6/15/06#)";
addMember5 ="insert into Member values (1236, 'Daniel', 'McKimm', 'Ballyness, Falcarragh, Co. Donegal', '(074)-9135212', '(087)-2030184', #5/14/73#, #6/16/06#)";
addMember6 ="insert into Member values (2346, 'Stephen', 'Doohan', 'Ballyness, Falcarragh, Co. Donegal', '(074)-9135213', '(087)-2030185', #6/13/85#, #5/13/06#)";
addMember7 ="insert into Member values (2347, 'James', 'Ferry', 'Meenlaragh, Gortahork, Co.Donegal', '(074)-9165360', '(087)-2031345', #9/12/85#, #5/14/06#)";
addMember8 ="insert into Member values (2348, 'Liam', 'Cannon', 'Derryconner, Gortahork, Co.Donegal', '(074)-9165324', '(087)-2031456', #4/11/86#, #5/15/06#)";
addMember9 ="insert into Member values (2401, 'Ciaran', 'Ferry', 'Brinalack, Gweedore, Co.Donegal', '(074)-9176425', '(087)-2030282', #9/12/85#, #5/16/06#)";
addMember10 ="insert into Member values (2402, 'Ciaran', 'McGee', 'Derrybeg, Gweedore, Co.Donegal', '(074)-9176536', '(087)-2030393', #9/14/85#, #5/18/06#)";
try{
stmt = con.createStatement();//Creates a Statement object for sending SQL statements to the database
//statements are allowed to be made once a connection is set up
stmt.executeUpdate(addMember1);
stmt.executeUpdate(addMember2);
stmt.executeUpdate(addMember3);
stmt.executeUpdate(addMember4);
stmt.executeUpdate(addMember5);
stmt.executeUpdate(addMember6);
stmt.executeUpdate(addMember7);
stmt.executeUpdate(addMember8);
stmt.executeUpdate(addMember9);
stmt.executeUpdate(addMember10);
stmt.close();//closes the Statement object
con.close();//terminates the connection with the database
}//end try
catch(SQLException ex){
System.err.println("SQLException: " + ex.getMessage());//returns an SQL error message
}//end catch
}//end maintainMemberDetails
publicstaticvoid maintainRentalDetails(){
Connection con = getConnection();//creates a connection with the database
String addRental1, addRental2, addRental3, addRental4, addRental5, addRental6, addRental7, addRental8, addRental9, addRental10;//string variables that represent information about the loan data that will be stored in the database
addRental1 ="insert into Rental values (110001, 'The Killers - Sams Town', 1234, 'Ann', 'Smyth', #9/01/06#, #9/10/06#, 'Yes', 2.00)";
addRental2 ="insert into Rental values (120001, 'Mission Impossible 3', 2345, 'John', 'Murphy', #9/02/06#, #9/09/06#, 'No', 0.00)";
addRental3 ="insert into Rental values (130001, 'Need for Special Carbon', 1324, 'James', 'McFadden', #9/03/06#, #9/12/06#, 'Yes', 2.00)";
addRental4 ="insert into Rental values (110002, 'Robbie Williams - Rudebox', 1235, 'Frankie', 'Ferry', #9/04/06#, #9/11/06#, 'No', 0.00)";
addRental5 ="insert into Rental values (120015, 'Prime', 1236, 'Daniel', 'McKimm', #9/05/06#, #9/14/06#, 'Yes', 2.00)";
addRental6 ="insert into Rental values (130015, 'FIFA 07', 2346, 'Stephen', 'Doohan', #9/06/06#, #9/13/06#, 'No', 0.00)";
addRental7 ="insert into Rental values (110009, 'Roxette - Roxette hits', 2347, 'James', 'Ferry', #9/07/06#, #9/16/06#, 'Yes', 2.00)";
addRental8 ="insert into Rental values (120003, 'The Break Up', 2348, 'Liam', 'Cannon', #9/08/06#, #9/15/06#, 'No', 0.00)";
addRental9 ="insert into Rental values (130027, 'Gears of War', 2401, 'Ciaran', 'Ferry', #9/09/06#, #9/18/06#, 'Yes', 2.00)";
addRental10 ="insert into Rental values (110021, 'Scooter - Mind the Gap', 2402, 'Ciaran', 'McGee', #9/10/06#, #9/17/06#, 'No', 0.00)";
try{
stmt = con.createStatement();//Creates a Statement object for sending SQL statements to the database
//statements are allowed to be made once a connection is set up
stmt.executeUpdate(addRental1);
stmt.executeUpdate(addRental2);
stmt.executeUpdate(addRental3);
stmt.executeUpdate(addRental4);
stmt.executeUpdate(addRental5);
stmt.executeUpdate(addRental6);
stmt.executeUpdate(addRental7);
stmt.executeUpdate(addRental8);
stmt.executeUpdate(addRental9);
stmt.executeUpdate(addRental10);
stmt.close();//closes the Statement object
con.close();//terminates the connection with the database
}//end try
catch(SQLException ex){
System.err.println("SQLException: " + ex.getMessage());//returns an SQL error message
}//end catch
}//end maintainRentalDetails
public Demo(){//a constructor
super("Demo Test Frame");//overrides the constructor
setSize(350, 200);//Resizes this component so that it has width of 350 and height of 200
comboBox =new JComboBox();//invokes the class JComboBox
comboBox.addItem("jdbc:odbc:VideoLibrary");//adds the specified item to the end of the scrolling list
qtm =new QueryTableModel();//invokes the class QueryTableModel
JTable table =new JTable(qtm);//a class that shows and changes regular two-dimensional tables of cells
JScrollPane scrollpane =new JScrollPane(table);//a class that provides a scrollable view of a lightweight component
JPanel p1 =new JPanel();//a class that puts the combo box and query field in a panel
p1.setLayout(new GridLayout(3, 2));//Sets the layout manager for this container
p1.add(comboBox);//Appends the specified component to the end of this container
p1.add(new JLabel("Enter your query: "));//Appends the specified component to the end of this container
p1.add(queryField =new JTextField());//Appends the specified component to the end of this container
p1.add(new JLabel("Click here to send: "));//Appends the specified component to the end of this container
JButton jb =new JButton("Search");//a class that is an implementation of a "push" button
jb.addActionListener(new ActionListener(){//Adds an ActionListener to the button
publicvoid actionPerformed(ActionEvent e){
qtm.setHostURL();//invokes the method setHostURL
qtm.setQuery(queryField.getText().trim());//invokes the method setQuery; and returns the text that is presented by this text component and returns a copy of the string, with leading and trailing whitespaces omitted
}
} );//end addActionListener
p1.add(jb);//Appends the specified component to the end of this container
getContentPane().add(p1, BorderLayout.NORTH);//Returns the content pane
getContentPane().add(scrollpane, BorderLayout.CENTER);//Returns the content pane
}//end Demo
}//end class Demo
import java.sql.*;//Provides the API for accessing and processing data stored in a data source using the Java programming language
import java.io.*;//Provides for system input and output through data streams, serialization and the file system
import java.util.Vector;//provides a class that implements a growable array of objects
import javax.swing.*;//Provides a set of lightweight components that, to the maximum degree possible, work the same on all platforms
import javax.swing.table.*;//Provides classes and interfaces for dealing with javax.swing.JTable
publicclass QueryTableModelextends AbstractTableModel{
Vector cache;//a class that constructs an empty vector so that its internal data array has size 10 and its standard capacity increment is zero
int colCount;//a variable that counts the number of columns in the three tables
String[] headers;//a class that represents character strings and all string literals in this program are implemented as instances of the String class
Connection db;//an interface that allows a connection to be made to a database
Statement statement;//an interface that allows executes the given SQL statement, which returns a single ResultSet object
String currentURL;//a variable that allows the URL to be displayed in a combo box
public QueryTableModel(){//a constructor
cache=new Vector();//constructs an empty vector so that its internal data array has size 10 and its standard capacity increment is zero
try{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");//used by opening a JDBC connection using an URL
}//end try
catch(Exception e){
System.out.println("problem loading the driver ");//an error message
}//end catch
}//end QueryTableModel
public String getColumnName(int i){//Returns the designated column's name
return headers[i];//returns the name of each column in the three table
}//end getColumnName
publicint getColumnCount(){//Returns the number of columns in the column model
return colCount;//returns the number of columns in the three tables
}//end getColumnCount
publicint getRowCount(){//Returns the number of rows in this table's model
return cache.size();//returns the number of components in the vector
}//end getRowCount
public Object getValueAt(int row,int col){//Returns the cell value at row and column
return ((String[])cache.elementAt(row))[col];//Returns the component at the specified index
}//end getValueAt
publicvoid setHostURL(){//sets the URL for the database
String url ="jdbc:odbc:VideoLibrary";//a variable that allows a connection to be made to a database called VideoLibrary
closeDB();//invokes the method closeDB()
try{
db=DriverManager.getConnection(url,"","");//tries to create a connection with the database using the DriverManager class
statement=db.createStatement();//Creates a Statement object for sending SQL statements to the database
}//end try
catch(Exception e){
System.out.println("Could not initialize the database.");//an error message
e.printStackTrace();//a Throwable method that prints this throwable and it's backtrace to the standard error stream
}//end catch
}//end setHostURL
publicvoid setQuery(String q){//sets the kind of query that is to be sent to the database
cache=new Vector();//constructs an empty vector so that its internal data array has size 10 and its standard capacity increment is zero
String s="select * from Product";//a variable that causes all the data that is in the product table to be displayed in a JTable, which also means that all the data that is in both the member and rental tables can also be displayed in a JTable
try{
ResultSet rs=statement.executeQuery(q);//an interface that is used to generate a database result set by executing a statement that queries the database
ResultSetMetaData meta=rs.getMetaData();//an interface that is used to get information about the types and properties of the columns in a ResultSet object
colCount=meta.getColumnCount();//Returns the number of columns in this ResultSet object
headers=new String[colCount];//gets the name of each column in the three tables
for(int h=1;h<=colCount;h++){
headers[h-1]=meta.getColumnName(h);//Get the designated column's name
}//end for
while(rs.next()){
String[] record=new String[colCount];//stores the name of each column in the three tables in memory
for(int i=0;i<colCount;i++){
record[i]=rs.getString(i+1);//Retrieves the value of the designated column in the current row of this ResultSet object as a String
}//end for
cache.addElement(record);//Adds the specified component to the end of this vector, increasing its size by one
}//end while
fireTableChanged(null);//Forwards the given notification event to all TableModelListeners that registered themselves as listeners for this table model
}//end try
catch(Exception e){
cache=new Vector();//constructs an empty vector so that its internal data array has size 10 and its standard capacity increment is zero
e.printStackTrace();//a Throwable method that prints this throwable and it's backtrace to the standard error stream
}//end catch
}//end setQuery
publicvoid initDB(String url){
try{
db=DriverManager.getConnection(url);//tries to create a connection with the database using the DriverManager class
statement=db.createStatement();//Creates a Statement object for sending SQL statements to the database
}//end try
catch(Exception e){
System.out.println("Could not initialize the database.");//an error message
e.printStackTrace();//a Throwable method that prints this throwable and it's backtrace to the standard error stream
}//end catch
}//end initDB
publicvoid closeDB(){
try{
if(statement!=null){
statement.close();//Releases this Statement object's database and JDBC resources immediately instead of waiting for this to happen when it is automatically closed
}//end if
if(db!=null){
db.close();//Releases this Connection object's database and JDBC resources immediately instead of waiting for them to be automatically released
}//end if
}//end try
catch(Exception e){
System.out.println("Could not close the current connection.");//an error message
e.printStackTrace();//a Throwable method that prints this throwable and it's backtrace to the standard error stream
}//end catch
}//end closeDB
}//end class QueryTableModel
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