how to put error checking on a code
hi im creating a daily dairy prototype i have almost finished the code it works but there no error checking and i dont know how to write a code to help me validate my prototype here is the code:
import java.applet.Applet;
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.Label;
import java.awt.Panel;
import java.awt.TextField;
import java.awt.Component;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.ParseException;
import java.awt.List;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JTextField;
public class DailyDairy extends Applet implements ActionListener {
DailyDairy panel1, panel2, panel3, panel4;
Component[][] rowData;
private JComboBox[] jcboxShapeCombo = new JComboBox[7];
private String [] shapeName={"Meeting", "Lunch", "Holiday", "Sickness", "Preparing report", "Administrative work", "Emails", "Query"};
/**
*
*/
public void init(){
setLayout(new BorderLayout());
setBounds (20, 30, 300, 180);
Panel headerPanel = new Panel();
headerPanel.setLayout(new GridLayout(1,4));
//JButton button1 = new JButton("SUBMIT");
//add(button1);
Label lblHeader = new Label("Start Time");
headerPanel.add(lblHeader);
lblHeader = new Label();
headerPanel.add(lblHeader);
add(headerPanel, BorderLayout.NORTH);
Label lblHeader1 = new Label("End Time");
headerPanel.add(lblHeader1);
lblHeader1 = new Label();
headerPanel.add(lblHeader1);
add(headerPanel, BorderLayout.NORTH);
Label lblHeader2 = new Label("Category of Task");
headerPanel.add(lblHeader2);
lblHeader2 = new Label();
headerPanel.add(lblHeader2);
add(headerPanel, BorderLayout.WEST);
Label lblHeader3 = new Label("Comment");
headerPanel.add(lblHeader3);
lblHeader3 = new Label();
headerPanel.add(lblHeader3);
add(headerPanel, BorderLayout.NORTH);
Label lblHeader4 = new Label("Total Time(Minutes)");
headerPanel.add(lblHeader4);
lblHeader4 = new Label();
headerPanel.add(lblHeader4);
add(headerPanel, BorderLayout.NORTH);
Panel data = new Panel();
data.setLayout(new GridLayout(7, 4));
rowData = new Component[ 7 ][];
// One row
for(int row = 0; row < 7; row++) {
rowData[ row ] = new Component[ 5 ];
rowData[ row ][ 0 ] = new TextField(10);
rowData[ row ][ 1 ] = new TextField(10);
((TextField)rowData[ row ][ 1 ]).addActionListener(this);
rowData[ row ][ 2 ]= new JComboBox (shapeName);
((JComboBox)rowData[ row ][ 2 ]).addActionListener(this);
//((TextField)rowData[ row ][ 2 ]).addActionListener(this);
rowData[ row ][ 3 ] = new TextField(10) ;
((TextField)rowData[ row ][ 3 ]).addActionListener(this);
//JComboBox jcboxShapeCombo;
//System.out.println(rowData[row][2]);
//jcboxShapeCombo[2] = new JComboBox (shapeName);
//rowData[ row ][ 3 ] = new TextField(10);
rowData[ row ][ 4 ] = new TextField(10);
((TextField)rowData[ row ][ 4 ]).addActionListener(this);
java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("h:mm");
((TextField) rowData[ row ][ 0 ]).setText(sdf.format(new java.util.Date()));
data.add(rowData[ row ][ 0 ]);
data.add(rowData[ row ][ 1 ]);
data.add(rowData[ row ][ 2 ]);
data.add(rowData[ row ][ 3 ]);
data.add(rowData[ row ][ 4 ]);
}
add(data, BorderLayout.CENTER);
}
public void actionPerformed(ActionEvent event) {
java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("h:mm");
java.util.Date start = new java.util.Date();
try {
start = sdf.parse(((TextField)rowData[ 0 ][ 0 ]).getText());
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
java.util.Date end = new java.util.Date();
try {
end = sdf.parse(((TextField)rowData[ 0 ][ 1 ]).getText());
//System.out.println("end" +end.getTime());
//System.out.println("start" +start.getTime());
if (end.getTime() > 0) {
long difference = (end.getTime() - start.getTime()) / 60000L;
((TextField)rowData[ 0 ][ 4 ]).setText(Long.toString(difference));
}
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//long difference = (end.getTime() - start.getTime()) / 60000;
//java.util.Date difference = new java.util.Date();
java.util.Date start1 = new java.util.Date();
try {
start1 = sdf.parse(((TextField)rowData[ 1 ][ 0 ]).getText());
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
java.util.Date end1 = new java.util.Date();
try {
end1 = sdf.parse(((TextField)rowData[ 1 ][ 1 ]).getText());
if (end1.getTime() > 0) {
long difference1 = (end1.getTime() - start1.getTime()) / 60000;
//java.util.Date difference = new java.util.Date();
((TextField)rowData[ 1 ][ 4 ]).setText(Long.toString(difference1));
}
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
java.util.Date start2 = new java.util.Date();
try {
start2 = sdf.parse(((TextField)rowData[ 2 ][ 0 ]).getText());
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
java.util.Date end2 = new java.util.Date();
try {
end2 = sdf.parse(((TextField)rowData[ 2 ][ 1 ]).getText());
if (end2.getTime() > 0) {
long difference2 = (end2.getTime() - start2.getTime()) / 60000;
//java.util.Date difference = new java.util.Date();
((TextField)rowData[ 2 ][ 4 ]).setText(Long.toString(difference2));
}
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//long difference2 = (end2.getTime() - start2.getTime()) / 60000;
//java.util.Date difference = new java.util.Date();
//((TextField)rowData[ 2 ][ 4 ]).setText(Long.toString(difference2));
java.util.Date start3 = new java.util.Date();
try {
start3 = sdf.parse(((TextField)rowData[ 3 ][ 0 ]).getText());
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
java.util.Date end3 = new java.util.Date();
try {
end3 = sdf.parse(((TextField)rowData[ 3 ][ 1 ]).getText());
if (end3.getTime() > 0) {
long difference3 = (end3.getTime() - start3.getTime()) / 60000;
((TextField)rowData[ 3 ][ 4 ]).setText(Long.toString(difference3));
}
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//long difference3 = (end3.getTime() - start3.getTime()) / 60000;
//java.util.Date difference = new java.util.Date();
java.util.Date start4 = new java.util.Date();
try {
start4 = sdf.parse(((TextField)rowData[ 4 ][ 0 ]).getText());
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
java.util.Date end4 = new java.util.Date();
try {
end4 = sdf.parse(((TextField)rowData[ 4 ][ 1 ]).getText());
if (end4.getTime() > 0) {
long difference4 = (end4.getTime() - start4.getTime()) / 60000;
((TextField)rowData[ 4 ][ 4 ]).setText(Long.toString(difference4));
}
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//long difference4 = (end4.getTime() - start4.getTime()) / 60000;
//java.util.Date difference = new java.util.Date();
//JTextField aField= (JTextField)event.getSource();
//if (aField)== rowData[ 0 ][ 1 ])calc row(0, 4);
//if (aField)== rowData[ 1 ][ 1 ])calc row(1, 4);
}
}
