GWT RPC - Why the results from database are printed twice ? - gwt

Question

I am writing a simple app to enter a user into database & display list of users using GWT RPC, Hibernate in Eclipse. The problem I am getting is that the list of users is printed twice.
Here is my code where I call insert user & display users list methods.
package rpctest.client;
import java.util.ArrayList;
import rpctest.shared.User;
import rpctest.shared.FieldVerifier;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.core.client.GWT;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyPressEvent;
import com.google.gwt.event.dom.client.KeyUpEvent;
import com.google.gwt.event.dom.client.KeyUpHandler;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.rpc.AsyncCallback;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.DialogBox;
import com.google.gwt.user.client.ui.FlexTable;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.TextBox;
import com.google.gwt.user.client.ui.VerticalPanel;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyPressEvent;
import com.google.gwt.event.dom.client.KeyPressHandler;
/**
* Entry point classes define <code>onModuleLoad()</code>.
*/
public class Rpctest implements EntryPoint {
final TextBox firstName = new TextBox();
final TextBox lastName = new TextBox();
final Button ans = new Button("Add User");
//final Label label1 = new Label("First Name");
//final Label label2 = new Label("Last Name");
private FlexTable userFlexTable = new FlexTable();
//final Label errorLabel = new Label();
private VerticalPanel mainpanel = new VerticalPanel();
private HorizontalPanel addpanel1 = new HorizontalPanel();
private HorizontalPanel addpanel2 = new HorizontalPanel();
private final RpctestServiceAsync callService = GWT
.create(RpctestService.class);
/**
* This is the entry point method.
*/
public void onModuleLoad() {
userFlexTable.setText(0, 0, "User ID");
userFlexTable.setText(0, 1, "First Name");
userFlexTable.setText(0, 2, "Second Name");
userFlexTable.setText(0, 3, "Remove");
//add input boxes to panel
addpanel1.add(firstName);
addpanel1.add(lastName);
firstName.setFocus(true);
//add input/result panels
mainpanel.add(userFlexTable);
mainpanel.add(addpanel1);
addpanel1.add(ans);
ans.addClickHandler(new ClickHandler() {
#Override
public void onClick(ClickEvent event) {
addStock();
}
});
lastName.addKeyPressHandler(new KeyPressHandler() {
public void onKeyPress(KeyPressEvent event) {
if (event.getCharCode() == KeyCodes.KEY_ENTER) {
addStock();
}
}
});
RootPanel.get().add(mainpanel);
getUser();
}
private void addStock(){
String name1 = firstName.getValue();
// Stock code must be between 1 and 10 chars that are numbers, letters, or dots.
/*if (!name1.matches("^[0-9A-Z\\.]{1,10}$")) {
Window.alert("'" + name1 + "' is not a valid name.");
firstName.selectAll();
return;
}*/
firstName.setValue("");
String name2 = lastName.getValue();
/*if (!name2.matches("^[0-9A-Z\\.]{1,10}$")) {
Window.alert("'" + name1 + "' is not a valid name.");
lastName.selectAll();
return;
}*/
lastName.setValue("");
firstName.setFocus(true);
callService.addUser(name1,name2,
new AsyncCallback<String>() {
public void onFailure(Throwable caught) {
// Show the RPC error message to the user
Window.alert("check your inputs");
}
#Override
public void onSuccess(String result) {
// TODO Auto-generated method stub
// Add the user to the table.
// int row = userFlexTable.getRowCount();
// userFlexTable.setText(row, 1, result);
getUser();
}
});
}
private void getUser(){
callService.getUser(new AsyncCallback<User[]>() {
public void onFailure(Throwable caught) {
// Show the RPC error message to the user
Window.alert("Problem in database connection");
}
#Override
public void onSuccess(User[] result) {
// TODO Auto-generated method stub
for(int i = 0; i < result.length; i ++)
{
//String s = result[i].getFirstName();
int row = userFlexTable.getRowCount();
userFlexTable.setText(row, 0, result[i].getId().toString());
userFlexTable.setText(row, 1, result[i].getFirstName());
userFlexTable.setText(row, 2, result[i].getLastName());
}
}
});
}
}

Answer 1

Man did you notice that you are calling getUser twice if the entered Name is valid and the call to the service is successfull??
You have to remove one of them!

Answer 2

getUser is called on every new entry & all data is entered again into table.