JSF + JAVA + MYSQL

Question

My code works, delete method works, select method works, but the update method doesn't work because overwrite the same, here it is the code:

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.io.Serializable;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
import javax.faces.FacesException;

@ManagedBean
@SessionScoped         
public class Teszt implements Serializable {

    String msg;
    int id;
    String name;
    int age;


    String URL = "jdbc:mysql://IP-cím:Port/osszesito";
    String USER = "osszesito";
    String PASSWORD = "Password";
    String DRIVER = "com.mysql.jdbc.Driver";

    public Connection getDBConnection() {

        Connection dbConnection = null;

        try {

            Class.forName(DRIVER);
            dbConnection = DriverManager.getConnection(URL, USER, PASSWORD);
            System.out.println("Connection completed.");

        } catch (SQLException e) {

            System.out.println(e.getMessage());

        } catch (ClassNotFoundException cnfe) {

            cnfe.printStackTrace();
            System.out.println(cnfe.getMessage());
            System.exit(-1);
        }

        return dbConnection;
    }


    public List < Teszt > selectTesztTable() throws SQLException {

        ResultSet rs = null;
        PreparedStatement pst = null;
        Connection con = getDBConnection();
        String stm = "select * from teszt";
        List < Teszt > records = new ArrayList < Teszt > ();

        try {
            pst = con.prepareStatement(stm);
            pst.execute();
            rs = pst.getResultSet();

            while (rs.next()) {

                Teszt objectMeghiv = new Teszt();

                objectMeghiv.setId(rs.getInt(1));
                objectMeghiv.setName(rs.getString(2));
                objectMeghiv.setAge(rs.getInt(3));

                records.add(objectMeghiv);
            }

            return records;
        } catch (SQLException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {

            rs.close();
            pst.close();
            con.close();
        }
        return records;
    }

    public void deleteOsszesito(Teszt t) {

        Connection connection = getDBConnection();
        PreparedStatement pst = null;

        try {

            String sql = "delete from teszt where id=?";
            pst = connection.prepareStatement(sql);
            pst.setInt(1, t.getId());
            pst.executeUpdate();

            pst.close();
            connection.close();

        } catch (SQLException se) {
            se.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void updateTable(Teszt t) throws SQLException {


        List < TesztSetGet > list = new ArrayList < TesztSetGet > ();
        Connection connection = null;
        PreparedStatement pst = null;
        ResultSet rs = null;

        String sql = "update teszt set name=?, age=? where id=?";

        TesztSetGet meghiv = new TesztSetGet();

        try {

            connection = getDBConnection();
            pst = connection.prepareStatement(sql);

            pst.setString(1, t.getName());
            pst.setInt(2, t.getAge());
            pst.setInt(3, t.getId());

            System.out.println(t.getName() + "        " + meghiv.age + "        " + id);
            pst.executeUpdate();

        } catch (SQLException se) {
            se.printStackTrace();
            se.getMessage();
            throw new FacesException(se);
        } catch (Exception e) {
            e.printStackTrace();
            e.getMessage();
            throw new FacesException(e);
        } finally {

            if (pst != null) {
                pst.close();
            }

            if (connection != null) {
                connection.close();
            }
        }
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public boolean isEditable() {
        return editable;
    }

    public void setEditable(boolean editable) {
        this.editable = editable;
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml"  
      xmlns:h="http://java.sun.com/jsf/html"
      xmlns:f="http://java.sun.com/jsf/core"
      xmlns:ui="http://java.sun.com/jsf/facelets"
      xmlns:p="http://primefaces.org/ui"
      >

    <h:head>    
            <title>Teszt</title>        
            <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>                        
            <link rel="stylesheet" type="text/css" href="style.css"/>            
    </h:head>

    <ui:debug />
    <h:form>
    <p:fieldset legend="Teszt:">  
        <p:dataTable id="dataTable" value="#{Teszt.selectTesztTable()}" var="t" paginator="true" rows="15">

            <p:column>
                   <f:facet name="header">ID:</f:facet>
                   <h:inputText value="#{t.id}"/>                  
            </p:column>

            <p:column>
                <f:facet name="header">Name:</f:facet>
                <h:inputText value="#{t.name}"/>

            </p:column>

            <p:column>                
                <f:facet name="header">Age:</f:facet>
                <h:inputText value="#{t.age}" />                
            </p:column>

            <p:column><f:facet name="header">DELETE</f:facet>
                <p:commandButton value="DELETE" action="#{Teszt.deleteOsszesito(t)}" update="@form" />                    
            </p:column>

            <p:column><f:facet name="header">UPDATE</f:facet>

                <p:commandButton value="Update" action="#{Teszt.updateTable(t)}" update="@form">                    
                   <f:ajax render="@all" execute="@form" />
                </p:commandButton>    
            </p:column>                                                            
        </p:dataTable>
     </p:fieldset>
    </h:form>
</html>

There are three fields. These fields are in inputText. When I modify the fields and i click update button, then the fields return to original state :(

Why?

Thank you very much

score 2 · Accepted Answer · edited May 23 '17 at 11:49

Because when you submit that form, JSF will reconstruct your view. Including reconstruction your table. Including re-executing selectTesztTable(). Try fetching the records up front and only passing them to the table via a getter:

@ManagedBean @SessionBean
public class TesztBean implements Serializable {
    private List<Teszt> values;

    @PostConstruct
    public void init() {
        try {
            values = selectTesztTable();
        } catch (SQLException e) { ... }
    }

    public List<Teszt> getValues() { return values; }
}

And in your xhtml:

<p:dataTable value="#{tesztBean.values}">...</p:dataTable>

That way, JSF will keep the values alive and can find them again when it tries to apply the supplied input text.

See also:

commandButton/commandLink/ajax action/listener method not invoked or input value not updated

you should have used editable datatable;also you should accept the answer. — Jalal Sordo, Feb 28 '14 at 21:23

JSF + JAVA + MYSQL

1 Answers1