JSF - 连接挂起

Question

我正在尝试创建JSF设置页面。这是页面的代码：

<div id="settingsdiv" style="width:350px; height:400px; position:absolute;  background-color:r; top:20px; left:1px">
                <h:form>
                <h:panelGrid columns="2">
                    <h:panelGroup>User Session Timeout</h:panelGroup>
                    <h:panelGroup>
                        <h:selectOneMenu value="#{ApplicationController.settings['SessionTTL']}">
                            <f:selectItem itemValue="#{ApplicationController.settings['SessionTTL']}" itemLabel="#{ApplicationController.settings['SessionTTL']}" />
                            <f:selectItem itemValue="two" itemLabel="Option two" />
                            <f:selectItem itemValue="three" itemLabel="Option three" />
                            <f:selectItem itemValue="custom" itemLabel="Define custom value" />
                            <f:ajax render="input" />
                        </h:selectOneMenu>
                        <h:panelGroup id="input">
                            <h:inputText value="#{ApplicationController.settings['SessionTTL']}" rendered="#{ApplicationController.settings['SessionTTL'] == 'custom'}" required="true" />
                        </h:panelGroup>

                    </h:panelGroup>

                    <h:panelGroup>Maximum allowed users</h:panelGroup>
                    <h:panelGroup></h:panelGroup>                                                                     
                </h:panelGrid>                         
                    <h:commandButton value="Submit" action="#{ApplicationController.updateDBSettings()}"/>
                </h:form> 

            </div>

这是托管bean：

import java.io.Serializable;
import javax.enterprise.context.SessionScoped;
// or import javax.faces.bean.SessionScoped;
import javax.inject.Named;
/* include SQL Packages */
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.HashMap;
import javax.annotation.PostConstruct;
import javax.sql.DataSource;
import javax.annotation.Resource;
import javax.faces.context.FacesContext;
import javax.inject.Inject;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
// or import javax.faces.bean.ManagedBean;   

import org.glassfish.osgicdi.OSGiService;

@Named("ApplicationController")
@SessionScoped
public class Application implements Serializable {

    /* This Hash Map will be used to store setting and value */
    private HashMap<String, String> settingsMap = null;    
    private HashMap<String, String> updatedSettingsMap = new HashMap<String, String>();

    public Application(){     
    }   

    /* Call the Oracle JDBC Connection driver */
    @Resource(name = "jdbc/Oracle")
    private DataSource ds;


    /* Hash Map
     * Send this hash map with the settings and values to the JSF page
     */
    public HashMap<String, String> getsettings(){
        return settingsMap;        
    }

    /* Hash Map
     * Returned from the JSF page with the updated settings
     */
    public HashMap<String, String> setsettings(){
        return updatedSettingsMap;
    }

    /* Get a Hash Map with settings and values. The table is genarated right 
     * after the constructor is initialized. 
     */
    @PostConstruct
    public void initSettings() throws SQLException
    {        
        settingsMap = new HashMap<String, String>();

        if(ds == null) {
                throw new SQLException("Can't get data source");
        }
        /* Initialize a connection to Oracle */
        Connection conn = ds.getConnection(); 

        if(conn == null) {
                throw new SQLException("Can't get database connection");
        }
        /* With SQL statement get all settings and values */
        PreparedStatement ps = conn.prepareStatement("SELECT * from GLOBALSETTINGS");

        try
        {
            //get data from database        
            ResultSet result = ps.executeQuery();
            while (result.next())
            {
               settingsMap.put(result.getString("SettingName"), result.getString("SettingValue"));
            }            
        }
        finally
        {
            ps.close();
            conn.close();         
        }        
    }

    /* Update Settings Values */
    public String updateDBSettings() throws SQLException {


        //here the values from the updatedSettingsMap will be inserted into the database

            String storedPassword = null;        
            String SQL_Statement = null;

            if (ds == null) throw new SQLException();      
       Connection conn = ds.getConnection();
            if (conn == null) throw new SQLException();      

       try {
            conn.setAutoCommit(false);
            boolean committed = false;
                try {
                       SQL_Statement = "UPDATE GLOBALSETTINGS " +
                                            "SET \"SettingValue\" = " +
                                              "CASE " +
                                                "WHEN \"SettingName\" = 'SessionTTL' THEN ? " +
                                                "WHEN \"SettingName\" = 'MaxUsersActive' THEN ? " +
                                              "END " +
                                       "WHERE \"SettingName\"  IN ('SessionTTL', 'MaxUsersActive')";


                       PreparedStatement updateQuery = conn.prepareStatement(SQL_Statement);
                       updateQuery.setString(1, "20");
                       updateQuery.setString(2, "40");

                       updateQuery.executeQuery();

                       conn.commit();
                       committed = true;
                 } finally {
                       if (!committed) conn.rollback();
                       }
            }
                finally {               
                conn.close();

                }  
          return "ok";    
       }    


}

当我点击页面提交按钮时，页面显示我正在连接....并且页面冻结。我查看了SQL开发人员 - 数据库表中的值没有改变。

知道网页冻结的原因吗？