在jsf中计算数据库中的值的总和

Question

我不确定从哪里开始，但基本上，我有一个将值保存到数据库的应用程序。我想要的是将某个用户的行中的所有值相加，然后除以13得到平均值

这就是我目前可以显示所选用户的所有值的方式：

                                         
                                         
                                                                                                                

                <p:outputLabel value="#{bundle.labelEditMarkSectionTwo}"/>
                <p:inputText id="mark2"
                             value="#{markingBean.markToEdit.markSectionTwo}"
                             required="true"
                             maxlength="3"
                             requiredMessage="Mark for section 2 is requried."
                             converterMessage="Must be a number greater than zero and less than 100" >
                    <f:validateLongRange minimum="0" maximum="100"/>
                    <p:ajax update="save"
                            listener="#{markingBean.editChange}"
                            event="keydown"/>
                </p:inputText>
                <p:outputLabel value="#{bundle.labelEditMarkSectionThree}"/>
                <p:inputText id="mark3"
                             value="#{markingBean.markToEdit.markSectionThree}"
                             required="true"
                             maxlength="3"
                             requiredMessage="Mark for section 3 is requried.">
                    <f:validateLongRange minimum="0" maximum="100"/>
                    <p:ajax update="save"
                            listener="#{markingBean.editChange}"
                            event="keydown"/>
                </p:inputText>

                <p:outputLabel value="#{bundle.labelEditMarkSectionFour}"/>
                <p:inputText id="mark4"
                             value="#{markingBean.markToEdit.markSectionFour}"
                             required="true"
                             maxlength="3"
                             requiredMessage="Mark for section 4 is requried.">
                    <f:validateLongRange minimum="0" maximum="100"/>
                    <p:ajax update="save"
                            listener="#{markingBean.editChange}"
                            event="keydown"/>
                </p:inputText>
                <p:outputLabel value="#{bundle.labelEditMarkSectionFive}"/>
                <p:inputText id="mark5"
                             value="#{markingBean.markToEdit.markSectionFive}"
                             required="true"
                             maxlength="3"
                             requiredMessage="Mark for section 5 is requried.">
                    <f:validateLongRange minimum="0" maximum="100"/>
                    <p:ajax update="save"
                            listener="#{markingBean.editChange}"
                            event="keydown"/>
                </p:inputText>
                <p:outputLabel value="#{bundle.labelEditMarkSectionSix}"/>
                <p:inputText id="mark6"
                             value="#{markingBean.markToEdit.markSectionSix}"
                             required="true"
                             maxlength="3"
                             requiredMessage="Mark for section 6 is requried.">
                    <f:validateLongRange minimum="0" maximum="100"/>
                    <p:ajax update="save"
                            listener="#{markingBean.editChange}"
                            event="keydown"/>
                </p:inputText>
                <p:outputLabel value="#{bundle.labelEditMarkSectionSeven}"/>
                <p:inputText id="mark7"
                             value="#{markingBean.markToEdit.markSectionSeven}"
                             required="true"
                             maxlength="3"
                             requiredMessage="Mark for section 7 is requried.">
                    <f:validateLongRange minimum="0" maximum="100"/>
                    <p:ajax update="save"
                            listener="#{markingBean.editChange}"
                            event="keydown"/>
                </p:inputText>
                <p:outputLabel value="#{bundle.labelEditMarkSectionEight}"/>
                <p:inputText id="mark8"
                             value="#{markingBean.markToEdit.markSectionEight}"
                             required="true"
                             maxlength="3"
                             requiredMessage="Mark for section 8 is requried.">
                    <f:validateLongRange minimum="0" maximum="100"/>
                    <p:ajax update="save"
                            listener="#{markingBean.editChange}"
                            event="keydown"/>
                </p:inputText>

                <p:outputLabel value="#{bundle.labelEditMarkSectionNine}"/>
                <p:inputText id="mark9"
                             value="#{markingBean.markToEdit.markSectionNine}"
                             required="true"
                             maxlength="3"
                             requiredMessage="Mark for section 9 is requried.">
                    <f:validateLongRange minimum="0" maximum="100"/>
                    <p:ajax update="save"
                            listener="#{markingBean.editChange}"
                            event="keydown"/>
                </p:inputText>
                <p:outputLabel value="#{bundle.labelEditMarkSectionTen}"/>
                <p:inputText id="mark10"
                             value="#{markingBean.markToEdit.markSectionTen}"
                             required="true"
                             maxlength="3"
                             requiredMessage="Mark for section 10 is requried.">
                    <f:validateLongRange minimum="0" maximum="100"/>
                    <p:ajax update="save"
                            listener="#{markingBean.editChange}"
                            event="keydown"/>
                </p:inputText>

            </p:panelGrid>

这只显示所有13个值

我想要做的是平均所有这些标记的总和，然后能够将此值传递回数据库

因此用户按下计算，该值将显示在

下方

传递价值是我能做的事情，但我不能做的是计算

谢谢你们