您好如何在 JSFh:selectOneMenu或 Primefaces中使用 POJO 列表p:selectOneMenu？
我知道有很多相关问题建议使用 Converter，但没有明确的从头开始构建的示例。
我想要一个用于上述目的的通用转换器代码。
如果重复，请提出任何替代方案/指出正确的问题。
问问题
21572 次
2 回答
5
这是一个使用带有 Primefaces p:selectOneMenu 的 POJO 的完整示例。primfaces 选择一个菜单显示学生列表。如果在选择任何学生后按详细信息按钮，将出现一个 primfaces 对话框，其中包含该学生的全名。
com.model 包：
学生班
package com.model;
import java.io.Serializable;
public class Student implements Serializable{
private static final long serialVersionUID = 1L;
private int Id;
public int getId() {
return Id;
}
public void setId(int id) {
Id = id;
}
private String lastName;
private String firstName;
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public Student() {
super();
}
public Student(String lastName, String firstName,int Id) {
super();
this.lastName = lastName;
this.firstName = firstName;
this.Id = Id;
}}
转换器
package com.model;
import java.util.ArrayList;
import java.util.List;
import javax.faces.application.FacesMessage;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.convert.Converter;
import javax.faces.convert.ConverterException;
import javax.faces.convert.FacesConverter;
@FacesConverter(forClass = com.model.Student.class,value="student")
public class StudentConverter implements Converter{
public static List<Student> studentDB;
static {
studentDB = new ArrayList<Student>();
studentDB.add(new Student("William", "Wong", 1));
studentDB.add(new Student("John", "Smith", 2));
studentDB.add(new Student("Mari", "Beckley", 3));
studentDB.add(new Student("Messi", "Leonardo",4));
studentDB.add(new Student("William", "Astrid", 5));
studentDB.add(new Student("William", "Banana", 6));
}
public Object getAsObject(FacesContext facesContext, UIComponent component, String submittedValue) {
if (submittedValue.trim().equals("")) {
return null;
} else {
try {
int number = Integer.parseInt(submittedValue);
for (Student s : studentDB) {
if (s.getId() == number) {
return s;
}
}
} catch(NumberFormatException exception) {
throw new ConverterException(new FacesMessage(FacesMessage.SEVERITY_ERROR, "Conversion Error", "Not a valid player"));
}
}
return null;
}
public String getAsString(FacesContext facesContext, UIComponent component, Object value) {
if (value == null || value.equals("")) {
return "";
} else {
return String.valueOf(((Student) value).getId());
}
}
}
com.managedbean 包
package com.managedbean;
import java.util.List;
import javax.annotation.PostConstruct;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ViewScoped;
import com.model.Student;
import com.model.StudentConverter;
@ManagedBean
@ViewScoped
public class StudentMB {
private Student selectedStudent;
public Student getSelectedStudent() {
return selectedStudent;
}
public void setSelectedStudent(Student selectedStudent) {
this.selectedStudent = selectedStudent;
}
public List<Student> getStudents() {
return students;
}
public void setStudents(List<Student> students) {
this.students = students;
}
private List<Student> students;
@PostConstruct
public void init(){
students=StudentConverter.studentDB;
}
}
选择菜单.xhtml
<!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:p="http://primefaces.org/ui">
<h:head>
</h:head>
<h:body>
<h:form>
<h:panelGrid columns="2" style="margin-bottom:10px" cellpadding="1">
<h:outputText value="Pojo: " />
<p:selectOneMenu value="#{studentMB.selectedStudent}" effect="fade" converter="student">
<f:selectItem itemLabel="Select One" itemValue="" />
<f:selectItems value="#{studentMB.students}" var="student" itemLabel="#{student.firstName}" itemValue="#{student}"/>
</p:selectOneMenu>
</h:panelGrid>
<p:commandButton value="Details" update="display" oncomplete="dlg.show()" />
<p:dialog header="Selected Value" modal="true" showEffect="fade" hideEffect="fade" widgetVar="dlg">
<h:panelGrid columns="1" id="display">
<h:outputText value="#{studentMB.selectedStudent.firstName} #{studentMB.selectedStudent.lastName}" rendered="#{not empty studentMB.selectedStudent}" />
</h:panelGrid>
</p:dialog>
</h:form>
</h:body>
</html>
获取源代码
您可以从此处下载使用 eclipse 构建并部署到 glassfish 的完整示例
于 2013-09-27T15:14:18.993 回答
3
在 h:selectOneMenu 中是可能的，但是你的 POJO 必须实现一个带有标识符属性的接口。
界面：
public inteface IConvertible {
public Integer getId();
}
波乔：
public class POJO implements IConvertible {
....
....
}
和通用转换器：
@SuppressWarnings("unchecked")
public class GenericConverter implements Converter {
@Override
public Object getAsObject(FacesContext arg0, UIComponent arg1, String arg2) {
IConvertible ret = null;
UIComponent src = arg1;
if (src != null) {
List<UIComponent> childs = src.getChildren();
UISelectItems itens = null;
if (childs != null) {
for (UIComponent ui : childs) {
if (ui instanceof UISelectItems) {
itens = (UISelectItems) ui;
break;
} else if (ui instanceof UISelectItem) {
UISelectItem item = (UISelectItem) ui;
try {
IConvertible val = (IConvertible) item.getItemValue();
if (arg2.equals("" + val.getId())) {
ret = val;
break;
}
} catch (Exception e) {
}
}
}
}
if (itens != null) {
List<IConvertible> values = (List<IConvertible>) itens.getValue();
if (values != null) {
for (IConvertible val : values) {
if (arg2.equals("" + val.getId())) {
ret = val;
break;
}
}
}
}
}
return ret;
}
@Override
public String getAsString(FacesContext arg0, UIComponent arg1, Object arg2) {
String ret = "";
if (arg2 != null && arg2 instanceof IConvertible) {
IConvertible m = (IConvertible) arg2;
if (m != null) {
Long id = m.getId();
if (id != null) {
ret = id.toString();
}
}
}
return ret;
}
}
JSF 页面：
<h:selectOneMenu id="combo" value="#{pojoMB.pojo}" converter="genericConverter">
<f:selectItem itemLabel="-- Select one --" itemValue="" />
<f:selectItems value="#{pojoMB.pojoList}" var="pj" itemValue="#{pj}" itemLabel="#{pj.labelOfPojo}" />
</h:selectOneMenu>
于 2013-10-16T16:20:29.313 回答