Java primefaces示例不'；行不通

我试着从primefaces.org上运行一个示例， 这个

但结果是

这是我的密码 xhtml：

ManagedBean代码：

import java.util.ArrayList;
import java.util.List;

import javax.annotation.PostConstruct;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.RequestScoped;
import javax.faces.model.SelectItem;
import javax.faces.model.SelectItemGroup;

        @ManagedBean(name="multiSelectListboxBean")
        @RequestScoped
        public class AddPacchettiBean {

            private List<SelectItem> categories;

            private String selection;

            @PostConstruct
            public void init() {
                categories = new ArrayList<SelectItem>();
                SelectItemGroup group1 = new SelectItemGroup("Group 1");
                SelectItemGroup group2 = new SelectItemGroup("Group 2");
                SelectItemGroup group3 = new SelectItemGroup("Group 3");
                SelectItemGroup group4 = new SelectItemGroup("Group 4");

                SelectItemGroup group11 = new SelectItemGroup("Group 1.1");
                SelectItemGroup group12 = new SelectItemGroup("Group 1.2");

                SelectItemGroup group21 = new SelectItemGroup("Group 2.1");

                SelectItem option31 = new SelectItem("Option 3.1", "Option 3.1");
                SelectItem option32 = new SelectItem("Option 3.2", "Option 3.2");
                SelectItem option33 = new SelectItem("Option 3.3", "Option 3.3");
                SelectItem option34 = new SelectItem("Option 3.4", "Option 3.4");

                SelectItem option41 = new SelectItem("Option 4.1", "Option 4.1");

                SelectItem option111 = new SelectItem("Option 1.1.1");
                SelectItem option112 = new SelectItem("Option 1.1.2");
                group11.setSelectItems(new SelectItem[]{option111, option112});

                SelectItem option121 = new SelectItem("Option 1.2.1", "Option 1.2.1");
                SelectItem option122 = new SelectItem("Option 1.2.2", "Option 1.2.2");
                SelectItem option123 = new SelectItem("Option 1.2.3", "Option 1.2.3");
                group12.setSelectItems(new SelectItem[]{option121, option122, option123});

                SelectItem option211 = new SelectItem("Option 2.1.1", "Option 2.1.1");
                group21.setSelectItems(new SelectItem[]{option211});

                group1.setSelectItems(new SelectItem[]{group11, group12});
                group2.setSelectItems(new SelectItem[]{group21});
                group3.setSelectItems(new SelectItem[]{option31, option32, option33, option34});
                group4.setSelectItems(new SelectItem[]{option41});

                categories.add(group1);
                categories.add(group2);
                categories.add(group3);
                categories.add(group4);
            }

            public List<SelectItem> getCategories() {
                return categories;
            }    

            public String getSelection() {
                return selection;
            }
            public void setSelection(String selection) {
                this.selection = selection;
            }
        }

import java.util.ArrayList；
导入java.util.List；
导入javax.annotation.PostConstruct；
导入javax.faces.bean.ManagedBean；
导入javax.faces.bean.RequestScope；
导入javax.faces.model.SelectItem；
导入javax.faces.model.SelectItemGroup；
@ManagedBean（name=“multiSelectListboxBean”）
@请求范围
公共类AddPacchettiBean{
私人名单类别；
私有字符串选择；
@施工后
公共void init（）{
categories=newarraylist（）；
SelectItemGroup group1=新建SelectItemGroup（“组1”）；
SelectItemGroup group2=新建SelectItemGroup（“Group 2”）；
SelectItemGroup group3=新建SelectItemGroup（“Group 3”）；
SelectItemGroup group4=新建SelectItemGroup（“Group 4”）；
SelectItemGroup group11=新建SelectItemGroup（“Group 1.1”）；
SelectItemGroup group12=新建SelectItemGroup（“Group 1.2”）；
SelectItemGroup Group 21=新建SelectItemGroup（“Group 2.1”）；
SelectItem option31=新建SelectItem（“选项3.1”、“选项3.1”）；
SelectItem option32=新建SelectItem（“选项3.2”、“选项3.2”）；
SelectItem option33=新建SelectItem（“选项3.3”、“选项3.3”）；
SelectItem option34=新建SelectItem（“选项3.4”、“选项3.4”）；
SelectItem option41=新建SelectItem（“选项4.1”、“选项4.1”）；
SelectItem option111=新建SelectItem（“选项1.1.1”）；
SelectItem option112=新建SelectItem（“选项1.1.2”）；
group11.setSelectItems（新建SelectItem[]{option111，option112}）；
SelectItem option121=新的SelectItem（“选项1.2.1”、“选项1.2.1”）；
SelectItem option122=新建SelectItem（“选项1.2.2”、“选项1.2.2”）；
SelectItem option123=新的SelectItem（“选项1.2.3”、“选项1.2.3”）；
group12.setSelectItems（新建SelectItem[]{option121，option122，option123}）；
SelectItem option211=新的SelectItem（“选项2.1.1”、“选项2.1.1”）；
group21.setSelectItems（新建SelectItem[]{option211}）；
group1.setSelectItems（新的SelectItem[]{group11，group12}）；
group2.setSelectItems（新的SelectItem[]{group21}）；
组3.setSelectItems（新建SelectItem[]{option31，option32，option33，option34}）；
group4.setSelectItems（新建SelectItem[]{option41}）；
类别。添加（第1组）；
类别。添加（第2组）；
添加类别（第3组）；
添加类别（第4组）；
}
公共列表getCategories（）{
退货类别；
}    
公共字符串getSelection（）{
返回选择；
}
公共选择（字符串选择）{
this.selection=选择；
}
}

---

我不明白，为什么

您的Primefaces安装似乎遗漏了一些内容

• 确保将Primefaces JAR放在WebContent/WEB-INF/lib下
• 检查Primefaces命名空间声明。（

  xmlns:p=”http://primefaces.org/ui“

  ）

---

在我看来，您似乎没有正确设置项目。看看这篇关于设置primefaces的教程eclipse和maven。完成后，请尝试此示例。

import java.util.ArrayList;
import java.util.List;

import javax.annotation.PostConstruct;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.RequestScoped;
import javax.faces.model.SelectItem;
import javax.faces.model.SelectItemGroup;

        @ManagedBean(name="multiSelectListboxBean")
        @RequestScoped
        public class AddPacchettiBean {

            private List<SelectItem> categories;

            private String selection;

            @PostConstruct
            public void init() {
                categories = new ArrayList<SelectItem>();
                SelectItemGroup group1 = new SelectItemGroup("Group 1");
                SelectItemGroup group2 = new SelectItemGroup("Group 2");
                SelectItemGroup group3 = new SelectItemGroup("Group 3");
                SelectItemGroup group4 = new SelectItemGroup("Group 4");

                SelectItemGroup group11 = new SelectItemGroup("Group 1.1");
                SelectItemGroup group12 = new SelectItemGroup("Group 1.2");

                SelectItemGroup group21 = new SelectItemGroup("Group 2.1");

                SelectItem option31 = new SelectItem("Option 3.1", "Option 3.1");
                SelectItem option32 = new SelectItem("Option 3.2", "Option 3.2");
                SelectItem option33 = new SelectItem("Option 3.3", "Option 3.3");
                SelectItem option34 = new SelectItem("Option 3.4", "Option 3.4");

                SelectItem option41 = new SelectItem("Option 4.1", "Option 4.1");

                SelectItem option111 = new SelectItem("Option 1.1.1");
                SelectItem option112 = new SelectItem("Option 1.1.2");
                group11.setSelectItems(new SelectItem[]{option111, option112});

                SelectItem option121 = new SelectItem("Option 1.2.1", "Option 1.2.1");
                SelectItem option122 = new SelectItem("Option 1.2.2", "Option 1.2.2");
                SelectItem option123 = new SelectItem("Option 1.2.3", "Option 1.2.3");
                group12.setSelectItems(new SelectItem[]{option121, option122, option123});

                SelectItem option211 = new SelectItem("Option 2.1.1", "Option 2.1.1");
                group21.setSelectItems(new SelectItem[]{option211});

                group1.setSelectItems(new SelectItem[]{group11, group12});
                group2.setSelectItems(new SelectItem[]{group21});
                group3.setSelectItems(new SelectItem[]{option31, option32, option33, option34});
                group4.setSelectItems(new SelectItem[]{option41});

                categories.add(group1);
                categories.add(group2);
                categories.add(group3);
                categories.add(group4);
            }

            public List<SelectItem> getCategories() {
                return categories;
            }    

            public String getSelection() {
                return selection;
            }
            public void setSelection(String selection) {
                this.selection = selection;
            }
        }