java - Spring mvc，制作菜单数据对象

Question

我真的是JAVA、spring mvc的新手。

我对“代码”的理解太差了，我什至无法想象我将如何应对即将出现的错误。

所以这个问题听起来就像“为我做这个!”。 (实际上可以)

无论如何，我正在尝试制作一个两层深度的菜单。它的结构如下所示。

TopMenu
  ::: menuNo
  ::: menuName
  ::: memberType
  ::: url
  ::: sort
  ::: subMenus
      ::: menuNo
      ::: menuName
      ::: memberType
      ::: url
      ::: sort

TopMenu2
  ::: menuNo2
  ::: menuName2
  ::: memberType2
  ::: url2
         .
         .
         .
         .

所以我为此创建了一个 Bean 类。

public class MenuInfoBean {

    private String menuNo;
    private String menuName;
    private String memberType;
    private String url;
    private int sort;
    List<MenuInfoBean> subMenus;    

    public MenuInfoBean() {

    }

    public String getMenuNo() {
        return menuNo;
    }

    public void setMenuNo(String menuNo) {
        this.menuNo = menuNo;
    }

    public String getMenuName() {
        return menuName;
    }

    public void setMenuName(String menuName) {
        this.menuName = menuName;
    }

    public String getMemberType() {
        return memberType;
    }

    public void setMemberType(String memberType) {
        this.memberType = memberType;
    }

    public String getUrl() {
        return url;
    }

    public void setUrl(String url) {
        this.url = url;
    }

    public int getSort() {
        return sort;
    }

    public void setSort(int sort) {
        this.sort = sort;
    }

    public List<MenuInfoBean> getSubMenus() {
        return subMenus;
    }

    public void setSubMenus(MenuInfoBean subMenus) {
        subMenus.menuName = subMenus.menuName;
        subMenus.memberType = subMenus.memberType;
        subMenus.url = subMenus.url;
        subMenus.sort = subMenus.sort;
    }
}

尚未决定使用哪个数据库，因此我暂时使用菜单数据的属性。

#TopMenu List
topmenu = M1000,M9000


#SubMenu List
M1000.submenu =
M9000.submenu = M9001,M9002,M9003,M9004



#TopMenu Info
#M1000 APPLICATION
M1000.menuName=APPLICATION
M1000.url=
M1000.memberType=00,10
M1000.sort=1

#M9000 ADMIN
M9000.menuName=ADMIN
M9000.url=/SYS01/memberList.mon
M9000.memberType=00,10
M9000.sort=1





#SubMenu Info
#M9000 ADMIN's
M9001.menuName=Member mgmt
M9001.url=/SYS01/memberList.mon
M9001.memberType=00,10
M9001.sort=1

M9002.menuName=menu2
M9002.url=/SYS01/memberList.mon
M9002.memberType=00,10
M9002.sort=1

M9003.menuName=menu3
M9003.url=/SYS01/memberList.mon
M9003.memberType=00,10
M9003.sort=1

M9004.menuName=menu4
M9004.url=/SYS01/memberList.mon
M9004.memberType=00,10
M9004.sort=1

在这里，我获取数据并尝试将它们放入列表中。

public class MenuManager {

    public List<MenuInfoBean> getMenus(String permissionCode) {
        LabelProperties msgResource = LabelProperties.getInstance();

        MenuInfoBean menuInfo = new MenuInfoBean();
        List<MenuInfoBean> menuList = new ArrayList<MenuInfoBean>();

        String topMenu = msgResource.getProperty("topmenu");        
        String[] topMenuItems = topMenu.split(",");

        for (int i = 0; topMenuItems.length > i; i++ ) {            


            String subMenuName =  msgResource.getProperty(topMenuItems[i] + ".submenu");

            if ( subMenuName.isEmpty() == false ) {
                menuInfo.setMenuName(msgResource.getProperty(subMenuName + ".menuName"));           
                menuInfo.setMemberType(msgResource.getProperty(subMenuName + ".memberType"));   
                menuInfo.setUrl(msgResource.getProperty(subMenuName + ".url")); 
                menuInfo.setSort(Integer.parseInt(msgResource.getProperty(subMenuName + ".sort")));
                menuInfo.setSubMenus(menuInfo);
            } else {
                menuInfo.setMenuName("");               
                menuInfo.setSubMenus(menuInfo);
            }

            menuInfo.setMenuNo("");
            menuInfo.setMenuName(msgResource.getProperty(topMenuItems[i] + ".menuName"));           
            menuInfo.setMemberType(msgResource.getProperty(topMenuItems[i] + ".memberType"));   
            menuInfo.setUrl(msgResource.getProperty(topMenuItems[i] + ".url")); 
            menuInfo.setSort(Integer.parseInt(msgResource.getProperty(topMenuItems[i] + ".sort")));

            menuList.add(menuInfo);
        }       

        return menuList;
    }
}

getProperty 方法效果很好。它正确获取属性值。

但正如您可能注意到的，正在生成一些空数据。

为了忽略这个NullPointerException，我做了

List<MenuInfoBean> menuList = new ArrayList<MenuInfoBean>();

因此异常已成功避免。但是出现了另一个错误，这在本文中并不重要......

无论如何，在尝试解决新错误时，我查看了 menuInfo 数据，发现出现了问题。

子菜单保存了顶级菜单的数据!

<小时/>

问题是，如何使用 MenuInfoBean 制作这个菜单，就像我在本文顶部提到的结构一样？

为什么 subMenus 数据保存 topMenu 的属性？

我先设置subMenus数据，然后再设置topMenu数据!为什么会发生这种情况？

Answer 1

首先，我通过添加附加方法 add(Meun) 来更新域对象

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

public class MenuInfoBean
{
private String menuNo;
private String menuName;
private String memberType;
private String url;
private int sort;
List<MenuInfoBean> subMenus;

public MenuInfoBean()
{

}

public String getMenuNo()
{
    return menuNo;
}

public void setMenuNo(String menuNo)
{
    this.menuNo = menuNo;
}

public String getMenuName()
{
    return menuName;
}

public void setMenuName(String menuName)
{
    this.menuName = menuName;
}

public String getMemberType()
{
    return memberType;
}

public void setMemberType(String memberType)
{
    this.memberType = memberType;
}

public String getUrl()
{
    return url;
}

public void setUrl(String url)
{
    this.url = url;
}

public int getSort()
{
    return sort;
}

public void setSort(int sort)
{
    this.sort = sort;
}

public List<MenuInfoBean> getSubMenus()
{
    return subMenus;
}

// This is new method added to the bean
public void addSubMenuItem(MenuInfoBean menuInfoBean)
{
    if (subMenus == null)
        subMenus = new ArrayList<MenuInfoBean>();
    subMenus.add(menuInfoBean);
}
}

这里是生成菜单并返回的类(查看获取菜单方法):

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

import org.apache.commons.lang.StringUtils;

public class MenuExtractionComponent
{
public List<MenuInfoBean> getMenus(String permissionCode)
{
    LabelProperties msgResource = LabelProperties.getInstance();
    List<MenuInfoBean> menuList = new ArrayList<MenuInfoBean>();
    String topMenu = msgResource.getProperty("topmenu");
    List<String> topMenuItems = new ArrayList<String>();
    // Checking is top menu empty
    if (StringUtils.isNotBlank(topMenu))
    {
        topMenuItems.addAll(Arrays.asList(topMenu.split(",")));
    }

    for (String topMenuItem : topMenuItems)
    {

        // Setting top menu details
        MenuInfoBean menuInfo = new MenuInfoBean();
        menuInfo.setMenuNo("");
        menuInfo.setMenuName(msgResource.getProperty(topMenuItem + ".menuName"));
        menuInfo.setMemberType(msgResource.getProperty(topMenuItem + ".memberType"));
        menuInfo.setUrl(msgResource.getProperty(topMenuItem + ".url"));
        menuInfo.setSort(Integer.parseInt(msgResource.getProperty(topMenuItem + ".sort")));

        String subMenu = msgResource.getProperty(topMenuItem + ".submenu");
        List<String> subMenuItems = new ArrayList<String>();
        // Checking is sub menu empty
        if (StringUtils.isNotBlank(subMenu))
        {
            subMenuItems.addAll(Arrays.asList(subMenu.split(",")));
        }

        for (String subMenuItem : subMenuItems)
        {
            MenuInfoBean subMenuInfo = new MenuInfoBean();
            subMenuInfo.setMenuName(msgResource.getProperty(subMenuItem + ".menuName"));
            subMenuInfo.setMemberType(msgResource.getProperty(subMenuItem + ".memberType"));
            subMenuInfo.setUrl(msgResource.getProperty(subMenuItem + ".url"));
            subMenuInfo.setSort(Integer.parseInt(msgResource.getProperty(subMenuItem + ".sort")));
            menuInfo.addSubMenuItem(subMenuInfo);
        }
        menuList.add(menuInfo);
    }

    return menuList;
}

}