有许多人有条件。如何根据条件在列表中添加有限的条目？

Question

我根据用户角色使用spring和hibernate创建动态菜单。它工作正常，菜单生成。但是菜单和子菜单之间的关系不能正常工作。我只想要分配了角色的子菜单。但它包含所有子菜单。

我的POJO如下所示。

Menu.java

package com.pmc.domain;

import java.io.Serializable;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import javax.persistence.Transient;

import org.hibernate.annotations.Fetch;

@Entity
@Table(name="menu", catalog="test")
public class Menu implements Serializable{

    @Id
    @Column(name = "menu_item_id")
    private Integer menuId;

    @ManyToMany(cascade={CascadeType.ALL})
    @JoinTable(name="MENU_ROLES",
    joinColumns={@JoinColumn(name="menu_item_id")},
    inverseJoinColumns={@JoinColumn(name="user_role_id")})
    private List<UserRole> userRoles;
    @Column(name = "label", length = 100)
    private String label;
    @Column(name = "link", length = 100)
    private String link;

    @ManyToOne(cascade={CascadeType.ALL})
    @JoinColumn(name = "parent")
    private Menu parent;

    @OneToMany(mappedBy="parent",fetch = FetchType.EAGER)
    private List<Menu> submenus;


    public Integer getMenuId() {
        return menuId;
    }
    public void setMenuId(Integer menuId) {
        this.menuId = menuId;
    }

    public List<UserRole> getUserRoles() {
        return userRoles;
    }
    public void setUserRoles(List<UserRole> userRoles) {
        this.userRoles = userRoles;
    }
    public String getLabel() {
        return label;
    }
    public void setLabel(String label) {
        this.label = label;
    }
    public String getLink() {
        return link;
    }
    public void setLink(String link) {
        this.link = link;
    }
    public Menu getParent() {
        return parent;
    }
    public void setParent(Menu parent) {
        this.parent = parent;
    }
    public List<Menu> getSubmenus() {
        return submenus;
    }
    public void setSubmenus(List<Menu> submenus) {
        this.submenus = submenus;
    }



}

UserRole.java

package com.pmc.domain;

import static javax.persistence.GenerationType.IDENTITY;

import java.util.List;
import java.util.Set;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import javax.persistence.UniqueConstraint;

@Entity
@Table (name = "roles", catalog = "test")
public class UserRole {

    private Integer userRoleId;
    private Set<User> users;
    private String role;

    private List<Menu> menus;

    public UserRole() {
    }

    public UserRole(Set<User> users, String role) {
        this.users = users;
        this.role = role;
    }

    @Id
    @GeneratedValue(strategy = IDENTITY)
    @Column(name = "user_role_id", 
        unique = true, nullable = false)
    public Integer getUserRoleId() {
        return this.userRoleId;
    }

    public void setUserRoleId(Integer userRoleId) {
        this.userRoleId = userRoleId;
    }

    @ManyToMany(fetch = FetchType.LAZY)
    @JoinTable(name="USER_ROLES",
    joinColumns={@JoinColumn(name="user_role_id")},
    inverseJoinColumns={@JoinColumn(name="username")})
    public Set<User> getUsers() {
        return this.users;
    }

    public void setUsers(Set<User> users) {
        this.users = users;
    }

    @Column(name = "role", nullable = false, length = 45)
    public String getRole() {
        return this.role;
    }

    public void setRole(String role) {
        this.role = role;
    }

    @ManyToMany(mappedBy="userRoles",fetch = FetchType.EAGER)
    public List<Menu> getMenus() {
        return menus;
    }

    public void setMenus(List<Menu> menus) {
        this.menus = menus;
    }


}

User.java

package com.pmc.domain;

import java.util.HashSet;
import java.util.Set;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.Id;
import javax.persistence.ManyToMany;
import javax.persistence.OneToMany;
import javax.persistence.Table;

@Entity
@Table(name="users", catalog="test")
public class User {

    private String username;
    private String password;
    private boolean enabled;
    private Set<UserRole> userRole = new HashSet<UserRole>(0);

    public User() {
    }

    public User(String username, String password, boolean enabled) {
        this.username = username;
        this.password = password;
        this.enabled = enabled;
    }

    public User(String username, String password, 
        boolean enabled, Set<UserRole> userRole) {
        this.username = username;
        this.password = password;
        this.enabled = enabled;
        this.userRole = userRole;
    }

    @Id
    @Column(name = "username", unique = true, 
        nullable = false, length = 45)
    public String getUsername() {
        return this.username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    @Column(name = "password", 
        nullable = false, length = 60)
    public String getPassword() {
        return this.password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Column(name = "enabled", nullable = false)
    public boolean isEnabled() {
        return this.enabled;
    }

    public void setEnabled(boolean enabled) {
        this.enabled = enabled;
    }

    @ManyToMany(mappedBy = "users")
    public Set<UserRole> getUserRole() {
        return this.userRole;
    }

    public void setUserRole(Set<UserRole> userRole) {
        this.userRole = userRole;
    }

}

我的查询是这样的。

select menu from User user, IN (user.userRole) roles, IN(roles.menus) menu where user.username = ?

它为用户提供了具有适当角色的所有必需菜单。但是每个菜单中的子菜单列表不会根据角色反映出来。

你能帮忙吗？ 感谢