菜鸡的Java笔记 - java 多对多映射

要求：
    1.将数据还原为简单java类
    2.数据的输出：
        可以根据一个用户输出它对应的角色以及每个角色对应的权限，以及包含的具体的权限详情：
        一个权限可以输出具备此权限的角色，以及具备此角色的所有管理员，同时输出该权限的所有权限详情
        一个角色可以输出它所包含的管理员，每个管理员对应的具体的权限，以及权限详情
    第一步：数据表转换为简单java类

class User{
    private String userid;
    private String name;
    private String password;
    public User(String userid,String name,String password){
        this.userid = userid;
        this.name = name;
        this.password;
    }
    public String getlnfo(){
        return     "用户ID："+this.userid
                +"，姓名："+this.name
                +"，密码："+this.password;
    }
}
class Role{  // 角色
    private int rid;
    private String title;
    public User(int rid,String title){
        this.rid = rid;
        this.title = title;
    }
    public String getlnfo(){
        return     "角色编号："+this.rid
                +"，名称："+this.title;
    }
}
class Group{ // 权限
    private int gid;
    private String title;
    public User(int gid,String title){
        this.gid = gid;
        this.title = title;
    }
    public String getlnfo(){
        return     "权限组编号："+this.gid
                +"，组名称："+this.title;
    }
}
classAction{// 权限
    private int aid;
    private String title;
    private String url;
    public User(int aid,String title,String url){
        this.rid = aid;
        this.title = title;
        this.url = url;
    }
    public String getlnfo(){
        return     "权限编号："+this.aid
                +"，权限名称："+this.title
                +"，路径"+this.url;
    }
}
public class manyToManyMapping{
    public static void main(String args[]){

    }

}

第二步：设置关系
        一个角色包含有多个用户，一对多关系
        一个权限组包含多个权限，属于一对多
        一个角色对应有多个权限组，每个权限组可能有多个角色，多对多

class User{
    private String userid;
    private String name;
    private String password;
    private Role role;
    public User(String userid,String name,String password){
        this.userid = userid;
        this.name = name;
        this.password = password;
    }
    public void setRole(Role role){
        this.role = role;
    }
    public Role getRole(){
        return this.role;
    }
    public String getlnfo(){
        return     "用户ID："+this.userid
                +"，姓名："+this.name
                +"，密码："+this.password;
    }
}
class Role{  // 角色
    private int rid;
    private String title;
    private User users [];
    private Group groups[];
    public  Role(int rid,String title){
        this.rid = rid;
        this.title = title;
    }
    public void setGroups(Group groups[]){
        this.groups = groups;
    }
    public Group[] getGroups(){
        return this.groups;
    }
    public void setUser(User users[]){
        this.users = users;
    }
    public User[] getUser(){
        return this.users;
    }
    public String getlnfo(){
        return     "角色编号："+this.rid
                +"，名称："+this.title;
    }
}
class Group{ // 权限组
    private int gid;
    private String title;
    private Action actions[];
    private Role roles[];
    public Group(int gid,String title){
        this.gid = gid;
        this.title = title;
    }
    public void setRoles(Role roles[]){
        this.roles = roles;
    }
    public Role[] getRoles(){
        return this.roles;
    }
    public void setActions(Action actions[]){
        this.actions = actions;
    }
    public Action[] getActions(){
        return this.actions;
    }
    public String getlnfo(){
        return     "权限组编号："+this.gid
                +"，组名称："+this.title;
    }
}
class Action{// 权限
    private int aid;
    private String title;
    private String url;
    private Group group;
    public Action(int aid,String title,String url){
        this.aid = aid;
        this.title = title;
        this.url = url;
    }
    public void setGroup(Group group){
        this.group = group;
    }
    public Group getGroup(){
        return this.group;
    }
    public String getlnfo(){
        return     "权限编号："+this.aid
                +"，权限名称："+this.title
                +"，路径"+this.url;
    }
}
public class manyToManyMapping{
    public static void main(String args[]){

    }

}

分杀完毕。迅速，一定是不需要使用脑子就直接写出来的
    第三步：设置关系

class User{
    private String userid;
    private String name;
    private String password;
    private Role role;
    public User(String userid,String name,String password){
        this.userid = userid;
        this.name = name;
        this.password = password;
    }
    public void setRole(Role role){
        this.role = role;
    }
    public Role getRole(){
        return this.role;
    }
    public String getlnfo(){
        return     "用户ID："+this.userid
                +"，姓名："+this.name
                +"，密码："+this.password;
    }
}
class Role{  // 角色
    private int rid;
    private String title;
    private User users [];
    private Group groups[];
    public  Role(int rid,String title){
        this.rid = rid;
        this.title = title;
    }
    public void setGroups(Group groups[]){
        this.groups = groups;
    }
    public Group[] getGroups(){
        return this.groups;
    }
    public void setUsers(User users[]){
        this.users = users;
    }
    public User[] getUsers(){
        return this.users;
    }
    public String getlnfo(){
        return     "角色编号："+this.rid
                +"，名称："+this.title;
    }
}
class Group{ // 权限组
    private int gid;
    private String title;
    private Action actions[];
    private Role roles[];
    public Group(int gid,String title){
        this.gid = gid;
        this.title = title;
    }
    public void setRoles(Role roles[]){
        this.roles = roles;
    }
    public Role[] getRoles(){
        return this.roles;
    }
    public void setActions(Action actions[]){
        this.actions = actions;
    }
    public Action[] getActions(){
        return this.actions;
    }
    public String getlnfo(){
        return     "权限组编号："+this.gid
                +"，组名称："+this.title;
    }
}
class Action{// 权限
    private int aid;
    private String title;
    private String url;
    private Group group;
    public Action(int aid,String title,String url){
        this.aid = aid;
        this.title = title;
        this.url = url;
    }
    public void setGroup(Group group){
        this.group = group;
    }
    public Group getGroup(){
        return this.group;
    }
    public String getlnfo(){
        return     "权限编号："+this.aid
                +"，权限名称："+this.title
                +"，路径"+this.url;
    }
}
public class manyToManyMapping{
    public static void main(String args[]){
        //第一步：根据表结构设置关系
        //1.定义单独的类对象
        User ua = new User("user-a","用户A","hello");
        User ub = new User("user-b","用户B","hello");
        User uc = new User("user-c","用户C","hello");
        //2.定义权限
        Action act1 = new Action(1,"新闻管理","naws");
        Action act2 = new Action(1,"用户管理","users");
        Action act3 = new Action(1,"备份管理","bks");
        Action act4 = new Action(1,"缓存管理","caches");
        Action act5 = new Action(1,"数据管理","datas");
        //3.定义权限组信息
        Group g1 = new Group(1,"数据管理");
        Group g2 = new Group(2,"人事管理");
        Group g3 = new Group(3,"信息管理");
        //4.定义角色信息
        Role r1 = new Role(10,"超级管理员角色");
        Role r2 = new Role(10,"普通管理员角色");
        //5.设置权限组与权限的关系，一对多关系
        act1.setGroup(g1); // 权限与权限组的关系
        act2.setGroup(g1);
        act3.setGroup(g2);
        act4.setGroup(g2);
        act5.setGroup(g3);
        g1.setActions(new Action[]{act1,act2});
        g2.setActions(new Action[]{act3,act4});
        g3.setActions(new Action[]{act5});
        //6.权限组与角色关系
        r1.setGroups(new Group[]{g1,g2,g3});
        r1.setGroups(new Group[]{g2,g3});
        g1.setRoles(new Role []{r1});
        g2.setRoles(new Role []{r1,r2});
        g3.setRoles(new Role []{r1,r2});
        //7.定义用户与角色关系
        ua.setRole(r1);
        ub.setRole(r2);
        uc.setRole(r2);
        r1.setUsers(new User[]{ua});
        r2.setUsers(new User[]{ub,uc});
        //第二步：根据要求通过关系取出数据
        //可以根据一个用户输出它对应的角色以及每个角色对应的权限，以及包含的具体的权限详情：
        System.out.println(ua.getlnfo());
        System.out.println("\t|-【角色】"+ua.getRole().getlnfo());
        for(int x = 0;x<ua.getRole().getGroups().length;x++){
            System.out.println("\t\t|-【权限组】"+ua.getRole().getGroups()[x].getlnfo());
            for(int y = 0;y<ua.getRole().getGroups()[x].getActions().length;y++){
                System.out.println("\t\t\t|-【权限】"+ua.getRole().getGroups()[x].getActions()[y].getlnfo());
            }
        }
        System.out.println("***************************");
        //一个权限可以输出具备此权限的角色，以及具备此角色的所有管理员，同时输出该权限的所有权限详情
        System.out.println(act1.getlnfo());
        //通过权限找到权限对应的权限组，一个权限组有多个角色
        for(int x = 0;x<act1.getGroup().getRoles().length;x++){
            System.out.println("\t\t|-【角色】 "+act1.getGroup().getRoles()[x].getlnfo());
            for(int y = 0;y<act1.getGroup().getRoles()[x].getUsers().length;y++){
                System.out.println("\t\t\t|-【用户】 "+act1.getGroup().getRoles()[x].getUsers()[y].getlnfo());
            }
        }
        System.out.println("***************************");
        //一个角色可以输出它所包含的管理员，每个管理员对应的具体的权限，以及权限详情
        System.out.println(r1.getlnfo());
        for(int x = 0;x<r1.getUsers().length;x++){
            System.out.println("\t|-【用户】 "+r1.getUsers()[x].getlnfo());
            for(int y = 0;y<r1.getGroups().length;y++){
                System.out.println("\t\t|-【权限组】 "+r1.getGroups()[y].getlnfo());
                for(int z = 0;z<r1.getGroups()[y].getActions().length;z++){
                    System.out.println("\t\t\t|-【权限】 "+r1.getGroups()[y].getActions()[z].getlnfo());
                }
            }
        }
    }
}

引用，引用，引用 就是java基础的核心
    
    总结
        这种转换必须做到零用脑编写