Bankadmin模型

Question

表关系参考的图像

Image of table relationship reference

从银行jsp页面提交后，由于新手的限制，从卡片jsp提交后全部在一张图片中 After submit from bank jsp page and after submit from card jsp all in one image because of limitation of newbie

我也是stackoverflow的新手SPRING。我试图用外键概念创建两个表。我已经关注了stackoverflow以及其他资源丰富的网站上的一些示例，并且管理创建了两个具有onetomany关系的表。但问题是，当我从卡片jsp页面提交时，我必须获取cart_id列下的第一行ID。相反，在从卡片jsp页面提交后，在bankadmin表下创建了新行，并且正在返回它的id。我很困惑，不知道如何纠正解决这个问题。请善待并指导我。而且我一直在搜索stackoverflow中的一周找不到任何帮助我的东西。提前谢谢。

Bankadmin模型

    @Entity
    @Table(name = "bankAdmin")
    public class bankAdmin implements Serializable{

    @GeneratedValue(strategy=GenerationType.AUTO)
    @Column (name = "bcode", nullable=false)
    @Id private int bcode;

    @Column (name = "bname")
    private String bname;

    @Column (name = "address")
    private String address;

    @Column (name = "phno")
    private int phno;

    @OneToMany(mappedBy="bankAdmin",cascade = CascadeType.ALL)
    private Set<Cards> cards;

卡片型号

    @Entity
    @Table(name = "cards")
    public class Cards implements Serializable {
    @GeneratedValue(strategy=GenerationType.AUTO)
    @Column(name="cname", unique=true)
    @Id private int cname;

    @Column (name = "ctype")
    private String ctype;

    @Column (name = "min_sal")
    private int min_sal;

    @Column (name = "year_fee")
    private int year_fee;

    @Column (name = "rewards")
    private String rewards;

    @Column (name = "jperks")
    private String jperks;

    @ManyToOne(cascade = CascadeType.ALL)
    @JoinColumn(name="cart_id", nullable=false)
    private bankAdmin bankAdmin;
    public Cards(){}

    public Cards(String ctype, int min_sal, int year_fee, String rewards, String jperks, bankAdmin b){//int cname, 
        this.ctype=ctype;
        this.min_sal=min_sal;
        this.year_fee=year_fee;
        this.jperks=jperks;
        this.rewards=rewards;
        this.bankAdmin=b;
    } 

    public bankAdmin getBankAdmin() {
        return bankAdmin;
    }
    public void setBankAdmin(bankAdmin bankAdmin) {
        this.bankAdmin = bankAdmin;
    }

的 CardDaoImpl

    public class CardsDaoImpl implements CardsDao{

    @Autowired
    SessionFactory sessionfactory;

    public void save(Cards cards) {
        Session session = null;
        Transaction tx = null;

        try 
        {
            session = this.sessionfactory.openSession();
            tx = session.beginTransaction();

            bankAdmin bankadmin =new bankAdmin(); //=null;
            String _ctype = cards.getctype();
            int _min_sal = cards.getmin_sal();
            int _year_fee = cards.getyear_fee();
            String _rewards = cards.getrewards();
            String _jperks = cards.getjperks();
            Set<Cards> card = new HashSet<Cards>();
            Cards config =  new Cards(_ctype,_min_sal,_year_fee,_rewards,_jperks,bankadmin);
            card.add(config);
            bankadmin.setcards(card);
//          System.out.println("bankadmin: before " + bankadmin);
//          bankadmin.setbname(bankadmin.getbname());// "SBI"
//          bankadmin.setphno(bankadmin.getphno());//1234567890
//          bankadmin.setaddress(bankadmin.getaddress());//Bengaluru
//          System.out.println("bankadmin: after " + bankadmin);

//          int _cname = cards.getcname();

//          int bankadmin = bankadmin.getbcode();

            //_cname,_ctype,_min_sal,_year_fee,_rewards,_jperks,bankadmin
//          card.add(config);
//          config.setBankAdmin(cards.getBankAdmin(bankadmin));

//          config.setcname(cards.getcname());
//          config.setctype(cards.getctype());
//          config.setmin_sal(cards.getmin_sal());
//          config.setyear_fee(cards.getyear_fee());
//          config.setrewards(cards.getrewards());
//          config.setjperks(cards.getjperks());
//          config.setBankAdmin(cards.getBankAdmin());
            session.save(bankadmin);
            session.save(config);
            tx.commit();
        } 
        catch (HibernateException e) 
        {
            e.printStackTrace();
        }
        finally 
        {
            session.close();
        }
    }

//  get lms lights config from DB
    public List<Cards> Ccards() {
        Session session = null;
//      Transaction tx = null;
        List<Cards> Ccards = null;

        try{
            session = this.sessionfactory.openSession();
            Ccards = session.createQuery("FROM Cards").list();
            System.out.println("cards dao impl executed...");
            System.out.println("cards config : "+ Ccards.toString());

        }
        catch (Exception e)
        {
            System.out.println("bankAdmin Dao impl Ex : " + e);
        }
        finally
        {
            session.close();
        }

        return Ccards;
    }



}

BankDaoImpl

    public class bankAdminDaoImpl implements bankAdminDao{
    @Autowired
    SessionFactory sessionfactory;

    public void save(bankAdmin badmin) {
        Session session = null;
        Transaction tx = null;

        try 
        {   
            session = this.sessionfactory.openSession();
            tx = session.beginTransaction();
//          bankAdmin bankadmin = new bankAdmin();
            bankAdmin config =  new bankAdmin();
            config.setbcode(badmin.getbcode());
            config.setbname(badmin.getbname());
            config.setaddress(badmin.getaddress());
            config.setphno(badmin.getphno());

            session.save(config);//save//persist
            tx.commit();
        } 
        catch (HibernateException e) 
        {
            e.printStackTrace();
        }
        finally 
        {
            session.close();
        }
    }

//  get lms lights config from DB
    public List<bankAdmin> BbankAdmin() {
        Session session = null;
//      Transaction tx = null;
        List<bankAdmin> BbankAdmin = null;

        try{
            session = this.sessionfactory.openSession();
            BbankAdmin = session.createQuery("FROM bankAdmin").list();
            System.out.println("bankAdmin dao impl executed...");
            System.out.println("bankAdmin config : "+ BbankAdmin.toString());

        }
        catch (Exception e)
        {
            System.out.println("bankAdmin Dao impl Ex : " + e);
        }
        finally
        {
            session.close();
        }

        return BbankAdmin;
    }


}

Answer 1

好。我已经解决了你的问题。

首先，Spring框架很棒。该框架有很多功能，你应该利用它们。我不确定我是否能够涵盖这篇文章中的所有内容，所以请随时问我。

我创建了一个简单的Spring Boot应用程序。我总共收到了6个重要的文件，这些文件发布在下面。

请注意，我使用大写字母将您的类重命名为CamelCase。例如BankAdmin。这被认为是编写java类的标准方法。另请注意，我将Cards重命名为Card，因此请记住在数据库中重命名您的表格。还记得将bankadmin表重命名为bank_admin。

您需要了解一些注释。 @Transactional，@Autowired和PersistenceContext。

这是一个快速简单的解释。 @Transactional为您管理所有事务，因此您不必开始和提交事务。 @Autowired为您创建对象，因此您不必自己管理对象依赖项。 PersistenceContext基本上为您创建了EntityManager并为您管理它。您不必创建会话也不必创建EntitManagerFactory。这三个注释的解释非常简短，所以你应该自己阅读它们。

我还删除了@Table(name = "bankAdmin")和@Table(name = "cards")。如果您遵循命名类和数据库表的标准方法，JPA可以自动查找这些表。它实际上很简单，但我仍然鼓励你自己调查一下。简而言之，资本来源变成小写，每个单词之间都以_开头，以大写字母开头。即如果您的班级名称为BankAdmin，则JPA会自动在您的数据库中查找名为bank_admin的表。

application.properties - 有关您数据库的详细信息

spring.datasource.url=jdbc:mysql://localhost:3306/stackoverflow?useSSL=false
spring.datasource.username = root
spring.datasource.password = root

spring.jpa.show-sql = true
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect
spring.jpa.hibernate.ddl-auto = update

以下代码仅用于测试功能

    @SpringBootApplication
    public class StackoverflowApplication {

    public static void main(String[] args) {

        ApplicationContext ctx = SpringApplication.run(StackoverflowApplication.class, args);

        //Calling a class that is only made with the purpose of testing
        Verification ts = ctx.getBean(Verification.class);
        ts.run();
    }
    }

    @Component
    class Verification{

    @Autowired
    private BankAdminDao bad;

    @Autowired
    private CardsDao cd;

    void run(){
        //Create a new BankAdmin
        BankAdmin ba = new BankAdmin();
        ba.setAddress("someStreet");
        ba.setPhno(12341234);
        ba.setBname("myBanker");

        //Create two cards and add them to a HashSet.
        Card c1 = new Card("Visa", 1000, 1999, "Alot of", "Babes", ba);
        Card c2 = new Card("Master Card", 2000, 500, "someThing", "anotherThing", ba);
        Set<Card> cardList = new HashSet<>();
        cardList.add(c1);
        cardList.add(c2);

        //Create a associatio between the BankAdmin and list of Cards
        ba.setCards(cardList);

        //Save them to the database.
        bad.save(ba);

        //Here we add a Card to an existing BankAdmin with the id 6 in the database.

        //Create a new Card.
        //The BankAdmin is set to null, because we not have not yet loaded the BankAdmin
        Card c3 = new Card("Visa", 9999, 1337, "Alot of", "Male Babes", null);

        //Save Card c3 with the BankAdmin id 6
        cd.save(c3, 6);

    }
    }

<强> BankAdmin

    @Entity
    public class BankAdmin implements Serializable{

    @GeneratedValue(strategy=GenerationType.AUTO)
    @Column (name = "bcode", nullable=false)
    @Id private int bcode;

    @Column (name = "bname")
    private String bname;

    @Column (name = "address")
    private String address;

    @Column (name = "phno")
    private int phno;

    @OneToMany(mappedBy="bankAdmin",cascade=CascadeType.ALL)
    private Set<Card> cards;

    //Getters and Setters have been removed to reduce the amount of code.
    }

<强> BankAdminDao

    @Repository
    //Transactional makes transaction automatical, so you do not have to begin and commit transactions yourself!
    @Transactional 
    public class BankAdminDao{

    //This makes your life a lot eaier!
    //It will take care of your EntitManagerFactory and Sessions
    @PersistenceContext
    EntityManager em;

    public void save(BankAdmin bank) {
        em.merge(bank);
    }

    //get lms lights config from DB
    public List<BankAdmin> getAllBankAdmin() {
         List<BankAdmin> bankList = (List<BankAdmin>)em.createQuery("SELECT b FROM BankAdmin b");
         return bankList;
    }

    public BankAdmin getBankAdmin(int bankId) {
        return em.find(BankAdmin.class, bankId);
    }
    }

<强>卡

    @Entity
    public class Card implements Serializable {
    @GeneratedValue(strategy=GenerationType.AUTO)
    @Column(name="cname", unique=true)
    @Id private int cname;

    @Column (name = "ctype")
    private String ctype;

    @Column (name = "min_sal")
    private int min_sal;

    @Column (name = "year_fee")
    private int year_fee;

    @Column (name = "rewards")
    private String rewards;

    @Column (name = "jperks")
    private String jperks;

    @ManyToOne(cascade = CascadeType.ALL)
    @JoinColumn(name="cart_id", nullable=false)
    private BankAdmin bankAdmin;

    public Card(){}

    public Card(String ctype, int min_sal, int year_fee, String rewards, String jperks, BankAdmin b){
        this.ctype=ctype;
        this.min_sal=min_sal;
        this.year_fee=year_fee;
        this.jperks=jperks;
        this.rewards=rewards;
        this.bankAdmin=b;
    } 

    public BankAdmin getBankAdmin() {
        return bankAdmin;
    }
    public void setBankAdmin(BankAdmin bankAdmin) {
        this.bankAdmin = bankAdmin;
    }
    }

<强> CardDao

    @Repository
    @Transactional
    public class CardsDao{

        @PersistenceContext
        EntityManager em;

        @Autowired
        BankAdminDao bad;

        public void save(Card cards, int bankId) {
            BankAdmin bank = bad.getBankAdmin(bankId);
            cards.setBankAdmin(bank);   
            bank.getCards().add(cards);
            em.merge(bank);
        }

        public List<Card> getAllCards() {
            List<Card> cardList = (List<Card>)em.createQuery("SELECT c FROM Cards c");
             return cardList;
        }

        public Card getCard(int cardId){
            return em.find(Card.class, cardId);
        }
    }

需要使用hibernate dao实现方法

Bankadmin模型

卡片型号

的 CardDaoImpl

1 个答案: