Question

我想问一下如何插入或更新我的课程中包含的hashmap 他们是我的班级设备：

package com.project.beans;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

import javax.persistence.ElementCollection;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Inheritance;
import javax.persistence.InheritanceType;
import javax.persistence.ManyToMany;

@Entity
@Inheritance( strategy = InheritanceType.JOINED )
public class Equipement {

    @Id
    @GeneratedValue( strategy = GenerationType.TABLE )
    private int                 idEquip;

    private String              reference;
    private static final int    HT       = 744;
    @ElementCollection
    Map<String, String>         HM;


    @ManyToMany( fetch = FetchType.EAGER )
    private Collection<Systeme> systemes = new ArrayList<Systeme>();

    public Equipement() {
        HM = new HashMap<String, String>();

    }

    public Equipement( String ref, ArrayList<Systeme> systemes ) {
        this.reference = ref;
        this.systemes = systemes;
        HM = new HashMap<String, String>();

    }

    public Collection<Systeme> getSystemes() {
        return systemes;
    }

    public void setSystemes( Collection<Systeme> systemes ) {
        this.systemes = systemes;
    }

    public String getReference() {
        return reference;
    }

    public void setReference( String reference ) {
        this.reference = reference;
    }

    public Map<String, String> getHM() {
        return HM;
    }

    public void setHM( Map<String, String> hM ) {
        HM = hM;
    }   

    public int getIdEquip() {
        return idEquip;
    }

    public static int getHt() {
        return HT;
    }

}

我的班级服务：

public class EquipementService2 {

    private Session           session;
    private Transaction       tx;

    public boolean update( Equipement o ) {
        try {
            session = HibernateUtil.getSessionFactory().openSession();
            tx = session.beginTransaction();
            session.update( o );
            tx.commit();
            return true;
        } catch ( Exception e ) {
            if ( tx != null )
                tx.rollback();
            return false;
        }
    }

    public Equipement findById( int id ) {
        Equipement equipement = null;
        try {
            session = HibernateUtil.getSessionFactory().openSession();
            tx = session.beginTransaction();
            equipement = (Equipement) session.get( Equipement.class, id );
            tx.commit();
            return equipement;
        } catch ( Exception e ) {
            if ( tx != null )
                tx.rollback();
            return null;
        }
    }}

我的servlet：

public class Validation_hm extends HttpServlet {

    public static final String VUE   = "/WEB-INF/entretientDra.jsp";


    public static final String VUE2  = "/WEB-INF/ajoutHM.jsp";

    public static final String VUE9  = "/accueil.jsp";

    public static final String ATT_1 = "form";
    public static final String ATT_2 = "mar";
    public static final String ATT_3 = "key";

    protected void doPost( HttpServletRequest request, HttpServletResponse response ) throws ServletException,
            IOException {

        HeurM_GST hg = new HeurM_GST();

        EquipementService2 es = new EquipementService2();
        Equipement equipement = hg.creeEquipement( request );
        int id = hg.idEquip( request );

        request.setAttribute( ATT_3, hg.key( request ) );
        request.setAttribute( ATT_2, equipement );
        request.setAttribute( ATT_1, hg );
        request.setAttribute( "idequip", id );

        if ( hg.getErreurs().isEmpty() ) {
            es.update( equipement );

                this.getServletContext().getRequestDispatcher( VUE ).forward( request, response );
            }
        } else {
            this.getServletContext().getRequestDispatcher( VUE2 ).forward( request, response );
        }
    }}

类HeurM_GST

public class HeurM_GST {
 private static final String CHAMP_DATE = "date";
    private static final String CHAMP_HM   = "hm";
    private static final String CHAMP_ID   = "idequip";
    private static final String CHAMP_KEY  = "key";
// .....
//......

    private static String getValeurChamp( HttpServletRequest
            request, String nomChamp ) {
        String valeur = request.getParameter( nomChamp );
        if ( valeur == null || valeur.trim().length() == 0 ) {
            return null;
        } else {
            return valeur;
        }
    }
public Equipement creeEquipement( HttpServletRequest request ) {

        String date = getValeurChamp( request, CHAMP_DATE );
        String hm = getValeurChamp( request, CHAMP_HM );

        EquipementService2 es = new EquipementService2();
        Equipement equipement = es.findById( this.idEquip( request ) );

        // date HM

        try {
            validationDate( date );
        } catch ( Exception e ) {
            setErreur( CHAMP_DATE, e.getMessage() );
        }

        // nbr heures

        try {
            validationHM( hm );
        } catch ( Exception e ) {
            setErreur(CHAMP_HM, e.getMessage() );
        }

        // HM
        equipement.getHM().put( date, hm );

        return equipement;

    }
}

我没有错误..但我的hashmap没有更新！

Answer 1

对我而言，它有效......是您在事务中的本机查询吗？...但更好的方法是使用该对象。

在您的情况下，您可以修改哈希图，而不是将修改后的对象用于更新方法。

会话示例：

您的代码中有Equipement-Object。使用它并删除或添加一些东西到hashmap。在您的服务中调用您的方法public boolean update( Equipement o ) {。数据库应该更新它。

仅限方法：

// Add to the entity.
public void addToEntity(EntityManager em, Long id, String value, String key){
    em.getTransaction().begin();
    Equipement eq = em.find(Equipement.class, id);
    eq.getHM().put(key, value);
    em.getTransaction().commit();
}
// Remove from the entity.
public void removeFromEntity(EntityManager em, Long id, String key){
    em.getTransaction().begin();
    Equipement eq= em.find(Equipement.class, id);
    eq.getHM().remove(key);
    em.getTransaction().commit();
}

// Merge entity with modified hashmap to database
public Equipement mergeEntity(EntityManager em, Equipement eq){
    em.getTransaction().begin();
    eq= em.merge(eq);
    em.getTransaction().commit();
    return eq;
}

HIBERNATE在HashMAp中更新/插入一个值

1 个答案: