問題

NetBeanのHibernateツールによって生成される注釈による以下のHibernateマッピングを参照してください。


File:Stock.java
 

package com.mkyong.stock.model;//...
@Entity
@Table(name = "stock", catalog = "mkyong");
public class Stock implements java.io.Serializable {

   //...
    private Set stockCategories = new HashSet(0);

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "stock")
    public Set getStockCategories() {
    return this.stockCategories;
    }

    public void setStockCategories(Set stockCategories) {
    this.stockCategories = stockCategories;
    }

}


File:StockCategory.java
 

package com.mkyong.stock.model;//...
@Entity
@Table(name = "stock__category", catalog = "mkyong");
public class StockCategory implements java.io.Serializable {

    private Stock stock;
   //...

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "STOCK__ID", nullable = false)
    public Stock getStock() {
    return this.stock;
    }

}

プログラムが実行されているときは、次の例外が発生します。 

Caused by: org.hibernate.AnnotationException:
    Collection has neither generic type or OneToMany.targetEntity()
    defined: com.mkyong.stock.model.Stock.stockCategories

解決策

これを修正するには、関係変数に正確なデータ型を宣言します。関係変数には、 `@ OneToMany`アノテーションが付いています。下記を参照してください。

File:Stock.java
 

package com.mkyong.stock.model;//...
@Entity
@Table(name = "stock", catalog = "mkyong");
public class Stock implements java.io.Serializable {

   //...
    private Set<StockCategory> stockCategories = new HashSet(0);

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "stock")
    public Set getStockCategories() {
    return this.stockCategories;
    }

    public void setStockCategories(Set<StockCategory> stockCategories) {
    this.stockCategories = stockCategories;
    }

}


hibernate