获取JSF下拉值并保存到数据库

Question

我在数据库中有两个表：预订和类别。现在我想制作用户可以在Book表中添加书籍的页面，但是从Category表中选择合适的类别。

我可以将图书添加到表格中，但我无法在图书表格中保存值类别。

[

正如您所看到图书表中的类别 外键， category_id 来自类别< / strong> table。

以下是模型类：

预订模型

AA<-read.csv("~/example.csv",header = T,sep = ";",dec = ",")
    AA$st <-
      shingle(Indl.Data$t,
              intervals = rbind(c(0, 14),
                                c(23, 26)))
    AA<-AA[with(AA, order(t)), ]



    my.panel.1 <- function(x, y, subscripts, col, pch,cex,sd,...) {
      low95 <- y-sd[subscripts]
      up95 <- y+sd[subscripts]
      panel.xyplot(x, y, col=col, pch=pch,cex=cex, ...)
      panel.arrows(x, low95, x, up95, angle=90, code=3,lwd=3, 
                   length=0.05, alpha=0.5,col=col)
    }
    xyplot( logOD~t|cs+st,
            data=AA,
            strip = T,
           sd=0,
            groups=cs,
            xlab = list("Time ", cex=1.5), 
            ylab = list("growth", cex=1.5),
            type="p",
            col=c("red","black"),
            scales = list(x = "free"), between = list(x = 0.5),
            panel.groups="my.panel.1", 
            panel="panel.superpose",
            par.settings = list(layout.widths = list(panel = c(6, 2))))

}

类别模型

@Entity
@Table(name = "book")
@XmlRootElement
@NamedQueries({
@NamedQuery(name = "Book.findAll", query = "SELECT b FROM Book b"),
@NamedQuery(name = "Book.findByBookId", query = "SELECT b FROM Book b WHERE b.bookId = :bookId")})

public class Book implements Serializable {

private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Basic(optional = false)
@Column(name = "book_id")
private Integer bookId;
@Basic(optional = false)
@NotNull
@Lob
@Size(min = 1, max = 65535)
@Column(name = "name")
private String name;
@Lob
@Size(max = 65535)
@Column(name = "description")
private String description;
@JoinColumn(name = "category", referencedColumnName = "category_id")
@ManyToOne
private Category category;

public Book() {
}

public Book(Integer bookId) {
    this.bookId = bookId;
}

public Book(Integer bookId, String name) {
    this.bookId = bookId;
    this.name = name;
}

public Integer getBookId() {
    return bookId;
}

public void setBookId(Integer bookId) {
    this.bookId = bookId;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getDescription() {
    return description;
}

public void setDescription(String description) {
    this.description = description;
}

public Category getCategory() {
    return category;
}

public void setCategory(Category category) {
    this.category = category;
}

@Override
public int hashCode() {
    int hash = 0;
    hash += (bookId != null ? bookId.hashCode() : 0);
    return hash;
}

@Override
public boolean equals(Object object) {
    // TODO: Warning - this method won't work in the case the id fields are not set
    if (!(object instanceof Book)) {
        return false;
    }
    Book other = (Book) object;
    if ((this.bookId == null && other.bookId != null) || (this.bookId != null && !this.bookId.equals(other.bookId))) {
        return false;
    }
    return true;
}

@Override
public String toString() {
    return "com.biblioteka.app.domen.Book[ bookId=" + bookId + " ]";
}

}

现在我有JSF页面，我将bookes添加到数据库。我有下拉列表，将类别加载到其中。用户应选择一个类别并将书保存到表格。

这是来自 JSF addBook page 的代码。

 @Entity
 @Table(name = "category")
 @XmlRootElement
 @NamedQueries({
@NamedQuery(name = "Category.findAll", query = "SELECT c FROM Category c"),
@NamedQuery(name = "Category.findByCategoryId", query = "SELECT c FROM Category c WHERE c.categoryId = :categoryId")})

 public class Category implements Serializable {

private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Basic(optional = false)
@Column(name = "category_id")
private Integer categoryId;
@Basic(optional = false)
@NotNull
@Lob
@Size(min = 1, max = 65535)
@Column(name = "name")
private String name;
@Lob
@Size(max = 65535)
@Column(name = "description")
private String description;
@OneToMany(mappedBy = "category")
private Collection<Book> bookCollection;

public Category() {
}

public Category(Integer categoryId) {
    this.categoryId = categoryId;
}

public Category(Integer categoryId, String name) {
    this.categoryId = categoryId;
    this.name = name;
}

public Integer getCategoryId() {
    return categoryId;
}

public void setCategoryId(Integer categoryId) {
    this.categoryId = categoryId;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getDescription() {
    return description;
}

public void setDescription(String description) {
    this.description = description;
}

@XmlTransient
public Collection<Book> getBookCollection() {
    return bookCollection;
}

public void setBookCollection(Collection<Book> bookCollection) {
    this.bookCollection = bookCollection;
}

@Override
public int hashCode() {
    int hash = 0;
    hash += (categoryId != null ? categoryId.hashCode() : 0);
    return hash;
}

@Override
public boolean equals(Object object) {
    // TODO: Warning - this method won't work in the case the id fields are not set
    if (!(object instanceof Category)) {
        return false;
    }
    Category other = (Category) object;
    if ((this.categoryId == null && other.categoryId != null) || (this.categoryId != null && !this.categoryId.equals(other.categoryId))) {
        return false;
    }
    return true;
}

@Override
public String toString() {
    return "com.biblioteka.app.domen.Category[ categoryId=" + categoryId + " ]";
}

正如您所看到的，我使用 selectOneMenu 并使用值 bookBean.category 然后我不确定我需要在 selectItems

这是 BookBean 代码：

  <p:layoutUnit position="center">
            <h:form>
                <p:inputText value="#{bookBean.name}" a:placeholder="Ime  knjige"></p:inputText><br/>
                <p:inputText value="#{bookBean.description}" a:placeholder="Opis knjige"></p:inputText><br/>
                <p:selectOneMenu value="#{bookBean.category}">
                    <f:selectItems value="#{categoryBean.allCategories}" var="c"
                                   itemLabel="#{c.name}" itemValue="#{c.categoryId}"/>

                </p:selectOneMenu>
                <b/><b/>
                <p:commandButton value="Dodaj knjigu" action="#{bookBean.addBook()}"/>
            </h:form>
        </p:layoutUnit>

}

Answer 1

试试这个：

div

列出的项目名称将是类别名称，类别将分配给 bookBean.category ，这可以设置为图书类别并保留。

希望这有帮助。