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私はJavaEEとVaadinを使用しているページ上のすべての製品データを表示していますが、カテゴリ名の代わりにオブジェクト全体を表示するカテゴリ列を除いて動作しています。Vaadinでは、結合されたテーブルからデータを表示する方法は？
私はcategory_id列とフェッチに基づいて2つのテーブルproductとcategoryに参加してcategoryテーブルからカテゴリ名を表示しています。クエリは下記のProductDaoImplクラスに記載されています。 POMで
Vaadinバージョン
<vaadin.version>7.6.5</vaadin.version>
ProductsUI.java
@Title("Home")
@Theme("mytheme")
@Widgetset("com.study.crud.MyAppWidgetset")
public class ProductsUI extends UI {
private static final Logger LOG = Logger.getLogger(ProductsUI.class);
private final Grid productsGrid = new Grid();
private DataSource dataSource;
@Override
protected void init(VaadinRequest vaadinRequest) {
getDataSource(vaadinRequest);
configureComponents();
buildLayout();
}
private void getDataSource(VaadinRequest vaadinRequest) {
VaadinServletRequest req = (VaadinServletRequest) vaadinRequest;
this.dataSource = (DataSource) req.getServletContext().getAttribute("dataSource");
}
private void configureComponents() {
// get all products
ProductDao productDao = new ProductDaoImpl(dataSource);
List<Product> products = productDao.getProducts();
//set all the products in grid
productsGrid.setContainerDataSource(new BeanItemContainer<>(Product.class, products));
productsGrid.setColumnOrder("productId", "name", "image", "listPrice", "category", "active");
productsGrid.removeColumn("description");
productsGrid.removeColumn("createdBy");
productsGrid.removeColumn("expiryDate");
productsGrid.removeColumn("modifiedOn");
}
private void buildLayout() {
VerticalLayout layout = new VerticalLayout();
//add products grid to the main layout
layout.addComponent(productsGrid);
productsGrid.setSizeFull();
layout.setSizeFull();
layout.setMargin(true);
layout.setSpacing(true);
setContent(layout);
}
@WebServlet(urlPatterns = "/*", name = "ProductsUIServlet", asyncSupported = true)
@VaadinServletConfiguration(ui = ProductsUI.class, productionMode = false)
public static class ProductsUIServlet extends VaadinServlet {
}
}
Product.java
public class Product implements Serializable {
private int productId;
private String name;
private String description;
private String image;
private BigDecimal listPrice;
private Category category;
private Date expiryDate;
private String createdBy;
private Date modifiedOn;
private String active;
public Product() {
}
public Product(int productId) {
this.productId = productId;
}
public Product(int productId, String name, String description, String image, BigDecimal listPrice, Category category, Date expiryDate, String createdBy, Date modifiedOn, String active) {
this.productId = productId;
this.name = name;
this.description = description;
this.image = image;
this.listPrice = listPrice;
this.category = category;
this.expiryDate = expiryDate;
this.createdBy = createdBy;
this.modifiedOn = modifiedOn;
this.active = active;
}
public int getProductId() {
return productId;
}
public void setProductId(int productId) {
this.productId = productId;
}
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 String getImage() {
return image;
}
public void setImage(String image) {
this.image = image;
}
public BigDecimal getListPrice() {
return listPrice;
}
public void setListPrice(BigDecimal listPrice) {
this.listPrice = listPrice;
}
public Category getCategory() {
return category;
}
public void setCategory(Category category) {
this.category = category;
}
public Date getExpiryDate() {
return expiryDate;
}
public void setExpiryDate(Date expiryDate) {
this.expiryDate = expiryDate;
}
public String getCreatedBy() {
return createdBy;
}
public void setCreatedBy(String createdBy) {
this.createdBy = createdBy;
}
public Date getModifiedOn() {
return modifiedOn;
}
public void setModifiedOn(Date modifiedOn) {
this.modifiedOn = modifiedOn;
}
public String getActive() {
return active;
}
public void setActive(String active) {
this.active = active;
}
@Override
public String toString() {
return "Product{" + "productId=" + productId + ", name=" + name + ", description=" + description + ", image=" + image + ", listPrice=" + listPrice + ", category=" + category + ", expiryDate=" + expiryDate + ", createdBy=" + createdBy + ", modifiedOn=" + modifiedOn + ", active=" + active + '}';
}
}
Category.java
public class Category implements Serializable {
private int categoryId;
private String name;
private String description;
private Date expiryDate;
private String createdBy;
private Date modifiedOn;
private String active;
public Category() {
}
public Category(int categoryId) {
this.categoryId = categoryId;
}
public Category(String name) {
this.name = name;
}
public Category(int categoryId, String name) {
this.categoryId = categoryId;
this.name = name;
}
public Category(int categoryId, String name, String description, Date expiryDate, String createdBy, Date modifiedOn, String active) {
this.categoryId = categoryId;
this.name = name;
this.description = description;
this.expiryDate = expiryDate;
this.createdBy = createdBy;
this.modifiedOn = modifiedOn;
this.active = active;
}
public int getCategoryId() {
return categoryId;
}
public void setCategoryId(int 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;
}
public Date getExpiryDate() {
return expiryDate;
}
public void setExpiryDate(Date expiryDate) {
this.expiryDate = expiryDate;
}
public String getCreatedBy() {
return createdBy;
}
public void setCreatedBy(String createdBy) {
this.createdBy = createdBy;
}
public Date getModifiedOn() {
return modifiedOn;
}
public void setModifiedOn(Date modifiedOn) {
this.modifiedOn = modifiedOn;
}
public String getActive() {
return active;
}
public void setActive(String active) {
this.active = active;
}
@Override
public String toString() {
return "Category{" + "categoryId=" + categoryId + ", name=" + name + ", description=" + description + ", expiryDate=" + expiryDate + ", createdBy=" + createdBy + ", modifiedOn=" + modifiedOn + ", active=" + active + '}';
}
}
ProductDaoImpl.java
public class ProductDaoImpl implements ProductDao {
private final DataSource dataSource;
public ProductDaoImpl(DataSource dataSource) {
this.dataSource = dataSource;
}
@Override
public List<Product> getProducts() {
String sql = "select a.*, b.name as category_name from product a, category b where a.category_id = b.category_id";
LOG.debug(sql);
Statement stmt = null;
ResultSet rs = null;
Connection cn = null;
List<Product> products = new ArrayList<>();
try {
cn = dataSource.getConnection();
stmt = cn.createStatement();
rs = stmt.executeQuery(sql);
while (rs != null && rs.next()) {
int productId = new Integer(StringUtils.defaultString(rs.getString("PRODUCT_ID")));
String name = StringUtils.defaultString(rs.getString("NAME"));
String description = StringUtils.defaultString(rs.getString("DESCRIPTION"));
String image = StringUtils.defaultString(rs.getString("IMAGE"));
BigDecimal listPrice = new BigDecimal(StringUtils.defaultString(rs.getString("LIST_PRICE")));
int categoryId = new Integer(StringUtils.defaultString(rs.getString("CATEGORY_ID")));
String categoryName = StringUtils.defaultString(rs.getString("CATEGORY_NAME"));
Category category = new Category(categoryId, categoryName);
Date expiryDate = rs.getDate("EXPIRY_DATE");
String createdBy = StringUtils.defaultString(rs.getString("CREATED_BY"));
Date modifiedOn = rs.getDate("MODIFIED_ON");
String active = StringUtils.defaultString(rs.getString("ACTIVE"));
Product product = new Product(productId, name, description, image, listPrice, category, expiryDate, createdBy, modifiedOn, active);
products.add(product);
}
LOG.debug("products = " + products);
LOG.debug("products.size() = " + products.size());
return products;
} catch (SQLException | NumberFormatException ex) {
LOG.error("Exception while getting products....", ex);
return null;
} //close resources
finally {
try {
if (rs != null) {
rs.close();
}
if (stmt != null) {
stmt.close();
}
if (cn != null) {
cn.close();
}
} catch (SQLException ex) {
LOG.error("Exception while closing DB resources rs, stmt or cn.......", ex);
} finally {
try {
if (cn != null) {
cn.close();
}
} catch (SQLException ex) {
LOG.error("Exception while closing cn.......", ex);
}
}
}
}
}
おかげで良いです！それは働いた:) – user2325154