Showing data in Grid

Grid lazy-loads data from a Container instance. There are different container implementations that e.g. fetch data from a database or use a list of Java objects. Assuming you already have code that initializes a Container, this is all that is needed for showing a Grid with the data from your container.

import com.vaadin.server.VaadinRequest;
import com.vaadin.ui.Grid;
import com.vaadin.ui.UI;

public class UsingGridWithAContainer extends UI {
  @Override
  protected void init(VaadinRequest request) {
    Grid grid = new Grid();
    grid.setContainerDataSource(GridExampleHelper.createContainer());

    setContent(grid);
  }
}

The container in this example contains three properties; name, count and amount. You can configure the columns in Grid using the property ids to do things like setting the column caption, removing a column or changing the order of the visible columns.

protected void init(VaadinRequest request) {
  Grid grid = new Grid();
  grid.setContainerDataSource(GridExampleHelper.createContainer());

  grid.getColumn("name").setHeaderCaption("Bean name");
  grid.removeColumn("count");
  grid.setColumnOrder("name", "amount");

  setContent(grid);
}

This is really all that is needed to get started with Grid.

For reference, this is how the example container is implemented.

public class GridExampleBean {
  private String name;
  private int count;
  private double amount;

  public GridExampleBean() {
  }

  public GridExampleBean(String name, int count, double amount) {
    this.name = name;
    this.count = count;
    this.amount = amount;
  }

  public String getName() {
    return name;
  }

  public int getCount() {
    return count;
  }

  public double getAmount() {
    return amount;
  }

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

  public void setCount(int count) {
    this.count = count;
  }

  public void setAmount(double amount) {
    this.amount = amount;
  }
}
import com.vaadin.data.util.BeanItemContainer;

public class GridExampleHelper {
  public static BeanItemContainer<GridExampleBean> createContainer() {
    BeanItemContainer<GridExampleBean> container = new BeanItemContainer<GridExampleBean>(GridExampleBean.class);
    for (int i = 0; i < 1000; i++) {
      container.addItem(new GridExampleBean("Bean " + i, i * i, i / 10d));
    }
    return container;
  }
}