在gwt编辑器中应用java泛型

Question

我正在使用gwt编辑器框架来绑定gwt中的表单.我能够成功绑定表单,但我的问题是我需要编写太多代码.我认为使用泛型会缩短我的代码,但我无法做到.

代码EditVendorWorkflow几乎相同,唯一的区别是这两行

interface Driver extends  SimpleBeanEditorDriver<Vendor, VendorEditor>{}
private VendorEditor editor;

例如,如果我写了PersonEditor相应的EditPersonWorkflow代码就会有

interface Driver extends  SimpleBeanEditorDriver<Person, PersonEditor>{}
private PersonEditor editor;

所以基本上有重复.

任何帮助都很明显.

public class EditVendorWorkflow{
      interface Driver extends  SimpleBeanEditorDriver<Vendor, VendorEditor>{}

      Driver driver = GWT.create(Driver.class);

      private VendorEditor editor;

      void edit(Vendor p) {
        driver.initialize(editor);
        driver.edit(p);
      }

      void save() {
        Vendor edited = driver.flush();
        //doSomethingWithEditedVendor(edited);

      }

    public void initialize(VendorEditor editor) {
        this.editor = editor;
    }
}


public class VendorEditor extends Composite implements Editor<Vendor> {

    private static VendorEditorUiBinder uiBinder = GWT
            .create(VendorEditorUiBinder.class);
    @UiField Button save;
    @UiField TextBox address;
    @UiField TextBox contactName;
    @UiField ValueBoxEditorDecorator<String> contactMobileNo;
    @Path("department.name")
    @UiField TextBox deptName;
    interface VendorEditorUiBinder extends UiBinder<Widget, VendorEditor> {
    }

    private final EditVendorWorkflow vendorDriver;
    public VendorEditor(Vendor p) {
        initWidget(uiBinder.createAndBindUi(this));
        vendorDriver = GWT.create(EditVendorWorkflow.class);
        vendorDriver.initialize(this);
        vendorDriver.edit(p);
    }


    @UiHandler("save")
    void onSaveClick(ClickEvent event) {
        vendorDriver.save();
    }
}

Answer 1

按照以下几行应该可以完成这项工作：

public class EditWorkflow<O, E extends Editor<O>> {

    SimpleBeanEditorDriver<O, E> driver; 

    private E editor;

    void edit(O p) {
        driver.initialize(editor);
        driver.edit(p);
    }

    void save() {
        O edited = driver.flush();
        //doSomethingWithEditedObject(edited);
    }

    public void initialize(E editor, SimpleBeanEditorDriver<O, E> driver) {
        this.editor = editor;
        this.driver = driver;
    }

}

但不幸的是，GWT.create()只能接受类文字，不能泛型。所以，我想你仍然必须Driver在某个地方创建你的界面。我添加了一个driver参数，initialize()以便您可以GWT.create()在外部调用并将结果传入。

如果您有一些特定于Vendor或 的代码Person，您可以使用抽象方法来抽象它们，例如

protected abstract void doSomethingWithEditedObject(O object); 

并在 的子类中实现它们EditWorkflow。

如果您继续创建 的子类EditWorkflow，则可以将Driver接口放入各自的EditWorkflow类中

public class EditVendorWorkflow extends EditWorkflow<Vendor, VendorEditor> {

    interface Driver extends  SimpleBeanEditorDriver<Vendor, VendorEditor>{}

    public void initialize(VendorEditor editor) {
        super.initialize(editor, GWT.create(Driver.class));
    }

    @Override
    protected void doSomethingWithEditedObject(Vendor object) {
        // Code specific to class Vendor...
    }
}