java - 方法内出现 AsyncCallback 的 GWT Java 错误

Question

在客户端，我向服务器端发出调用，以获取数据库中的名称列表。当此列表返回到客户端时，我会在 TabPanel 中显示每个名称。当显示每个名称时，我向服务器端发出调用，以从服务器端的数据库中获取该名称的地址列表(这样我就可以更新和添加)。返回地址列表后，我将它们添加到 DisclosurePanel 内的 FlexTable 中。

所以我有一个包含名称的 TabPanel 和一个包含关联地址的 DisclosurePanel。

问题是我无法在 DisclosurePanel 方法中调用数据库来获取正确的地址。

代码是:

private DisclosurePanel addressDisclosurePanel(String nameId) {
    DisclosurePanel addressDisclosurePanel = new DisclosurePanel("Address");

    //Get the Addresses
    AsyncCallback<List<Address>> callback = new GetAddressHandler<List<Address>>();
    rpc.getAddressList(nameId, callback);


    class GetAddressHandler<T> implements AsyncCallback<List<Address>> {
        //Get the list of Addresses.
        PersonalDetailsView view;

        public GetAddressHandler(PersonalDetailsView view) {
            this.view = view;
        }

        public void onFailure(Throwable ex) {
            System.out.println("RPC call failed - GetAddressHandler - Notify Administrator.");
            Window.alert("Connection failed - please retry.");
        }
        public void onSuccess(List<Address> result) {
            view.renderAddresses(result);
        }
    }

    public void renderAddresses(List<Address> addressList) {
        //Load each TabPanel with Addresses

        final FlexTable flexTableAddress = new FlexTable();

        if (addressList == null || addressList.isEmpty()) {
            //Add a place to add an address

            //Address Type
            final Label lblAddressType = new Label("Address Type:");
            lblAddressType.setStyleName("gwt-Label-Login");
            flexTableAddress.setWidget(0, 0, lblAddressType);

            final TextBox textBoxAddressType = new TextBox();
            textBoxAddressType.setStyleName("gwt-TextBox");
            textBoxAddressType.setWidth("300px");
            flexTableAddress.setWidget(0, 1, textBoxAddressType);

            addressDisclosurePanel.add(flexTableAddress);

        }else{
            int row = 0;
            //
            //Create a place to display each Address and allow update
            //
            for (final Address eachAddress : addressList) {
                //Store key
                final String addId = eachAddress.getAddId();

                //Address Type
                final Label lblAddressType = new Label("Address Type:");
                lblAddressType.setStyleName("gwt-Label-Login");
                flexTableAddress.setWidget(row, 0, lblAddressType);

                final TextBox textBoxAddressType = new TextBox();
                textBoxAddressType.setText(eachAddress.getAddType());
                textBoxAddressType.setStyleName("gwt-TextBox");
                textBoxAddressType.setWidth("300px");
                flexTableAddress.setWidget(row, 1, textBoxAddressType);

                row++;
            }
            addressDisclosurePanel.add(flexTableAddress);
        }
    }
    return addressDisclosurePanel;
}

错误上线:

view.renderAddresses(result);

错误消息是“PersonalDetailsView 类型的 renderAddresses(List) 方法未定义”。

上线:

public void renderAddresses(List<Address> addressList) {

错误消息是“此行有多个标记 - 标记“)”上的语法错误，;预期的 - 标记“(”上的语法错误；预期 - void 是变量的无效类型 渲染地址”

我做了这个改变:

    private DisclosurePanel addressDisclosurePanel(String nameId) {
    final DisclosurePanel addressDisclosurePanel = new DisclosurePanel("Address");

    //Get the Addresses
    AsyncCallback<List<Address>> callback = new GetAddressHandler<List<Address>>(PersonalDetailsView.this);
    rpc.getAddressList(nameId, callback);

    //addressDisclosurePanel.add(addressHorizontalPanel);

    return addressDisclosurePanel;
}

class GetAddressHandler<T> implements AsyncCallback<List<Address>> {
    //Get the list of Addresses.
    PersonalDetailsView view;

    final HorizontalPanel addressHorizontalPanel = new HorizontalPanel();

    public GetAddressHandler(PersonalDetailsView view) {
        this.view = view;
    }

    public void onFailure(Throwable ex) {
        System.out.println("RPC call failed - GetAddressHandler - Notify Administrator.");
        Window.alert("Connection failed - please retry.");
    }
    public void onSuccess(List<Address> result) {
        Window.alert("Render address.");
        addressHorizontalPanel.add(view.renderAddresses(result));
    }
}

private FlexTable renderAddresses(List<Address> addressList) {
    //Load each TabPanel with Addresses
    Window.alert("get address.");;

    final FlexTable flexTableAddress = new FlexTable();

    if (addressList == null || addressList.isEmpty()) {
        //Add a place to add an address

        //Address Type
        final Label lblAddressType = new Label("Address Type:");
        lblAddressType.setStyleName("gwt-Label-Login");
        flexTableAddress.setWidget(0, 0, lblAddressType);

        final TextBox textBoxAddressType = new TextBox();
        textBoxAddressType.setStyleName("gwt-TextBox");
        textBoxAddressType.setWidth("300px");
        flexTableAddress.setWidget(0, 1, textBoxAddressType);

    }else{
        int row = 0;
        //
        //Create a place to display each Address and allow update
        //
        for (final Address eachAddress : addressList) {
            //Store key
            final String addId = eachAddress.getAddId();
            Window.alert("addId = " + addId);

            //Address Type
            final Label lblAddressType = new Label("Address Type:");
            lblAddressType.setStyleName("gwt-Label-Login");
            flexTableAddress.setWidget(row, 0, lblAddressType);

            final TextBox textBoxAddressType = new TextBox();
            textBoxAddressType.setText(eachAddress.getAddType());
            textBoxAddressType.setStyleName("gwt-TextBox");
            textBoxAddressType.setWidth("300px");
            flexTableAddress.setWidget(row, 1, textBoxAddressType);

            row++;
        }
    }
    return flexTableAddress;
}

那么我如何返回地址:

class GetAddressHandler<T> implements AsyncCallback<List<Address>> {

到披露面板？

Answer 1

您不能在方法内声明类。所以改变:

   //Get the Addresses
    AsyncCallback<List<Address>> callback = new GetAddressHandler<List<Address>>();
    rpc.getAddressList(nameId, callback);


    class GetAddressHandler<T> implements AsyncCallback<List<Address>> {
        //Get the list of Addresses.
        PersonalDetailsView view;

        public GetAddressHandler(PersonalDetailsView view) {
            this.view = view;
        }

        public void onFailure(Throwable ex) {
            System.out.println("RPC call failed - GetAddressHandler - Notify Administrator.");
            Window.alert("Connection failed - please retry.");
        }
        public void onSuccess(List<Address> result) {
            view.renderAddresses(result);
        }
    }

至:

//Get the Addresses
AsyncCallback<List<Address>> callback = new AsyncCallback<List<Address>> {
    //Get the list of Addresses.
    PersonalDetailsView view;

    public GetAddressHandler(PersonalDetailsView view) {
        this.view = view;
    }

    public void onFailure(Throwable ex) {
        System.out.println("RPC call failed - GetAddressHandler - Notify Administrator.");
        Window.alert("Connection failed - please retry.");
    }
    public void onSuccess(List<Address> result) {
        view.renderAddresses(result);
    }
}
    rpc.getAddressList(nameId, callback);

希望我的编辑中没有语法错误；)