我创建了一个包含图表的 gwt 应用程序，并将其部署在 Tomcat 中。我能够显示带有静态数据的图表。
我正在进行 rpc 调用以从数据库中获取数据。我想使用这些数据来绘制图表。但是当我在 tomcat 中部署和运行我的应用程序时，不显示图表。显示图表标题并显示“无数据”消息而不是图表。
但是我可以在警告框中显示检索到的数据。这意味着 RPC 成功。
下面是我使用的代码片段：
public class MyGWTApp implements EntryPoint {
/**
* Create a remote service proxy to talk to the server-side Greeting service.
*/
private final DataServiceAsync dataService = GWT
.create(DataService.class);
/**
* This is the entry point method.
*/
@SuppressWarnings("deprecation")
public void onModuleLoad() {
Runnable onLoadCallback=new Runnable(){
public void run()
{
TabPanel tabPanel = new TabPanel();
//tabPanel.setAnimationDuration(1000);
tabPanel.getElement().getStyle().setMarginBottom(10.0, Unit.PX);
tabPanel.setSize("100%", "100%");
//code to populate datatable and setting options for motion chart here
final MotionChart motionchart=new MotionChart(data, options);
final ColumnChart columnchart=new ColumnChart(createCategoryTable(),createCategoryBarOptions());
final ColumnChart columnchart2=new ColumnChart(createCategoryTable(),createCategoryBarOptions());
final ColumnChart columnchart3=new ColumnChart(createCategoryTable(),createCategoryBarOptions());
final PieChart pie=new PieChart(createSentimentTable(), createSentimentPieOptions());
FlexTable flexTable=new FlexTable();
FlexCellFormatter flexCellFormatter=flexTable.getFlexCellFormatter();
flexCellFormatter.setHorizontalAlignment(0, 0, HasHorizontalAlignment.ALIGN_CENTER);
flexCellFormatter.setVerticalAlignment(0, 0, HasVerticalAlignment.ALIGN_MIDDLE);
//flexTable.addStyleName("cw-FlexTable");
flexCellFormatter.setColSpan(0, 0, 2);
flexTable.setWidget(0, 0, pie);
flexTable.setWidget(1, 0,columnchart2);
flexTable.setWidget(1, 1, columnchart3);
FlexTable flexTable2=new FlexTable();
FlexCellFormatter flexCellFormatter2=flexTable.getFlexCellFormatter();
flexCellFormatter2.setHorizontalAlignment(0, 0, HasHorizontalAlignment.ALIGN_CENTER);
flexCellFormatter2.setVerticalAlignment(0, 0, HasVerticalAlignment.ALIGN_MIDDLE);
flexTable2.setWidget(0, 0, motionchart);
//tabPanel.add(new HTML("Testing tab panel"),"Text");
tabPanel.add(flexTable,"Charts");
tabPanel.add(flexTable2,"Motion Chart");
/*tabPanel.setHeight("600");
tabPanel.setWidth("900");*/
tabPanel.selectTab(0);
RootPanel.get("motionChartContainer").add(tabPanel);
}
};
VisualizationUtils.loadVisualizationApi(onLoadCallback, MotionChart.PACKAGE,ColumnChart.PACKAGE);
}
通过 GWt-RPC 获取数据的代码
private AbstractDataTable createCategoryTable(){
final DataTable data = DataTable.create();
data.addColumn(ColumnType.STRING, "Category");
data.addColumn(ColumnType.NUMBER,"TweetCount");
//dataService.getRowIDData(input, callback)
dataService.getRowIDData("category",
new AsyncCallback<List<Record>>(){
public void onFailure(Throwable caught) {
// Show the RPC error message to the user
System.out.println("RPC Call failed");
Window.alert("category : RPC call failed");
}
public void onSuccess(List<Record> result) {
data.addRows(result.size());
String msg;
msg=result.size()+"\n";
System.out.println(msg);
for(int i=0;i<result.size();i++)
{
data.setValue(i,0,result.get(i).getQualifier());
data.setValue(i,1,Integer.parseInt(result.get(i).getValue()));
msg="\n"+" Qualifier : "+result.get(i).getQualifier()+"Value : "+Integer.parseInt(result.get(i).getValue());
}
Window.alert("category : RPC Call successfull :size"+ result.size()+"\n "+ msg);
}
});
return data;
}
和
private AbstractDataTable createSentimentTable(){
final DataTable data = DataTable.create();
//final DataTable dTable = DataTable.create(jso);
data.addColumn(ColumnType.STRING,"Sentiment");
data.addColumn(ColumnType.NUMBER,"TweetCount");
dataService.getRowIDData("sentiment",
new AsyncCallback<List<Record>>(){
public void onFailure(Throwable caught) {
// Show the RPC error message to the user
System.out.println("RPC Call failed");
Window.alert("Sentiment : RPC call failed");
}
public void onSuccess(List<Record> result) {
data.addRows(result.size());
String msg=result.size()+"\n";
System.out.println(msg);
for(int i=0;i<result.size();i++)
{
data.setValue(i,0,result.get(i).getQualifier());
data.setValue(i,1,Integer.parseInt(result.get(i).getValue()));
msg="\n"+" Qualifier : "+result.get(i).getQualifier()+"Value : "+Integer.parseInt(result.get(i).getValue());
}
Window.alert("Sentiment :RPC Call successfull "+ msg);
}
});
return data;
}