[GXT3 Beta2]: Solve Caused by: java.lang.NoClassDefFoundError: org/json/JSONObject

[BayerBusiness]

Hi eveyone,

not an actual bug (I think), but something I had a major problems. If the following code was run in developer mode, clicking on the "Send" button produced a long error stack trace. Within the stack trace the following problem was described: Caused by: java.lang.NoClassDefFoundError: org/json/JSONObject.

Solution: Include gwt-servlet-deps.jar explicitely to the build path
(see http://stackoverflow.com/questions/6...-i-doing-wrong)

The file is located (for my installation) in:
%Program Files%\eclipse_3.7_SR1_indigo\eclipse\plugins\com.google.gwt.eclipse.sdkbundle_2.4.0.v201201120043-rel-r37\gwt-2.4.0

Used code:

/**
 * Entry point classes define <code>onModuleLoad()</code>.
 */
public class LearningGXT3 implements EntryPoint {
      public interface Role {
          long getId();
            
          void setId(long id);

          String getName();
            
          void setName(String name);
      }
      
      interface RoleProperties extends PropertyAccess<Role> {
            @Path("id")
            ModelKeyProvider<Role> key();

            ValueProvider<Role, Long> id();
            
            ValueProvider<Role, String> name();
          }
    
      
      public interface RoleAutoBeanFactory extends AutoBeanFactory {
          AutoBean<RecordResult> items();
          AutoBean<ListLoadConfig> loadConfig();
      }
      
      /**
       * Defines the structure of the root JSON object being returned by the server.
       * This class is needed as we cannot return a list of objects. Instead, we
       * return a single object with a single property that contains the data
       * records.
       */
      public interface RecordResult {
          List<Role> getRecords();
      }

      class DataRecordJsonReader extends JsonReader<ListLoadResult<Role>, RecordResult> {
            public DataRecordJsonReader(AutoBeanFactory factory, Class<RecordResult> rootBeanType) {
              super(factory, rootBeanType);
            }

            @Override
            protected ListLoadResult<Role> createReturnData(Object loadConfig, RecordResult incomingData) {
              return new ListLoadResultBean<Role>(incomingData.getRecords());
            }
          }
      
    /**
     * This is the entry point method.
     */
    public void onModuleLoad() {
        RoleAutoBeanFactory factory = GWT.create(RoleAutoBeanFactory.class);
        
        DataRecordJsonReader reader = new DataRecordJsonReader(factory, RecordResult.class);

        String path = "http://<server>/roles.asmx/getItemsGXT3";
        RequestBuilder builder = new RequestBuilder(RequestBuilder.POST, path);
        builder.setHeader("content-type", "application/json");
        
        HttpProxy<ListLoadConfig> proxy = new HttpProxy<ListLoadConfig>(builder);
        // Create JSON
        proxy.setWriter(new JsonWriter<ListLoadConfig>(factory, ListLoadConfig.class));

        final ListLoader<ListLoadConfig, ListLoadResult<Role>> loader =
                new ListLoader<ListLoadConfig, ListLoadResult<Role>>(proxy, reader);
        
        RoleProperties props = GWT.create(RoleProperties.class);
        
        ListStore<Role> store = new ListStore<Role>(props.key());
        
        ColumnConfig<Role, Long> cc1 = new ColumnConfig<Role, Long>(props.id(), 100, "ID");
        ColumnConfig<Role, String> cc2 = new ColumnConfig<Role, String>(props.name(), 100, "Name");
        
        List<ColumnConfig<Role, ?>> l = new ArrayList<ColumnConfig<Role, ?>>();
        l.add(cc1);
        l.add(cc2);
        ColumnModel<Role> cm = new ColumnModel<Role>(l);

        Grid<Role> view = new Grid<Role>(store, cm);
        view.getView().setForceFit(true);
        view.setLoader(loader);

        Button sendButton = new Button("Send");
        sendButton.addClickHandler(new ClickHandler() {

            @Override
            public void onClick(ClickEvent event) {
                loader.load();
            }
        });

        // We can add style names to widgets
        sendButton.addStyleName("sendButton");

        // Add the nameField and sendButton to the RootPanel
        // Use RootPanel.get() to get the entire body element
        RootPanel.get("sendButtonContainer").add(sendButton);
        RootPanel.get().add(view);
    }
}

If there is a better way to solve this issue: Any hints are appreciated.

Regards,
Björn

[robferguson]

Hi,

I ran into the same issue. I then checked the WEB-INF/lib directory of the examples war (gxt-examples-3.0.0-beta1.war) and noticed the JSON jar (json-20090211.jar). So I updated my POM to include the gwt-servlet-deps dependency:

<dependency>
  <groupId>com.google.gwt</groupId>
  <artifactId>gwt-servlet-deps</artifactId> <!-- required for AutoBean support -->
  <version>${gwt.version}</version>
  <scope>runtime</scope>
</dependency>

Your approach is fine.

Cheers
Rob

http://code.google.com/p/gwt-cx/