将BIRT整合到自己的Java项目中(三)

1. 渲染报表
   BIRT支持HTML格式和PDF格式，这两种报表生成的过程相同，只是设置不同的RenderContext和RenderOptions。我们把相同的部分提取为父类的公共方法，不同的部分留给子类实现：

   IReportDocument iReportDocument = engine.openReportDocument(docFilename);
         //Create Render Task
          IRenderTask task = engine.createRenderTask(iReportDocument);
          task.addScriptableJavaObject("jsBirtObject",
              getScriptableObject(scriptObj));
         if(params != null && !params.isEmpty()) ...{
            task.setParameterValues(params);
          }
          setRenderContext(task); //设置Render Context，具体由子类实现
          setRenderOptions(task, out); //设置Render Options，具体由子类实现
          task.render();
          task.close();
        } catch (EngineException e) ...{
          e.printStackTrace();
        } finally ...{
          engine.shutdown();
        }

1. 渲染PDF和HTML报表
2. PDF
   
     /** *//**
       * @see AbstractBirtReportParser#setRenderContext(IRenderTask)
      */
      @Override
     protected void setRenderContext(IRenderTask task) ...{
        PDFRenderContext renderContext = new PDFRenderContext();
        renderContext.setEmbededFont(true);    
        HashMap contextMap = new HashMap();
        contextMap.put( EngineConstants.APPCONTEXT_PDF_RENDER_CONTEXT, renderContext);
        task.setAppContext( contextMap );        
      }
   
     /** *//**
       * @see AbstractBirtReportParser#setRenderOptions(IRenderTask, OutputStream)
      */
      @Override
     protected void setRenderOptions(IRenderTask task, OutputStream out) ...{
        RenderOptionBase options = new RenderOptionBase();
        options.setOutputStream(out);
        options.setOutputFormat(RenderOptionBase.OUTPUT_FORMAT_PDF);
        task.setRenderOption(options);
      }

• HTML
  我们要生成一个HTML的一部分，而非包含<html/>标记的完整的HTML文档
  
    /** *//**
      * @see AbstractBirtReportParser#setRenderContext(IRenderTask)
     */
     @Override
    protected void setRenderContext(IRenderTask task) ...{
       HTMLRenderContext renderContext = new HTMLRenderContext();
       renderContext.setBaseURL(context.getBaseURL());        
     //You must define HTMLServerImageHandler to use a URL
       renderContext.setBaseImageURL(context.getBaseImageURL());
      //renderContext.setImageDirectory("myimages");
       renderContext.setImageDirectory(context.getImageDirectory());
       renderContext.setSupportedImageFormats("JPG;PNG");
       HashMap contextMap = new HashMap();
       contextMap.put( EngineConstants.APPCONTEXT_HTML_RENDER_CONTEXT, renderContext);
       task.setAppContext( contextMap );    
     }
  
    /** *//**
      * @see AbstractBirtReportParser#setRenderOptions(oIRenderTask, OutputStream)
     */
     @Override
    protected void setRenderOptions(IRenderTask task, OutputStream out) ...{
       HTMLRenderOption options = new HTMLRenderOption();
       options.setOutputStream(out);
       options.setEmbeddable(true);
       task.setRenderOption(options);   
     }