BIRT報表一線揭祕2

收到不少人的郵件諮詢我能否直接用JAVA設計報表然後直接展示出來，而非運行導出或者生成一個文件，畢竟生成或者導出的文件不是在服務器端就是要客戶瀏覽器接收，不算友好。其實這並非難事，只需把生成的設計文檔放在服務器端然後又直接用webviewer打開便是。代碼如下：

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.eclipse.birt.core.framework.Platform;
import org.eclipse.birt.report.model.api.CellHandle;
import org.eclipse.birt.report.model.api.DesignConfig;
import org.eclipse.birt.report.model.api.DesignElementHandle;
import org.eclipse.birt.report.model.api.ElementFactory;
import org.eclipse.birt.report.model.api.GridHandle;
import org.eclipse.birt.report.model.api.IDesignEngine;
import org.eclipse.birt.report.model.api.IDesignEngineFactory;
import org.eclipse.birt.report.model.api.ImageHandle;
import org.eclipse.birt.report.model.api.LabelHandle;
import org.eclipse.birt.report.model.api.ReportDesignHandle;
import org.eclipse.birt.report.model.api.RowHandle;
import org.eclipse.birt.report.model.api.SessionHandle;
import org.eclipse.birt.report.model.api.activity.SemanticException;

import com.ibm.icu.util.ULocale;

@WebServlet("/SimpleCreate")
public class SimpleCreate extends HttpServlet {
    private static final long serialVersionUID = 1L;

    public SimpleCreate() {
        super();
    }

    protected void doGet(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        try
           {
               buildReport(request, response);
           }
           catch( IOException e )
           {
               e.printStackTrace();
           }
           catch( SemanticException e )
           {
               e.printStackTrace();
           }
    }


    protected void doPost(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        try
           {
               buildReport(request, response);
           }
           catch( IOException e )
           {
               e.printStackTrace();
           }
           catch( SemanticException e )
           {
               e.printStackTrace();
           }

    }

    static void buildReport(HttpServletRequest request,
            HttpServletResponse response) throws IOException, SemanticException {
        DesignConfig config = new DesignConfig();

        //config.setProperty("BIRT_HOME","D:\\Develop Install Files\\birt-runtime-4_2_1\\ReportEngine");
        IDesignEngine engine = null;
        try {
            Platform.startup(config);
            IDesignEngineFactory factory = (IDesignEngineFactory) Platform
                    .createFactoryObject(IDesignEngineFactory.EXTENSION_DESIGN_ENGINE_FACTORY);
            engine = factory.createDesignEngine(config);
        } catch (Exception ex) {
            ex.printStackTrace();
        }

        SessionHandle session = engine.newSessionHandle(ULocale.ENGLISH);
        ReportDesignHandle design = session.createDesign();
        ElementFactory efactory = design.getElementFactory();
        DesignElementHandle element = efactory
                .newSimpleMasterPage("Page Master");
        design.getMasterPages().add(element);
        GridHandle grid = efactory.newGridItem(null, 2 /* cols */, 1 /* row */);
        design.getBody().add(grid);
        grid.setWidth("100%");

        //在行加入一個圖片
        RowHandle row = (RowHandle) grid.getRows().get(0);
        ImageHandle image = efactory.newImage(null);
        CellHandle cell = (CellHandle) row.getCells().get(0);
        cell.getContent().add(image);
        image.setURL("\"https://img-my.csdn.net/uploads/201301/09/1357690895_3463.png\"");

        // 產生一個標籤
        LabelHandle label = efactory.newLabel(null);
        cell = (CellHandle) row.getCells().get(1);
        cell.getContent().add(label);
        label.setText("測試，用Java生成報表並用報表展示器展示報表");

        // 保存報表
        String path=request.getSession().getServletContext().getRealPath("/");
        System.out.println(path);
        design.saveAs(path+"/sample.rptdesign");
        design.close();

        //用報表展示器打開報表
        String reportpath=request.getContextPath();
        System.out.println(reportpath);
        response.sendRedirect(reportpath+"/frameset?__report=sample.rptdesign");
        System.out.println("Finished");
    }

}

關鍵的是最後幾步：

保存報表

String path=request.getSession().getServletContext().getRealPath("/");
design.saveAs(path+"/sample.rptdesign");
展示報表

String reportpath=request.getContextPath();
response.sendRedirect(reportpath+"/frameset?__report=sample.rptdesign");

這個servlet運行並直接生成了一個報表sample.rptdesign，並通過報表展示器查看報表

需要在web.xml中加入如下的配置：

<servlet>

<servlet-name>SimpleCreate</servlet-name>

<servlet-class>birt.SimpleCreate</servlet-class>

</servlet>

<servlet-mapping>

<servlet-name>SimpleCreate</servlet-name>

<url-pattern>/SimpleCreate</url-pattern>

</servlet-mapping>

我們把他發佈到WebViewerExample工程下，訪問http://localhost:8080/WebViewerExample/SimpleCreate，控制檯會打印出程序中的輸出

D:\apache-tomcat-7.0.33\webapps\WebViewerExample\

/WebViewerExample

Finished

注意地址欄上的地址信息是http://localhost:8080/WebViewerExample/frameset?__report=sample.rptdesign，是因爲我們在程序中用的response.sendRedirect()方法。