From Gossip@caterpillar

Spring Gossip: 自訂 View Class

 

 


您 可以繼承org.springframework.web.servlet.view.AbstractView自訂自己的View類別，以產生所需的 View層展示技術，這邊以產生Pdf的結果頁面為例，您可以直接繼承 org.springframework.web.servlet.view.document.AbstractPdfView類別，並重新定義它的 buildPdfDocument()方法，例如：
  • CustomPdfView.java
package onlyfun.caterpillar;

import com.lowagie.text.Document;
import com.lowagie.text.Paragraph;
import com.lowagie.text.pdf.PdfWriter;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.servlet.
                  view.document.AbstractPdfView;

public class CustomPdfView extends AbstractPdfView {
    protected void buildPdfDocument(Map model, 
                        Document document,
                        PdfWriter writer, 
                        HttpServletRequest request,
                        HttpServletResponse response) 
                                      throws Exception {
        String header = (String) model.get("header");

        Paragraph headerParagraph = 
                     new Paragraph(header);
        headerParagraph.font().setSize(20);
        document.add(headerParagraph);

        String content = (String) model.get("content");
        Paragraph contentParagraph = 
                        new Paragraph(content);
        document.add(contentParagraph);
    
        String copyright = (String) model.get("copyright");
        Paragraph copyrightParagraph = 
                              new Paragraph(copyright);
        copyrightParagraph.setAlignment(
                               Paragraph.ALIGN_BOTTOM);
        document.add(copyrightParagraph);
    }
}

假設在您的Controller中提供了Model資料物件：
  • PdfController.java
package onlyfun.caterpillar;

import java.util.HashMap;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;

public class PdfController implements Controller {
    public ModelAndView handleRequest(HttpServletRequest req, 
                        HttpServletResponse res) throws Exception {
        Map model = new HashMap();
        model.put("header", "Pdf View Test");
        model.put("content", "This is content for pdf view test.");
        model.put("copyright", "caterpillar.onlyfun.net");
        
        return new ModelAndView("customPdfView", model);
    }
}

而在Bean定義檔中是這麼設計的：
  • mvc-config.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING/DTD BEAN/EN" 
 "http://www.springframework.org/dtd/spring-beans.dtd"> 

<beans>   
    <bean id="viewResolver"
          class="org.springframework.web.servlet.
                   → view.BeanNameViewResolver"/>
        
    <bean id="customPdfView" 
          class="onlyfun.caterpillar.CustomPdfView"/>
          
    <bean name="/pdf.do" 
          class="onlyfun.caterpillar.PdfController"/>
</beans>

則接上/pdf.do時，會顯示pdf的結果畫面。