2014-12-27 96 views
2

我无法让JEditorPane将HTML img标记呈现为图像。所有显示的都是一个占位符图形。以下是我的代码。提前致谢。Java JEditorPane不显示图像

我看到:

enter image description here

我的代码:

import java.awt.*; 
import java.io.File; 
import java.net.URL; 
import java.util.Hashtable; 

import javax.swing.*; 
import javax.swing.text.html.HTMLEditorKit; 

public class test 
{ 
    private static Hashtable image_cache; 

public static void main(String[] args) 
{ 
    image_cache = new Hashtable(); 

    URL img_url = null; 

    try 
    { 
     img_url = new File("C:/img/mypic.png").toURI().toURL(); 
     Image img = Toolkit.getDefaultToolkit().createImage (img_url); 
     image_cache.put(img_url.toURI(), img); 
    } 
    catch (Exception e) 
    { 
     e.printStackTrace(); 
    } 

    String html = "<html>" + 
      "<body>"+ 
      "<img src=\"" + img_url.toString() + "\">" + 
      "</body>" + 
      "</html>"; 

    JEditorPane swingbox = new JEditorPane(); 
    swingbox.setEditorKit(new HTMLEditorKit()); 
    swingbox.setContentType("text/html"); 
    swingbox.setText(html); 
    swingbox.getDocument().putProperty("imageCache", image_cache); 

    JFrame frame=new JFrame("Example"); 
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
    frame.getContentPane().add(swingbox); 
    frame.setSize(800,600); 
    frame.setLocationRelativeTo(null); 
    frame.setVisible(true); 
} 
} 

回答

4

的问题是在你的代码:

swingbox.getDocument().putProperty("imageCache", image_cache); 

评论了这条线,它应该工作精细。经过一番挖掘,我发现问题是image_cache.put(img_url.toURI(),img)。它应该是image_cache.put(img_url,img)

自定义图像缓存可能会帮助您稍后调试代码。这里有一些改变对我来说很有用。创建一个ImageCache类,并使其成为当得到被调用要么图像从缓存返回,如果找到或图像被创建,放入缓存,如果没有找到返回。

示例代码:

public class TestClass { 

    private static ImageCache image_cache; 

    public static void main(String[] args) { 
     URL img_url = null; 
     image_cache = new ImageCache(); 

     try 
     { 
      img_url = new File("C:/Users/User/Images/image.png").toURI().toURL(); 
      Image img = Toolkit.getDefaultToolkit().createImage (img_url); 
      image_cache.put(img_url, img); 
     } 
     catch (Exception e) 
     { 
      e.printStackTrace(); 
     } 

     String html = "<html>" + 
       "<body>"+ 
       "<img src=\"" + img_url.toString() + "\">" + 
       "</body>" + 
       "</html>"; 

     JEditorPane swingbox = new JEditorPane(); 
     swingbox.setEditorKit(new HTMLEditorKit()); 
     swingbox.setContentType("text/html"); 
     swingbox.setText(html); 



     JFrame frame=new JFrame("Example"); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.getContentPane().add(swingbox); 

     Dictionary cache=(Dictionary)swingbox.getDocument().getProperty("imageCache"); 

     // put the cache if it is not present. it should be null in the beginning 
     if (cache==null) { 
      swingbox.getDocument().putProperty("imageCache",image_cache); 
     } 

     frame.setSize(800,600); 
     frame.setLocationRelativeTo(null); 
     frame.setVisible(true); 

    } 

    static class ImageCache extends Hashtable { 

     public Object get(Object key) { 

      Object result = super.get(key); 

      if (result == null){ 
       result = Toolkit.getDefaultToolkit().createImage((URL) key); 
       put(key, result); 
      } 

      return result; 
     } 
    } 

} 
+0

谢谢!所以这个工作。 – SoupMonster 2014-12-27 18:15:22

+0

我很惊讶,实际的解决方案更简单。您可以使用我提供的Custom ImageCache,但实际问题很愚蠢。它应该是image_cache.put(img_url,img)而不是image_cache.put(img_url.toURI(),img);; – ZakiMak 2014-12-27 19:18:12