1、Java截取网页形成图片

 1 final int perHight=2027;
 2     public void render(final File saveLocation) throws RenderingException
 3     {
 4         final File localSaveLocation = new File(saveLocation.getParentFile().getAbsolutePath() + File.separator + "localhost");
 5         localSaveLocation.mkdirs();
 6         System.out.println("Saving temporary images in directory :" + localSaveLocation.getAbsolutePath());
 7 
 8         String widthStr = null;
 9         //根据javascript脚本得到网页内容的宽度和高度
10         widthStr = this.getJavascriptValue("document.body.scrollWidth+‘-‘+document.body.scrollHeight");
11         if (widthStr == null)
12             throw new RenderingException("Could not acquire Document height andf width by javascript.");
13 
14         final int width = SCREEN_WIDTH;
15         //如果网页内容高度大于10000那么就取值10000，否则就是内容高度本身
16         int nonFinalHeight = Math.min(10000, Integer.parseInt(widthStr.split("-")[1]));
17         
18         //perHight就是每一帧刷多高，如果网页内容高度小于一帧的取值高度就取值一帧的高度；否则，就取值内容的高度
19         final int height = nonFinalHeight < perHight ? perHight: nonFinalHeight;
20 
21         System.out.println("Screen sizes :" + width + " ," + height);
22         
23         int start=0;
24         
25         //然后将作为内容高度的height变量除以一帧高度，也就是要对这个网页进行刷屏多少次。
26         //我们也就要将网页内容进行移动，移动网页内容，只要移动浏览器Y轴上的滚动条就行，
27         //初始状态，不需要滚动，也就是当i=0时。当i=1时，就需要滚动一帧的内容，因为每次滚动，滚动条初始在0位置，因此每次start都是从0开始。
28         
29         
30         for (int i = 0; i < 1 + (height / perHight); i++)
31         {
32             if (i != 0)
33             {
34                 this.execute("window.scrollTo("+start+"," + i * (perHight - scrollbarY) + ");");
35                 try
36                 {
37                     Thread.sleep(10000);//这个时间稍微长点，要不页面还没有刷出来就已经捕获了这一帧
38                 }
39                 catch (InterruptedException e)
40                 {
41                     throw new RenderingException(e);
42                 }
43             }
44             final int j = i;
45             //下面的异步方法就是捕获一帧的网页
46             //这里呈现的屏幕的高度和宽度是固定的，只是在这个固定的区域当中，内容在变而已。
47             //因此，我们只要对这一块固定的区域进行捕获就可以了。
48             display.syncExec(new Runnable()
49             {
50                 public void run()
51                 {
52                     if (j == 0 || j < (height / perHight))
53                         capture(localSaveLocation.getAbsolutePath(), j, SCREEN_WIDTH,perHight, 0, 0);
54                     else
55                         capture(localSaveLocation.getAbsolutePath(), j, SCREEN_WIDTH, (height % perHight == 0 ? perHight : height % perHight), 0, perHight - (height % perHight));
56                 }
57             });
58         }
59         display.syncExec(new Runnable()
60         {
61             public void run()
62             {
63                 try
64                 {
65                     final Image result = new Image(display, width, height);
66                     GC gc = new GC(result);
67                     for (int i = 0; i < (1 + height / perHight); i++)
68                     {
69 
70                         ImageLoader imageLoader = new ImageLoader();
71                         File partialImageFile = new File(localSaveLocation, "savedImage" + i + ".jpg");
72                         FileInputStream fis = new FileInputStream(partialImageFile);
73                         Image loadedImage = new Image(display, imageLoader.load(fis)[0]);
74                         gc.drawImage(loadedImage, 0, i * (perHight - scrollbarY));
75                         loadedImage.dispose();
76                         fis.close();
77                         // Delete the partial image file once we are done with
78                         // it :
79                         partialImageFile.delete();
80                     }
81                     gc.dispose();
82                     ImageLoader imageSaver = new ImageLoader();
83                     imageSaver.data = new ImageData[] { result.getImageData() };
84                     System.out.println("Saving image to location :" + saveLocation);
85                     FileOutputStream fos = new FileOutputStream(saveLocation);
86                     imageSaver.save(fos, SWT.IMAGE_JPEG);
87                     fos.close();
88                     result.dispose();
89 
90                 }
91                 catch (Exception e)
92                 {
93                     e.printStackTrace();
94                 }
95             }
96         });
97 
98     }