第一次尝试：用awt 包将HTML源码转换为图片

优点：不依赖任何外部JAR包，缺点：对CSS的支持比较差，复杂点的样式就无法展示，且不支持外部引入的CSS和写在style中的CSS，只能写在标签上

Eg:

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.util.ArrayList;
import java.util.UUID;import javax.swing.JTextPane;
import javax.swing.border.EmptyBorder;
import javax.swing.plaf.basic.BasicEditorPaneUI;import org.apache.commons.io.FileUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGEncodeParam;
import com.sun.image.codec.jpeg.JPEGImageEncoder;public class GraphUtils {private final static Log log                  = LogFactory.getLog(GraphUtils.class);public static int        DEFAULT_IMAGE_WIDTH  = 1000;//默认值最好设置大点，因为我们再导之前，不知道这个流有多大，如果过小，则生成的图片后面的为黑色，因为流没有读取完整public static int        DEFAULT_IMAGE_HEIGHT = 200;public static boolean paintPage(Graphics g, int hPage, int pageIndex, JTextPane panel) {Graphics2D g2 = (Graphics2D) g;Dimension d = ((BasicEditorPaneUI) panel.getUI()).getPreferredSize(panel);double panelHeight = d.height;double pageHeight = hPage;int totalNumPages = (int) Math.ceil(panelHeight / pageHeight);g2.translate(0f, -(pageIndex - 1) * pageHeight);panel.paint(g2);boolean ret = true;if (pageIndex >= totalNumPages) {ret = false;return ret;}return ret;}/*** 将BufferedImage转换为图片的信息*/public static String toJpeg(BufferedImage image) {// 获取图片文件的在服务器的路径String imageName = "G:\\" + UUID.randomUUID().toString() + ".jpg";try {ByteArrayOutputStream baos = new ByteArrayOutputStream();JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(baos);JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(image);param.setQuality(1.0f, false);encoder.setJPEGEncodeParam(param);encoder.encode(image);byte[] buff = baos.toByteArray();baos.close();// 将字节流写入文件保存为图片FileUtils.writeByteArrayToFile(new File(imageName), buff);} catch (Exception ex) {log.error("保存删除图片失败:" + ex.getMessage());}return imageName;}/*** html转换为ｊｐｅｇ文件* @param bgColor 图片的背景色* @param html html的文本信息* @param width 显示图片的Ｔｅｘｔ容器的宽度* @param height 显示图片的Ｔｅｘｔ容器的高度* @param eb 設置容器的边框* @return* @throws Exception*/private static ArrayList<String> html2jpeg(Color bgColor, String html, int width, int height, EmptyBorder eb)throws Exception {ArrayList<String> ret = new ArrayList<String>();try {JTextPane tp = new JTextPane();tp.setSize(width, height);if (eb == null) {eb = new EmptyBorder(0, 50, 0, 50);}if (bgColor != null) {tp.setBackground(bgColor);}if (width <= 0) {width = DEFAULT_IMAGE_WIDTH;}if (height <= 0) {height = DEFAULT_IMAGE_HEIGHT;}tp.setBorder(eb);tp.setContentType("text/html");tp.setText(html);int pageIndex = 1;boolean bcontinue = true;while (bcontinue) {BufferedImage image = new java.awt.image.BufferedImage(width, height,java.awt.image.BufferedImage.TYPE_INT_RGB);Graphics g = image.getGraphics();g.setClip(0, 0, width, height);bcontinue = paintPage(g, height, pageIndex, tp);g.dispose();String path = toJpeg(image);ret.add(path);pageIndex++;}} catch (Exception ex) {throw ex;}return ret;}/*** 将一個html转换为图片* @param htmls* @return* @throws Exception*/public static ArrayList<String> toImages(String html) throws Exception {return html2jpeg(Color.white, html, DEFAULT_IMAGE_WIDTH, DEFAULT_IMAGE_HEIGHT, new EmptyBorder(0, 0, 0, 0));}

TestCase:

@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration
@ContextConfiguration(locations = { "classpath*:spring/application.xml", "classpath*:spring/plugin-*.xml" })
public class GraphUtilsTest extends TestCase {@Autowiredprivate TaskService            taskService;@Autowiredprivate VelocitySimpleRelolver velocitySimpleRelolver;@Testpublic void testHtml2Image() {try {String imageTemplateFile = "mail/weekly/mile_schedule_task.vm";//邮件内容Map<String, Object> velocityData = new HashMap<String, Object>();String projId = "6a9fb54e3439453e86e819a4d46fdafb";MileSchedule mileSchedule = taskService.getMileSchedule(projId);velocityData.put("mileSchedule", mileSchedule);String htmlstr = velocitySimpleRelolver.relolve(imageTemplateFile, velocityData);Assert.assertNotNull(htmlstr);GraphUtils.toImages(htmlstr);} catch (Exception e) {e.printStackTrace();}}
}

Second: 利用html2image组件

优点：方便，代码简单  缺点：CSS支持极差，比不上Java自身的转化

maven引入：

<dependency> <groupId>gui.ava</groupId> <artifactId>html2image</artifactId> <version>0.9</version>
</dependency>

TestCase:

@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration
@ContextConfiguration(locations = { "classpath*:spring/application.xml", "classpath*:spring/plugin-*.xml" })
public class Html2ImageTest extends TestCase {@Autowiredprivate TaskService            taskService;@Autowiredprivate VelocitySimpleRelolver velocitySimpleRelolver;@Testpublic void testHtml2Image() {try {String imageTemplateFile = "mail/weekly/mile_schedule_task.vm";//邮件内容Map<String, Object> velocityData = new HashMap<String, Object>();String projId = "6a9fb54e3439453e86e819a4d46fdafb";MileSchedule mileSchedule = taskService.getMileSchedule(projId);velocityData.put("mileSchedule", mileSchedule);String htmlstr = velocitySimpleRelolver.relolve(imageTemplateFile, velocityData);System.out.println(htmlstr);Assert.assertNotNull(htmlstr);String imageName = "G:/weekly_mile_" + projId + ".png";HtmlImageGenerator imageGenerator = new HtmlImageGenerator();imageGenerator.setSize(new Dimension(1000, 200));imageGenerator.loadHtml(htmlstr);imageGenerator.getBufferedImage();imageGenerator.saveAsImage(imageName);} catch (Exception e) {e.printStackTrace();}}@Testpublic void testImage() {HtmlImageGenerator imageGenerator = new HtmlImageGenerator();imageGenerator.setSize(new Dimension(1000, 200));imageGenerator.loadUrl("http://www.baidu.com");imageGenerator.getBufferedImage();imageGenerator.saveAsImage("G:/aaa.png");}
}

Third:DJNativeSwing

参考：http://blog.csdn.net/cping1982/article/details/5353049

其中：JAR包下载地址：

http://sourceforge.net/projects/djproject/?source=navbar  此地址下down DJNativeSwing.jar 和DJNativeSwing-SWT.jar

http://maven-repository.com/artifact/org.eclipse.swt.org.eclipse.swt.win32.win32.x86_64.4.3.swt/org.eclipse.swt.win32.win32.x86_64/4.3

此地址下down org.eclipse.swt 包，选择适合你的开发环境

注意：swt 包针对不同的环境有不同的要求，windows与Linux下的不同，使用maven引入时采用properties方式，将下载的包放入你的maven库，然后在POM中进行maven引入

eg:

<!-- DJNativeSwing --><dependency> <groupId>chrriis.dj.nativeswing</groupId> <artifactId>DJNativeSwing</artifactId> <version>1.0.2</version> </dependency> <dependency> <groupId>chrriis.dj.nativeswing.swt</groupId> <artifactId>DJNativeSwing-SWT</artifactId> <version>1.0.2</version> </dependency><dependency><groupId>${swt.groupId}</groupId><artifactId>${swt.artifactId}</artifactId><version>4.3</version></dependency>

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.concurrent.Semaphore;import javax.imageio.ImageIO;
import javax.swing.JPanel;import chrriis.dj.nativeswing.swtimpl.NativeComponent;
import chrriis.dj.nativeswing.swtimpl.NativeInterface;
import chrriis.dj.nativeswing.swtimpl.components.JWebBrowser;
import chrriis.dj.nativeswing.swtimpl.components.WebBrowserAdapter;
import chrriis.dj.nativeswing.swtimpl.components.WebBrowserEvent;public class DJNativeSwingUtils extends JPanel {private static final long  serialVersionUID = 8675106494733722832L;// 行分隔符  final static public String     LS = System.getProperty("line.separator", "/n");// 文件分割符  final static public String     FS = System.getProperty("file.separator", "//");//以javascript脚本获得网页全屏后大小  final static StringBuffer      jsDimension;static {jsDimension = new StringBuffer();jsDimension.append("var width = 0;").append(LS);jsDimension.append("var height = 0;").append(LS);jsDimension.append("if(document.documentElement) {").append(LS);jsDimension.append("  width = Math.max(width, document.documentElement.scrollWidth);").append(LS);jsDimension.append("  height = Math.max(height, document.documentElement.scrollHeight);").append(LS);jsDimension.append("}").append(LS);jsDimension.append("if(self.innerWidth) {").append(LS);jsDimension.append("  width = Math.max(width, self.innerWidth);").append(LS);jsDimension.append("  height = Math.max(height, self.innerHeight);").append(LS);jsDimension.append("}").append(LS);jsDimension.append("if(document.body.scrollWidth) {").append(LS);jsDimension.append("  width = Math.max(width, document.body.scrollWidth);").append(LS);jsDimension.append("  height = Math.max(height, document.body.scrollHeight);").append(LS);jsDimension.append("}").append(LS);jsDimension.append("return width + ':' + height;");}public static JPanel createContent(String htmlStr, final String fileName, final Semaphore semp) {//浏览器面板JPanel webBrowserPanel = new JPanel(new BorderLayout());//swing的内嵌浏览器final JWebBrowser webBrowser = new JWebBrowser();//隐藏所有的栏webBrowser.setBarsVisible(false);//向浏览器写入html内容webBrowser.setHTMLContent(htmlStr);//将浏览器嵌入浏览器面板webBrowserPanel.add(webBrowser, BorderLayout.CENTER);//向浏览器增加监听事件webBrowser.addWebBrowserListener(new WebBrowserAdapter() {// 监听加载进度  public void loadingProgressChanged(WebBrowserEvent e) {// 当加载完毕时  if (e.getWebBrowser().getLoadingProgress() == 100) {try {//执行JS获取图片的宽度，高度String result = (String) webBrowser.executeJavascriptWithResult(jsDimension.toString());int index = result == null ? -1 : result.indexOf(":");NativeComponent nativeComponent = webBrowser.getNativeComponent();//获取图片的原始尺寸Dimension originalSize = nativeComponent.getSize();//根据JS返回结果设定新的图片尺寸Dimension imageSize = new Dimension(Integer.parseInt(result.substring(0, index)), Integer.parseInt(result.substring(index + 1)));//计算图片的新尺寸imageSize.width = Math.max(originalSize.width, imageSize.width);imageSize.height = Math.max(originalSize.height, imageSize.height);nativeComponent.setSize(imageSize);//创建一个不带透明色的BufferedImage对象BufferedImage image = new BufferedImage(imageSize.width, imageSize.height,BufferedImage.TYPE_INT_RGB);//对浏览器中图片进行绘色nativeComponent.paintComponent(image);//截图image = image.getSubimage(0, 0, imageSize.width - 25, imageSize.height);try {// 输出图像  ImageIO.write(image, "jpg", new File(fileName));} catch (IOException ex) {ex.printStackTrace();}} finally {//  退出操作  :释放线程NativeInterface.close();semp.release();}}}});return webBrowserPanel;}
}

service调用：

private String createImage(final String htmlStr, final Semaphore semaphore) {final String fileName = FileUtils.getNewFileName("jpg");NativeInterface.open();UIUtils.setPreferredLookAndFeel();SwingUtilities.invokeLater(new Runnable() {public void run() {// SWT组件转Swing组件，不初始化父窗体将无法启动webBrowser  JFrame frame = new JFrame();frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);// 加载指定页面frame.getContentPane().add(DJNativeSwingUtils.createContent(htmlStr, fileName, semaphore),BorderLayout.CENTER);// 仅初始化，但不显示  frame.invalidate();frame.pack();frame.setVisible(false);}});// 在MAC上使用时，因为MAC不支持双进程，仅支持进程内模式，调用此方法进行事件调度。windows和Linux可以忽略此事件调度//NativeInterface.runEventPump();return new File(fileName).getAbsolutePath();}

 private int fillPicture(HSSFSheet sheet, Report report, int startRow) throws IOException {if(null == weekly.getMileSchedule()){return startRow + 1;}// 将高度设置为图片的高度HSSFRow pictureRow = sheet.getRow(startRow);pictureRow.setHeightInPoints(162);String htmlStr = this.createHtml(report);String imagePath = null;final Semaphore semp = new Semaphore(1);//设置信号量try {semp.acquire();// 子线程生成图片imagePath = this.createImage(htmlStr, semp);// 等待子线程释放信号量semp.acquire();} catch (InterruptedException e) {LOG.error("", e);} finally {semp.release();}try {ExcelExportUtils.insertPicture(sheet, startRow, (short) 0, (short) 15, imagePath);} catch (Exception e) {e.printStackTrace();} finally {// delete 文件new File(imagePath).delete();}return ++startRow;}

windows 下截图正常，Linux下异常，Linux下必须安装Mollizia内核的浏览器，在服务器上安装了一个Firefox后，也必须安装图形界面，刚开始采用安装虚拟x-server,但是在CentOS 下安装各种依赖，尝试安装图形界面后tomcat也必须在图形界面下启动才能正常截图，后废弃此种方式，采用java原生绘图方式，下一篇博文介绍