Jbpm流程图

以前写的一个画流程图的Serlvet，发出来和大家共享

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Container;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.Stroke;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.dom4j.DocumentException;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.XPath;
import org.dom4j.xpath.DefaultXPath;
import org.jbpm.JbpmContext;
import org.jbpm.graph.def.ProcessDefinition;
import org.jbpm.graph.exe.Token;
import org.jbpm.taskmgmt.exe.TaskInstance;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;
import org.springmodules.workflow.jbpm31.JbpmCallback;
import org.springmodules.workflow.jbpm31.JbpmTemplate;

import com.sun.image.codec.jpeg.ImageFormatException;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

public class JbpmImageServlet extends HttpServlet {
	/**
	 * 
	 */
    private static final long serialVersionUID = 1L;
    //
    private WebApplicationContext wac = null;
    //
    private Token currentToken = null;
    private List<Token> childrens = null;
    
    private String message = "无流程图型信息";
    // 图像参数
	final static Color RunningColor = new Color(0,0,255);
	final static Color RunningBackColor = new Color(153,153,255);//#9999FF
	final static Color SuspenedColor = new Color(170,102,0); //#AA6600
	final static Color SuspenedBackColor = new Color(255,204,153);
	final static Color LockedColor = new Color(170,102,0); //#AA6600
	final static Color LockedBackColor = new Color(255,204,153);//#FFAA99
	final static Color EndedColor = new Color(204,0,0); //#CC0000
	final static Color EndedBackColor = new Color(102,0,0);//#66000
	final static int BorderWidth = 1;
	final static int BoderBackWidth = 2;
	final static int FontSize = 10;
	final static int TitleHeight = 12;

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        if(wac == null) {
        	System.out.println("初始化Spring上下文");
        	wac = WebApplicationContextUtils.getRequiredWebApplicationContext(request.getSession().getServletContext());
        }
        // 设置该类型,可以使浏览器识别出它是一张图片
        response.setContentType("image/jpeg");
        
        // 显示token状态图
        String tokenId = request.getParameter("tokenId");
        if(tokenId != null) {
        	childrens = new ArrayList<Token>();
        	showTokenImage(Long.parseLong(tokenId), response.getOutputStream());
        	return;
        }
        // 显示task实例状态图
        String taskId = request.getParameter("taskId");
        if(taskId != null) {
        	showTaskImage(Long.parseLong(taskId), response.getOutputStream());
        	return;
        }
        // 显示流程定义图
        String processDefinitionId = request.getParameter("definitionId");
        if(processDefinitionId != null) {
        	showProcessDefinitionImage(Long.parseLong(processDefinitionId), response.getOutputStream());
        	return;
        }
    }
    
    /**
     * 输出token状态图
     * 
     * @param id  tokenid
     * @param out 输出流
     * @throws ImageFormatException
     * @throws IOException
     */
    public void showTokenImage(long id, OutputStream out) throws ImageFormatException, IOException {
    	byte [] imageBytes = getProcessDefinitionImageBytesByTokenId(id);
    	// 流程定义图(背景)
    	BufferedImage bi = getProcessDefinitionImage(imageBytes);
    	if(imageBytes != null) {
    		byte [] gpdBytes = getGpdBytesByTokenId(id);
    		try {
				Element rootDiagramElement = DocumentHelper.parseText(new String(gpdBytes)).getRootElement();
				// 当前token所在座标
				int[] boxConstraint = extractBoxConstraint(rootDiagramElement, currentToken);
				int x = boxConstraint[0] - BorderWidth + 1;
				int y = boxConstraint[1] - TitleHeight - BorderWidth + 1;
				int w = boxConstraint[2] - 1;
				int h = boxConstraint[3] + TitleHeight - 1;
				String title = "";
				Font font = new Font("verdana,sans-serif", Font.PLAIN, FontSize);
				Stroke stroke = new BasicStroke(BorderWidth);
				Color color = null;
				Color bColor = null;
				if(currentToken.isSuspended()) {
					title = "Suspended";
					color = SuspenedColor;
					bColor = SuspenedBackColor;
				} else if(currentToken.isLocked()) {
					title = "Locked";
					color = LockedColor;
					bColor = LockedBackColor;
				} else if(currentToken.hasEnded()) {
					title = "Ended";
					color = EndedColor;
					bColor = EndedBackColor;
				} else {
					title = "Running";
					color = RunningColor;
					bColor = RunningBackColor;
				}
				if(currentToken.getName() != null) {
					title += " \"" + currentToken.getName() + "\"";
				}
				
				Graphics2D g = bi.createGraphics();
				g.setFont(font);
				g.setColor(color);
				g.setStroke(stroke);
				// 画边框
				g.drawRect(x, y, w, h);
				// 画Title
				g.fillRect(x, y, w, TitleHeight + BorderWidth);
				g.setColor(bColor);
				// 画竖阴影
				g.fillRect(x + w + BorderWidth - BorderWidth/2, y + BoderBackWidth, BoderBackWidth, h + BorderWidth - BorderWidth/2);
				// 画横阴影
				g.fillRect(x + BoderBackWidth, y + h + BorderWidth - BorderWidth/2, w + BorderWidth - BorderWidth/2, BoderBackWidth);
				
				g.setColor(Color.WHITE);
				// 字符串要离开边框3个宽度.下同
				g.drawString(title, x + BorderWidth + 3, y + TitleHeight/2 + FontSize/2);
				
				for(Token token : childrens) {
					// 子token所在座标
					boxConstraint = extractBoxConstraint(rootDiagramElement, token);
					x = boxConstraint[0] - BorderWidth + 1;
					y = boxConstraint[1] - TitleHeight - BorderWidth + 1;
					w = boxConstraint[2] - 1;
					h = boxConstraint[3] + TitleHeight - 1;
					
					
					if(token.isSuspended()) {
						title = "Suspended";
						color = SuspenedColor;
						bColor = SuspenedBackColor;
					} else if(token.isLocked()) {
						title = "Locked";
						color = LockedColor;
						bColor = LockedBackColor;
					} else if(token.hasEnded()) {
						title = "Ended";
						color = EndedColor;
						bColor = EndedBackColor;
					} else {
						title = "Running";
						color = RunningColor;
						bColor = RunningBackColor;
					}
					
					g.setColor(color);
					// 画边框
					g.drawRect(x, y, w, h);
					// 画Title
					g.fillRect(x, y, w, TitleHeight + BorderWidth);
					g.setColor(bColor);
					// 画竖阴影
					g.fillRect(x + w + BorderWidth - BorderWidth/2, y + BoderBackWidth, BoderBackWidth, h + BorderWidth - BorderWidth/2);
					// 画横阴影
					g.fillRect(x + BoderBackWidth, y + h + BorderWidth - BorderWidth/2, w + BorderWidth - BorderWidth/2, BoderBackWidth);
					
					g.setColor(Color.WHITE);
					if(token.getName() != null) {
						title += " \"" + token.getName() + "\"";
					}
					g.drawString(title, x + BorderWidth + 3, y + TitleHeight/2 + FontSize/2);
				}
			} catch (DocumentException e) {
				e.printStackTrace();
			}
    	}
        JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
        encoder.encode(bi);
        out.flush();
    }
    
    /**
     * 输出task状态图
     * 
     * @param id  taskid
     * @param out 输出流
     * @throws ImageFormatException
     * @throws IOException
     */
    public void showTaskImage(long id, OutputStream out) throws ImageFormatException, IOException {
    	byte [] imageBytes = getProcessDefinitionImageBytesByTaskId(id);
    	BufferedImage bi = getProcessDefinitionImage(imageBytes);
    	if(imageBytes != null) {
    		byte [] gpdBytes = getGpdBytesByTaskId(id);
    		try {
				Element rootDiagramElement = DocumentHelper.parseText(new String(gpdBytes)).getRootElement();
				int[] boxConstraint = extractBoxConstraint(rootDiagramElement, currentToken);
				Graphics2D g = bi.createGraphics();
				g.setColor(RunningColor);
				Stroke stroke = new BasicStroke(BorderWidth);
				g.setStroke(stroke);
				g.drawRect(boxConstraint[0]-BorderWidth, boxConstraint[1]-BorderWidth, boxConstraint[2]+BorderWidth*2, boxConstraint[3]+BorderWidth*2);
			} catch (DocumentException e) {
				e.printStackTrace();
			}
    	}
        JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
        encoder.encode(bi);
        out.flush();
    }
    
    /**
     * 输出流程定义图
     * 
     * @param id  processdefinitionid
     * @param out 输出流
     * @throws ImageFormatException
     * @throws IOException
     */
    public void showProcessDefinitionImage(long id, OutputStream out) throws ImageFormatException, IOException {
        JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
        encoder.encode(getProcessDefinitionImage(getProcessDefinitionImageBytes(id)));
        out.flush();
    }
    
    /**
     * 生成流程定义图
     * 
     * @param bytes 流程定义图字节码
     * @return
     */
    private BufferedImage getProcessDefinitionImage(final byte[] bytes) {
    	// 图型缓存
    	BufferedImage bi = null;
    	// 原始图型
    	Image img = null;
    	// MediaTracker 类是一个跟踪多种媒体对象状态的实用工具类。
		// 媒体对象可以包括音频剪辑和图像，但目前仅支持图像。
        MediaTracker tracker = null;
    	// 图像默认宽度
    	int w = 400;
    	// 图像默认高度
	    int h = 400;
    	
    	if(bytes == null) {
    		bi = new BufferedImage(w, h, BufferedImage.TYPE_3BYTE_BGR);
    	} else {
	        img = Toolkit.getDefaultToolkit().createImage(bytes);
	        // 接收Image信息通知的异步更新接口
	    	Container p = new Container();
	        tracker = new MediaTracker(p);
	        tracker.addImage(img, 0);
	        try {
	        	// 至关重要:没有它,图片的高宽无法得到
	        	// 它将等待图像信息加载完毕
				tracker.waitForAll();
				// tracker.waitForID(0);
				w = img.getWidth(p);
		        h = img.getHeight(p);
			} catch (InterruptedException e) {
				e.printStackTrace();
				message = e.getLocalizedMessage();
			} catch (Exception e) {
				e.printStackTrace();
				message = e.getLocalizedMessage();
			}
			bi = new BufferedImage(w, h, BufferedImage.TYPE_3BYTE_BGR);
    	}
    	
    	Graphics2D g = bi.createGraphics();
    	// 如果不设背景色,默认为黑色
    	g.setBackground(Color.WHITE);
    	// 留1个宽度的边
    	g.clearRect(1, 1, w-2, h-2);
    	if(tracker != null && MediaTracker.COMPLETE == tracker.statusAll(false)) {
    		g.drawImage(img, 0, 0, null);
    	} else {
    		g.setColor(Color.BLACK);
    		g.setFont(new Font("黑体", Font.PLAIN, 20));
    		// 用于获取字符宽度
    		FontMetrics fm = g.getFontMetrics();
    		g.drawString(message, w/2 - fm.stringWidth(message)/2, h/2);
    	}
    	//g.dispose();
    	return bi;
    }
    
    /**
     * 根据taskid获得流程定义图字节码
     * 
     * @param id taskid
     * @return
     */
    private byte[] getProcessDefinitionImageBytesByTaskId(final long id) {
    	JbpmTemplate jbpmTemplate = (JbpmTemplate) wac.getBean("jbpmTemplate");
    	return (byte[])jbpmTemplate.execute(new JbpmCallback() {
            public Object doInJbpm(JbpmContext context) {
            	try {
	            	TaskInstance taskInstance = context.getTaskMgmtSession().loadTaskInstance(id);
	            	currentToken = taskInstance.getToken();
	            	// 这里currentToken有可能为null
	            	ProcessDefinition pd = currentToken.getProcessInstance().getProcessDefinition();
	            	if(pd.getFileDefinition() == null) {
	            		message = "没有流程图";
	            		return null;
	            	} else {
	            		return pd.getFileDefinition().getBytes("processimage.jpg");
	            	}
            	} catch(Exception e) {
            		e.printStackTrace();
            		message = "No TaskInstance:" + id;
            		return null;
            	}
            }
        });
    }
    
    /**
     * 根据tokenid获得流程定义图字节码
     * 
     * @param id tokenid
     * @return
     */
    private byte[] getProcessDefinitionImageBytesByTokenId(final long id) {
    	JbpmTemplate jbpmTemplate = (JbpmTemplate) wac.getBean("jbpmTemplate");
    	return (byte[])jbpmTemplate.execute(new JbpmCallback() {
            public Object doInJbpm(JbpmContext context) {
            	try {
	            	currentToken = context.loadToken(id);
	            	Collection childTokens = currentToken.getChildren().values();
	    			for (Iterator iterator = childTokens.iterator(); iterator.hasNext();) {
	    				Token child = (Token) iterator.next();
	    				childrens.add(child);
	    			}
	    			// 这里token可能没有processInstanceId 即getProcessInstance为null.
	            	ProcessDefinition pd = currentToken.getProcessInstance().getProcessDefinition();
	            	if(pd.getFileDefinition() == null) {
	            		message = "没有流程图";
	            		return null;
	            	} else {
	            		return pd.getFileDefinition().getBytes("processimage.jpg");
	            	}
            	} catch(Exception e) {
            		e.printStackTrace();
            		message = "No Token:" + id;
            		return null;
            	}
            }
        });
    }
    
    /**
     * 根据processdefinitionid获得流程定义图字节码
     * 
     * @param id processdefinitionid
     * @return
     */
    private byte[] getProcessDefinitionImageBytes(final long id) {
    	JbpmTemplate jbpmTemplate = (JbpmTemplate) wac.getBean("jbpmTemplate");
    	return (byte[])jbpmTemplate.execute(new JbpmCallback() {
            public Object doInJbpm(JbpmContext context) {
            	try {
            		ProcessDefinition pd = context.getGraphSession().loadProcessDefinition(id);
	            	if(pd.getFileDefinition() == null) {
	            		message = "没有流程图";
	            		return null;
	            	} else {
	            		return pd.getFileDefinition().getBytes("processimage.jpg");
	            	}
            	} catch(Exception e) {
            		e.printStackTrace();
            		message = "No ProcessDefinition:" + id;
            		return null;
            	}
            }
        });
    }
    
    private byte[] getGpdBytesByTaskId(final long id) {
    	JbpmTemplate jbpmTemplate = (JbpmTemplate) wac.getBean("jbpmTemplate");
    	return (byte[])jbpmTemplate.execute(new JbpmCallback() {
            public Object doInJbpm(JbpmContext context) {
            	try {
            		TaskInstance taskInstance = context.getTaskMgmtSession().loadTaskInstance(id);
	            	currentToken = taskInstance.getToken();
	            	ProcessDefinition pd = currentToken.getProcessInstance().getProcessDefinition();
	            	if(pd.getFileDefinition() == null) {
	            		message = "没有流程图";
	            		return null;
	            	} else {
	            		return pd.getFileDefinition().getBytes("gpd.xml");
	            	}
            	} catch(Exception e) {
            		e.printStackTrace();
            		message = "No TaskInstance:" + id;
            		return null;
            	}
            }
        });
    }
    
    private byte[] getGpdBytesByTokenId(final long id) {
    	JbpmTemplate jbpmTemplate = (JbpmTemplate) wac.getBean("jbpmTemplate");
    	return (byte[])jbpmTemplate.execute(new JbpmCallback() {
            public Object doInJbpm(JbpmContext context) {
            	try {
	            	currentToken = context.loadToken(id);
	            	ProcessDefinition pd = currentToken.getProcessInstance().getProcessDefinition();
	            	if(pd.getFileDefinition() == null) {
	            		message = "没有流程图";
	            		return null;
	            	} else {
	            		return pd.getFileDefinition().getBytes("gpd.xml");
	            	}
            	} catch(Exception e) {
            		e.printStackTrace();
            		message = "No Token:" + id;
            		return null;
            	}
            }
        });
    }
    
    /**
     * 提取座标及宽高
     * 
     * @param root 根节点
     * @param token
     * @return
     */
    private int[] extractBoxConstraint(Element root, Token token) {
		int[] result = new int[4];
		String nodeName = token.getNode().getName();
		XPath xPath = new DefaultXPath("//node[@name='" + nodeName + "']");
		Element node = (Element) xPath.selectSingleNode(root);

		result[0] = Integer.valueOf(node.attribute("x").getValue()).intValue();
		result[1] = Integer.valueOf(node.attribute("y").getValue()).intValue();

		result[2] = Integer.valueOf(node.attribute("width").getValue())
				.intValue();
		result[3] = Integer.valueOf(node.attribute("height").getValue())
				.intValue();
		return result;
	}

}