OSWorkflow的第一個程序

OSWorkflow的第一支程式

(史帝芬, 2005/6/4, [email protected])

自從C的聖經版以Hello World程式開始引導初學者學習程式語言以來，多數的程式語言入門書也都如法刨製。 OSWorkflow沒辦法寫出那種一目瞭然的程式，但是我仍盡量將程式簡化，希望初學者能在看完這第一支程式後，就能有所體會。接下來將講解如何寫出第一支OSWorkflow程式!

• jar file
  將以下jar file放置到WEB-INF/lib底下…
  activation.jar
  bsh-1.2b7.jar
  commons-logging.jar
  designer.jar
  mail.jar
  oscore-2.2.2.jar
  osuser-1.0-dev-3Dec03.jar
  osworkflow-2.7.0.jar
  propertyset-1.3-21Apr04.jar
  quartz.jar
  這些jar file可以在OSWorkflow提供的example裡找到。
  
• 建立資料庫
  在SQL Server中建立一資料庫，名稱可自取，這裡取名OSWorkflow，然後執行%OSWorkflow%/src/etc/deployment/jdbc/mssql.sql，建立OSWorkflow所需的Table。
  然後在Tomcat設定DataSource取名jdbc/DefaultDS並指向資料庫OSWorkflow，方法可參考Connection Pool (2)。
  接下來將以下內容放入osworkflow.xml，並將osworkflow.xml放置在WEB-INF/classes底下。
  

  <osworkflow>
  <!--
  <persistence class="com.opensymphony.workflow.spi.memory.MemoryWorkflowStore"/>
  -->
  <persistence class="com.opensymphony.workflow.spi.jdbc.JDBCWorkflowStore">
  
  	<property key="datasource" value="jdbc/DefaultDS"/>
  	<property key="entry.sequence"
                        value="select count(*) + 1 from os_wfentry"/>
  	<property key="entry.table" value="OS_WFENTRY"/>
  	<property key="entry.id" value="ID"/>
  	<property key="entry.name" value="NAME"/>
  	<property key="entry.state" value="STATE"/>
  	<property key="step.sequence"
  value="select sum(c1) + 1 from (select 1 as tb, count(*) as c1 
         from os_currentstep union 
         select 2 as tb, count(*) as c1 from os_historystep) as TabelaFinal"/>
  	<property key="history.table" value="OS_HISTORYSTEP"/>
  	<property key="current.table" value="OS_CURRENTSTEP"/>
  	<property key="historyPrev.table" value="OS_HISTORYSTEP_PREV"/>
  	<property key="currentPrev.table" value="OS_CURRENTSTEP_PREV"/>
  	<property key="step.id" value="ID"/>
  	<property key="step.entryId" value="ENTRY_ID"/>
  	<property key="step.stepId" value="STEP_ID"/>
  	<property key="step.actionId" value="ACTION_ID"/>
  	<property key="step.owner" value="OWNER"/>
  	<property key="step.caller" value="CALLER"/>
  	<property key="step.startDate" value="START_DATE"/>
  	<property key="step.finishDate" value="FINISH_DATE"/>
  	<property key="step.dueDate" value="DUE_DATE"/>
  	<property key="step.status" value="STATUS"/>
  	<property key="step.previousId" value="PREVIOUS_ID"/>
  </persistence>
  
      <factory class="com.opensymphony.workflow.loader.XMLWorkflowFactory">
          <property key="resource" value="workflows.xml" />
      </factory>
  </osworkflow>
  

• 建立流程
  建立一個命名為leave.xml的檔案，並將它放入WEB-INF/classes底下，檔名可自取，這個檔案就是記載流程的檔案。
  

  <?xml version="1.0" encoding="UTF-8" ?>
  <!DOCTYPE workflow PUBLIC "-//OpenSymphony Group//DTD OSWorkflow 2.7//EN" 
  "http://www.opensymphony.com/osworkflow/workflow_2_7.dtd">
  <workflow>
    <initial-actions>
     <action id="0" name="開始">
        <results>
          <unconditional-result old-status="Finished" status="Queued" step="1" />
        </results>
      </action>
    </initial-actions>
  
    <steps>
      <step id="1" name="填假單">
        <actions>
          <action id="1" name="送出">
  	  <pre-functions>
  	    <function type="class">
  	      <arg name="class.name">com.opensymphony.workflow.util.Caller</arg>
  	    </function>
  	  </pre-functions>
            <results>
              <unconditional-result old-status="Finished" status="Queued" 
  step="2"  owner="User100" />
            </results>
          </action>
        </actions>
      </step>
  
      <step id="2" name="批假單">
        <actions>
          <action id="2" name="準許">
  	  <pre-functions>
  	    <function type="class">
  	      <arg name="class.name">com.opensymphony.workflow.util.Caller</arg>
  	    </function>
  	  </pre-functions>
            <results>
              <unconditional-result old-status="Finished" status="Queued" 
  step="3"  owner="${caller}"/>
            </results>
          </action>
  
          <action id="3" name="駁回">
  	  <pre-functions>
  	    <function type="class">
  	      <arg name="class.name">com.opensymphony.workflow.util.Caller</arg>
  	    </function>
  	  </pre-functions>
            <results>
              <unconditional-result old-status="Finished" status="Queued" 
  step="1"  owner="${caller}"/>
            </results>
          </action>
        </actions>      
      </step>
  
      <step id="3" name="停止" />
    </steps>
  </workflow>

  接著在workflows.xml中加入如下的設定，即可讓系統於啟動後載入請假的流程，workflows.xml也放至WEB-INF/classes。
  

  <workflows>
      <workflow name="leave" type="resource" location="leave.xml"/>
  </workflows>
  

• 程式
  這裡將建立兩個網頁分別給員工和主管使用，另外有兩個servlet及一個類別作為趨動流程。
      Leave.java
  

  package tw.idv.idealist;
  
  import com.opensymphony.workflow.InvalidActionException;
  import com.opensymphony.workflow.InvalidEntryStateException;
  import com.opensymphony.workflow.InvalidInputException;
  import com.opensymphony.workflow.InvalidRoleException;
  import com.opensymphony.workflow.Workflow;
  import com.opensymphony.workflow.WorkflowException;
  import com.opensymphony.workflow.basic.BasicWorkflow;
  import com.opensymphony.workflow.config.DefaultConfiguration;
  import com.opensymphony.workflow.spi.Step;
  
  /**
   * 請假流程
   * @author steven
   */
  public class Leave {
  	/**
  	 * 送出假單
  	 */
  	public long send(String employee) {
  		Workflow workflow = new BasicWorkflow(employee);
  		DefaultConfiguration config = new DefaultConfiguration();
  		workflow.setConfiguration(config);
  		long workflowId = -1;
  		try {
  			//leave是workflowx.xml中定的名稱
  			workflowId = workflow.initialize("leave", 0, null); 
  			workflow.doAction(workflowId, 1, null);
  		} catch (InvalidActionException e) {
  			e.printStackTrace();
  		} catch (InvalidRoleException e) {
  			e.printStackTrace();
  		} catch (InvalidInputException e) {
  			e.printStackTrace();
  		} catch (InvalidEntryStateException e) {
  			e.printStackTrace();
  		} catch (WorkflowException e) {
  			e.printStackTrace();
  		}
  		
  		return workflowId;
  	}
  	
  	/**
  	 * 准假假單
  	 * @param workflowId 工作流編號
  	 * @param actionId 動作編號, 2 準許, 3 駁回
  	 */
  	public void allow(long workflowId, int actionId) {
  		Workflow workflow = new BasicWorkflow("manager1");
  		DefaultConfiguration config = new DefaultConfiguration();
  		workflow.setConfiguration(config);
  		try {
  			workflow.doAction(workflowId, actionId, null);
  		} catch (InvalidInputException e) {
  			e.printStackTrace();
  		} catch (WorkflowException e) {
  			e.printStackTrace();
  		}
  		catch (InvalidActionException e) {
  			e.printStackTrace();
  		}
  	}	
  }

      LeaveAction.java (servlet)
  

  package tw.idv.idealist.actions;
  
  import java.io.IOException;
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServlet;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import tw.idv.idealist.Leave;
  
  /**
   * @author Steven
   */
  public class LeaveAction extends HttpServlet {
  
  	public void doGet(HttpServletRequest req, HttpServletResponse resp)
  		throws ServletException, IOException {
  		doPost(req, resp);
  	}
  
  	public void doPost(HttpServletRequest req, HttpServletResponse resp)
  		throws ServletException, IOException {
  		Leave leave = new Leave();
  		String employee = req.getParameter("employee");
  		long workflowId = leave.send(employee);
  		resp.sendRedirect("allow.jsp?workflowId=" + workflowId);
  	}
  
  }

      AllowAction.java (servlet)
  

  package tw.idv.idealist.actions;
  
  import java.io.IOException;
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServlet;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import tw.idv.idealist.Leave;
  
  /**
   * @author Steven
   */
  public class AllowAction extends HttpServlet {
  
  	public void doGet(HttpServletRequest req, HttpServletResponse resp)
  		throws ServletException, IOException {
  		doPost(req, resp);
  	}
  
  	public void doPost(HttpServletRequest req, HttpServletResponse resp)
  		throws ServletException, IOException {
  		String workflowId = req.getParameter("workflowId");
  		String actionId = req.getParameter("actionId");
  		Leave leave = new Leave();
  		leave.allow(Long.parseLong(workflowId), Integer.parseInt(actionId));
  	}
  
  }

      leave.jsp
  

  <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
  
  <HTML>
  <HEAD>
  <%@ page language="java" contentType="text/html; charset=BIG5" 
  pageEncoding="BIG5" %>
  <%@ page import="tw.idv.idealist.*" %>
  
  <META http-equiv="Content-Type" content="text/html; charset=BIG5">
  <META http-equiv="Content-Style-Type" content="text/css">
  <TITLE>填寫假單</TITLE>
  </HEAD>
  <BODY>
  <P>員工請假</P>
  
  <form action="LeaveAction">
  	員工代號: <input type="text" name="employee">&nbsp;
          <input type="submit" value="送出">
  </form>
  
  </BODY>
  </HTML>
  

      allow.jsp
  

  <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
  
  <HTML>
  <HEAD>
  <%@ page language="java" contentType="text/html; charset=BIG5" 
  pageEncoding="BIG5" %>
  
  <META http-equiv="Content-Type" content="text/html; charset=BIG5">
  <META http-equiv="Content-Style-Type" content="text/css">
  <TITLE>批准假單</TITLE>
  <Script Language="JavaScript">
  function DoAction(actionId) {
  	document.myForm.actionId.value = actionId;
  	document.myForm.submit();
  }
  </Script>
  </HEAD>
  <BODY>
  
  <%
  String workflowId = request.getParameter("workflowId");
  %>
  
  <P>主管批假單</P>
  <form action="AllowAction" name="myForm">
  	<input type="hidden" name="actionId" value="">
  	工作流編號: <input type="text" name="workflowId" value=<%= workflowId %>>
  <input type="button" value="準許" OnClick="DoAction(2)">&nbsp;
  <input type="button" value="駁回" OnClick="DoAction(3)">
  </form>
  
  </BODY>
  </HTML>
  

• 測試
  啟動Tomcat，並執行leave.jsp，按"送出"後，假單即送出，接著會出現allow.jsp的網頁供主管簽核，主管按"淮許"後，請假流程即完成，記得在執行過程中多觀察資料庫中資料的變化。
      請假
  
      准假