工作流activiti-02事物控制、流程引擎创建

2023-12-05 23:15:10

 使用activiti中有个很重要的问题就是需要保证事物的控制

      activiti使用的是mybatis作为orm技术 封装了一系列的操作数据库操作  这也就是大家调用的api 操作的数据库表都是activit自带的数据表 一般情况下使用spring整合

activiti的事物是很强大的 但是往往就不能如愿 因为公司使用的都是自己的框架不能利用spring来整合事物。

      通过java程序来控制activiti的事物

       activiti的事物依赖于TransactionFactory 在创建流程引擎ProcessEngine来指定事物工厂，其原因分析如下：

       创建流程引擎：   ProcessEngine processEngine = conf.buildProcessEngine() ; 

       conf为StandaloneProcessEngineConfiguration的对象其buildProcessEngine方法如下：

      

?
1
2
3
4
5
public ProcessEngine buildProcessEngine() {
    init();
    return new ProcessEngineImpl(this);
  }
<br>//调用init方法  <br> <br>  protected void init() {<br>    initHistoryLevel();<br>    initExpressionManager();<br>    initVariableTypes();<br>    initBeans();<br>    initFormEngines();<br>    initFormTypes();<br>    initScriptingEngines();<br>    initBusinessCalendarManager();<br>    initCommandContextFactory();<br>    initTransactionContextFactory();<br>    initCommandExecutors();<br>    initServices();<br>    initIdGenerator();<br>    initDeployers();<br>    initJobExecutor();<br>    initMailScanner();<br>    initDataSource();<br>   <span style="color: rgb(255, 0, 0);"> initTransactionFactory();</span><br>    initSqlSessionFactory();<br>    initSessionFactories();<br>    initJpa();<br>    initDelegateInterceptor();<br>    initEventHandlers();<br>  }<br>其中初始化了很多信息，可以依次看看源码  其中initTransactionFactory（）方法代码如下： <br><br>  // myBatis SqlSessionFactory ////////////////////////////////////////////////<br>  <br>  protected void initTransactionFactory() {<br>    if (transactionFactory==null) {<br>      if (transactionsExternallyManaged) {<br>        transactionFactory = new ManagedTransactionFactory();<br>      } else {<br>        transactionFactory = new JdbcTransactionFactory();<br>      }<br>    }<br>  }<br>

 其中transactionFactory为 protected TransactionFactory transactionFactory;  类中的属性
由代码可知  如果transactionFactory不为空则事物工厂为JdbcTransactionFactory的实例化对象
那么设置StandaloneProcessEngineConfiguration的transactionFactory的值为一JdbcTransactionFactory对象即可

代码如下：创建一个servlet监听器 在容器启动的时候创建一个流程引擎 （需要配置web.xml文件）

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
/**********************************************************************
 * <pre>
 * FILE : MyServletListener.java
 * CLASS : MyServletListener
 *
 * AUTHOR : Liaokailin
 *
 * FUNCTION :
 *
 *
 * Contact: <a href="mailto:Sina284888279@qq.com">Sina L凯林</a><br> *
 *======================================================================
 * CHANGE HISTORY LOG
 *----------------------------------------------------------------------
 * MOD. NO.|   DATE   |   NAME  | REASON  | CHANGE REQ.
 *----------------------------------------------------------------------
 *          |2014年1月17日|Liaokailin| Created |
 * DESCRIPTION:
 * </pre>
 ***********************************************************************/
package com.infodms.dms.actions;
 
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
 
import org.activiti.engine.ProcessEngine;
import org.activiti.engine.ProcessEngineConfiguration;
import org.activiti.engine.ProcessEngines;
import org.activiti.engine.impl.cfg.StandaloneProcessEngineConfiguration;
 
import com.infodms.dms.db.DBManager;
import com.infodms.dms.utils.DmsActivitiTransactionFactory;
 
public class MyServletListener implements ServletContextListener {
 
    @Override
    public void contextDestroyed(ServletContextEvent arg0) {
       ProcessEngines.destroy();
    }
 
    @Override
    public void contextInitialized(ServletContextEvent arg0) {
        StandaloneProcessEngineConfiguration conf = (StandaloneProcessEngineConfiguration) ProcessEngineConfiguration.createStandaloneProcessEngineConfiguration();
        conf.setDataSource(DBManager.getDataSource()).setDatabaseSchemaUpdate("true").setDbHistoryUsed(true) ;
      <span style="color: rgb(255, 0, 0);">  conf.setTransactionFactory(new DmsActivitiTransactionFactory()) ;
  </span>       ProcessEngine processEngine = conf.buildProcessEngine() ; 
        
    }
}

 conf.setTransactionFactory(new DmsActivitiTransactionFactory()) ;设置事物

DmsActivitiTransactionFactory代码如下：

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
/**********************************************************************
 * <pre>
 * FILE : DmsActivitiTransactionFactory.java
 * CLASS : DmsActivitiTransactionFactory
 *
 * AUTHOR : Liaokailin
 *
 * FUNCTION :
 *
 *
 * Contact: <a href="mailto:Sina284888279@qq.com">Sina L凯林</a> <br> *
 *======================================================================
 * CHANGE HISTORY LOG
 *----------------------------------------------------------------------
 * MOD. NO.|   DATE   |   NAME  | REASON  | CHANGE REQ.
 *----------------------------------------------------------------------
 *          |2014年1月21日|Liaokailin| Created |
 * DESCRIPTION:
 * </pre>
 ***********************************************************************/
package com.infodms.dms.utils;
 
import java.sql.Connection;
import java.util.Properties;
 
import org.apache.ibatis.transaction.Transaction;
import org.apache.ibatis.transaction.jdbc.JdbcTransactionFactory;
 
import com.infoservice.po3.core.context.DBService;
 
 
public class DmsActivitiTransactionFactory extends JdbcTransactionFactory {
 
    @Override
    public Transaction newTransaction(Connection conn, boolean autoCommit) {
        System.out.println("开启新的事物");
         return new DmsActitiviTransaction(conn,autoCommit) ;
        //return (Transaction) DBService.getInstance().getTransaction() ;
    }
 
    @Override
    public void setProperties(Properties props) {
        super.setProperties(props);
    }
 
}

 DmsActitiviTransaction 代码如下：

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
/**********************************************************************
 * <pre>
 * FILE : DmsActitiviTransaction.java
 * CLASS : DmsActitiviTransaction
 *
 * AUTHOR : Liaokailin
 *
 * FUNCTION :
 *
 *
 * Contact: <a href="mailto:Sina284888279@qq.com">Sina L凯林</a>
 *
 *======================================================================
 * CHANGE HISTORY LOG
 *----------------------------------------------------------------------
 * MOD. NO.|   DATE   |   NAME  | REASON  | CHANGE REQ.
 *----------------------------------------------------------------------
 *          |2014年1月21日|Liaokailin| Created |
 * DESCRIPTION:
 * </pre>
 ***********************************************************************/
package com.infodms.dms.utils;
 
import java.sql.Connection;
import java.sql.SQLException;
 
import org.apache.ibatis.transaction.jdbc.JdbcTransaction;
 
import com.infodms.dms.db.DBManager;
import com.infoservice.po3.core.context.DBService;
 
public class DmsActitiviTransaction extends JdbcTransaction {
    private static Connection conn = null ;
    public DmsActitiviTransaction(Connection connection,
            boolean desiredAutoCommit) {
        //connection.setAutoCommit(desiredAutoCommit);
     super(connection, desiredAutoCommit);
     try {
        connection.setAutoCommit(desiredAutoCommit);
    } catch (SQLException e) {
        e.printStackTrace();
    }
      
    }
 
    @Override
    public Connection getConnection() {
        /*DBService d = DBService.getInstance() ;
        d.loadConf("/DataAccessContext.xml");
        return d.getConnection() ;*/
      //     return DBService.getInstance().getConnection() ;
        try {
            if(conn==null){
                synchronized (DmsActitiviTransaction.class) {
                    conn = DBManager.getConnection() ;
                }
            }
            return conn ;
        } catch (Exception e) {
            System.out.println("获取链接失败："+e);
            return null ;
        }
    }
 
    @Override
    public void close() throws SQLException {
    /*  if(conn!=null&&!conn.isClosed()){
            conn.close();
        }*/
        System.out.println("activit:close()");
    }
 
    @Override
    public void commit() throws SQLException {
        /*if(conn!=null&&!conn.isClosed()){
            conn.commit();
        }*/
        System.out.println("activit:commit()");
    }
 
    @Override
    protected void resetAutoCommit() {
        System.out.println("resetAutoCommit()");
        /*try {
            if (conn != null && !conn.isClosed()) {
                conn.setAutoCommit(false);
            }
        } catch (SQLException e) {
            e.printStackTrace();
 
        }*/
    }
 
    @Override
    public void rollback() throws SQLException {
        /*if(conn!=null&&!conn.isClosed()){
            conn.rollback();
        }*/
        System.out.println("activit:rollback()");
    }
 
    @Override
    protected void setDesiredAutoCommit(boolean arg0) {
        System.out.println("setDesiredAutoCommit:"+arg0);
    }
     
 
}

 其中DBManager

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
/**********************************************************************
 * <pre>
 * FILE : DBManager.java
 * CLASS : DBManager
 *
 * AUTHOR : Liaokailin
 *
 * FUNCTION :
 *
 *
 * Contact: <a href="mailto:Sina284888279@qq.com">Sina L凯林</a>
 *
 *======================================================================
 * CHANGE HISTORY LOG
 *----------------------------------------------------------------------
 * MOD. NO.|   DATE   |   NAME  | REASON  | CHANGE REQ.
 *----------------------------------------------------------------------
 *          |2014年1月22日|Liaokailin| Created |
 * DESCRIPTION:
 * </pre>
 ***********************************************************************/
package com.infodms.dms.db;
 
import java.sql.Connection;
import java.sql.SQLException;
 
import javax.sql.DataSource;
 
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
 
import com.infoservice.po3.core.context.DBInfo;
 
public class DBManager {
    public static DataSource dataSource = null  ;
    public static Connection conn = null ;
    public static DataSource getDataSource(){
            if(dataSource==null){
                synchronized (DBManager.class) {
                    Resource resource = new ClassPathResource("/DataAccessContext.xml");
                    BeanFactory springBeanFactory = new XmlBeanFactory(resource);
                    DBInfo dbInfo = ((DBInfo)springBeanFactory.getBean("DBInfo"));
                    dataSource = (DataSource)springBeanFactory.getBean(dbInfo.getDefDataSource());
                    System.out.println("获取数据源");
                }
            }else{
                System.out.println("默认数据源调用");
            }
            
             
        return dataSource ;
    }
     
    public static Connection getConnection() throws SQLException{
        if(conn!=null&&!conn.isClosed()){
            System.out.println("获取默认连接");
 
        }else{
            synchronized (DBManager.class) {
                System.out.println("获取连接");
                conn = getDataSource().getConnection() ;
            }
        }
        return conn ;
    }
     
     
    public static void startTransaction(Connection connection) throws SQLException {
        System.out.println("开启事物");
        connection.setAutoCommit(false);
    }
     
    public static void endTransaction(Connection connection) throws SQLException{
        System.out.println("提交事物 ");
        connection.commit();
        connection.setAutoCommit(true);
    }
     
    public static void rollBack(Connection connection) throws SQLException{
        System.out.println("回滚事物");
        connection.rollback();
    }
}

 调用的使用DBManager就ok了

 

    

工作流activiti-02事物控制、流程引擎创建

上一篇：document cookie用法


下一篇：HashMap HashTable HashSet