废话不多说直接上代码。

项目完整源码链接

1、添加maven依赖包

        <dependency>
            <groupId>org.flowable</groupId>
            <artifactId>flowable-engine</artifactId>
            <version>6.4.2</version> 
        </dependency>

2、集成核心代码

package com.nutzfw.core.plugin.flowable;

import com.nutzfw.core.plugin.flowable.transaction.NutzTransactionFactory;
import com.nutzfw.core.plugin.flowable.util.FlowStrongUuidGenerator;
import org.flowable.common.engine.impl.history.HistoryLevel;
import org.flowable.engine.*;
import org.flowable.engine.impl.cfg.StandaloneProcessEngineConfiguration;
import org.nutz.ioc.loader.annotation.Inject;
import org.nutz.ioc.loader.annotation.IocBean;
import org.nutz.lang.Encoding;

import javax.sql.DataSource;

/**
 * @author 黄川 huchuc@vip.qq.com
 * @date: 2019/4/8
 */
@IocBean
public class FlowAbleContext {

    @Inject
    DataSource dataSource;

    @Inject
    ProcessEngine processEngine;

    @IocBean
    public ProcessEngine processEngine() {
        ProcessEngineConfiguration engineConfiguration = new StandaloneProcessEngineConfiguration();
        engineConfiguration.setDatabaseSchemaUpdate(ProcessEngineConfiguration.DB_SCHEMA_UPDATE_TRUE);
        engineConfiguration.setActivityFontName("宋体");
        engineConfiguration.setLabelFontName("宋体");
        engineConfiguration.setAnnotationFontName("宋体");
        engineConfiguration.setXmlEncoding(Encoding.UTF8);
        engineConfiguration.setDataSource(dataSource);
        engineConfiguration.setHistoryLevel(HistoryLevel.FULL);
        engineConfiguration.setIdGenerator(new FlowStrongUuidGenerator());
        //设置外部管理的事务
        engineConfiguration.setTransactionsExternallyManaged(true);
        engineConfiguration.setTransactionFactory(new NutzTransactionFactory());
        return engineConfiguration.buildProcessEngine();
    }

    @IocBean
    public RepositoryService repositoryService() {
        return processEngine.getRepositoryService();
    }

    @IocBean
    public RuntimeService runtimeService() {
        return processEngine.getRuntimeService();
    }

    @IocBean
    public IdentityService identityService() {
        return processEngine.getIdentityService();
    }

    @IocBean
    public TaskService taskService() {
        return processEngine.getTaskService();
    }

    @IocBean
    public HistoryService historyService() {
        return processEngine.getHistoryService();
    }

    @IocBean
    public ManagementService managementService() {
        return processEngine.getManagementService();
    }

    @IocBean
    public FormService formService() {
        return processEngine.getFormService();
    }

    @IocBean
    public DynamicBpmnService dynamicBpmnService() {
        return processEngine.getDynamicBpmnService();
    }

}

3、我们需要在Nutz线程启用事务的时候将flowable工作流的事务管理权限交给nutz的事务，而Nutz线程没有启用事务时还是由flowable工作流自己管理

package com.nutzfw.core.plugin.flowable.transaction;

import org.apache.ibatis.session.TransactionIsolationLevel;
import org.apache.ibatis.transaction.Transaction;
import org.apache.ibatis.transaction.TransactionFactory;

import javax.sql.DataSource;
import java.sql.Connection;
import java.util.Properties;

/**
 * @author 黄川 huchuc@vip.qq.com
 * @date: 2019/4/19
 */
public class NutzTransactionFactory implements TransactionFactory {


    @Override
    public void setProperties(Properties props) {

    }

    @Override
    public Transaction newTransaction(Connection conn) {
        return new NutzTransaction(conn);
    }

    @Override
    public Transaction newTransaction(DataSource ds, TransactionIsolationLevel level, boolean autoCommit) {
        return new NutzTransaction(ds, level, autoCommit);
    }
}


package com.nutzfw.core.plugin.flowable.transaction;

import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.session.TransactionIsolationLevel;
import org.apache.ibatis.transaction.Transaction;
import org.apache.ibatis.transaction.TransactionException;
import org.nutz.trans.Trans;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.SQLException;

/**
 * @author 黄川 huchuc@vip.qq.com
 * @date: 2019/4/19
 */
@Slf4j
public class NutzTransaction implements Transaction {


    private DataSource dataSource;
    private TransactionIsolationLevel level;
    private Connection connection;
    private boolean autoCommmit;

    public NutzTransaction(Connection connection) {
        this.connection = connection;
    }

    public NutzTransaction(DataSource ds, TransactionIsolationLevel level, boolean autoCommmit) {
        this.dataSource = ds;
        this.level = level;
        this.autoCommmit = autoCommmit;
    }

    @Override
    public Connection getConnection() throws SQLException {
        if (Trans.isTransactionNone()) {
            if (this.connection == null) {
                openConnection();
            }
        } else {
            this.connection = Trans.get().getConnection(dataSource);
        }
        return this.connection;
    }

    @Override
    public void commit() throws SQLException {
        // Does nothing
    }

    @Override
    public void rollback() throws SQLException {
        // Does nothing
    }

    @Override
    public void close() throws SQLException {
        if (this.connection != null) {
            if (Trans.isTransactionNone()) {
                resetAutoCommit();
                if (log.isDebugEnabled()) {
                    log.debug("Closing JDBC Connection [" + this.connection + "]");
                }
                this.connection.close();
            }
        }
    }

    protected void openConnection() throws SQLException {
        if (log.isDebugEnabled()) {
            log.debug("Opening JDBC Connection");
        }
        this.connection = dataSource.getConnection();
        if (level != null) {
            this.connection.setTransactionIsolation(level.getLevel());
        }
        setDesiredAutoCommit(autoCommmit);
    }

    protected void setDesiredAutoCommit(boolean desiredAutoCommit) {
        try {
            if (connection.getAutoCommit() != desiredAutoCommit) {
                if (log.isDebugEnabled()) {
                    log.debug("Setting autocommit to " + desiredAutoCommit + " on JDBC Connection [" + connection + "]");
                }
                connection.setAutoCommit(desiredAutoCommit);
            }
        } catch (SQLException e) {
            // Only a very poorly implemented driver would fail here,
            // and there's not much we can do about that.
            throw new TransactionException("Error configuring AutoCommit.  "
                    + "Your driver may not support getAutoCommit() or setAutoCommit(). "
                    + "Requested setting: " + desiredAutoCommit + ".  Cause: " + e, e);
        }
    }

    protected void resetAutoCommit() {
        try {
            if (!connection.getAutoCommit()) {
                // MyBatis does not call commit/rollback on a connection if just selects were performed.
                // Some databases start transactions with select statements
                // and they mandate a commit/rollback before closing the connection.
                // A workaround is setting the autocommit to true before closing the connection.
                // Sybase throws an exception here.
                if (log.isDebugEnabled()) {
                    log.debug("Resetting autocommit to true on JDBC Connection [" + connection + "]");
                }
                connection.setAutoCommit(true);
            }
        } catch (SQLException e) {
            if (log.isDebugEnabled()) {
                log.debug("Error resetting autocommit to true "
                        + "before closing the connection.  Cause: " + e);
            }
        }
    }

    @Override
    public Integer getTimeout() throws SQLException {
        return null;
    }
}