[Jboss数据源一]初始化

先来看看jboss数据源的整体类图。

 

1.入口类LocalTxDataSource，负责对外参数设置和初始化框架

2.获取数据库连接的入口类WrapperDataSource，其实现了DataSource接口

3.ManagedConnectionFactory接口用来获取真实连接和创建WrapperDataSource

4.LocalManagedConnectionFactory负责从driver获取连接，driver层面的参数都在这里维护

5.JBossManagedConnectionPool维护着连接池必须的参数，管理着连接池的状态

6.ManagedConnectionPool提供了获取和归还连接的功能

 

接下来看一下jboss数据源的初始化过程，主要关注一个问题：数据源连接池如何从配置的参数启动?

入口代理类为LocalTxDataSource，一般使用方式如下

 

LocalTxDataSource localTxDataSource = new LocalTxDataSource();
localTxDataSource.setName(dataSourceDO.getDsName());
localTxDataSource.setBackgroundValidation(dataSourceDO.isBackgroundValidation());
localTxDataSource.setBackGroundValidationMinutes(dataSourceDO
    .getBackgroundValidationMinutes());
localTxDataSource.setBlockingTimeoutMillis(dataSourceDO.getBlockingTimeoutMillis());
localTxDataSource.setCheckValidConnectionSQL(dataSourceDO.getCheckValidConnectionSQL());
localTxDataSource.setConnectionProperties(dataSourceDO.getConnectionProperties());
localTxDataSource.setConnectionURL(dataSourceDO.getConnectionURL());
localTxDataSource.setDriverClass(dataSourceDO.getDriverClass());
localTxDataSource.setExceptionSorterClassName(dataSourceDO.getExceptionSorterClassName());
localTxDataSource.setIdleTimeoutMinutes(dataSourceDO.getIdleTimeoutMinutes());
localTxDataSource.setMaxSize(dataSourceDO.getMaxPoolSize());
localTxDataSource.setMinSize(dataSourceDO.getMinPoolSize());
localTxDataSource.setNewConnectionSQL(dataSourceDO.getNewConnectionSQL());
localTxDataSource.setNoTxSeparatePools(dataSourceDO.isNoTxSeparatePools());
localTxDataSource.setPassword(dataSourceDO.getPassWord());
localTxDataSource.setEncPassword(dataSourceDO.getEncPassword());
localTxDataSource.setPrefill(dataSourceDO.isPrefill());
localTxDataSource.setPreparedStatementCacheSize(dataSourceDO
    .getPreparedStatementCacheSize());
localTxDataSource.setQueryTimeout(dataSourceDO.getQueryTimeout());
localTxDataSource.setSharePreparedStatements(dataSourceDO.isSharePreparedStatements());
localTxDataSource.setTrackStatements(dataSourceDO.getTrackStatements());
localTxDataSource.setTransactionIsolation(dataSourceDO.getTransactionIsolation());
localTxDataSource.setTxQueryTimeout(dataSourceDO.isTxQueryTimeout());
localTxDataSource.setUseFastFail(dataSourceDO.isUseFastFail());
localTxDataSource.setUserName(dataSourceDO.getUserName());
localTxDataSource.setValidateOnMatch(dataSourceDO.isValidateOnMatch());
localTxDataSource.setValidConnectionCheckerClassName(dataSourceDO
    .getValidConnectionCheckerClassName());
localTxDataSource.setCriteria(dataSourceDO.getCriteria());
localTxDataSource.init(zdatasource);

 初始化过程如下：

    public void init(ZDataSource zdatasource) throws Exception {
        initPool();
        initConnectionManager();
        pool.start();
        initDataSource(zdatasource);
        this.zdatasource = zdatasource;
    }

 其最核心的start方法

    public void start() throws Exception {
        pool.startService();
        connectionManager.setPoolingStrategy(pool.getPoolingStrategy());
        connectionManager.startService();
        if (logger.isDebugEnabled()) {
            logger.debug("Connection pool " + name + " is started");
        }
    }

 启动pool，根据criteria配置生成不同的Pool类型，默认OnePool

    public void startService() throws Exception {
        if ("ByContainerAndApplication".equals(criteria))
            poolingStrategy = new PoolBySubjectAndCri(mcf, name, poolParams, noTxSeparatePools, log);
        else if ("ByContainer".equals(criteria))
            poolingStrategy = new PoolBySubject(mcf, name, poolParams, noTxSeparatePools, log);
        else if ("ByApplication".equals(criteria))
            poolingStrategy = new PoolByCri(mcf, name, poolParams, noTxSeparatePools, log);
        else
            // "ByNothing".equals(criteria)
            poolingStrategy = new OnePool(mcf, name, poolParams, noTxSeparatePools, log);
    }

 启动ConnectionManager，顺便做下预热

 public void startService() {
        poolingStrategy.setConnectionListenerFactory(this);

        if (poolingStrategy instanceof PreFillPoolSupport) {
            PreFillPoolSupport prefill = (PreFillPoolSupport) poolingStrategy;
            if (prefill.shouldPreFill()) {
                prefill.prefill();
            }
        }
    }

 最后初始化datasource

 private void initDataSource(ZDataSource zdatasource) throws ResourceException {
        datasource = (DataSource) mcf.createConnectionFactory(new ConnectionManagerDelegate(),
            this.name, zdatasource);
    }
public Object createConnectionFactory(ConnectionManager cm, String dataSourceName,
                                          ZDataSource zdatasource) throws ResourceException {
        return new WrapperDataSource(this, cm, dataSourceName, zdatasource);
    }