day18 16.dbcp连接池使用介绍

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package cn.itcast.datasource;

import java.io.FileInputStream;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Properties;

import javax.sql.DataSource;

import org.apache.commons.dbcp.BasicDataSource;
import org.apache.commons.dbcp.BasicDataSourceFactory;
import org.junit.Test;
//我们以前那个连接池底层是JdbcUtils.getConnection(),那个就找配置文件
//BasicDataSource缺少连接数据库最基本的四个条件:驱动,url,username,password
public class DbcpTest {

    //1.手动配置
    @Test
    public void test1() throws SQLException{
        //我们以前那个连接池底层是JdbcUtils.getConnection(),那个就找配置文件
        BasicDataSource bds = new BasicDataSource();//BasicDataSource不会去找配置文件
        //需要设置连接数据库最基本四个条件
        bds.setDriverClassName("com.mysql.jdbc.Driver");
        bds.setUrl("jdbc:mysql:///day18");
        bds.setUsername("root");
        bds.setPassword("");
        //得到一个Connection
        Connection con = bds.getConnection();
        ResultSet rs= con.createStatement().executeQuery("select * from account");
        while(rs.next()){
            System.out.println(rs.getInt("id")+"   "+rs.getString("name"));
        }

    
    rs.close();
    con.close();//将Connection对象重新装入到连接池.
    //那连接池人家底层肯定实现了,肯定读这close方法进行功能增强了
    //只要是连接池,Connection对象肯定放回去了,不是关
    
    
}    
  //2.自动配置
    @Test
    public void test2() throws Exception{
        
        Properties props = new Properties();//差一个Properties对象,new一个呗
        /*
        props.setProperty("driverClassName", "com.mysql.jdbc.driver");//key值要查看BasicDataSourceFactory的源码里面的常量才知道
        props.setProperty("url", "jdbc:mysql:///day18");//key值要查看BasicDataSourceFactory的源码里面的常量才知道
        props.setProperty("username", "root");//key值要查看BasicDataSourceFactory的源码里面的常量才知道
        props.setProperty("password", "");//key值要查看BasicDataSourceFactory的源码里面的常量才知道
*/        //Properties里面的东西可以直接从文件里面加载  
        //之所以为自动,是因为查看jdk文档知道Properties对象可以用文件流加载配置文件
        FileInputStream fis = new FileInputStream("E:\北风网\day18_2\src\dbcp.properties");
        props.load(fis);
    DataSource ds = BasicDataSourceFactory.createDataSource(props);//createDataSource是静态方法
    Connection con = ds.getConnection();
    ResultSet rs= con.createStatement().executeQuery("select * from account");
    while(rs.next()){
        System.out.println(rs.getInt("id")+"   "+rs.getString("name"));
    }
    rs.close();
    con.close();//人Connection最后关闭时还是把它放到连接池不会关不会销毁
    }


}

driverClassName=com.mysql.jdbc.Driver
url=jdbc:mysql:///day18
username=root
password=

#driverClass=oracle.jdbc.driver.OracleDriver
#url=jdbc:oracle:thin:@localhost:1521:XE
#username=system
#password=system

BasicDataSoureFactory源码

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.commons.dbcp;

import java.io.ByteArrayInputStream;
import java.sql.Connection;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Properties;
import java.util.StringTokenizer;
import java.util.Collections;

import javax.naming.Context;
import javax.naming.Name;
import javax.naming.RefAddr;
import javax.naming.Reference;
import javax.naming.spi.ObjectFactory;
import javax.sql.DataSource;

/**
 * <p>JNDI object factory that creates an instance of
 * <code>BasicDataSource</code> that has been configured based on the
 * <code>RefAddr</code> values of the specified <code>Reference</code>,
 * which must match the names and data types of the
 * <code>BasicDataSource</code> bean properties.</p>
 *
 * @author Craig R. McClanahan
 * @author Dirk Verbeeck
 * @version $Revision: 828639 $ $Date: 2009-10-22 06:27:43 -0400 (Thu, 22 Oct 2009) $
 */
public class BasicDataSourceFactory implements ObjectFactory {

    private final static String PROP_DEFAULTAUTOCOMMIT = "defaultAutoCommit";
    private final static String PROP_DEFAULTREADONLY = "defaultReadOnly";
    private final static String PROP_DEFAULTTRANSACTIONISOLATION = "defaultTransactionIsolation";
    private final static String PROP_DEFAULTCATALOG = "defaultCatalog";
    private final static String PROP_DRIVERCLASSNAME = "driverClassName";
    private final static String PROP_MAXACTIVE = "maxActive";
    private final static String PROP_MAXIDLE = "maxIdle";
    private final static String PROP_MINIDLE = "minIdle";
    private final static String PROP_INITIALSIZE = "initialSize";
    private final static String PROP_MAXWAIT = "maxWait";
    private final static String PROP_TESTONBORROW = "testOnBorrow";
    private final static String PROP_TESTONRETURN = "testOnReturn";
    private final static String PROP_TIMEBETWEENEVICTIONRUNSMILLIS = "timeBetweenEvictionRunsMillis";
    private final static String PROP_NUMTESTSPEREVICTIONRUN = "numTestsPerEvictionRun";
    private final static String PROP_MINEVICTABLEIDLETIMEMILLIS = "minEvictableIdleTimeMillis";
    private final static String PROP_TESTWHILEIDLE = "testWhileIdle";
    private final static String PROP_PASSWORD = "password";
    private final static String PROP_URL = "url";
    private final static String PROP_USERNAME = "username";
    private final static String PROP_VALIDATIONQUERY = "validationQuery";
    private final static String PROP_VALIDATIONQUERY_TIMEOUT = "validationQueryTimeout";
    /**
     * The property name for initConnectionSqls.
     * The associated value String must be of the form [query;]*
     * @since 1.3
     */
    private final static String PROP_INITCONNECTIONSQLS = "initConnectionSqls";
    private final static String PROP_ACCESSTOUNDERLYINGCONNECTIONALLOWED = "accessToUnderlyingConnectionAllowed";
    private final static String PROP_REMOVEABANDONED = "removeAbandoned";
    private final static String PROP_REMOVEABANDONEDTIMEOUT = "removeAbandonedTimeout";
    private final static String PROP_LOGABANDONED = "logAbandoned";
    private final static String PROP_POOLPREPAREDSTATEMENTS = "poolPreparedStatements";
    private final static String PROP_MAXOPENPREPAREDSTATEMENTS = "maxOpenPreparedStatements";
    private final static String PROP_CONNECTIONPROPERTIES = "connectionProperties";

    private final static String[] ALL_PROPERTIES = {
        PROP_DEFAULTAUTOCOMMIT,
        PROP_DEFAULTREADONLY,
        PROP_DEFAULTTRANSACTIONISOLATION,
        PROP_DEFAULTCATALOG,
        PROP_DRIVERCLASSNAME,
        PROP_MAXACTIVE,
        PROP_MAXIDLE,
        PROP_MINIDLE,
        PROP_INITIALSIZE,
        PROP_MAXWAIT,
        PROP_TESTONBORROW,
        PROP_TESTONRETURN,
        PROP_TIMEBETWEENEVICTIONRUNSMILLIS,
        PROP_NUMTESTSPEREVICTIONRUN,
        PROP_MINEVICTABLEIDLETIMEMILLIS,
        PROP_TESTWHILEIDLE,
        PROP_PASSWORD,
        PROP_URL,
        PROP_USERNAME,
        PROP_VALIDATIONQUERY,
        PROP_VALIDATIONQUERY_TIMEOUT,
        PROP_INITCONNECTIONSQLS,
        PROP_ACCESSTOUNDERLYINGCONNECTIONALLOWED,
        PROP_REMOVEABANDONED,
        PROP_REMOVEABANDONEDTIMEOUT,
        PROP_LOGABANDONED,
        PROP_POOLPREPAREDSTATEMENTS,
        PROP_MAXOPENPREPAREDSTATEMENTS,
        PROP_CONNECTIONPROPERTIES
    };

    // -------------------------------------------------- ObjectFactory Methods

    /**
     * <p>Create and return a new <code>BasicDataSource</code> instance.  If no
     * instance can be created, return <code>null</code> instead.</p>
     *
     * @param obj The possibly null object containing location or
     *  reference information that can be used in creating an object
     * @param name The name of this object relative to <code>nameCtx</code>
     * @param nameCtx The context relative to which the <code>name</code>
     *  parameter is specified, or <code>null</code> if <code>name</code>
     *  is relative to the default initial context
     * @param environment The possibly null environment that is used in
     *  creating this object
     *
     * @exception Exception if an exception occurs creating the instance
     */
    public Object getObjectInstance(Object obj, Name name, Context nameCtx,
                                    Hashtable environment)
        throws Exception {

        // We only know how to deal with <code>javax.naming.Reference</code>s
        // that specify a class name of "javax.sql.DataSource"
        if ((obj == null) || !(obj instanceof Reference)) {
            return null;
        }
        Reference ref = (Reference) obj;
        if (!"javax.sql.DataSource".equals(ref.getClassName())) {
            return null;
        }

        Properties properties = new Properties();
        for (int i = 0 ; i < ALL_PROPERTIES.length ; i++) {
            String propertyName = ALL_PROPERTIES[i];
            RefAddr ra = ref.get(propertyName);
            if (ra != null) {
                String propertyValue = ra.getContent().toString();
                properties.setProperty(propertyName, propertyValue);
            }
        }

        return createDataSource(properties);
    }

    /**
     * Creates and configures a {@link BasicDataSource} instance based on the
     * given properties.
     * 
     * @param properties the datasource configuration properties
     * @throws Exception if an error occurs creating the data source
     */
    public static DataSource createDataSource(Properties properties) throws Exception {
        BasicDataSource dataSource = new BasicDataSource();
        String value = null;

        value = properties.getProperty(PROP_DEFAULTAUTOCOMMIT);
        if (value != null) {
            dataSource.setDefaultAutoCommit(Boolean.valueOf(value).booleanValue());
        }

        value = properties.getProperty(PROP_DEFAULTREADONLY);
        if (value != null) {
            dataSource.setDefaultReadOnly(Boolean.valueOf(value).booleanValue());
        }

        value = properties.getProperty(PROP_DEFAULTTRANSACTIONISOLATION);
        if (value != null) {
            int level = PoolableConnectionFactory.UNKNOWN_TRANSACTIONISOLATION;
            if ("NONE".equalsIgnoreCase(value)) {
                level = Connection.TRANSACTION_NONE;
            }
            else if ("READ_COMMITTED".equalsIgnoreCase(value)) {
                level = Connection.TRANSACTION_READ_COMMITTED;
            }
            else if ("READ_UNCOMMITTED".equalsIgnoreCase(value)) {
                level = Connection.TRANSACTION_READ_UNCOMMITTED;
            }
            else if ("REPEATABLE_READ".equalsIgnoreCase(value)) {
                level = Connection.TRANSACTION_REPEATABLE_READ;
            }
            else if ("SERIALIZABLE".equalsIgnoreCase(value)) {
                level = Connection.TRANSACTION_SERIALIZABLE;
            }
            else {
                try {
                    level = Integer.parseInt(value);
                } catch (NumberFormatException e) {
                    System.err.println("Could not parse defaultTransactionIsolation: " + value);
                    System.err.println("WARNING: defaultTransactionIsolation not set");
                    System.err.println("using default value of database driver");
                    level = PoolableConnectionFactory.UNKNOWN_TRANSACTIONISOLATION;
                }
            }
            dataSource.setDefaultTransactionIsolation(level);
        }

        value = properties.getProperty(PROP_DEFAULTCATALOG);
        if (value != null) {
            dataSource.setDefaultCatalog(value);
        }

        value = properties.getProperty(PROP_DRIVERCLASSNAME);
        if (value != null) {
            dataSource.setDriverClassName(value);
        }

        value = properties.getProperty(PROP_MAXACTIVE);
        if (value != null) {
            dataSource.setMaxActive(Integer.parseInt(value));
        }

        value = properties.getProperty(PROP_MAXIDLE);
        if (value != null) {
            dataSource.setMaxIdle(Integer.parseInt(value));
        }

        value = properties.getProperty(PROP_MINIDLE);
        if (value != null) {
            dataSource.setMinIdle(Integer.parseInt(value));
        }

        value = properties.getProperty(PROP_INITIALSIZE);
        if (value != null) {
            dataSource.setInitialSize(Integer.parseInt(value));
        }

        value = properties.getProperty(PROP_MAXWAIT);
        if (value != null) {
            dataSource.setMaxWait(Long.parseLong(value));
        }

        value = properties.getProperty(PROP_TESTONBORROW);
        if (value != null) {
            dataSource.setTestOnBorrow(Boolean.valueOf(value).booleanValue());
        }

        value = properties.getProperty(PROP_TESTONRETURN);
        if (value != null) {
            dataSource.setTestOnReturn(Boolean.valueOf(value).booleanValue());
        }

        value = properties.getProperty(PROP_TIMEBETWEENEVICTIONRUNSMILLIS);
        if (value != null) {
            dataSource.setTimeBetweenEvictionRunsMillis(Long.parseLong(value));
        }

        value = properties.getProperty(PROP_NUMTESTSPEREVICTIONRUN);
        if (value != null) {
            dataSource.setNumTestsPerEvictionRun(Integer.parseInt(value));
        }

        value = properties.getProperty(PROP_MINEVICTABLEIDLETIMEMILLIS);
        if (value != null) {
            dataSource.setMinEvictableIdleTimeMillis(Long.parseLong(value));
        }

        value = properties.getProperty(PROP_TESTWHILEIDLE);
        if (value != null) {
            dataSource.setTestWhileIdle(Boolean.valueOf(value).booleanValue());
        }

        value = properties.getProperty(PROP_PASSWORD);
        if (value != null) {
            dataSource.setPassword(value);
        }

        value = properties.getProperty(PROP_URL);
        if (value != null) {
            dataSource.setUrl(value);
        }

        value = properties.getProperty(PROP_USERNAME);
        if (value != null) {
            dataSource.setUsername(value);
        }

        value = properties.getProperty(PROP_VALIDATIONQUERY);
        if (value != null) {
            dataSource.setValidationQuery(value);
        }

        value = properties.getProperty(PROP_VALIDATIONQUERY_TIMEOUT);
        if (value != null) {
            dataSource.setValidationQueryTimeout(Integer.parseInt(value));
        }
        
        value = properties.getProperty(PROP_ACCESSTOUNDERLYINGCONNECTIONALLOWED);
        if (value != null) {
            dataSource.setAccessToUnderlyingConnectionAllowed(Boolean.valueOf(value).booleanValue());
        }

        value = properties.getProperty(PROP_REMOVEABANDONED);
        if (value != null) {
            dataSource.setRemoveAbandoned(Boolean.valueOf(value).booleanValue());
        }

        value = properties.getProperty(PROP_REMOVEABANDONEDTIMEOUT);
        if (value != null) {     
            dataSource.setRemoveAbandonedTimeout(Integer.parseInt(value));
        }

        value = properties.getProperty(PROP_LOGABANDONED);
        if (value != null) {
            dataSource.setLogAbandoned(Boolean.valueOf(value).booleanValue());
        }

        value = properties.getProperty(PROP_POOLPREPAREDSTATEMENTS);
        if (value != null) {
            dataSource.setPoolPreparedStatements(Boolean.valueOf(value).booleanValue());
        }

        value = properties.getProperty(PROP_MAXOPENPREPAREDSTATEMENTS);
        if (value != null) {
            dataSource.setMaxOpenPreparedStatements(Integer.parseInt(value));
        }

        value = properties.getProperty(PROP_INITCONNECTIONSQLS);
        if (value != null) {
            StringTokenizer tokenizer = new StringTokenizer(value, ";");
            dataSource.setConnectionInitSqls(Collections.list(tokenizer));
        }

        value = properties.getProperty(PROP_CONNECTIONPROPERTIES);
        if (value != null) {
          Properties p = getProperties(value);
          Enumeration e = p.propertyNames();
          while (e.hasMoreElements()) {
            String propertyName = (String) e.nextElement();
            dataSource.addConnectionProperty(propertyName, p.getProperty(propertyName));
          }
        }

        // DBCP-215
        // Trick to make sure that initialSize connections are created
        if (dataSource.getInitialSize() > 0) {
            dataSource.getLogWriter();
        }

        // Return the configured DataSource instance
        return dataSource;
    }

    /**
     * <p>Parse properties from the string. Format of the string must be [propertyName=property;]*<p>
     * @param propText
     * @return Properties
     * @throws Exception
     */
    static private Properties getProperties(String propText) throws Exception {
      Properties p = new Properties();
      if (propText != null) {
        p.load(new ByteArrayInputStream(propText.replace(';', '
').getBytes()));
      }
      return p;
    }
}