day18 16.dbcp连接池使用介绍
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(';', '\n').getBytes())); } return p; } }
