• day39-Spring 13-Spring的JDBC模板:默认连接池的配置


    Spring内置的连接池DriverManagerDataSource的源码.

    /*
     * Copyright 2002-2008 the original author or authors.
     *
     * Licensed 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.springframework.jdbc.datasource;
    
    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.SQLException;
    import java.util.Properties;
    
    import org.springframework.util.Assert;
    import org.springframework.util.ClassUtils;
    
    /**
     * Simple implementation of the standard JDBC {@link javax.sql.DataSource} interface,
     * configuring the plain old JDBC {@link java.sql.DriverManager} via bean properties, and
     * returning a new {@link java.sql.Connection} from every <code>getConnection</code> call.
     *
     * <p><b>NOTE: This class is not an actual connection pool; it does not actually
     * pool Connections.</b> It just serves as simple replacement for a full-blown
     * connection pool, implementing the same standard interface, but creating new
     * Connections on every call.
     *
     * <p>Useful for test or standalone environments outside of a J2EE container, either
     * as a DataSource bean in a corresponding ApplicationContext or in conjunction with
     * a simple JNDI environment. Pool-assuming <code>Connection.close()</code> calls will
     * simply close the Connection, so any DataSource-aware persistence code should work.
     *
     * <p><b>NOTE: Within special class loading environments such as OSGi, this class
     * is effectively superseded by {@link SimpleDriverDataSource} due to general class
     * loading issues with the JDBC DriverManager that be resolved through direct Driver
     * usage (which is exactly what SimpleDriverDataSource does).</b>
     *
     * <p>In a J2EE container, it is recommended to use a JNDI DataSource provided by
     * the container. Such a DataSource can be exposed as a DataSource bean in a Spring
     * ApplicationContext via {@link org.springframework.jndi.JndiObjectFactoryBean},
     * for seamless switching to and from a local DataSource bean like this class.
     * For tests, you can then either set up a mock JNDI environment through Spring's
     * {@link org.springframework.mock.jndi.SimpleNamingContextBuilder}, or switch the
     * bean definition to a local DataSource (which is simpler and thus recommended).
     *
     * <p>If you need a "real" connection pool outside of a J2EE container, consider
     * <a href="http://jakarta.apache.org/commons/dbcp">Apache's Jakarta Commons DBCP</a>
     * or <a href="http://sourceforge.net/projects/c3p0">C3P0</a>.
     * Commons DBCP's BasicDataSource and C3P0's ComboPooledDataSource are full
     * connection pool beans, supporting the same basic properties as this class
     * plus specific settings (such as minimal/maximal pool size etc).
     *
     * @author Juergen Hoeller
     * @since 14.03.2003
     * @see SimpleDriverDataSource
     */
    public class DriverManagerDataSource extends AbstractDriverBasedDataSource {
    
        /**
         * Constructor for bean-style configuration.
         */
        public DriverManagerDataSource() {
        }
    
        /**
         * Create a new DriverManagerDataSource with the given JDBC URL,
         * not specifying a username or password for JDBC access.
         * @param url the JDBC URL to use for accessing the DriverManager
         * @see java.sql.DriverManager#getConnection(String)
         */
        public DriverManagerDataSource(String url) {
            setUrl(url);
        }
    
        /**
         * Create a new DriverManagerDataSource with the given standard
         * DriverManager parameters.
         * @param url the JDBC URL to use for accessing the DriverManager
         * @param username the JDBC username to use for accessing the DriverManager
         * @param password the JDBC password to use for accessing the DriverManager
         * @see java.sql.DriverManager#getConnection(String, String, String)
         */
        public DriverManagerDataSource(String url, String username, String password) {
            setUrl(url);
            setUsername(username);
            setPassword(password);
        }
    
        /**
         * Create a new DriverManagerDataSource with the given JDBC URL,
         * not specifying a username or password for JDBC access.
         * @param url the JDBC URL to use for accessing the DriverManager
         * @param conProps JDBC connection properties
         * @see java.sql.DriverManager#getConnection(String)
         */
        public DriverManagerDataSource(String url, Properties conProps) {
            setUrl(url);
            setConnectionProperties(conProps);
        }
    
        /**
         * Create a new DriverManagerDataSource with the given standard
         * DriverManager parameters.
         * @param driverClassName the JDBC driver class name
         * @param url the JDBC URL to use for accessing the DriverManager
         * @param username the JDBC username to use for accessing the DriverManager
         * @param password the JDBC password to use for accessing the DriverManager
         * @deprecated since Spring 2.5. DriverManagerDataSource is primarily
         * intended for accessing <i>pre-registered</i> JDBC drivers.
         * If you need to register a new driver, consider using
         * {@link SimpleDriverDataSource} instead.
         */
        @Deprecated
        public DriverManagerDataSource(String driverClassName, String url, String username, String password) {
            setDriverClassName(driverClassName);
            setUrl(url);
            setUsername(username);
            setPassword(password);
        }
    
    
        /**
         * Set the JDBC driver class name. This driver will get initialized
         * on startup, registering itself with the JDK's DriverManager.
         * <p><b>NOTE: DriverManagerDataSource is primarily intended for accessing
         * <i>pre-registered</i> JDBC drivers.</b> If you need to register a new driver,
         * consider using {@link SimpleDriverDataSource} instead. Alternatively, consider
         * initializing the JDBC driver yourself before instantiating this DataSource.
         * The "driverClassName" property is mainly preserved for backwards compatibility,
         * as well as for migrating between Commons DBCP and this DataSource.
         * @see java.sql.DriverManager#registerDriver(java.sql.Driver)
         * @see SimpleDriverDataSource
         */
        public void setDriverClassName(String driverClassName) {
            Assert.hasText(driverClassName, "Property 'driverClassName' must not be empty");
            String driverClassNameToUse = driverClassName.trim();
            try {
                Class.forName(driverClassNameToUse, true, ClassUtils.getDefaultClassLoader());
            }
            catch (ClassNotFoundException ex) {
                throw new IllegalStateException("Could not load JDBC driver class [" + driverClassNameToUse + "]", ex);
            }
            if (logger.isInfoEnabled()) {
                logger.info("Loaded JDBC driver: " + driverClassNameToUse);
            }
        }
    
    
        @Override
        protected Connection getConnectionFromDriver(Properties props) throws SQLException {
            String url = getUrl();
            if (logger.isDebugEnabled()) {
                logger.debug("Creating new JDBC DriverManager Connection to [" + url + "]");
            }
            return getConnectionFromDriverManager(url, props);
        }
    
        /**
         * Getting a Connection using the nasty static from DriverManager is extracted
         * into a protected method to allow for easy unit testing.
         * @see java.sql.DriverManager#getConnection(String, java.util.Properties)
         */
        protected Connection getConnectionFromDriverManager(String url, Properties props) throws SQLException {
            return DriverManager.getConnection(url, props);
        }
    
    }
    DriverManagerDataSource的父类AbstractDriverBasedDataSource的源码
    /*
    * Copyright 2002-2008 the original author or authors. * * Licensed 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.springframework.jdbc.datasource; import java.sql.Connection; import java.sql.SQLException; import java.util.Properties; import org.springframework.util.Assert; /** * Abstract base class for JDBC {@link javax.sql.DataSource} implementations * that operate on a JDBC {@link java.sql.Driver}. * * @author Juergen Hoeller * @since 2.5.5 * @see SimpleDriverDataSource * @see DriverManagerDataSource */ public abstract class AbstractDriverBasedDataSource extends AbstractDataSource { private String url; private String username; private String password; private Properties connectionProperties; /** * Set the JDBC URL to use for connecting through the Driver. * @see java.sql.Driver#connect(String, java.util.Properties) */ public void setUrl(String url) { Assert.hasText(url, "Property 'url' must not be empty"); this.url = url.trim(); } /** * Return the JDBC URL to use for connecting through the Driver. */ public String getUrl() { return this.url; } /** * Set the JDBC username to use for connecting through the Driver. * @see java.sql.Driver#connect(String, java.util.Properties) */ public void setUsername(String username) { this.username = username; } /** * Return the JDBC username to use for connecting through the Driver. */ public String getUsername() { return this.username; } /** * Set the JDBC password to use for connecting through the Driver. * @see java.sql.Driver#connect(String, java.util.Properties) */ public void setPassword(String password) { this.password = password; } /** * Return the JDBC password to use for connecting through the Driver. */ public String getPassword() { return this.password; } /** * Specify arbitrary connection properties as key/value pairs, * to be passed to the Driver. * <p>Can also contain "user" and "password" properties. However, * any "username" and "password" bean properties specified on this * DataSource will override the corresponding connection properties. * @see java.sql.Driver#connect(String, java.util.Properties) */ public void setConnectionProperties(Properties connectionProperties) { this.connectionProperties = connectionProperties; } /** * Return the connection properties to be passed to the Driver, if any. */ public Properties getConnectionProperties() { return this.connectionProperties; } /** * This implementation delegates to <code>getConnectionFromDriver</code>, * using the default username and password of this DataSource. * @see #getConnectionFromDriver(String, String) * @see #setUsername * @see #setPassword */ public Connection getConnection() throws SQLException { return getConnectionFromDriver(getUsername(), getPassword()); } /** * This implementation delegates to <code>getConnectionFromDriver</code>, * using the given username and password. * @see #getConnectionFromDriver(String, String) */ public Connection getConnection(String username, String password) throws SQLException { return getConnectionFromDriver(username, password); } /** * Build properties for the Driver, including the given username and password (if any), * and obtain a corresponding Connection. * @param username the name of the user * @param password the password to use * @return the obtained Connection * @throws SQLException in case of failure * @see java.sql.Driver#connect(String, java.util.Properties) */ protected Connection getConnectionFromDriver(String username, String password) throws SQLException { Properties props = new Properties(getConnectionProperties()); if (username != null) { props.setProperty("user", username); } if (password != null) { props.setProperty("password", password); } return getConnectionFromDriver(props); } /** * Obtain a Connection using the given properties. * <p>Template method to be implemented by subclasses. * @param props the merged connection properties * @return the obtained Connection * @throws SQLException in case of failure */ protected abstract Connection getConnectionFromDriver(Properties props) throws SQLException; }

        public void setDriverClassName(String driverClassName) {
            Assert.hasText(driverClassName, "Property 'driverClassName' must not be empty");
            String driverClassNameToUse = driverClassName.trim();
            try {
    public abstract class AbstractDriverBasedDataSource extends AbstractDataSource {
    
        private String url;
    
        private String username;
    
        private String password;
    
        private Properties connectionProperties;
        <!-- 配置Spring默认的连接池 -->
        <!-- 这个类由Spring来帮我们创建,它默认情况下只创建一次,因为是单例的. -->
        <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        
            <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
            <property name="url" value="jdbc:mysql:///spring3_day02"></property>
            <property name="username" value="root"></property>
            <property name="password" value="123"></property>
            
        </bean>
        <!-- 定义jdbctemplate -->
        <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
              <property name="dataSource" ref="dataSource"></property><!-- 把上面定义好的连接池注入进来了 -->
        </bean>

    7:26:03,403  INFO XmlBeanDefinitionReader:315 - Loading XML bean definitions from class path resource [applicationContext.xml]
    17:26:03,514  INFO GenericApplicationContext:510 - Refreshing org.springframework.context.support.GenericApplicationContext@1fa78298: startup date [Fri May 05 17:26:03 CST 2017]; root of context hierarchy
    17:26:03,595  INFO DefaultListableBeanFactory:577 - Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@63a52fe6: defining beans [dataSource,jdbcTemplate,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.annotation.ConfigurationClassPostProcessor.importAwareProcessor]; root of factory hierarchy
    17:26:03,633  INFO DriverManagerDataSource:153 - Loaded JDBC driver: com.mysql.jdbc.Driver
    17:26:03,998  INFO GenericApplicationContext:1042 - Closing org.springframework.context.support.GenericApplicationContext@1fa78298: startup date [Fri May 05 17:26:03 CST 2017]; root of context hierarchy
    17:26:03,999  INFO DefaultListableBeanFactory:444 - Destroying singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@63a52fe6: defining beans [dataSource,jdbcTemplate,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.annotation.ConfigurationClassPostProcessor.importAwareProcessor]; root of factory hierarchy

    不会把SQL语句打印出来,因为它不是Hibernate.


    package cn.itcast.spring3.demo1;
    
    import java.sql.DriverManager;
    
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.beans.factory.annotation.Qualifier;
    import org.springframework.jdbc.core.JdbcTemplate;
    import org.springframework.jdbc.datasource.DriverManagerDataSource;
    import org.springframework.test.context.ContextConfiguration;
    import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
    import org.springframework.transaction.jta.SpringJtaSynchronizationAdapter;
    @RunWith(SpringJUnit4ClassRunner.class)
    @ContextConfiguration("classpath:applicationContext.xml")
    public class SpringTest1 {
        
        @Autowired
        @Qualifier("jdbcTemplate")
        private JdbcTemplate jdbcTemplate;//注入Jdbc模板
        @Test
        public void demo2(){
            jdbcTemplate.execute("create table user (id int primary key auto_increment,name varchar(20))");
        }
        
        
        @Test
        public void demo1(){
            // 创建连接池:
            DriverManagerDataSource dataSource = new DriverManagerDataSource();//Spring自带的连接池
            // 设置参数:
            dataSource.setDriverClassName("com.mysql.jdbc.Driver");
            dataSource.setUrl("jdbc:mysql:///spring3_day02");
            dataSource.setUsername("root");
            dataSource.setPassword("");
            
            //使用JDBC的模板:
            //JdbcTemplate jdbcTemplate = new JdbcTemplate();
            //jdbcTemplate.setDataSource(dataSource);
            JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);
            jdbcTemplate.execute("create table user (id int primary key auto_increment,name varchar(20))");
        }
    }
    <?xml version="1.0" encoding="UTF-8"?>
    <!-- 引入beans的头 -->
    <beans xmlns="http://www.springframework.org/schema/beans"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="
    http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
        <!-- 配置Spring默认的连接池 -->
        <!-- 这个类由Spring来帮我们创建,它默认情况下只创建一次,因为是单例的. -->
        <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        
            <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
            <property name="url" value="jdbc:mysql:///spring3_day02"></property>
            <property name="username" value="root"></property>
            <property name="password" value=""></property>
            
        </bean>
        <!-- 定义jdbctemplate -->
        <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
              <property name="dataSource" ref="dataSource"></property><!-- 把上面定义好的连接池注入进来了 -->
        </bean>
    </beans>

     



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  • 原文地址:https://www.cnblogs.com/ZHONGZHENHUA/p/6813465.html
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