Java Spring：为什么我的容器初始化了两次？

看起来我的Spring容器初始化了两次。那不好！我发现这是在从C3P0连接池获取连接时发现的。在我的Spring上下文中有一个C3P0 ComboPooledDataSource

@Bean
@Named("comboPooledDataSource")
public ComboPooledDataSource comboPooledDataSource() {

    Properties properties = properties();

    String environment = getEnvironment();

    ComboPooledDataSource pool = new ComboPooledDataSource();
    try {
        pool.setDriverClass(properties.getProperty("com.pledgeling.platform.db.driver"));
    } catch (PropertyVetoException e) {
        e.printStackTrace();
    }
    pool.setJdbcUrl(properties.getProperty("com.company.db.dsn." + environment));
    pool.setUser(properties.getProperty("com.company.db.user." + environment));
    pool.setPassword(properties.getProperty("com.company.db.pass." + environment));
    pool.setMaxIdleTimeExcessConnections(30 * 60);
    pool.setMaxIdleTime(3 * 60 * 60);

    try {
        Connection testConnection = null;
        testConnection = pool.getConnection();
        System.out.println("Initialized Data Source " + testConnection.toString());
        testConnection.close();
    } catch (SQLException e) {
        e.printStackTrace();
    }
    return pool;
}

当容器初始化时，它可以正常工作：

Dec 03, 2013 4:43:49 PM com.mchange.v2.log.MLog <clinit>
INFO: MLog clients using java 1.4+ standard logging.
Dec 03, 2013 4:43:49 PM com.mchange.v2.c3p0.C3P0Registry banner
INFO: Initializing c3p0-0.9.1.2 [built 21-May-2007 15:04:56; debug? true; trace: 10]
Dec 03, 2013 4:43:50 PM com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource getPoolManager
INFO: Initializing c3p0 pool... com.mchange.v2.c3p0.ComboPooledDataSource [ acquireIncrement -> 3, acquireRetryAttempts -> 30, acquireRetryDelay -> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, checkoutTimeout -> 0, connectionCustomizerClassName -> null, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, dataSourceName -> z8kflt8y1fq2h6a1npdfoy|7dd8fdd6, debugUnreturnedConnectionStackTraces -> false, description -> null, driverClass -> org.postgresql.Driver, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> z8kflt8y1fq2h6a1npdfoy|7dd8fdd6, idleConnectionTestPeriod -> 0, initialPoolSize -> 3, jdbcUrl -> ..., maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 10800, maxIdleTimeExcessConnections -> 1800, maxPoolSize -> 15, maxStatements -> 0, maxStatementsPerConnection -> 0, minPoolSize -> 3, numHelperThreads -> 3, numThreadsAwaitingCheckoutDefaultUser -> 0, preferredTestQuery -> null, properties -> {user=******, password=******}, propertyCycle -> 0, testConnectionOnCheckin -> false, testConnectionOnCheckout -> false, unreturnedConnectionTimeout -> 0, usesTraditionalReflectiveProxies -> false ]
Initialized Data Source com.mchange.v2.c3p0.impl.NewProxyConnection@2df8e5e4
Dec 03, 2013 4:43:50 PM org.springframework.web.context.ContextLoader initWebApplicationContext
INFO: Root WebApplicationContext: initialization completed in 5795 ms

点击此按钮时，整个容器似乎再次初始化：

Dec 03, 2013 4:46:28 PM org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider registerDefaultFilters
INFO: JSR-330 'javax.inject.Named' annotation found and supported for component scanning
Dec 03, 2013 4:46:28 PM org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@db03ddc: startup date [Tue Dec 03 16:46:28 EST 2013]; root of context hierarchy
Dec 03, 2013 4:46:28 PM org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider registerDefaultFilters
INFO: JSR-330 'javax.inject.Named' annotation found and supported for component scanning
Dec 03, 2013 4:46:29 PM org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor <init>
INFO: JSR-330 'javax.inject.Inject' annotation found and supported for autowiring
Dec 03, 2013 4:46:29 PM org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@4c84f510: defining beans [org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,config,org.springframework.context.annotation.ConfigurationClassPostProcessor.importAwareProcessor,properties,jaxRsServer,comboPooledDataSource,cxf,jaxRsApiApplication,jsonProvider,serverHealthCheck,applicationHealthCheck]; root of factory hierarchy
Dec 03, 2013 4:46:30 PM com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource getPoolManager
INFO: Initializing c3p0 pool... com.mchange.v2.c3p0.ComboPooledDataSource [ acquireIncrement -> 3, acquireRetryAttempts -> 30, acquireRetryDelay -> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, checkoutTimeout -> 0, connectionCustomizerClassName -> null, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, dataSourceName -> z8kflt8y1fq2h6a1npdfoy|e9fd18b, debugUnreturnedConnectionStackTraces -> false, description -> null, driverClass -> org.postgresql.Driver, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> z8kflt8y1fq2h6a1npdfoy|e9fd18b, idleConnectionTestPeriod -> 0, initialPoolSize -> 3, jdbcUrl -> ... , maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 10800, maxIdleTimeExcessConnections -> 1800, maxPoolSize -> 15, maxStatements -> 0, maxStatementsPerConnection -> 0, minPoolSize -> 3, numHelperThreads -> 3, numThreadsAwaitingCheckoutDefaultUser -> 0, preferredTestQuery -> null, properties -> {user=******, password=******}, propertyCycle -> 0, testConnectionOnCheckin -> false, testConnectionOnCheckout -> false, unreturnedConnectionTimeout -> 0, usesTraditionalReflectiveProxies -> false ]
Initialized Data Source com.mchange.v2.c3p0.impl.NewProxyConnection@636ab40a

---

已注册的

ContextLoaderListener

context.addEventListener(new ContextLoaderListener());

将使用指定的

@Configuration

类初始化

注释ConfigWebApplicationContext

实例

context.setInitParameter("contextClass", AnnotationConfigWebApplicationContext.class.getName());
context.setInitParameter("contextConfigLocation", Config.class.getName());

这将加载一次上下文

然后，您还将在此处加载上下文的第二个副本

private static ApplicationContext context = new AnnotationConfigApplicationContext(Config.class);

---

当加载并初始化包含此成员的类时，将发生这种情况。

已注册的

ContextLoaderListener

context.addEventListener(new ContextLoaderListener());

将使用指定的

@Configuration

类初始化

注释ConfigWebApplicationContext

实例

context.setInitParameter("contextClass", AnnotationConfigWebApplicationContext.class.getName());
context.setInitParameter("contextConfigLocation", Config.class.getName());

这将加载一次上下文

然后，您还将在此处加载上下文的第二个副本

private static ApplicationContext context = new AnnotationConfigApplicationContext(Config.class);

---

加载并初始化包含此成员的类时会发生这种情况。

明白了，您有推荐的替代方案吗？我想有两个容器，一个用于Spring（路由、提供者）等，另一个类的类数据指向我的单例和资源。框架狂热者会谴责这是邪恶的，但我对此不感兴趣。你的想法？@davidspring不能很好地处理用于

static

成员的类。如果您需要访问

ApplicationContext

，可以创建

ApplicationContextAware

bean。明白了，您有推荐的替代方案吗？我想有两个容器，一个用于Spring（路由、提供者）等，另一个类的类数据指向我的单例和资源。框架狂热者会谴责这是邪恶的，但我对此不感兴趣。你的想法？@davidspring不能很好地处理用于

static

成员的类。如果需要访问

ApplicationContext

，可以创建

ApplicationContextAware

bean。