正在初始化 c3p0 池...超时

Question

我正在尝试使用休眠和 c3p0 连接到 mysql 数据库，但出现服务器超时错误（即使我将超时增加到几分钟）

我正在使用 mysql、eclipse、maven、spring、tomcat 8.5、hibernate 和 c3p0。

这是我的 .properties 文件

# MySQL properties
mysql.driver=com.mysql.cj.jdbc.Driver
mysql.user=root
mysql.password=root
# Hibernate properties
hibernate.show_sql=true
hibernate.hbm2ddl.auto=create
# C3P0 properties
hibernate.c3p0.min_size=5
hibernate.c3p0.max_size=20
hibernate.c3p0.acquire_increment=1
hibernate.c3p0.timeout=180
hibernate.c3p0.max_statements=150

配置

package com.bookshop.configuration;
import java.util.Properties;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.ComponentScans;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.core.env.Environment;
import org.springframework.orm.hibernate5.HibernateTransactionManager;
import org.springframework.orm.hibernate5.LocalSessionFactoryBean;
import org.springframework.transaction.annotation.EnableTransactionManagement;
import static org.hibernate.cfg.Environment.*;

@Configuration
@PropertySource("classpath:db.properties")
@EnableTransactionManagement
@ComponentScans(value = {
        @ComponentScan("com.bookshop.model"),
        @ComponentScan("com.bookshop.dao"),
        @ComponentScan("com.bookshop.service")
})
public class AppConfig {

    @Autowired
    private Environment env;

    @Bean
    public LocalSessionFactoryBean getSessionFactory() {
        LocalSessionFactoryBean factoryBean = new LocalSessionFactoryBean();
        Properties prop = new Properties();

        // Setting JDBC properties
        prop.put(DRIVER, env.getProperty("mysql.driver"));
        prop.put(URL, env.getProperty("mysql.url"));
        prop.put(USER, env.getProperty("mysql.user"));
        prop.put(PASS, env.getProperty("mysql.password"));

        // Setting hibernate properties
        prop.put(SHOW_SQL, env.getProperty("hibernate.show_sql"));
        prop.put(HBM2DDL_AUTO, env.getProperty("hibernate.hbm2ddl.auto"));

        // Setting C3P0 properties
        prop.put(C3P0_MIN_SIZE, env.getProperty("hibernate.c3p0.min_size"));
        prop.put(C3P0_MAX_SIZE, env.getProperty("hibernate.c3p0.max_size"));
        prop.put(C3P0_ACQUIRE_INCREMENT, env.getProperty("hibernate.c3p0.acquire_increment"));
        prop.put(C3P0_TIMEOUT, env.getProperty("hibernate.c3p0.timeout"));
        prop.put(C3P0_MAX_STATEMENTS, env.getProperty("hibernate.c3p0.max_statements")); 


        factoryBean.setHibernateProperties(prop);
        factoryBean.setPackagesToScan("com.bookshop.model");
        return factoryBean;
    }

     @Bean
     public HibernateTransactionManager getTransactionManager() {
        HibernateTransactionManager transactionManager = new HibernateTransactionManager();
       transactionManager.setSessionFactory(getSessionFactory().getObject());
        return transactionManager;
     }
}

这些日志行后发生服务器超时

...
INFO: Root WebApplicationContext: initialization started
jan 13, 2019 7:33:51 PM org.springframework.web.context.support.AnnotationConfigWebApplicationContext prepareRefresh
INFO: Refreshing Root WebApplicationContext: startup date [Sun Jan 13 19:33:51 MSK 2019]; root of context hierarchy
jan 13, 2019 7:33:51 PM    org.springframework.web.context.support.AnnotationConfigWebApplicationContext loadBeanDefinitions
INFO: Registering annotated classes: [class com.bookshop.configuration.AppConfig]
jan 13, 2019 7:33:52 PM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {5.4.0.CR2}
jan 13, 2019 7:33:52 PM org.hibernate.cfg.Environment <clinit>
INFO: HHH000206: hibernate.properties not found
jan 13, 2019 7:33:52 PM org.hibernate.annotations.common.reflection.java.JavaReflectionManager <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {5.1.0.Final}
jan 13, 2019 7:33:53 PM org.hibernate.c3p0.internal.C3P0ConnectionProvider configure
INFO: HHH010002: C3P0 using driver: com.mysql.cj.jdbc.Driver at URL: jdbc:mysql://localhost:3306/bookshop?autoReconnect=true&useSSL=false
jan 13, 2019 7:33:53 PM org.hibernate.c3p0.internal.C3P0ConnectionProvider configure
INFO: HHH10001001: Connection properties: {user=root, password=****}
jan 13, 2019 7:33:53 PM org.hibernate.c3p0.internal.C3P0ConnectionProvider configure
INFO: HHH10001003: Autocommit mode: false
jan 13, 2019 7:33:53 PM com.mchange.v2.log.MLog 
INFO: MLog clients using java 1.4+ standard logging.
jan 13, 2019 7:33:53 PM com.mchange.v2.c3p0.C3P0Registry 
INFO: Initializing c3p0-0.9.5.2 [built 08-December-2015 22:06:04 -0800; debug? true; trace: 10]
jan 13, 2019 7:33:53 PM org.hibernate.c3p0.internal.C3P0ConnectionProvider configure
INFO: HHH10001007: JDBC isolation level: <unknown>
jan 13, 2019 7:33:53 PM com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource
INFO: Initializing c3p0 pool...
com.mchange.v2.c3p0.PoolBackedDataSource@27499807
connectionPoolDataSource -> com.mchange.v2.c3p0.WrapperConnectionPoolDataSource@69d301cd
[ acquireIncrement -> 1,
acquireRetryAttempts -> 30,
acquireRetryDelay -> 1000,
autoCommitOnClose -> false,
automaticTestTable -> null,
breakAfterAcquireFailure -> false,
checkoutTimeout -> 0,
connectionCustomizerClassName -> null,
connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester,
contextClassLoaderSource -> caller, 
debugUnreturnedConnectionStackTraces -> false,
factoryClassLocation -> null, 
forceIgnoreUnresolvedTransactions -> false,
forceSynchronousCheckins -> false, 
identityToken -> 1hge0wga0jzt7ghyoftwg|30ba8455, 
idleConnectionTestPeriod -> 0, 
initialPoolSize -> 5, 
maxAdministrativeTaskTime -> 0, 
maxConnectionAge -> 0, 
maxIdleTime -> 1800, 
maxIdleTimeExcessConnections -> 0, 
maxPoolSize -> 20, 
maxStatements -> 150, 
maxStatementsPerConnection -> 0, 
minPoolSize -> 5,
nestedDataSource -> com.mchange.v2.c3p0.DriverManagerDataSource@2a1a6154 
[ description -> null, 
driverClass -> null, 
factoryClassLocation -> null, 
forceUseNamedDriverClass -> false, 
identityToken -> 1hge0wga0jzt7ghyoftwg|15fd41d6, 
jdbcUrl -> jdbc:mysql://localhost:3306/bookshop?autoReconnect=true&useSSL=false, 
properties -> {user=******, password=******} ], 
preferredTestQuery -> null, 
privilegeSpawnedThreads -> false, 
propertyCycle -> 0, 
statementCacheNumDeferredCloseThreads -> 0, 
testConnectionOnCheckin -> false, 
testConnectionOnCheckout -> false, 
unreturnedConnectionTimeout -> 0, 
usesTraditionalReflectiveProxies -> false; 
userOverrides: {} ], 
dataSourceName -> null, 
extensions -> {}, 
factoryClassLocation -> null, 
identityToken -> 1hge0wga0jzt7ghyoftwg|6b84d329, 
numHelperThreads -> 3 ]

（我正在学习并且有人关注了这些视频：https://www.youtube.com/watch?v=OyLF640v7WE）

谁能告诉我哪里出了问题？

Answer 1

终于解决了

日志中写有 'hibernate.properties not found'，所以我将 .properties 文件从 db.properties 重命名为 hibernate.properties，我还将属性文件方言添加为

hibernate.dialect=org.hibernate.dialect.MySQL5Dialect

并将其添加到 AppConfig class:

prop.put(DIALECT, env.getProperty("hibernate.dialect"));

现在一切正常。

正在初始化 c3p0 池...超时

Initializing c3p0 pool... timeout

mysql

eclipse

tomcat

hibernate

c3p0