Spring加载Hibernate失败：Error creating bean with name 'sessionFactory' defined in ServletContext... Null

      昨天突然发现Spring加载Hibernate触发NullPointerException 异常：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in ServletContext resource [/WEB-INF/spring-config/spring-hibernate.xml]: Invocation of init method failed; nested exception is java.lang.NullPointerException
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1578)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
	at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:305)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:301)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:196)
.....
Caused by: java.lang.NullPointerException
	at org.postgresql.jdbc.TypeInfoCache.getSQLType(TypeInfoCache.java:182)
	at org.postgresql.jdbc.TypeInfoCache.getSQLType(TypeInfoCache.java:178)
	at org.postgresql.jdbc.TypeInfoCache.requiresQuoting(TypeInfoCache.java:851)
	at org.postgresql.jdbc.PgDatabaseMetaData.getTypeInfo(PgDatabaseMetaData.java:2785)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.logicalcobwebs.proxool.ProxyDatabaseMetaData.intercept(ProxyDatabaseMetaData.java:60)
	at $java.sql.Wrapper$$EnhancerByProxool$$5b0813c3.getTypeInfo()
	at org.hibernate.engine.jdbc.spi.TypeInfo.extractTypeInfo(TypeInfo.java:101)
	at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:163)
	at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:111)
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:234)
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:206)
	at org.hibernate.cfg.Configuration.buildTypeRegistrations(Configuration.java:1885)
	at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1843)
	at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1928)
	at org.springframework.orm.hibernate4.LocalSessionFactoryBuilder.buildSessionFactory(LocalSessionFactoryBuilder.java:372)
	at org.springframework.orm.hibernate4.LocalSessionFactoryBean.buildSessionFactory(LocalSessionFactoryBean.java:454)
	at org.springframework.orm.hibernate4.LocalSessionFactoryBean.afterPropertiesSet(LocalSessionFactoryBean.java:439)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1637)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1574)
	... 28 more

          感觉相当郁闷，因为不是第一天用啊，这个spring+hibernate的配置一直没问题，后来花了两个小时不断查度娘和google，未果。心有不甘，打开spring-hibernate.xml仔细看：

    
	
	
	  
	
	
	  
		
		 
							
				com.alco.bms.entities				
									
		
		
			
				org.hibernate.dialect.PostgreSQLDialect
				
				update
				
				 
				true
				
                
                 
                true
                
                
                
                false
                
                false
                
                100
                                
                50
                
                false
                
                auto
                false
                
                TRACE
			
    
	



    


    
        
    
    
    
    
    
          
    
     

    在spring里面配置LocalSessionFactoryBean，也就设置了3个属性，发生NullPointerException应该就这三个其中一个是null值引发的吧，于是写了一个壳MyLocalSessionFactoryBean是extends LocalSessionFactoryBean的，我在新类里面调试一下看传进入的是不是null值：

package com.freestyle.common.spring;

import java.util.Properties;

import javax.sql.DataSource;

import org.springframework.orm.hibernate4.LocalSessionFactoryBean;

import com.freestyle.utils.Util;



public class MyLocalSessionFactoryBean extends LocalSessionFactoryBean {
	public void setDataSource(DataSource dataSource){
		if (dataSource==null){
			Util.sleep(100);
		}
		System.out.println(dataSource);
		super.setDataSource(dataSource);		
	}
	public void setPackagesToScan(String ...packagesToScan){
		if (packagesToScan==null){
			Util.sleep(100);
		}
		System.out.println(packagesToScan);
		super.setPackagesToScan(packagesToScan);
	}
	public void setHibernateProperties(Properties hibernateProperties){
		if (hibernateProperties==null){
			Util.sleep(100);
		}
		System.out.println(hibernateProperties);
		super.setHibernateProperties(hibernateProperties);
	}

	public MyLocalSessionFactoryBean() {
		super();
		
		// TODO Auto-generated constructor stub
	}

}

将.sleep处都打上断点，将spring-hibernate.xml里面的sessionFactory类换成MyLocalSessionFactoryBean再调试，发现传进来的参数都不为null啊，这下傻了。

              后来再看Exception的细节，发现这行：at org.postgresql.jdbc.TypeInfoCache.getSQLType(TypeInfoCache.java:182)， 说明可能是数据库或jdbc驱动方面发生的exception，应该与spring/hibernate没关系，于是将proxool.xml数据源切换到另一服务器（两个服务器的database结构一样）再运行，居然没事！！！

              这有点不解，最后没招了，只有怀疑jdbc驱动，因为用的是postgresql数据库，服务器是postgresql 9.4 64bit，jdbc驱动用的是postgresql-9.4.1208.jre6.jar，后来上postgresql官网下了postgresql-9.4.1209.jar 换上。 一切OK!!! 

             开始不相信，于是再换回版本号为1208的jar, 出exception,换1209的jar , OK!!

             原来你是这样的PostgreSQL 驱动啊！！！