[英]Null Pointer Exception - spring 3
我在applicationContext.xml
文件(春季3)中使用以下語句。
<bean name="loggingAutoProxy"
class="org.springframework.aop.framework.autoproxy.BeanNameAutoProxyCreator">
在這個applicationContext文件中,當我嘗試為bean屬性名稱和引用指定其他名稱時,它返回空對象。 但是,如果我為名稱和引用提供相同的值,則它工作正常/正確返回了bean引用。 這是因為org.springframework.aop.framework.autoproxy.BeanNameAutoProxyCreator
嗎? 是,如何解決?
這不起作用(在我的Java代碼中將bean引用返回為null):
<bean id="cacheDelegate" class="com.srsa.wiradmin.delegate.CacheDelegate" >
<property name="statusDBDAO"><ref bean="BMOStatusDBDAO" /></property>
</bean>
<bean id="BMOStatusDBDAO" class="com.srsa.wiradmin.dao.StatusDBDAO">
<property name="dataSource">
<ref bean="BMOAdminDataSource" />
</property>
</bean>
<bean id="BMOAdminDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
destroy-method="close" lazy-init="default" autowire="default" dependency-check="default">
<property name="driverClass" value="${jdbc.driver}" ></property>
<property name="jdbcUrl" value="${admin.jdbc.url}" ></property>
<property name="user" value="${admin.jdbc.user}" ></property>
<property name="password" value="${admin.jdbc.password}" ></property>
<property name="initialPoolSize" value="3" ></property>
<property name="minPoolSize" value="3" ></property>
<property name="maxPoolSize" value="25" ></property>
<property name="acquireIncrement" value="1" ></property>
<property name="acquireRetryDelay" value="1000" ></property>
<property name="debugUnreturnedConnectionStackTraces" value="true" ></property>
<property name="maxIdleTime" value="300" ></property>
<property name="unreturnedConnectionTimeout" value="300000" ></property>
<property name="preferredTestQuery" value="SELECT COUNT(*) FROM LOCALE_CODE" ></property>
<property name="checkoutTimeout" value="300000" ></property>
<property name="idleConnectionTestPeriod" value="600000" ></property>
</bean>
這有效(正確返回對象):
<bean id="cacheDelegate" class="com.srsa.wiradmin.delegate.CacheDelegate" >
<property name="statusDBDAO"><ref bean="statusDBDAO" /></property>
</bean>
<bean id="statusDBDAO" class="com.srsa.wiradmin.dao.StatusDBDAO">
<property name="dataSource">
<ref bean="BMOAdminDataSource" />
</property>
</bean>
<bean id="BMOAdminDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
destroy-method="close" lazy-init="default" autowire="default" dependency-check="default">
<property name="driverClass" value="${jdbc.driver}" ></property>
<property name="jdbcUrl" value="${admin.jdbc.url}" ></property>
<property name="user" value="${admin.jdbc.user}" ></property>
<property name="password" value="${admin.jdbc.password}" ></property>
<property name="initialPoolSize" value="3" ></property>
<property name="minPoolSize" value="3" ></property>
<property name="maxPoolSize" value="25" ></property>
<property name="acquireIncrement" value="1" ></property>
<property name="acquireRetryDelay" value="1000" ></property>
<property name="debugUnreturnedConnectionStackTraces" value="true" ></property>
<property name="maxIdleTime" value="300" ></property>
<property name="unreturnedConnectionTimeout" value="300000" ></property>
<property name="preferredTestQuery" value="SELECT COUNT(*) FROM LOCALE_CODE" ></property>
<property name="checkoutTimeout" value="300000" ></property>
<property name="idleConnectionTestPeriod" value="600000" ></property>
</bean>
再見...
您的cacheDelegate
bean正在查找一個引用到ID statusDBDAO
的bean,但DAO上的ID實際上是BMOStatusDBDAO
。
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