Question

我已经在Spring配置中定义了一个数据源。

<bean id="dataSource"
    class="org.springframework.jdbc.datasource.DriverManagerDataSource">

    <property name="driverClassName" value="com.mysql.jdbc.Driver" />
    <property name="url" value="jdbc:mysql://localhost:3306/db" />
    <property name="username" value="root" />
    <property name="password" value="password" />
</bean>

对于LOG4J2 JDBCAppender，我知道我们需要获取数据源：

 <JDBC name="databaseAppender" tableName="error_log">
        <ConnectionFactory class="net.example.db"
            method="getDatabaseConnection" />
        <Column name="EVENT_DATE" isEventTimestamp="true" />
        <Column name="LEVEL" pattern="%level" />
        <Column name="LOGGER" pattern="%logger" />
        <Column name="MESSAGE" pattern="%message" />
        <Column name="THROWABLE" pattern="%ex{full}" />
    </JDBC>

我已将软件包添加到组件扫描中：

<context:component-scan base-package="com.test,net.example.db" />

在ConnectionFactory类中添加注释作为Component

import java.sql.Connection;
import javax.sql.DataSource;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

@Component
public class ConnectionFactory {

    @Autowired
    private DataSource dataSource;

    public void setDataSource(DataSource dataSource) {
        this.dataSource = dataSource;
    }

    public Connection getDatabaseConnection() throws Exception {
        return dataSource.getConnection();
    }

}

但是，当调用getDatabaseConnection（）

时，我得到null

2017-01-14 14:17:24,579 localhost-startStop-1 ERROR JdbcDatabaseManager jdbcManager{ description=databaseAppender, bufferSize=0, connectionSource=factory{ public static java.sql.Connection net.example.db.ConnectionFactory.getDatabaseConnection() }, tableName=error_log, columns=[ { name=EVENT_DATE, layout=null, literal=null, timestamp=true }, { name=LEVEL, layout=%level, literal=null, timestamp=false }, { name=LOGGER, layout=%logger, literal=null, timestamp=false }, { name=MESSAGE, layout=%message, literal=null, timestamp=false }, { name=THROWABLE, layout=%ex{full}, literal=null, timestamp=false } ] } Could not perform database startup operations: java.sql.SQLException: Failed to obtain connection from factory method. java.sql.SQLException: Failed to obtain connection from factory method.
    at org.apache.logging.log4j.core.appender.db.jdbc.FactoryMethodConnectionSource$1.getConnection(FactoryMethodConnectionSource.java:107)
    at org.apache.logging.log4j.core.appender.db.jdbc.FactoryMethodConnectionSource.getConnection(FactoryMethodConnectionSource.java:53)
    at org.apache.logging.log4j.core.appender.db.jdbc.JdbcDatabaseManager.startupInternal(JdbcDatabaseManager.java:60)
    at org.apache.logging.log4j.core.appender.db.AbstractDatabaseManager.startup(AbstractDatabaseManager.java:65)
    at org.apache.logging.log4j.core.appender.db.AbstractDatabaseAppender.start(AbstractDatabaseAppender.java:89)
    at org.apache.logging.log4j.core.config.AbstractConfiguration.start(AbstractConfiguration.java:255)
    at org.apache.logging.log4j.core.LoggerContext.setConfiguration(LoggerContext.java:530)
    at org.apache.logging.log4j.core.LoggerContext.start(LoggerContext.java:258)
    at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:239)
    at org.apache.logging.log4j.core.config.Configurator.initialize(Configurator.java:158)
    at org.apache.logging.log4j.web.Log4jWebInitializerImpl.initializeNonJndi(Log4jWebInitializerImpl.java:168)
    at org.apache.logging.log4j.web.Log4jWebInitializerImpl.start(Log4jWebInitializerImpl.java:110)
    at org.apache.logging.log4j.web.Log4jServletContainerInitializer.onStartup(Log4jServletContainerInitializer.java:57)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5604)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1571)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1561)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.apache.logging.log4j.core.appender.db.jdbc.FactoryMethodConnectionSource$1.getConnection(FactoryMethodConnectionSource.java:105)
    ... 20 more

我怀疑当LOGJ2调用getDatabaseConnection（）时是否还没有创建bean dataSource。请告诉我原因和解决方案。

Answer 1

请完成本教程[Log4j2 JDBC]（http://self-learning-java-tutorial.blogspot.in/2015/10/log4j2-jdbcappender-write-log-messages.html）

如上所述：请参阅此部分

以下是ConnectionFactory参数。

Class : Name of the class, that contains a static factory method for obtaining JDBC connections.
method : The name of a static factory method for obtaining JDBC connections. Method return type must be either java.sql.Connection or DataSource.

请注意，它需要静态工厂方法。这就是为什么反射调用失败。

Answer 2

最后，我找到了一个解决方案。 LOG4J在Spring之前初始化，因此bean Datasource将返回null。

我按照以下网址的说明操作： How to use Spring BoneCPDataSource bean as data source for Log4j 2 JDBC appender?

现在一切都很好。

使用Spring的log4j2 JDBCAppender

2 个答案: