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学习配置Log4j2提供的JDBCAppender,该appender使用标准JDBC将日志记录写入关系型数据库表。
JDBCAppender从配置的连接工厂或JNDI数据源获取数据库连接。然后,它使用提供的列配置每次执行日志语句时在日志表中插入新行。
1.简介
在本教程中,我们使用的是H2内存数据库。
- 当演示运行时,它将创建内存数据库并执行schema.sql文件以创建一个新表EVENT_LOGS。此表将用于存储日志事件。在您的应用程序中,您可能有一个持久性数据库,因此可以跳过模式文件部分。
- 然后我们执行几个日志语句。这些语句被记录在控制台和数据库中。
- 我们可以在控制台日志中验证日志语句和插入查询,因为我们启用了H2数据库的跟踪日志记录。您必须在生产环境中禁用它。
- 不要忘记使用数据库连接池,否则日志记录在性能方面将非常糟糕。
2. 依赖项
对于这个简单的演示应用程序,我们只需要必要的maven依赖项。
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>2.14.1</version>
</dependency>
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<version>2.0.202</version>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-dbcp2</artifactId>
<version>2.9.0</version>
</dependency>
3. 连接工厂
让我们从连接工厂开始,连接工厂将提供当我们想要将事件插入数据库时所需的连接。
请注意以下属性的使用:
- TRACE_LEVEL_SYSTEM_OUT–用于启用H2的跟踪日志记录。
- INIT=RUNSCRIPT FROM–用于在应用程序启动之初执行模式文件。
连接工厂类:
import java.sql.Connection;
import java.sql.SQLException;
import org.apache.commons.dbcp2.BasicDataSource;
public class LogsStoreConnectionFactory
{
private static BasicDataSource dataSource;
private LogsStoreConnectionFactory() {
}
public static Connection getConnection() throws SQLException {
if (dataSource == null) {
dataSource = new BasicDataSource();
dataSource.setUrl("jdbc:h2:mem:testdb;TRACE_LEVEL_SYSTEM_OUT=2;INIT=RUNSCRIPT FROM 'classpath:schema.sql'\\;");
dataSource.setDriverClassName("org.h2.Driver");
dataSource.setUsername("sa");
dataSource.setPassword("");
}
return dataSource.getConnection();
}
}
schema.sql 创建EVENT_LOGS表:
create table EVENT_LOGS (
ID varchar(50) primary key,
DATE_TIME timestamp,
CLASS varchar(100),
LEVEL varchar(10),
MESSAGE TEXT,
EXCEPTION TEXT
);
4. Log4j2配置
现在是映射数据库中的表名和列的时候了。log4j2.xml配置:
<?xml version="1.0" encoding="UTF-8"?>
<Configuration>
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout
pattern="%d{yyyy-MMM-dd hh:mm:ss a} %level %c - %m %n" />
</Console>
<JDBC name="dbLogsStore" tableName="EVENT_LOGS">
<!-- 如果使用 JNDI 数据源-->
<!-- <DataSource jndiName="java:/comp/env/jdbc/LoggingDataSource" /> -->
<ConnectionFactory
class="com.howtodoinjava.demo.jdbcappender.LogsStoreConnectionFactory"
method="getConnection" />
<Column name="ID" pattern="%u" />
<Column name="DATE_TIME" isEventTimestamp="true" />
<Column name="CLASS" pattern="%logger" />
<Column name="LEVEL" pattern="%level" />
<Column name="MESSAGE" pattern="%message" />
<Column name="EXCEPTION" pattern="%ex{full}" isClob="true"/>
</JDBC>
</Appenders>
<Loggers>
<Root level="trace">
<AppenderRef ref="Console" />
<AppenderRef ref="dbLogsStore" />
</Root>
</Loggers>
</Configuration>
5. 演示
让我们运行这个测试案例。
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
public class JDBCAppenderExample {
private static final Logger logger = LogManager.getLogger(JDBCAppenderExample.class);
public static void main(String[] args)
{
logger.info("JDBCAppender Example ");
try {
logger.debug("Demo Statement");
int i = 1/0;
} catch (Exception e) {
logger.error("Runtime error", e);
}
}
}
请检查控制台日志:
Console Logs/*SQL #:1 t:14*/RUNSCRIPT FROM 'classpath:schema.sql';
2021-12-07 23:39:21 jdbc[3]:
/**/Connection conn0 = DriverManager.getConnection("jdbc:h2:mem:testdb; TRACE_LEVEL_SYSTEM_OUT=2;INIT=RUNSCRIPT FROM 'classpath:schema.sql'\\;", "SA", "");
...
...
2021-Dec-07 11:39:21 pm DEBUG com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample - Demo Statement
2021-12-07 23:39:21 jdbc[3]:
/*SQL l:88 #:1*/insert into EVENT_LOGS (ID,DATE_TIME,CLASS,LEVEL,MESSAGE,EXCEPTION) values (?,?,?,?,?,?) {1: 'cd4e6b02-5788-11ec-a719-70cf49366217', 2: TIMESTAMP '2021-12-07 23:39:21.328', 3: 'com.howtodoinjava.demo.jdbcappender.JDBCAppenderExample', 4: 'DEBUG', 5: 'Demo Statement', 6: ''};
...
...
2021-Dec-07 11:39:21 pm ERROR com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample - Runtime error
java.lang.ArithmeticException: / by zero
at com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample.main(JDBCAppenderExample.java:15) [classes/:?]
2021-12-07 23:39:21 jdbc[3]:
/*SQL l:88 #:1*/insert into EVENT_LOGS (ID,DATE_TIME,CLASS, LEVEL,MESSAGE,EXCEPTION) values (?,?,?,?,?,?) {1: 'cd5018b3-5788-11ec-a719-70cf49366217', 2: TIMESTAMP '2021-12-07 23:39:21.329', 3: 'com.howtodoinjava.demo.jdbcappender.JDBCAppenderExample', 4: 'ERROR', 5: 'Runtime error', 6: U&'java.lang.ArithmeticException: / by zero\Console Logs/*SQL #:1 t:14*/RUNSCRIPT FROM 'classpath:schema.sql';
2021-12-07 23:39:21 jdbc[3]:
/**/Connection conn0 = DriverManager.getConnection("jdbc:h2:mem:testdb; TRACE_LEVEL_SYSTEM_OUT=2;INIT=RUNSCRIPT FROM 'classpath:schema.sql'\\;", "SA", "");
...
...
2021-Dec-07 11:39:21 pm DEBUG com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample - Demo Statement
2021-12-07 23:39:21 jdbc[3]:
/*SQL l:88 #:1*/insert into EVENT_LOGS (ID,DATE_TIME,CLASS,LEVEL,MESSAGE,EXCEPTION) values (?,?,?,?,?,?) {1: 'cd4e6b02-5788-11ec-a719-70cf49366217', 2: TIMESTAMP '2021-12-07 23:39:21.328', 3: 'com.howtodoinjava.demo.jdbcappender.JDBCAppenderExample', 4: 'DEBUG', 5: 'Demo Statement', 6: ''};
...
...
2021-Dec-07 11:39:21 pm ERROR com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample - Runtime error
java.lang.ArithmeticException: / by zero
at com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample.main(JDBCAppenderExample.java:15) [classes/:?]
2021-12-07 23:39:21 jdbc[3]:
/*SQL l:88 #:1*/insert into EVENT_LOGS (ID,DATE_TIME,CLASS, LEVEL,MESSAGE,EXCEPTION) values (?,?,?,?,?,?) {1: 'cd5018b3-5788-11ec-a719-70cf49366217', 2: TIMESTAMP '2021-12-07 23:39:21.329', 3: 'com.howtodoinjava.demo.jdbcappender.JDBCAppenderExample', 4: 'ERROR', 5: 'Runtime error', 6: U&'java.lang.ArithmeticException: / by zero\\000d\\000a\\0009at com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample.main(JDBCAppenderExample.java:15)\\000d\\000a'};
0d\Console Logs/*SQL #:1 t:14*/RUNSCRIPT FROM 'classpath:schema.sql';
2021-12-07 23:39:21 jdbc[3]:
/**/Connection conn0 = DriverManager.getConnection("jdbc:h2:mem:testdb; TRACE_LEVEL_SYSTEM_OUT=2;INIT=RUNSCRIPT FROM 'classpath:schema.sql'\\;", "SA", "");
...
...
2021-Dec-07 11:39:21 pm DEBUG com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample - Demo Statement
2021-12-07 23:39:21 jdbc[3]:
/*SQL l:88 #:1*/insert into EVENT_LOGS (ID,DATE_TIME,CLASS,LEVEL,MESSAGE,EXCEPTION) values (?,?,?,?,?,?) {1: 'cd4e6b02-5788-11ec-a719-70cf49366217', 2: TIMESTAMP '2021-12-07 23:39:21.328', 3: 'com.howtodoinjava.demo.jdbcappender.JDBCAppenderExample', 4: 'DEBUG', 5: 'Demo Statement', 6: ''};
...
...
2021-Dec-07 11:39:21 pm ERROR com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample - Runtime error
java.lang.ArithmeticException: / by zero
at com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample.main(JDBCAppenderExample.java:15) [classes/:?]
2021-12-07 23:39:21 jdbc[3]:
/*SQL l:88 #:1*/insert into EVENT_LOGS (ID,DATE_TIME,CLASS, LEVEL,MESSAGE,EXCEPTION) values (?,?,?,?,?,?) {1: 'cd5018b3-5788-11ec-a719-70cf49366217', 2: TIMESTAMP '2021-12-07 23:39:21.329', 3: 'com.howtodoinjava.demo.jdbcappender.JDBCAppenderExample', 4: 'ERROR', 5: 'Runtime error', 6: U&'java.lang.ArithmeticException: / by zero\\000d\\000a\\0009at com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample.main(JDBCAppenderExample.java:15)\\000d\\000a'};
0a\Console Logs/*SQL #:1 t:14*/RUNSCRIPT FROM 'classpath:schema.sql';
2021-12-07 23:39:21 jdbc[3]:
/**/Connection conn0 = DriverManager.getConnection("jdbc:h2:mem:testdb; TRACE_LEVEL_SYSTEM_OUT=2;INIT=RUNSCRIPT FROM 'classpath:schema.sql'\\;", "SA", "");
...
...
2021-Dec-07 11:39:21 pm DEBUG com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample - Demo Statement
2021-12-07 23:39:21 jdbc[3]:
/*SQL l:88 #:1*/insert into EVENT_LOGS (ID,DATE_TIME,CLASS,LEVEL,MESSAGE,EXCEPTION) values (?,?,?,?,?,?) {1: 'cd4e6b02-5788-11ec-a719-70cf49366217', 2: TIMESTAMP '2021-12-07 23:39:21.328', 3: 'com.howtodoinjava.demo.jdbcappender.JDBCAppenderExample', 4: 'DEBUG', 5: 'Demo Statement', 6: ''};
...
...
2021-Dec-07 11:39:21 pm ERROR com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample - Runtime error
java.lang.ArithmeticException: / by zero
at com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample.main(JDBCAppenderExample.java:15) [classes/:?]
2021-12-07 23:39:21 jdbc[3]:
/*SQL l:88 #:1*/insert into EVENT_LOGS (ID,DATE_TIME,CLASS, LEVEL,MESSAGE,EXCEPTION) values (?,?,?,?,?,?) {1: 'cd5018b3-5788-11ec-a719-70cf49366217', 2: TIMESTAMP '2021-12-07 23:39:21.329', 3: 'com.howtodoinjava.demo.jdbcappender.JDBCAppenderExample', 4: 'ERROR', 5: 'Runtime error', 6: U&'java.lang.ArithmeticException: / by zero\\000d\\000a\\0009at com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample.main(JDBCAppenderExample.java:15)\\000d\\000a'};
09at com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample.main(JDBCAppenderExample.java:15)\Console Logs/*SQL #:1 t:14*/RUNSCRIPT FROM 'classpath:schema.sql';
2021-12-07 23:39:21 jdbc[3]:
/**/Connection conn0 = DriverManager.getConnection("jdbc:h2:mem:testdb; TRACE_LEVEL_SYSTEM_OUT=2;INIT=RUNSCRIPT FROM 'classpath:schema.sql'\\;", "SA", "");
...
...
2021-Dec-07 11:39:21 pm DEBUG com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample - Demo Statement
2021-12-07 23:39:21 jdbc[3]:
/*SQL l:88 #:1*/insert into EVENT_LOGS (ID,DATE_TIME,CLASS,LEVEL,MESSAGE,EXCEPTION) values (?,?,?,?,?,?) {1: 'cd4e6b02-5788-11ec-a719-70cf49366217', 2: TIMESTAMP '2021-12-07 23:39:21.328', 3: 'com.howtodoinjava.demo.jdbcappender.JDBCAppenderExample', 4: 'DEBUG', 5: 'Demo Statement', 6: ''};
...
...
2021-Dec-07 11:39:21 pm ERROR com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample - Runtime error
java.lang.ArithmeticException: / by zero
at com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample.main(JDBCAppenderExample.java:15) [classes/:?]
2021-12-07 23:39:21 jdbc[3]:
/*SQL l:88 #:1*/insert into EVENT_LOGS (ID,DATE_TIME,CLASS, LEVEL,MESSAGE,EXCEPTION) values (?,?,?,?,?,?) {1: 'cd5018b3-5788-11ec-a719-70cf49366217', 2: TIMESTAMP '2021-12-07 23:39:21.329', 3: 'com.howtodoinjava.demo.jdbcappender.JDBCAppenderExample', 4: 'ERROR', 5: 'Runtime error', 6: U&'java.lang.ArithmeticException: / by zero\\000d\\000a\\0009at com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample.main(JDBCAppenderExample.java:15)\\000d\\000a'};
0d\Console Logs/*SQL #:1 t:14*/RUNSCRIPT FROM 'classpath:schema.sql';
2021-12-07 23:39:21 jdbc[3]:
/**/Connection conn0 = DriverManager.getConnection("jdbc:h2:mem:testdb; TRACE_LEVEL_SYSTEM_OUT=2;INIT=RUNSCRIPT FROM 'classpath:schema.sql'\\;", "SA", "");
...
...
2021-Dec-07 11:39:21 pm DEBUG com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample - Demo Statement
2021-12-07 23:39:21 jdbc[3]:
/*SQL l:88 #:1*/insert into EVENT_LOGS (ID,DATE_TIME,CLASS,LEVEL,MESSAGE,EXCEPTION) values (?,?,?,?,?,?) {1: 'cd4e6b02-5788-11ec-a719-70cf49366217', 2: TIMESTAMP '2021-12-07 23:39:21.328', 3: 'com.howtodoinjava.demo.jdbcappender.JDBCAppenderExample', 4: 'DEBUG', 5: 'Demo Statement', 6: ''};
...
...
2021-Dec-07 11:39:21 pm ERROR com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample - Runtime error
java.lang.ArithmeticException: / by zero
at com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample.main(JDBCAppenderExample.java:15) [classes/:?]
2021-12-07 23:39:21 jdbc[3]:
/*SQL l:88 #:1*/insert into EVENT_LOGS (ID,DATE_TIME,CLASS, LEVEL,MESSAGE,EXCEPTION) values (?,?,?,?,?,?) {1: 'cd5018b3-5788-11ec-a719-70cf49366217', 2: TIMESTAMP '2021-12-07 23:39:21.329', 3: 'com.howtodoinjava.demo.jdbcappender.JDBCAppenderExample', 4: 'ERROR', 5: 'Runtime error', 6: U&'java.lang.ArithmeticException: / by zero\\000d\\000a\\0009at com.howtodoinjava.demo.jdbcappender. JDBCAppenderExample.main(JDBCAppenderExample.java:15)\\000d\\000a'};
0a'};
6. 结论
上面的Log4j2 JDBCAppender详解示例仅旨在让你更加清楚地了解整体工作方式,但请不要在生产环境中使用此配置。
请阅读更多Log4J2文档中的相关配置。