在系统中采用了spring boot + logback＋slf4j的日志框架，将系统日志记录到数据库。
相关参考来源：
官方文档-DBAppender
Logback输出日志到自定义MySQL数据库（重写DBAppender）
logback日志框架中filter的使用
1. 添加依赖：
从 logback 版本 1.2.8 开始，DBAppender 不再随 logback-classic 一起提供，所以需要单独引入
<dependency>
<groupId>ch.qos.logback.db</groupId>
<artifactId>logback-classic-db</artifactId>
<version>1.2.11.1</version>
</dependency>
2. 自定义表结构:
可以根据实际情况增加或减少和修改字段
CREATE TABLE t_log_logback (
`id` VARCHAR ( 64 ) NOT NULL COMMENT '主键',
`create_time` VARCHAR ( 32 ) NOT NULL COMMENT '创建时间',
`message` TEXT NOT NULL COMMENT '内容',
`level_string` VARCHAR ( 254 ) NOT NULL COMMENT '日志等级：TRACE,DEBUG,INFO,WARNING,ERROR,FATAL',
`logger_name` VARCHAR ( 254 ) NOT NULL COMMENT '发出日志记录请求的记录器的名称',
`thread_name` VARCHAR ( 254 ) COMMENT '线程名称',
`reference_flag` INT ( 11 ) COMMENT 'MDC属性',
`caller_filename` VARCHAR ( 254 ) NOT NULL COMMENT '发出日志记录请求的文件名',
`caller_class` VARCHAR ( 254 ) NOT NULL COMMENT '发出日志记录请求的类',
`caller_method` VARCHAR ( 254 ) NOT NULL COMMENT '发出日志记录请求的方法的名称',
`caller_line` VARCHAR ( 4 ) NOT NULL COMMENT '发出日志记录请求的行号',
PRIMARY KEY ( `id` ) USING BTREE
) ENGINE = INNODB DEFAULT CHARSET = utf8mb4 COLLATE = utf8mb4_bin ROW_FORMAT = DYNAMIC COMMENT = 'logback系统日志记录表';
3. 自定义追加器DbLogbackAppender
import ch.qos.logback.classic.spi.CallerData;
import ch.qos.logback.classic.spi.ILoggingEvent;
import ch.qos.logback.core.db.DBAppenderBase;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.time.Instant;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
/**
* <p>
* 自定义DB日志追加器，参考实现类 {@link ch.qos.logback.classic.db.DBAppender}
* 参考来源：https://blog.csdn.net/qq_20914913/article/details/92830914
* </p>
*/
public class DbLogbackAppender extends DBAppenderBase<ILoggingEvent> {
private String insertSQL;
private static final Method GET_GENERATED_KEYS_METHOD;
// 对应于数据库字段的插入数据序号
private static final int ID_INDEX = 1;
private static final int CREATE_TIME_INDEX = 2;
private static final int MESSAGE_INDEX = 3;
private static final int LEVEL_STRING_INDEX = 4;
private static final int LOGGER_NAME_INDEX = 5;
private static final int THREAD_NAME_INDEX = 6;
private static final int REFERENCE_FLAG_INDEX = 7;
private static final int CALLER_FILENAME_INDEX = 8;
private static final int CALLER_CLASS_INDEX = 9;
private static final int CALLER_METHOD_INDEX = 10;
private static final int CALLER_LINE_INDEX = 11;
private static final StackTraceElement EMPTY_CALLER_DATA = CallerData.naInstance();
// 处理主键的自动生成，这里我们使用手工生成，因此下面代码可忽略
static {
// PreparedStatement.getGeneratedKeys() method was added in JDK 1.4
Method getGeneratedKeysMethod;
try {
// the
getGeneratedKeysMethod = PreparedStatement.class.getMethod("getGeneratedKeys", (Class[]) null);
} catch (Exception ex) {
getGeneratedKeysMethod = null;
}
GET_GENERATED_KEYS_METHOD = getGeneratedKeysMethod;
}
@Override
public void start() {
insertSQL = buildInsertSQL();
cnxSupportsBatchUpdates = connectionSource.supportsBatchUpdates();
// super.start();
super.started = true;
}
// 核心代码，构建插入语句，并对应数据库字段
private static String buildInsertSQL() {
return "INSERT INTO t_log_logback " +
"(id, create_time, message, level_string, logger_name, thread_name, " +
"reference_flag, caller_filename, caller_class, caller_method, caller_line) "+
"VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)";
}
// 管理每个字段插入的数据
private void bindLoggingEventWithInsertStatement(PreparedStatement stmt, ILoggingEvent event) throws SQLException {
// TODO 手工处理ID的生成
stmt.setString(ID_INDEX, IdUtils.simpleUUID());
stmt.setString(CREATE_TIME_INDEX, LocalDateTime.ofInstant(Instant.ofEpochMilli(event.getTimeStamp()),
ZoneId.systemDefault()).format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
stmt.setString(MESSAGE_INDEX, event.getFormattedMessage());
stmt.setString(LEVEL_STRING_INDEX, event.getLevel().toString());
stmt.setString(LOGGER_NAME_INDEX, event.getLoggerName());
stmt.setString(THREAD_NAME_INDEX, event.getThreadName());
}
// 管理每个字段插入的数据
private void bindCallerDataWithPreparedStatement(PreparedStatement stmt, StackTraceElement[] callerDataArray) throws SQLException {
StackTraceElement caller = extractFirstCaller(callerDataArray);
stmt.setInt(REFERENCE_FLAG_INDEX, 0);
stmt.setString(CALLER_FILENAME_INDEX, caller.getFileName());
stmt.setString(CALLER_CLASS_INDEX, caller.getClassName());
stmt.setString(CALLER_METHOD_INDEX, caller.getMethodName());
stmt.setString(CALLER_LINE_INDEX, Integer.toString(caller.getLineNumber()));
}
// 核心方法，插入具体日志数据
@Override
protected void subAppend(ILoggingEvent event, Connection connection, PreparedStatement insertStatement) throws Throwable {
bindLoggingEventWithInsertStatement(insertStatement, event);
// This is expensive... should we do it every time?
bindCallerDataWithPreparedStatement(insertStatement, event.getCallerData());
int updateCount = insertStatement.executeUpdate();
if (updateCount != 1) {
addWarn("Failed to insert loggingEvent");
}
}
private StackTraceElement extractFirstCaller(StackTraceElement[] callerDataArray) {
StackTraceElement caller = EMPTY_CALLER_DATA;
if (hasAtLeastOneNonNullElement(callerDataArray))
caller = callerDataArray[0];
return caller;
}
private boolean hasAtLeastOneNonNullElement(StackTraceElement[] callerDataArray) {
return callerDataArray != null && callerDataArray.length > 0 && callerDataArray[0] != null;
}
@Override
protected Method getGeneratedKeysMethod() {
return GET_GENERATED_KEYS_METHOD;
}
@Override
protected String getInsertSQL() {
return insertSQL;
}
protected void secondarySubAppend(ILoggingEvent event, Connection connection, long eventId) throws Throwable {
}
@Override
protected long selectEventId(PreparedStatement insertStatement, Connection connection) throws SQLException, InvocationTargetException {
return 0;
}
}
4. logback-spring.xml配置关联
添加自定义的追加器DbLogbackAppender
<?xml version="1.0" encoding="UTF-8"?>
<configuration debug="false">
<!-- 获取springboot中的数据库配置 -->
<springProperty scope="context" name="driverClassName" source="spring.datasource.master.driverClassName" defaultValue="driverClassName"/>
<springProperty scope="context" name="url" source="spring.datasource.master.url" defaultValue="url"/>
<springProperty scope="context" name="username" source="spring.datasource.master.username" defaultValue="username"/>
<springProperty scope="context" name="encryptPassword" source="spring.datasource.master.encryptPassword" defaultValue="encryptPassword"/>
<!-- 添加自定义DbLogbackAppender -->
<appender name="DB" class="com.xxx.DbLogbackAppender">
<connectionSource class="ch.qos.logback.core.db.DriverManagerConnectionSource">
<driverClass>${driverClassName}</driverClass>
<url>${url}</url>
<user>${username}</user>
<password>${password}</password>
</connectionSource>
<!--临界值过滤。只记录指定级别以及高于该级别的日志-->
<filter class="ch.qos.logback.classic.filter.ThresholdFilter">
<level>WARN</level>
</filter>
</appender>
<root level="DEBUGE">
<appender-ref ref="DB" />
</root>
</configuration>
到这里，就配置完成了，重启系统，访问日志，会将warn级别以上的日志记录到数据库表。
由于数据源是使用logback的LogbackConnectionSource，如果要自定义数据源，请往下看
5.自定义数据源
创建类LogbackConnectionSource.java，继承ConnectionSourceBase
import ch.qos.logback.core.db.ConnectionSourceBase;
import java.sql.Connection;
import java.sql.SQLException;
/**
* <p>
* 获取数据库连接用于logback，并提供DbLogbackAppender使用
* 参考类：ch.qos.logback.core.db.DriverManagerConnectionSource
* </p>
*/
public class LogbackConnectionSource extends ConnectionSourceBase {
public Connection getConnection() {
获取数据库连接
Connection connection = null;
// 自行构建连接
// ...
return connection;
}
}
修改logback-spring.xml配置为如下
<!-- 添加自定义DbLogbackAppender -->
<appender name="DB" class="com.xxx.DbLogbackAppender">
<!-- 添加自定义的数据源 -->
<connectionSource class="com.xxx.LogbackConnectionSource">
<!-- <driverClass>${driverClassName}</driverClass>
<url>${url}</url>
<user>${username}</user>
<password>${password}</password>-->
</connectionSource>
<!--临界值过滤。只记录指定级别以及高于该级别的日志-->
<filter class="ch.qos.logback.classic.filter.ThresholdFilter">
<level>WARN</level>
</filter>
</appender>
