一般做法

使用mybatis打印sql和参数的一般做法是在配置文件中配置log-impl,例如

mybatis:
configuration:
map-underscore-to-camel-case: true
log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

但是这样使用的话最终输出还是没有完成拼接的sql,如果一条sql有很多个参数的情况下,我们还要手动一个个参数填上去

==>  Preparing: select * from db where host = ? 
==> Parameters: localhost(String)

增加Interceptor

import java.text.DateFormat;
import java.util.Date;
import java.util.List;
import java.util.Locale;
import java.util.Properties;

import org.apache.ibatis.executor.Executor;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.ParameterMapping;
import org.apache.ibatis.plugin.Interceptor;
import org.apache.ibatis.plugin.Intercepts;
import org.apache.ibatis.plugin.Invocation;
import org.apache.ibatis.plugin.Plugin;
import org.apache.ibatis.plugin.Signature;
import org.apache.ibatis.reflection.MetaObject;
import org.apache.ibatis.session.Configuration;
import org.apache.ibatis.session.ResultHandler;
import org.apache.ibatis.session.RowBounds;
import org.apache.ibatis.type.TypeHandlerRegistry;

@Intercepts({
@Signature(type = Executor.class, method = "update", args = { MappedStatement.class, Object.class }),
@Signature(type = Executor.class, method = "query", args = { MappedStatement.class, Object.class,
RowBounds.class, ResultHandler.class }) })
public class MybatisInterceptor implements Interceptor {

private Properties properties;

public Object intercept(Invocation invocation) throws Throwable {
MappedStatement mappedStatement = (MappedStatement) invocation.getArgs()[0];
Object parameter = null;
if (invocation.getArgs().length > 1) {
parameter = invocation.getArgs()[1];
}
String sqlId = mappedStatement.getId();
BoundSql boundSql = mappedStatement.getBoundSql(parameter);
Configuration configuration = mappedStatement.getConfiguration();
Object returnValue = null;
long start = System.currentTimeMillis();
returnValue = invocation.proceed();
long end = System.currentTimeMillis();
long time = (end - start);
if (time > 1) {
String sql = getSql(configuration, boundSql, sqlId, time);
System.err.println(sql);
}
return returnValue;
}

public static String getSql(Configuration configuration, BoundSql boundSql, String sqlId, long time) {
String sql = showSql(configuration, boundSql);
StringBuilder str = new StringBuilder(100);
str.append(sqlId);
str.append(":");
str.append(sql);
str.append(":");
str.append(time);
str.append("ms");
return str.toString();
}

private static String getParameterValue(Object obj) {
String value = null;
if (obj instanceof String) {
value = "'" + obj.toString() + "'";
} else if (obj instanceof Date) {
DateFormat formatter = DateFormat.getDateTimeInstance(DateFormat.DEFAULT, DateFormat.DEFAULT, Locale.CHINA);
value = "'" + formatter.format(new Date()) + "'";
} else {
if (obj != null) {
value = obj.toString();
} else {
value = "";
}

}
return value;
}

public static String showSql(Configuration configuration, BoundSql boundSql) {
Object parameterObject = boundSql.getParameterObject();
List<ParameterMapping> parameterMappings = boundSql.getParameterMappings();
String sql = boundSql.getSql().replaceAll("[\\s]+", " ");
if (parameterMappings.size() > 0 && parameterObject != null) {
TypeHandlerRegistry typeHandlerRegistry = configuration.getTypeHandlerRegistry();
if (typeHandlerRegistry.hasTypeHandler(parameterObject.getClass())) {
sql = sql.replaceFirst("\\?", getParameterValue(parameterObject));

} else {
MetaObject metaObject = configuration.newMetaObject(parameterObject);
for (ParameterMapping parameterMapping : parameterMappings) {
String propertyName = parameterMapping.getProperty();
if (metaObject.hasGetter(propertyName)) {
Object obj = metaObject.getValue(propertyName);
sql = sql.replaceFirst("\\?", getParameterValue(obj));
} else if (boundSql.hasAdditionalParameter(propertyName)) {
Object obj = boundSql.getAdditionalParameter(propertyName);
sql = sql.replaceFirst("\\?", getParameterValue(obj));
}
}
}
}
return sql;
}

public Object plugin(Object target) {
return Plugin.wrap(target, this);
}

public void setProperties(Properties properties0) {
this.properties = properties0;
}
}

需要注意的是这里导入的类都是org.apache.ibatis下的,不是aop的。

然后把这个拦截器加入到mybatis的拦截器配置中,就可以打印完整的sql语句了

具体有三种做法

  1. 添加component注解,交给springboot管理
  2. 通过配置类注入
  3. 通过添加mybatis的xml配置文件

最终执行结果

com.mjc.druid.data.mapper.HelloMapper.getHosts:select * from db where host = 'localhost':118ms

参考文章: