参照这个视频:https://www.bilibili.com/video/BV1MS411N7mn/?vd_source=90ebeef3261cec486646b6583e9f45f5
实现mybatis对外暴露的接口Interceptor
使用@Intercepts接口,这里的写法参照mybatis-plus中的拦截器写法
@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}),
@Signature(type = Executor.class, method = "query", args = {MappedStatement.class, Object.class, RowBounds.class
, ResultHandler.class, CacheKey.class, BoundSql.class}),
})
public class MybatisSqlPrint implements Interceptor {
@Override
public Object intercept(Invocation invocation) throws Throwable {
// 计算这一次SQL执行钱后的时间,统计一下执行耗时
long startTime = System.currentTimeMillis();
Object proceed = invocation.proceed();
long endTime = System.currentTimeMillis();
String printSql = null;
try {
// 通过generateSql方法拿到最终生成的SQL
printSql = generateSql(invocation);
}catch (Exception exception){
System.err.println(String.format("获取sql异常:%s",exception));
}finally {
// 拼接日志打印过程
long costTime = endTime - startTime;
System.out.println(String.format("\n 执行SQL耗时:%dms \n 执行SQL:%s",costTime,printSql));
}
return proceed;
}
private static String generateSql(Invocation invocation){
// 获取到BoundSql以及Configuration对象
// BoundSql 对象存储了一条具体的 SQL 语句及其相关参数信息。
// Configuration 对象保存了 MyBatis 框架运行时所有的配置信息
MappedStatement statement = (MappedStatement) invocation.getArgs()[0];
Object parameter = null;
if (invocation.getArgs().length>1){
parameter = invocation.getArgs()[1];
}
Configuration configuration = statement.getConfiguration();
BoundSql boundSql = statement.getBoundSql(parameter);
// 获取参数对象
Object parameterObject = boundSql.getParameterObject();
// 获取参数映射
List<ParameterMapping> params = boundSql.getParameterMappings();
// 获取到执行的SQL
String sql = boundSql.getSql();
// SQL中多个空格使用一个空格代替
sql = sql.replaceAll("[\\s]+", " ");
if (!ObjectUtils.isEmpty(params) && !ObjectUtils.isEmpty(parameterObject)){
// TypeHandlerRegistry 是 MyBatis 用来管理 TypeHandler 的注册器。TypeHandler 用于在 Java 类型和 JDBC 类型之间进行转换
TypeHandlerRegistry typeHandlerRegistry = configuration.getTypeHandlerRegistry();
// 如果参数对象的类型有对应的 TypeHandler,则使用 TypeHandler 进行处理
if (typeHandlerRegistry.hasTypeHandler(parameterObject.getClass())){
sql = sql.replaceFirst("\\?", Matcher.quoteReplacement(getParameterValue(parameterObject)));
}else {
// 否则,逐个处理参数映射
for (ParameterMapping param : params) {
// 获取参数的属性名
String propertyName = param.getProperty();
MetaObject metaObject = configuration.newMetaObject(parameterObject);
// 检查对象中是否存在该属性的 getter 方法,如果存在就取出来进行替换
if (metaObject.hasGetter(propertyName)){
Object obj = metaObject.getValue(propertyName);
sql = sql.replaceFirst("\\?", Matcher.quoteReplacement(getParameterValue(obj)));
// 检查 BoundSql 对象中是否存在附加参数。附加参数可能是在动态 SQL 处理中生成的,有的话就进行替换
}else if (boundSql.hasAdditionalParameter(propertyName)){
Object obj = boundSql.getAdditionalParameter(propertyName);
sql = sql.replaceFirst("\\?", Matcher.quoteReplacement(getParameterValue(obj)));
}else {
// 如果都没有,说明SQL匹配不上,带上“缺失”方便找问题
sql = sql.replaceFirst("\\?", "缺失");
}
}
}
}
return sql;
}
private static String getParameterValue(Object object) {
String value = "";
if (object instanceof String){
value = "'" + object.toString() + "'";
}else if (object instanceof Date){
DateFormat format = DateFormat.getDateTimeInstance(DateFormat.DEFAULT, DateFormat.DEFAULT, Locale.CHINA);
value = "'" + format.format((Date) object) + "'";
} else if (!ObjectUtils.isEmpty(object)) {
value = object.toString();
}
return value;
}
}
最后将拦截器添加到mybatis中
@Configuration
public class MybatisConfig {
public MybatisConfig() {
System.out.println("MybatisConfig loaded");
}
SqlSessionFactory sqlSessionFactory;
@Autowired
public void setSqlSessionFactory(SqlSessionFactory sqlSessionFactory) {
this.sqlSessionFactory = sqlSessionFactory;
}
@PostConstruct
public void addInterceptor(){
sqlSessionFactory.getConfiguration().addInterceptor(new MybatisSqlPrint());
}
}
实现效果