使用MyBatis拦截器实现Mybatis sql控制台完整输出
Mybatis拦截器
介绍
-
拦截器顾名思义，肯定是拦截某个请求或者接口，进行某种操作，例如我们可以实现HandlerInterceptor 接口，可以对web请求接口进行拦截，从而校验用户是否登录等。
-
MyBatis 允许你在已映射语句执行过程中的某一点进行拦截调用。默认情况下，MyBatis 允许使用插件来拦截的方法调用包括：
- 拦截执行器的方法：Executor (update, query, flushStatements, commit, rollback, getTransaction, close, isClosed)
- 拦截参数的处理：ParameterHandler (getParameterObject, setParameters)
- 拦截结果集的处理：ResultSetHandler (handleResultSets, handleOutputParameters)
- 拦截Sql语法构建的处：StatementHandler (prepare, parameterize, batch, update, query)
源码预览
Interceptor：
Mybatis对该接口没有默认实现，使用的时候可以根据需求自行实现。分页查询工具pagehelper中有对Interceptor接口的实现从而辅助实现分页查询。
public interface Interceptor {
Object intercept(Invocation var1) throws Throwable;
default Object plugin(Object target) {
return Plugin.wrap(target, this);
}
default void setProperties(Properties properties) {
}
}
官网配置拦截器实例
- ExamplePlugin：所有执行executor的update方法都会被该拦截器拦截到。
@Intercepts({
@Signature(
type= Executor.class,
method = "update",
args = {
MappedStatement.class,Object.class})})
public class ExamplePlugin implements Interceptor {
public Object intercept(Invocation invocation) throws Throwable {
return invocation.proceed();
}
public Object plugin(Object target) {
return Plugin.wrap(target, this);
}
public void setProperties(Properties properties) {
}
}
- xml配置
<plugins>
<plugin interceptor="org.format.mybatis.cache.interceptor.ExamplePlugin"></plugin>
</plugins>
-
Object intercept(Invocation invocation)是实现拦截逻辑的地方，内部要通过invocation.proceed()显式地推进责任链前进，也就是调用下一个拦截器拦截目标方法。
-
Object plugin(Object target) 就是用当前这个拦截器生成对目标target的代理，实际是通过Plugin.wrap(target,this) 来完成的，把目标target和拦截器this传给了包装函数。
-
setProperties(Properties properties)用于设置额外的参数，参数配置在拦截器的Properties节点里。
注解里描述的是指定拦截方法的签名 [type,method,args] （即对哪种对象的哪种方法进行拦截），它在拦截前用于决断。
Plugin.wrap方法
public staticObject wrap(Object target, Interceptor interceptor) {
//从拦截器的注解中获取拦截的类名和方法信息
Map<Class<?>, Set<Method>> signatureMap =getSignatureMap(interceptor);
Class<?> type = target.getClass();
//解析被拦截对象的所有接口（注意是接口）
Class<?>[] interfaces = getAllInterfaces(type, signatureMap);
if(interfaces.length > 0) {
//生成代理对象， Plugin对象为该代理对象的InvocationHandler
returnProxy.newProxyInstance(type.getClassLoader(), interfaces, new Plugin(target,interceptor,signatureMap));
}
returntarget;
}
控制台Sql 完整输出实现
- SqlLoogerConfig
/**
* @Description：Sql 完整输出sql
* @Author：LiDong
* @Create：2020/12/26
* @Version：1.0.0
*/
@Configuration
public class SqlLoogerConfig {
@Bean
public SqlInterceptor sqlInterceptor() {
return new SqlInterceptor();
}
}
- SqlInterceptor
package com.li.core.config.mybatis;
import com.github.pagehelper.util.StringUtil;
import org.apache.ibatis.cache.CacheKey;
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.mapping.ParameterMode;
import org.apache.ibatis.plugin.*;
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;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Properties;
/**
* @Description：mybatis sql拦截器 控制打印出完整sql
* @Author：LiDong
* @Create：2020/12/26
* @Version：1.0.0
*/
@Intercepts({
@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}),
@Signature(type = Executor.class, method = "update", args = {
MappedStatement.class, Object.class})}
)
public class SqlInterceptor implements Interceptor {
private static final Logger logger = LoggerFactory.getLogger(SqlInterceptor.class);
private static final ThreadLocal<SimpleDateFormat> DATETIME_FORMATTER = new ThreadLocal<SimpleDateFormat>() {
@Override
protected SimpleDateFormat initialValue() {
return new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
}
};
@Override
public Object intercept(Invocation invocation) throws Throwable {
Object result = null;
//捕获掉异常，不要影响业务
try {
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();
long startTime = System.currentTimeMillis();
try {
result = invocation.proceed();
} finally {
long endTime = System.currentTimeMillis();
long sqlCostTime = endTime - startTime;
String sql = this.getSql(configuration, boundSql);
this.formatSqlLog(sqlId, sql, sqlCostTime, result);
}
return result;
} catch (Exception e) {
return result;
}
}
@Override
public Object plugin(Object target) {
if (target instanceof Executor) {
return Plugin.wrap(target, this);
}
return target;
}
@Override
public void setProperties(Properties properties) {
}
/**
* 获取完整的sql语句
*
* @param configuration
* @param boundSql
* @return
*/
private String getSql(Configuration configuration, BoundSql boundSql) {
// 输入sql字符串空判断
String sql = boundSql.getSql();
if (StringUtil.isEmpty(sql)) {
return "";
}
return formatSql(sql, configuration, boundSql);
}
/**
* 将占位符替换成参数值
*
* @param sql
* @param configuration
* @param boundSql
* @return
*/
private String formatSql(String sql, Configuration configuration, BoundSql boundSql) {
//美化sql
sql = beautifySql(sql);
//填充占位符, 目前基本不用mybatis存储过程调用,故此处不做考虑
Object parameterObject = boundSql.getParameterObject();
List<ParameterMapping> parameterMappings = boundSql.getParameterMappings();
TypeHandlerRegistry typeHandlerRegistry = configuration.getTypeHandlerRegistry();
List<String> parameters = new ArrayList<>();
if (parameterMappings != null) {
MetaObject metaObject = parameterObject == null ? null : configuration.newMetaObject(parameterObject);
for (int i = 0; i < parameterMappings.size(); i++) {
ParameterMapping parameterMapping = parameterMappings.get(i);
if (parameterMapping.getMode() != ParameterMode.OUT) {
// 参数值
Object value;
String propertyName = parameterMapping.getProperty();
// 获取参数名称
if (boundSql.hasAdditionalParameter(propertyName)) {
// 获取参数值
value = boundSql.getAdditionalParameter(propertyName);
} else if (parameterObject == null) {
value = null;
} else if (typeHandlerRegistry.hasTypeHandler(parameterObject.getClass())) {
// 如果是单个值则直接赋值
value = parameterObject;
} else {
value = metaObject == null ? null : metaObject.getValue(propertyName);
}
if (value instanceof Number) {
parameters.add(String.valueOf(value));
} else {
StringBuilder builder = new StringBuilder();
builder.append("'");
if (value instanceof Date) {
builder.append(DATETIME_FORMATTER.get().format((Date) value));
} else if (value instanceof String) {
builder.append(value);
}
builder.append("'");
parameters.add(builder.toString());
}
}
}
}
for (String value : parameters) {
sql = sql.replaceFirst("\\?", value);
}
return sql;
}
/**
* 格式化sql日志
*
* @param sqlId
* @param sql
* @param costTime
* @return
*/
private void formatSqlLog(String sqlId, String sql, long costTime, Object obj) {
String sqlLog = "=====> " + sql;
StringBuffer result = new StringBuffer();
if (obj instanceof List) {
List list = (List) obj;
int count = list.size();
result.append("=====> Total:" + count);
} else if (obj instanceof Integer) {
result.append("=====> Total:" + obj);
}
result.append(" SpendTime:" + costTime + " ms");
logger.info("\n------------------------------------------------------------------------------------------------------------------\n"
+ sqlLog + "\n" + result +
"\n------------------------------------------------------------------------------------------------------------------");
}
public static String beautifySql(String sql) {
sql = sql.replaceAll("[\\s\n ]+", " ");
return sql;
}
}
实现效果
