springboot+mybatis 使用mybatis的拦截器修改+打印sql语句

参考文章:https://www.cnblogs.com/leavescy/p/7642113.html

参考文章:https://blog.csdn.net/u011546032/article/details/95242792

 

package com.example.demo.config;


import java.sql.Connection;
import java.text.DateFormat;
import java.util.Date;
import java.util.List;
import java.util.Locale;
import java.util.Properties;
import java.util.regex.Matcher;
import org.apache.commons.collections4.CollectionUtils;
import org.apache.ibatis.executor.statement.StatementHandler;
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.DefaultReflectorFactory;
import org.apache.ibatis.reflection.MetaObject;
import org.apache.ibatis.reflection.SystemMetaObject;
import org.apache.ibatis.session.Configuration;
import org.apache.ibatis.type.TypeHandlerRegistry;

/**
 * 拦截StatementHandler类中参数类型为Statement的 prepare 方法
 * 即拦截 Statement prepare(Connection var1, Integer var2) 方法
 * @author zyh
 * @date 2020/2/27
 */
@Intercepts({@Signature(type = StatementHandler.class, method = "prepare", args = {Connection.class, Integer.class})})
public class MybatisInterceptor implements Interceptor {


    @Override
    public Object intercept(Invocation invocation) throws Throwable {

        StatementHandler statementHandler = (StatementHandler) invocation.getTarget();
        //通过MetaObject优雅访问对象的属性，这里是访问statementHandler的属性;：MetaObject是Mybatis提供的一个用于方便、
        //优雅访问对象属性的对象，通过它可以简化代码、不需要try/catch各种reflect异常，同时它支持对JavaBean、Collection、Map三种类型对象的操作。
        MetaObject metaObject = MetaObject
                .forObject(statementHandler, SystemMetaObject.DEFAULT_OBJECT_FACTORY, SystemMetaObject.DEFAULT_OBJECT_WRAPPER_FACTORY,
                        new DefaultReflectorFactory());
        //先拦截到RoutingStatementHandler，里面有个StatementHandler类型的delegate变量，其实现类是BaseStatementHandler，然后就到BaseStatementHandler的成员变量mappedStatement
        MappedStatement mappedStatement = (MappedStatement) metaObject.getValue("delegate.mappedStatement");
        //id为执行的mapper方法的全路径名，如com.uv.dao.UserMapper.insertUser
        String id = mappedStatement.getId();
        System.out.println("id ==> " + id);
        //sql语句类型 select、delete、insert、update
        String sqlCommandType = mappedStatement.getSqlCommandType().toString();
        System.out.println("类型 ==> " + sqlCommandType);

        BoundSql boundSql = statementHandler.getBoundSql();
       /* //获取到原始sql语句
        String sql = boundSql.getSql();
        *//*String mSql = sql + " limit 1"*//*;
        //通过反射修改sql语句
        Field field = boundSql.getClass().getDeclaredField("sql");
        field.setAccessible(true);
        field.set(boundSql, sql);
        System.out.println(""+sql);*/
        // 获取节点的配置
        Configuration configuration = mappedStatement.getConfiguration();
        // 获取到最终的sql语句
        String newsql = getSql(configuration, boundSql, id);
        System.out.println("拦截的sql ==>: " + newsql);
        return invocation.proceed();
        //return null;
    }

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

    @Override
    public void setProperties(Properties properties) {
    }


    /**
     * 封装了一下sql语句，
     * 使得结果返回完整xml路径下的sql语句节点id + sql语句
     *
     * @param configuration
     * @param boundSql
     * @param sqlId
     * @return
     */
    private String getSql(Configuration configuration, BoundSql boundSql, String sqlId) {
        String sql = showSql(configuration, boundSql);
        StringBuilder str = new StringBuilder(100);
        str.append(sqlId);
        str.append(":");
        str.append(sql);
        return str.toString();
    }

    /**
     * 如果参数是String，则添加单引号， 如果是日期，则转换为时间格式器并加单引号；
     * 对参数是null和不是null的情况作了处理

     *
     * @param obj
     * @return
     */
    private 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;
    }

    /**
     * 进行？的替换
     * @param configuration
     * @param boundSql
     * @return
     */
    public String showSql(Configuration configuration, BoundSql boundSql) {
        // 获取参数
        Object parameterObject = boundSql.getParameterObject();
        List parameterMappings = boundSql
                .getParameterMappings();
        // sql语句中多个空格都用一个空格代替
        String sql = boundSql.getSql().replaceAll("[\\s]+", " ");
        if (CollectionUtils.isNotEmpty(parameterMappings) && parameterObject != null) {
            // 获取类型处理器注册器，类型处理器的功能是进行java类型和数据库类型的转换　　　　　　　
            // 如果根据parameterObject.getClass(）可以找到对应的类型，则替换
            TypeHandlerRegistry typeHandlerRegistry = configuration.getTypeHandlerRegistry();
            if (typeHandlerRegistry.hasTypeHandler(parameterObject.getClass())) {
                sql = sql.replaceFirst("\\?", Matcher.quoteReplacement(getParameterValue(parameterObject)));

            } else {
                //MetaObject主要是封装了originalObject对象，
                // 提供了get和set的方法用于获取和设置originalObject的属性值,
                // 主要支持对JavaBean、Collection、Map三种类型对象的操作
                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("\\?", Matcher.quoteReplacement(getParameterValue(obj)));
                    } else if (boundSql.hasAdditionalParameter(propertyName)) {
                        // 该分支是动态sql
                        Object obj = boundSql.getAdditionalParameter(propertyName);
                        sql = sql.replaceFirst("\\?", Matcher.quoteReplacement(getParameterValue(obj)));

                    } else {
                        //打印出缺失，提醒该参数缺失并防止错位
                        sql = sql.replaceFirst("\\?", "缺失");
                    }
                }
            }
        }
        return sql;
    }

}

运行结果