spring boot Mybatis 拦截器实现拼接sql和修改的代码详解_Java教程

定义一个 SqlIntercepor 类

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									import com.culturalCenter.placeManage.globalConfig.Interface.InterceptAnnotation;

									import org.apache.ibatis.executor.statement.StatementHandler;

									import org.apache.ibatis.mapping.BoundSql;

									import org.apache.ibatis.mapping.MappedStatement;

									import org.apache.ibatis.plugin.*;

									import org.apache.ibatis.reflection.DefaultReflectorFactory;

									import org.apache.ibatis.reflection.MetaObject;

									import org.apache.ibatis.reflection.SystemMetaObject;

									import org.apache.ibatis.session.ResultHandler;

									import org.slf4j.Logger;

									import org.slf4j.LoggerFactory;

									import org.springframework.context.annotation.Configuration;

									import org.springframework.stereotype.Component;

									import java.lang.reflect.Field;

									import java.lang.reflect.Method;

									import java.sql.Statement;

									import java.util.Properties;

									@Intercepts({@Signature(type = StatementHandler.class, method = "query", args = {Statement.class, ResultHandler.class}),

									        @Signature(type = StatementHandler.class, method = "update", args = {Statement.class}),

									        @Signature(type = StatementHandler.class, method = "batch", args = {Statement.class})})

									@Component

									@Configuration

									public class SqlInterceptor implements Interceptor {

									    private Logger logger = LoggerFactory.getLogger(SqlInterceptor.class);

									    @Override

									    public Object intercept(Invocation invocation) throws Throwable {

									        StatementHandler statementHandler = (StatementHandler) invocation.getTarget();

									        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();

									        logger.info("拦截到当前请求方法的全路径名为--->:  " + id);

									        //sql语句类型 select、delete、insert、update

									        String sqlCommandType = mappedStatement.getSqlCommandType().toString();

									        BoundSql boundSql = statementHandler.getBoundSql();

									        //获取到原始sql语句

									        String sql = boundSql.getSql();

									        String mSql = sql;

									        //获取参数

									        Object parameter = statementHandler.getParameterHandler().getParameterObject();

									        logger.info("拦截到当前请求SQL为--->: " + sql + "<------------>请求类型为:  " + sqlCommandType);

									        logger.info("拦截到当前请求参数为--->: " + parameter);

									        //TODO 修改位置

									        //注解逻辑判断  添加注解了才拦截//InterceptAnnotation

									        Class<?> classType = Class.forName(mappedStatement.getId().substring(0, mappedStatement.getId().lastIndexOf(".")));

									        String mName = mappedStatement.getId().substring(mappedStatement.getId().lastIndexOf(".") + 1, mappedStatement.getId().length());

									        for (Method method : classType.getDeclaredMethods()) {

									            if (method.isAnnotationPresent(InterceptAnnotation.class) && mName.equals(method.getName())) {

									                InterceptAnnotation interceptorAnnotation = method.getAnnotation(InterceptAnnotation.class);

									                if (interceptorAnnotation.flag()) {

									                    mSql = sql + " limit 2";

									                }

									            }

									        }

									        //通过反射修改sql语句

									        Field field = boundSql.getClass().getDeclaredField("sql");

									        field.setAccessible(true);

									        field.set(boundSql, mSql);

									        return invocation.proceed();

									    }

									    @Override

									    public Object plugin(Object target) {

									        return Plugin.wrap(target, new SqlInterceptor());

									    }

									    @Override

									    public void setProperties(Properties properties) {

									//        this.setProperties(properties);

									    }

自定义一个注解类实现局部处理SQL修改

InterceptAnnotation

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									import java.lang.annotation.ElementType;

									import java.lang.annotation.Retention;

									import java.lang.annotation.RetentionPolicy;

									import java.lang.annotation.Target;

									/**

									 * 配合SqlInterceptor实现局部拦截

									 * */

									@Target({ElementType.METHOD,ElementType.PARAMETER})

									@Retention(RetentionPolicy.RUNTIME)

									public @interface InterceptAnnotation {

									    boolean flag() default  true;

									}

自定义数据源工厂类

SqlSessionFactoryConfig

				?

									package com.culturalCenter.placeManage.globalConfig;

									import com.alibaba.druid.pool.DruidDataSource;

									import org.apache.ibatis.plugin.Interceptor;

									import org.apache.ibatis.session.SqlSessionFactory;

									import org.mybatis.spring.SqlSessionFactoryBean;

									import org.springframework.beans.factory.annotation.Autowired;

									import org.springframework.context.annotation.Bean;

									import org.springframework.context.annotation.Configuration;

									import org.springframework.context.annotation.Primary;

									import org.springframework.core.io.Resource;

									import org.springframework.core.io.support.PathMatchingResourcePatternResolver;

									import javax.sql.DataSource;

									/**

									 * @author wulincheng

									 * @Date 2020年6月23日18:25:22

									 *  创建SQL连接工厂类

									 * */

									@Configuration

									public class SqlSessionFactoryConfig {

									    @javax.annotation.Resource

									    DruidDataSource dataSource;

									    /**

									     * @Autowired SqlSessionFactory sqlSessionFactory;

									     * SqlSession session = sqlSessionFactory.openSession();

									     * //创建sqlMapper

									     * SqlMapper sqlMapper = new SqlMapper(session);

									     */

									    @Bean

									    @Primary

									    public SqlSessionFactory sqlSessionFactory() throws Exception {

									        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();

									        bean.setDataSource(dataSource);//更多参数请自行注入

									        bean.setPlugins(new Interceptor[]{new SqlInterceptor()});

									        Resource[] resources = new PathMatchingResourcePatternResolver()

									                .getResources("classpath*:mapper/*.xml");

									        bean.setMapperLocations(resources);

									        return bean.getObject();

									    }

									}