mybatis项目实现动态表名的三种方法
作者:沉默的旋律
有时在开发过程中java代码中的表名和数据库的表名并不是一致的,此时我们就需要动态的设置表名,本文主要介绍了mybatis项目实现动态表名的三种方法,具有一定的参考价值,感兴趣的可以了解一下
实现动态表名是个很常见的需求,网上也有很多解决方法,这边总结了三种实现方式。
一、手动给每个方法加个表名的变量
缺点很明显,侵入性大,不方便,不推荐
二、mybatis插件机制拦截sql替换表名实现动态表名
import org.apache.ibatis.executor.statement.StatementHandler; import org.apache.ibatis.mapping.BoundSql; import org.apache.ibatis.plugin.*; import org.apache.ibatis.reflection.MetaObject; import org.apache.ibatis.reflection.SystemMetaObject; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.stereotype.Component; import java.lang.reflect.Proxy; import java.sql.Connection; import java.util.LinkedHashMap; import java.util.Map; import java.util.Properties; /** * mybatis插件实现动态表名,可以拦截器新增、编辑、删除、查询等 */ @Component @Intercepts({ @Signature(type = StatementHandler.class, method = "prepare", args = { Connection.class, Integer.class})}) public class ReplaceTablePlugin implements Interceptor { private static final Logger LOG = LoggerFactory.getLogger(ReplaceTablePlugin.class); private final static Map<String, String> TABLE_MAP = new LinkedHashMap<>(); /** * 需要替换的表(替换前的表名和替换后的表名) */ static { TABLE_MAP.put("t_user", "t_user_20220101"); TABLE_MAP.put("t_org", "t_org_20220202"); } @Override public Object intercept(Invocation invocation) throws Throwable { StatementHandler statementHandler = realTarget(invocation.getTarget()); MetaObject metaObject = SystemMetaObject.forObject(statementHandler); doTable(statementHandler, metaObject); return invocation.proceed(); } private void doTable(StatementHandler handler, MetaObject metaStatementHandler) throws ClassNotFoundException { BoundSql boundSql = handler.getBoundSql(); String originalSql = boundSql.getSql(); if (originalSql != null && !originalSql.equals("")) { LOG.info("拦截前的sql:{}", originalSql); if (isReplaceTableName(originalSql)) { for (Map.Entry<String, String> entry : TABLE_MAP.entrySet()) { originalSql = originalSql.replace(entry.getKey(), entry.getValue()); } LOG.info("拦截后的sql:{}", originalSql); metaStatementHandler.setValue("delegate.boundSql.sql", originalSql); } } } private boolean isReplaceTableName(String sql) { for (String tableName : TABLE_MAP.keySet()) { if (sql.contains(tableName)) { return true; } } return false; } @Override public Object plugin(Object target) { if (target instanceof StatementHandler) { return Plugin.wrap(target, this); } return target; } @Override public void setProperties(Properties properties) { } /** * Obtain real processing objects, possibly multi-layer agents * * @param target * @param <T> * @return */ public static <T> T realTarget(Object target) { if (Proxy.isProxyClass(target.getClass())) { MetaObject metaObject = SystemMetaObject.forObject(target); return realTarget(metaObject.getValue("h.target")); } return (T) target; } }
三、mybatis-plus的DynamicTableNameInnerInterceptor实现
3.1引入mybatis-plus的pom jar包依赖
<dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus-extension</artifactId> <version>3.5.2</version> </dependency> <dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus-annotation</artifactId> <version>3.5.2</version> </dependency> <dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus-core</artifactId> <version>3.5.2</version> </dependency>
3.2 实现的配置类
import java.util.Map; import cn.hutool.core.collection.CollectionUtil; import cn.hutool.json.JSONUtil; import com.baomidou.mybatisplus.annotation.DbType; import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor; import com.baomidou.mybatisplus.extension.plugins.inner.DynamicTableNameInnerInterceptor; import com.baomidou.mybatisplus.extension.plugins.inner.OptimisticLockerInnerInterceptor; import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor; import lombok.extern.slf4j.Slf4j; import org.apache.commons.lang3.StringUtils; import org.mybatis.spring.annotation.MapperScan; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Value; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.ComponentScan; import org.springframework.data.redis.core.RedisTemplate; /** * * mybatis-plus实现动态替换表名 */ @MapperScan("com.xiaweiyi8080.dal.mapper") @ComponentScan({"com.xiaweiyi8080.dal.manager"}) @Slf4j public class MyBatisPlusConfiguration { @Autowired private RedisTemplate redisTemplate; // 配置文件里配置的哪些表需要动态表名 @Value("${xxxxx.tableName:}") private String dynamicTableName; @Bean public MybatisPlusInterceptor dynamicTableNameInterceptor() { log.info("------拿到的dynamicTableName={}", dynamicTableName); MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor(); DynamicTableNameInnerInterceptor dynamicTableNameInnerInterceptor = new DynamicTableNameInnerInterceptor(); dynamicTableNameInnerInterceptor.setTableNameHandler((sql, tableName) -> { // 获取参数方法 Map<String, Object> paramMap = RequestDataHelper.getRequestData(); if (CollectionUtil.isNotEmpty(paramMap)) { paramMap.forEach((k, v) -> log.info(k + "----" + v)); } if (StringUtils.isNotBlank(dynamicTableName) && dynamicTableName.contains(tableName)) { log.info("------替换前表名={}", tableName); String suffix = "_20220101"; tableName += suffix; log.info("------替换后表名={}", tableName); } return tableName; }); interceptor.addInnerInterceptor(dynamicTableNameInnerInterceptor); return interceptor; } }
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