mybatis多租户实现

多租户实现

参考文章：https://blog.csdn.net/qq_37361535/article/details/121212070
1.两个配置文件，需要修改字段就修改getTenantIdColumn的返回值，值的修改同理

import com.baomidou.mybatisplus.extension.plugins.handler.TenantLineHandler;

import lombok.extern.slf4j.Slf4j;
import net.sf.jsqlparser.expression.Expression;
import net.sf.jsqlparser.expression.LongValue;
import org.springframework.stereotype.Component;

import java.util.Arrays;
import java.util.List;

@Component
@Slf4j
public class CustomTenantLineHandler implements TenantLineHandler {
    private static final List<String> IGNORE_TENANT_TABLES = Arrays.asList("`sys_user`");//不配置多租户功能的表；这里需要注意表名不要写错，是否需要``根据自己所写的sql语句来定
    //sql语句中``的作用就是与数据库的关键字区分

    /**
     * 获取租户 ID 值表达式，只支持单个 ID 值
     * @return 租户 ID 值表达式
     */
    @Override
    public Expression getTenantId() {
        return new LongValue(1);
    }

    /**
     * 获取租户字段名
     * 默认字段名叫: tenant_id
     * 数据库中字段用的userId
     * @return 租户字段名
     */
    @Override
    public String getTenantIdColumn() {
        return "tenant_id";
    }

    /**
     * 根据表名判断是否忽略拼接多租户条件
     * 默认都要进行解析并拼接多租户条件
     *
     * @param tableName 表名
     * @return 是否忽略, true:表示忽略，false:需要解析并拼接多租户条件
     */
    @Override
    public boolean ignoreTable(String tableName) {
        return IGNORE_TENANT_TABLES.stream().anyMatch(ignoreTableName -> ignoreTableName.equalsIgnoreCase(tableName));
    }

    
}

第二个：

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.baomidou.mybatisplus.autoconfigure.ConfigurationCustomizer;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.handler.TenantLineHandler;
import com.baomidou.mybatisplus.extension.plugins.inner.TenantLineInnerInterceptor;

import net.sf.jsqlparser.expression.Expression;
import net.sf.jsqlparser.expression.LongValue;
import org.springframework.transaction.annotation.EnableTransactionManagement;


@Configuration
@EnableTransactionManagement
@MapperScan(basePackages = {"com.example.demo.dao"})
public class MybatisPlusConfig {
    /**
     * 配置拦截器（包括分页拦截器）
     * 新多租户插件配置,一缓和二缓遵循mybatis的规则,需要设置 MybatisConfiguration#useDeprecatedExecutor = false 避免缓存万一出现问题
     */
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        // 多租户拦截器
        interceptor.addInnerInterceptor(new TenantLineInnerInterceptor(new CustomTenantLineHandler()));
        //interceptor.addInnerInterceptor(new MyTenantLineInnerInterceptor(new MyTenantLineHandler()));
        // 如果用了分页插件注意先 add TenantLineInnerInterceptor 再 add PaginationInnerInterceptor
        // 用了分页插件必须设置 MybatisConfiguration#useDeprecatedExecutor = false
        // 分页插件


        return interceptor;
    }
    @Bean
    public ConfigurationCustomizer configurationCustomizer() {
        return configuration -> configuration.setUseDeprecatedExecutor(false);
    }


}

如果是多个参数，即

原来是

select * from xx where tenant_id=1

修改为

select * from xx where tenant_id in (1,2)

不看上面的配置文件，新的几个配置文件：

import com.baomidou.mybatisplus.extension.plugins.handler.TenantLineHandler;
import lombok.extern.slf4j.Slf4j;
import net.sf.jsqlparser.expression.Expression;
import net.sf.jsqlparser.expression.StringValue;
import net.sf.jsqlparser.util.cnfexpression.MultipleExpression;
import org.springframework.stereotype.Component;

import java.util.ArrayList;
import java.util.List;


public class MyTenantLineHandler  implements TenantLineHandler {
    @Override
    public Expression getTenantId() {
        List<Expression> childlist =new ArrayList<>();
        childlist.add(new StringValue("1"));
        childlist.add(new StringValue("2"));
        MultipleExpression multipleExpression=new MultipleExpression(childlist) {
            @Override
            public String getStringExpression() {
                return ",";
            }
        };
        return multipleExpression;
    }

    @Override
    public String getTenantIdColumn() {
        return "tenant_id";
    }

    /**
     * 这个地方需要排除没有这个权限字段的表,如果是嵌套或者连表,都会添加上这个多租户
     * @param tableName
     * @return
     */
    @Override
    public boolean ignoreTable(String tableName) {
//        if(tableName.equals("subselect")){
//            return false;
//        }
//        return true;
        return false;
    }
}

第二个：

import com.baomidou.mybatisplus.extension.plugins.handler.TenantLineHandler;
import com.baomidou.mybatisplus.extension.plugins.inner.TenantLineInnerInterceptor;
import lombok.extern.slf4j.Slf4j;
import net.sf.jsqlparser.expression.Expression;
import net.sf.jsqlparser.expression.Parenthesis;
import net.sf.jsqlparser.expression.StringValue;
import net.sf.jsqlparser.expression.operators.conditional.AndExpression;
import net.sf.jsqlparser.expression.operators.conditional.OrExpression;
import net.sf.jsqlparser.expression.operators.relational.InExpression;
import net.sf.jsqlparser.schema.Column;
import net.sf.jsqlparser.schema.Table;
import net.sf.jsqlparser.statement.delete.Delete;
import net.sf.jsqlparser.statement.insert.Insert;
import net.sf.jsqlparser.statement.select.SelectBody;
import net.sf.jsqlparser.statement.update.Update;
import net.sf.jsqlparser.util.cnfexpression.MultipleExpression;
import org.springframework.stereotype.Component;

import java.util.ArrayList;
import java.util.List;

public class MyTenantLineInnerInterceptor extends TenantLineInnerInterceptor {

    public MyTenantLineInnerInterceptor(TenantLineHandler tenantLineHandler) {
        super(tenantLineHandler);
    }

    /**
     * 重构mybatispuls的多租户改为支持in
     * @param currentExpression
     * @param table
     * @return
     */
    @Override
    protected Expression builderExpression(Expression currentExpression, Table table) {
        Column aliasColumn = this.getAliasColumn(table);
        boolean presenceOfField=true;

        if(presenceOfField) {
            InExpression inExpression = new InExpression();
            inExpression.setLeftExpression(aliasColumn);
            inExpression.setRightExpression(getTenantLineHandler().getTenantId());
            if (currentExpression == null) {
                return inExpression;
            } else {
                return currentExpression instanceof OrExpression ? new AndExpression(new Parenthesis(currentExpression), inExpression) : new AndExpression(currentExpression, inExpression);
            }
        }else{
            return currentExpression;
        }

    }

//    @Override
//    protected void processInsert(Insert insert, int index, String sql, Object obj) {
//
//    }
//
//    @Override
//    protected void processUpdate(Update update, int index, String sql, Object obj) {
//
//    }
//
//    @Override
//    protected void processDelete(Delete delete, int index, String sql, Object obj) {
//
//    }

    @Override
    protected void processInsertSelect(SelectBody selectBody) {

    }

}

第三个

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.baomidou.mybatisplus.autoconfigure.ConfigurationCustomizer;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.handler.TenantLineHandler;
import com.baomidou.mybatisplus.extension.plugins.inner.TenantLineInnerInterceptor;

import net.sf.jsqlparser.expression.Expression;
import net.sf.jsqlparser.expression.LongValue;
import org.springframework.transaction.annotation.EnableTransactionManagement;


@Configuration
@EnableTransactionManagement
@MapperScan(basePackages = {"com.example.demo.dao"})
public class MybatisPlusConfig {
    /**
     * 配置拦截器（包括分页拦截器）
     * 新多租户插件配置,一缓和二缓遵循mybatis的规则,需要设置 MybatisConfiguration#useDeprecatedExecutor = false 避免缓存万一出现问题
     */
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        // 多租户拦截器
        //interceptor.addInnerInterceptor(new TenantLineInnerInterceptor(new CustomTenantLineHandler()));
        interceptor.addInnerInterceptor(new MyTenantLineInnerInterceptor(new MyTenantLineHandler()));
        // 如果用了分页插件注意先 add TenantLineInnerInterceptor 再 add PaginationInnerInterceptor
        // 用了分页插件必须设置 MybatisConfiguration#useDeprecatedExecutor = false
        // 分页插件


        return interceptor;
    }
    @Bean
    public ConfigurationCustomizer configurationCustomizer() {
        return configuration -> configuration.setUseDeprecatedExecutor(false);
    }


}