MyBatisPlus多租户架构的完整实现方案

import com.baomidou.mybatisplus.core.plugins.InterceptorIgnore;
import com.baomidou.mybatisplus.core.plugins.InterceptorIgnoreHelper;
import org.apache.ibatis.executor.statement.StatementHandler;
import org.apache.ibatis.plugin.*;
import org.springframework.stereotype.Component;

import java.sql.Connection;
import java.util.Properties;

@Intercepts({@Signature(type = StatementHandler.class, method = "prepare", args = {Connection.class, Integer.class})})
@Component
public class TenantInterceptor implements Interceptor {

    private final String tenantIdFieldName = "tenant_id";

    @Override
    public Object intercept(Invocation invocation) throws Throwable {
        // 1. 检查是否忽略多租户
        if (InterceptorIgnoreHelper.willIgnoreTenantLine(InterceptorIgnore::tenantLine)) {
            return invocation.proceed();
        }

        // 2. 获取当前租户ID
        Long tenantId = TenantContext.getTenantId(); // 假设TenantContext使用ThreadLocal存储租户ID

        // 3. 如果没有租户ID，则抛出异常
        if (tenantId == null) {
            throw new RuntimeException("TenantId is null");
        }

        // 4. 获取SQL语句
        StatementHandler statementHandler = (StatementHandler) invocation.getTarget();
        String sql = statementHandler.getBoundSql().getSql();

        // 5. 修改SQL语句，加入租户ID过滤条件
        String modifiedSql = addTenantIdCondition(sql, tenantId);
        statementHandler.getBoundSql().setSql(modifiedSql);

        return invocation.proceed();
    }

    private String addTenantIdCondition(String sql, Long tenantId) {
        // 这里需要根据具体的SQL语句进行判断，是否需要加入租户ID过滤条件
        // 可以使用正则表达式或者字符串匹配等方式
        // 这里只是一个简单的示例
        if (sql.toLowerCase().contains("where")) {
            return sql + " AND " + tenantIdFieldName + " = " + tenantId;
        } else {
            return sql + " WHERE " + tenantIdFieldName + " = " + tenantId;
        }
    }

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

    @Override
    public void setProperties(Properties properties) {
        // 可以设置一些属性，例如租户ID字段名
    }
}