mapper.xml 

<mapper namespace="com.summaryexcel.mapper.IncrementalBaseMapper">

  <select id="getSegmentNo" resultType="com.summaryexcel.pojo.IncrementalBase">
    SELECT SUM(members_making_purchase) as members_making_purchase,
    SUM(transactions) as transactions,SUM(amount) as amount,SUM(quantity) as
    quantity,if_select
    ,distinguishing_type,incremental_base_type,segment_no
    FROM incremental_base
    <where>
      <if test="segment_no !=null">
        segment_no = #{segment_no}
      </if>
      <if test="startTime ==null and endTime != null">
        and data_time = #{endTime}
      </if>
      <if test="startTime !=null and endTime != null">
        and data_time between #{startTime} and #{endTime}
      </if>
      <if test="campaignId !=null">
        and campaign_id = #{campaignId}
      </if>
      <if test="distinguishing_type !=null">
        and distinguishing_type = #{distinguishing_type}
      </if>
      <if test="incremental_base_type !=null">
        and incremental_base_type = #{incremental_base_type}
      </if>
      <choose>
        <when test="calRange == 'REGION'">
          and home_region = #{calPart}
        </when>
        <when test="calRange == 'DAY_PART'">
          AND day_part = #{calPart}
        </when>
        <when test="calRange == 'TRADE_ZONE'">
          AND trade_zone = #{calPart}
        </when>
        <otherwise>
          and home_region!=''
        </otherwise>
      </choose>
          and segment_no != 'total'
    </where>
    group by if_select,segment_no
  </select>
</mapper>

获取xml中的sql

@Autowired
private SqlSessionFactory sqlSessionFactory;


List<Object> params = new ArrayList<>();
Collections.addAll(params,null, endTime, campaignId, distinguishing_type,
       incremental_base_type, calPart, null, calRangeType);

String sql = SqlHelper.getNamespaceSql(sqlSessionFactory,
       "com.summaryexcel.mapper.IncrementalBaseMapper.getSegmentNo", params);
log.info("sql="+sql);

*getNamespaceSql方法参数里说明 

sqlSessionFactory：spring依赖注入

"com.summaryexcel.mapper.IncrementalBaseMapper.getSegmentNo"：

           xxxmapper.xml里对应的namespace和select标签的id属性值

params：调用的Mapper需要用的参数放到一个集合params里

SqlHelper工具类

import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.ParameterMapping;
import org.apache.ibatis.mapping.ParameterMode;
import org.apache.ibatis.reflection.MetaObject;
import org.apache.ibatis.session.Configuration;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.type.JdbcType;
import org.apache.ibatis.type.TypeHandlerRegistry;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

import static org.apache.ibatis.type.JdbcType.VARCHAR;

/**
 * Mybatis - 获取Mybatis查询sql工具
 */
public class SqlHelper {

	/**
	 * 通过命名空间方式获取sql
	 * @param sqlSessionFactory
	 * @param namespace
	 * @param params
	 * @return
	 */
	public static String getNamespaceSql(SqlSessionFactory sqlSessionFactory, String namespace, Object params) {
		params = wrapCollection(params);
		Configuration configuration = sqlSessionFactory.getConfiguration();
		MappedStatement mappedStatement = configuration.getMappedStatement(namespace);
		TypeHandlerRegistry typeHandlerRegistry = mappedStatement.getConfiguration().getTypeHandlerRegistry();
		BoundSql boundSql = mappedStatement.getBoundSql(params);
		List<ParameterMapping> parameterMappings = boundSql.getParameterMappings();
		StringBuilder sqlStringBuilder = new StringBuilder(boundSql.getSql().replaceAll("\n", ""));
		if (params != null && parameterMappings != null && parameterMappings.size() > 0) {
			for (ParameterMapping parameterMapping : parameterMappings) {
				if (parameterMapping.getMode() != ParameterMode.OUT) {
					Object value;
					String propertyName = parameterMapping.getProperty();
					if (boundSql.hasAdditionalParameter(propertyName)) {
						value = boundSql.getAdditionalParameter(propertyName);
					} else if (typeHandlerRegistry.hasTypeHandler(params.getClass())) {
						value = params;
					} else {
						MetaObject metaObject = configuration.newMetaObject(params);
						value = metaObject.getValue(propertyName);
					}
					JdbcType jdbcType = parameterMapping.getJdbcType();
					if (jdbcType == null) {
						jdbcType = VARCHAR;
					}
					replaceParameter(sqlStringBuilder, value, jdbcType);
				}
			}
		}
		return sqlStringBuilder.toString();
	}

	/**
	 * 根据类型替换参数
	 * 仅作为数字和字符串两种类型进行处理，需要特殊处理的可以继续完善这里
	 *
	 * @param sqlStringBuilder
	 * @param value
	 * @param jdbcType
	 * @return
	 */
	private static void replaceParameter(StringBuilder sqlStringBuilder, Object value, JdbcType jdbcType) {
		if (value == null) {
			return;
		}

		String strValue = String.valueOf(value);
		switch (jdbcType) {
			//数字
			case BIT:
				break;
			case TINYINT:
				break;
			case SMALLINT:
				break;
			case INTEGER:
				break;
			case BIGINT:
				break;
			case FLOAT:
				break;
			case REAL:
				break;
			case DOUBLE:
				break;
			case NUMERIC:
				break;
			case DECIMAL:
				break;
			//其他，包含字符串和其他特殊类型，加单引号
			default:
				strValue = "'" + strValue + "'";
		}
		int index = sqlStringBuilder.indexOf("?");
		sqlStringBuilder.replace(index, index+1, strValue);
	}

	/**
	 * 简单包装参数
	 *
	 * @param object
	 * @return
	 */
	private static Object wrapCollection(final Object object) {
		if (object instanceof List) {
			Map<String, Object> map = new HashMap<>();
			map.put("list", object);
			return map;
		} else if (object != null && object.getClass().isArray()) {
			Map<String, Object> map = new HashMap<>();
			map.put("array", object);
			return map;
		}
		return object;
	}
}