jeecgboot按字段分表

在jeecgboot 使用mybatis框架，mybatis-plus3.1.1后支持分表，以下是在jeecg项目中实行分表
一、修改mybatis-plus版本后，必须要在3.1.1版本后

 <dependency>
    <groupId>com.baomidou</groupId>
     <artifactId>mybatis-plus-core</artifactId>
     <version>3.1.2</version>
 </dependency>
<dependency>
	<groupId>com.baomidou</groupId>
	<artifactId>mybatis-plus-extension</artifactId>
	<version>3.1.2</version>
</dependency>

二、修改entity实体把@TableName注释掉

@Data
//@TableName("empss_visual_meter_usage_hour")
@EqualsAndHashCode(callSuper = false)
@Accessors(chain = true)
@ApiModel(value="empss_visual_meter_usage_hour对象", description="表具每小时用量")
public class UsageHour{
/**统计时间*/
	@Excel(name = "统计时间", width = 20, format = "yyyy-MM-dd HH:mm:ss")
	@JsonFormat(timezone = "GMT+8",pattern = "yyyy-MM-dd HH:mm:ss")
    @DateTimeFormat(pattern="yyyy-MM-dd HH:mm:ss")
    @ApiModelProperty(value = "统计时间")
	private java.util.Date statTime;
	/**表具编号*/
	@Excel(name = "表具编号", width = 15)
    @ApiModelProperty(value = "表具编号")
	private java.lang.String code;
}

其他的controller、service、mapperd类等不需要改变

三、修改MybatisPlusConfig配置类paginationInterceptor()方法

@Bean
    public PaginationInterceptor paginationInterceptor() {
//        return new PaginationInterceptor();
    	PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
        DynamicTableNameParser dynamicTableNameParser = new DynamicTableNameParser();
        dynamicTableNameParser.setTableNameHandlerMap(new HashMap<String, ITableNameHandler>(2) {{
           //实现entity中usageHour类分表，这里按statTime，statTime为Date类型，分表时要转为年和类，注意usage_hour对应usageHour类的类名
        	put("usage_hour", (metaObject, sql, tableName) -> {
                // 通过metaObject 可以获取传入参数，这里实现你自己的动态规则
            	//获取参数
                Object originalObject = metaObject.getOriginalObject();
                JSONObject originalObjectJSON = JSON.parseObject(JSON.toJSONString(originalObject));
                JSONObject boundSql = originalObjectJSON.getJSONObject("boundSql");
                JSONObject parameterObject = boundSql.getJSONObject("parameterObject");
                String valueOf = String.valueOf(parameterObject);
                Long statTime=0L;
                if(valueOf.contains("{\"ew\":{")) {
                	statTime=getTimeByEw(parameterObject);
                }else if(valueOf.contains("{\"et\":{")){
                	statTime=getTimeByEt(parameterObject);
                }else {
                	statTime = parameterObject.getLong("statTime");
                }
                String formatDate = DateUtils.formatDate(statTime);
                String year=formatDate.substring(0, 4);
                //表名
                return "empss_visual_meter_usage_hour_"+year;
            });
        	 //多个entity分表，实现entity中usageDay类分表，
            put("usage_day", (metaObject, sql, tableName) -> {
            	//获取参数
            	Object originalObject = metaObject.getOriginalObject();
            	JSONObject originalObjectJSON = JSON.parseObject(JSON.toJSONString(originalObject));
            	JSONObject boundSql = originalObjectJSON.getJSONObject("boundSql");
            	JSONObject parameterObject = boundSql.getJSONObject("parameterObject");
            	String valueOf = String.valueOf(parameterObject);
                Long statTime=0L;
                if(valueOf.contains("{\"ew\":{")) {
                	statTime=getTimeByEw(parameterObject);
                }else if(valueOf.contains("{\"et\":{")){
                	statTime=getTimeByEt(parameterObject);
                }else {
                	// save ,update
                	statTime = parameterObject.getLong("statTime");
                }
                String formatDate = DateUtils.formatDate(statTime);
                String year=formatDate.substring(0, 4);
                return "empss_visual_meter_usage_day_"+year;
            });
            
        }
        	/**
        	   * 使用QueryWrapper<T> query 查询时获取stat_time参数
        	 * @param parameterObject
        	 * @return
        	 */
        	private Long getTimeByEw(JSONObject parameterObject) { 
        		JSONObject ew=parameterObject.getJSONObject("ew");
            	String sqlSegment = ew.getString("sqlSegment");
            	JSONObject paramNameValuePairs=ew.getJSONObject("paramNameValuePairs");
            	int indexOf = sqlSegment.indexOf("stat_time = #{ew.paramNameValuePairs.");
            	String substring = sqlSegment.substring(indexOf+37, indexOf+37+9);
            	Long statTime = paramNameValuePairs.getLong(substring);
        		return statTime; 
        	}
        	/**
	      	   * 使用saveOrUpdateBatch 批量更新时时获取statTime参数
	      	 * @param parameterObject
	      	 * @return
	      	 */
        	private Long getTimeByEt(JSONObject parameterObject) { 
        		JSONObject et=parameterObject.getJSONObject("et");
        		Long statTime = et.getLong("statTime");
        		return statTime; 
        	}
			 
        });
        paginationInterceptor.setSqlParserList(Collections.singletonList(dynamicTableNameParser));
        return paginationInterceptor;
    }

四、分表时，应该要按某个字段分表，在增删改查时必须要带了了改字段信息，如果要实行更新ID进行修改和查询，可以在保存实现时加上分表字段信息，例如我按statTime（统计时间分表），我在save方法时，在ID前加上统计时间信息

Date statTime = usageHour.getStatTime();
SimpleDateFormat shortDateFormat = new SimpleDateFormat("yyyy");
String format = shortDateFormat.format(statTime);
usageHour.setId(format+UUID.fastUUID().toString());
usageHourService.save(usageHour);

在queryById或增删改时，更加传入的ID获取不同的表。