MyBatis 物理分页foreach 参数失效

场景：MyBatis 物理分页，查询条件中需要用到foreach ，参数失效，查不到结果

 

分析：把java.sql的debug打开，sql语句正常，参数也正常。debug物理分页代码，setParameters时，boundSql.getAdditionalParameter(propertyName)获取值始终是null，没有拿到参数。但是BoundSql的metaParameters中可以看到相关的参数值。

解决方法：

BoundSql countBS = new BoundSql(configuration, sql, boundSql.getParameterMappings(), parameterObject);
            Field metaParamsField = ReflectUtil.getFieldByFieldName(boundSql, "metaParameters");
            if (metaParamsField != null) {
                MetaObject mo = (MetaObject) ReflectUtil.getValueByFieldName(boundSql, "metaParameters");
                ReflectUtil.setValueByFieldName(countBS, "metaParameters", mo);
            }
            setParameters(prepStat, configuration, countBS, parameterObject);

 

ReflectUtil 代码：

 

public class ReflectUtil {
    /**
     * 获取obj对象fieldName的Field
     *
     * @param obj
     * @param fieldName
     * @return
     */
    public static Field getFieldByFieldName(Object obj, String fieldName) {
        for (Class<?> superClass = obj.getClass(); superClass != Object.class; superClass = superClass.getSuperclass()) {
            try {
                return superClass.getDeclaredField(fieldName);
            } catch (NoSuchFieldException e) {
            }
        }
        return null;
    }

    /**
     * 获取obj对象fieldName的属性值
     *
     * @param obj
     * @param fieldName
     * @return
     * @throws SecurityException
     * @throws NoSuchFieldException
     * @throws IllegalArgumentException
     * @throws IllegalAccessException
     */
    public static Object getValueByFieldName(Object obj, String fieldName) throws SecurityException,
            NoSuchFieldException, IllegalArgumentException, IllegalAccessException {
        Field field = getFieldByFieldName(obj, fieldName);
        Object value = null;
        if (field != null) {
            if (field.isAccessible()) {
                value = field.get(obj);
            } else {
                field.setAccessible(true);
                value = field.get(obj);
                field.setAccessible(false);
            }
        }
        return value;
    }

    /**
     * 设置obj对象fieldName的属性值
     *
     * @param obj
     * @param fieldName
     * @param value
     * @throws SecurityException
     * @throws NoSuchFieldException
     * @throws IllegalArgumentException
     * @throws IllegalAccessException
     */
    public static void setValueByFieldName(Object obj, String fieldName, Object value) throws SecurityException,
            NoSuchFieldException, IllegalArgumentException, IllegalAccessException {
        Field field = getFieldByFieldName(obj, fieldName);
        if (field.isAccessible()) {
            field.set(obj, value);
        } else {
            field.setAccessible(true);
            field.set(obj, value);
            field.setAccessible(false);
        }
    }

}

 

 

评论

4 楼 wujingyong 2016-01-25  

zhuzf 写道

  , 我的就是这个问题，解决了，3Q

具体是怎么解决的啊

楼主说的是在哪里添加代码，没看太懂。我的是pagehelper4.1.1

3 楼 xuqiao2009 2016-01-02  

    高人高人，佩服

void processIntercept(final Object[] queryArgs) {
//queryArgs = query(MappedStatement ms, Object parameter, RowBounds rowBounds, ResultHandler resultHandler)
MappedStatement ms = (MappedStatement)queryArgs[MAPPED_STATEMENT_INDEX];
Object parameter = queryArgs[PARAMETER_INDEX];
final RowBounds rowBounds = (RowBounds)queryArgs[ROWBOUNDS_INDEX];
int offset = rowBounds.getOffset();
int limit = rowBounds.getLimit();

if(dialect.supportsLimit() && (offset != RowBounds.NO_ROW_OFFSET || limit != RowBounds.NO_ROW_LIMIT)) {
BoundSql boundSql = ms.getBoundSql(parameter);
String sql = boundSql.getSql().trim();
if (dialect.supportsLimitOffset()) {
sql = dialect.getLimitString(sql, offset, limit);
offset = RowBounds.NO_ROW_OFFSET;
} else {
sql = dialect.getLimitString(sql, 0, limit);
}
limit = RowBounds.NO_ROW_LIMIT;

queryArgs[ROWBOUNDS_INDEX] = new RowBounds(offset,limit);
BoundSql newBoundSql = new BoundSql(ms.getConfiguration(),sql, boundSql.getParameterMappings(), boundSql.getParameterObject());
Field metaParamsField = ReflectUtil.getFieldByFieldName(boundSql, "metaParameters");
        if (metaParamsField != null) {
          try {
                MetaObject mo = (MetaObject) ReflectUtil.getValueByFieldName(boundSql, "metaParameters");
         
ReflectUtil.setValueByFieldName(newBoundSql, "metaParameters", mo);
MappedStatement newMs = copyFromMappedStatement(ms, new BoundSqlSqlSource(newBoundSql));
queryArgs[MAPPED_STATEMENT_INDEX] = newMs;
} catch (Exception e) {

e.printStackTrace();
}
        }
}
}

2 楼 zhuzf 2015-08-10  

  , 我的就是这个问题，解决了，3Q

1 楼 victory_yong 2013-09-18  

lz给力，foreach分页解决了，受教,受教了......