EAS BOS ORMapping 元数据解析示例

　　近期在项目中出于性能考虑，需要将单据的数据使用SQL的方式直接写入数据库或修改数据，经过自己的捉摸，自己实现了一些工具方法，用于动态生成有关SQL，目前只有：insert、update，具体实现如下（后面有重构过，稍后会同步上来）：

/**
 * ksql工具类
 * 
 */
public class KSQLBuilder {
 public static IMetaDataLoader metaDataLoader = null;
 public static final String splitchar = ",";// 字段间 的分隔符
 public static final String KEY_SELECT = "SELECT";
 public static final String KEY_FROM = "FROM";
 public static final String KEY_UPDATE = "UPDATE";
 public static final String KEY_INSERT = "INSERT INTO";
 public static final String KEY_VALUES = "VALUES";
 public static final String KEY_WHERE = "WHERE";
 public static final String KEY_AND = "AND";
 public static final String KEY_OR = "OR";

 public static void initInstance(Context ctx) {
  if (metaDataLoader == null) {
   if (ctx == null) {
    metaDataLoader = MetaDataLoaderFactory.getRemoteMetaDataLoader();
   } else {
    metaDataLoader = MetaDataLoaderFactory.getLocalMetaDataLoader(ctx);
   }
  }
 }

 /**
  * 根据单个对象生成预编译语句使用的参数
  * 
  * @param entity
  * @param objVal
  * @return
  */
 public static List getParams(EntityObjectInfo entity, IObjectValue objVal) {
  List params = new ArrayList();
  if (entity == null) {
   entity = metaDataLoader.getEntity(objVal.getBOSType());
  }
  PropertyInfo property = null;
  String propName = "";
  PropertyCollection properties = entity.getInheritedNoDuplicatedPropertiesRuntime();
  for (int i = 0; i < properties.size(); i++) {
   property = properties.get(i);
   propName = property.getName();
   if (property instanceof LinkPropertyInfo) {
    if (objVal.getObjectValue(propName) != null) {
     params.add(objVal.getObjectValue(propName).getString("id"));// 联接属性取ID
    } else {
     params.add(null);
    }
   } else {
    params.add(objVal.get(propName));
   }
  }
  return params;
 }

 /**
  * 根据批量的数据，构建预编译参数值
  * 
  * @param objCols
  * @param list
  * @return
  */
 public static List getBatchInsertParams(IObjectCollection objCols) {
  List list = new ArrayList();
  if (objCols == null || objCols.isEmpty()) {
   return list;
  }
  BOSObjectType bosType = objCols.getObject(0).getBOSType();
  EntityObjectInfo entity = metaDataLoader.getEntity(bosType);
  IObjectValue objVal = null;
  for (int j = 0, k = objCols.size(); j < k; j++) {
   objVal = objCols.getObject(j);
   list.add(getParams(entity, objVal));
  }
  return list;
 }

 /**
  * 此方法适合单条数据插入使用
  * 
  * @param objVal
  * @param list
  * @return
  */
 public static String getInsertSQL(IObjectValue objVal, List list) {
  BOSObjectType bosType = objVal.getBOSType();
  EntityObjectInfo entity = metaDataLoader.getEntity(bosType);
  String ksql = getInsertSQL(entity);
  list.addAll(getParams(entity, objVal));
  return ksql;
 }
 public static String getInsertSQL(BOSObjectType bosType) {
  EntityObjectInfo entity = metaDataLoader.getEntity(bosType);
  return getInsertSQL(entity);
 }
 protected static String getInsertSQL(EntityObjectInfo entity) {
  StringBuffer ksql = new StringBuffer();
  StringBuffer params = new StringBuffer();
  PropertyCollection properties = entity.getInheritedNoDuplicatedPropertiesRuntime();
  String[] fields = getTableFields(properties);
  ksql.append(KEY_INSERT).append(" ").append(entity.getTable().getName()).append("\n");
  ksql.append("(");
  for (int i = 0; i < fields.length; i++) {
   ksql.append(fields[i]).append(",");
   if (fields[i].equals("FID")) {
    params.append("newBosId('").append(entity.getBOSType().toString()).append("'),");
   } else {
    params.append("?,");
   }
  }
  ksql = ksql.deleteCharAt(ksql.lastIndexOf(","));
  ksql.append(")");
  params = params.deleteCharAt(params.lastIndexOf(","));
  ksql.append(KEY_VALUES).append("(").append(params.toString()).append(")");
  return ksql.toString();
 }

 /**
  * 根据指定的bostype构建查询的SQL
  * 
  * @param bosType
  *            实体的BOSTYpe
  * @param fields
  *            返回查询的字段，方便在外部获取结果集数据,方法调用时传递空集合即可
  * @param selectors
  *            指定的查询字段，经营分析中暂时用不到，以后扩展可使用
  * @return
  */
 public static String getQuerySQL(BOSObjectType bosType, List fields, SelectorItemCollection selectors) {
  StringBuffer ksql = new StringBuffer();
  if (fields == null) {
   fields = new ArrayList();
  }
  EntityObjectInfo entity = metaDataLoader.getEntity(bosType);
  PropertyCollection properties = entity.getInheritedNoDuplicatedPropertiesRuntime();
  String tableName = entity.getTable().getName();
  PropertyInfo property = null;
  String field = ""; // 表的字段
  String propName = "";// 表字段的别名，例如 [ID] select FID AS ID
  ksql.append(KEY_SELECT).append("\n");
  for (int i = 0, c = properties.size(); i < c; i++) {
   property = properties.get(i);
   propName = property.getName();
   if (property.getMappingField() == null || StringUtils.isEmpty(property.getMappingField().getName())) {
    continue;
   }
   field = property.getMappingField().getName();
   ksql.append(field).append(" AS ").append(propName).append(",\n");
   fields.add(propName);
  }
  ksql = ksql.deleteCharAt(ksql.lastIndexOf(","));
  ksql.append(KEY_FROM).append("\n").append(tableName);
  return ksql.toString();
 }

 /**
  * 获取更新数据的SQL
  * 
  * @param objVal
  *            被更新的业务对象，由于更新时需要用到主键字段，所以主键不能为空
  * @param params
  *            参数
  * @param updateSelectors
  *            更新的字段
  * @throws InvalidDAOMetaDataException 
  */
 public static String getUpdateSQL(IObjectValue objVal, List params, SelectorItemCollection updateSelectors) throws InvalidDAOMetaDataException {
  
  StringBuffer ksql = new StringBuffer();
  if (objVal == null || objVal.getString(objVal.getPKField()) == null) {
   return ksql.toString();
  }
  String keyField = objVal.getPKField();
  String pk = objVal.getString(keyField);
  
  BOSObjectType bosType = objVal.getBOSType();
  EntityObjectInfo bo = metaDataLoader.getEntity(bosType);
  String tableName = bo.getTable().getName();
  ksql.append(KEY_UPDATE).append("\n");
  ksql.append(tableName).append("\n").append("set ").append("\n");
  for (int i = 0, fldSize = updateSelectors.size(); i < fldSize; ++i) {
   SelectorItemInfo item = updateSelectors.get(i);
   String itemName = item.getPropertyName();
   PropertyInfo fld = bo.getPropertyByNameRuntime(getFirstName(itemName));
   if (fld == null || fld.getMappingField() == null)
    continue;
   String fldName = fld.getName();
   if(fldName.equals(keyField) || fldName.equals("name")){
    continue;
   }
   String mappFld = MetaDataUtils.getColumnInfoByPropFromEntity(bo,fld).getName();
   
   ksql.append(mappFld).append("= ? ,");
   if (fld instanceof LinkPropertyInfo) {
    params.add(objVal.getObjectValue(fldName).getString("id"));
   } else {
    params.add(objVal.get(fldName));
   }
  }
  ksql = ksql.deleteCharAt(ksql.lastIndexOf(",")).append("\n");
  String keyFldName = MetaDataUtils.getColumnInfoByPropFromEntity(bo,bo.getPropertyByNameRuntime(keyField)).getName();
  ksql.append(KEY_WHERE).append(" ").append(keyFldName);
  ksql.append("= ? \n");
  params.add(pk);
  return ksql.toString();
 }

 /**
  * 联接属性的处理
  * 
  * @param fullName
  * @return
  */
 private static String getFirstName(String fullName) {
  if (StringUtils.isEmpty(fullName))
   return "";
  int pos = fullName.indexOf('.');
  if (pos > 0)
   return fullName.substring(0, pos);
  else
   return fullName;
 }

 /**
  * 获取字段
  */
 protected static String[] getTableFields(PropertyCollection properties) {
  int count = properties.size();
  List fieldsList = new ArrayList();
  PropertyInfo property = null;
  String field = "";
  for (int i = 0; i < count; i++) {
   property = properties.get(i);
   // LinkPropertyInfo
   if (property.getMappingField() == null || StringUtils.isEmpty(property.getMappingField().getName())) {
    continue;
   }
   field = property.getMappingField().getName();
   fieldsList.add(field);
  }
  return (String[]) fieldsList.toArray(new String[fieldsList.size()]);
 }
}

 以上方法中需要注意对数据的处理，比如业务对象中的枚举类型、布尔类型、日期类型的值需要处理为正确的格式才能确保和数据库的交互。

日期类型的属性，需要是java.sql.Date类型写入数据库，在EAS BOS中通过Info.getDate获取的就是java.sql.Date类型，同时info.getUtilDate获取的是另一个类型；

布尔类型的属性值，需要将true、false转换为1、0；枚举类型就不多说了。