我創建了擴展BasicTransformerAdapter的自定義結果轉換器。在transformTuple方法中,我創建實體的新對象:Hibernate ResultTransformer和gwt requestfactory
@Override
public Object transformTuple(Object[] tuple, String[] aliases) {
RegistryRow row = new RegistryRow();
DataRow dataRow = new DataRow();
Registry registry = new Registry();
for (int i = 0; i < aliases.length; i++) {
if ("id".equals(aliases[i])) {
row.setId((Long) tuple[i]);
} else if ("entityVersion".equals(aliases[i])) {
row.setEntityVersion((Long) tuple[i]);
} else if ("gridRowId".equals(aliases[i])) {
dataRow.setId((Long) tuple[i]);
} else if ("rowEntityVersion".equals(aliases[i])) {
dataRow.setEntityVersion((Long) tuple[i]);
} else if (tuple[i] != null && aliases[i] != null && aliases[i].startsWith("set")) {
try {
DataType type = DataRow.getDataType(tuple[i].getClass());
Method m = DataRow.class.getMethod(aliases[i], type.getDataClass());
m.invoke(dataRow, DataRow.castValue(tuple[i], type));
} catch (Exception e) {
LOG.error("--Error while setting dataRow data: ", e);
}
} else if ("registryCode".equals(aliases[i])) {
registry.setCode((String) tuple[i]);
} else if ("registryEntityVersion".equals(aliases[i])) {
registry.setEntityVersion((Long) tuple[i]);
}
}
row.setRegistry(registry);
row.setGridRow(dataRow);
return row;
}
一切工作正常。有創建RegistryRow對象的列表。 在客戶端有RegistryRowProxy看起來像這樣:
@ProxyFor(value = RegistryRow.class, locator = LongEntityLocator.class)
public interface RegistryRowProxy extends EntityProxy, BeanModelTag {
Long getId();
DataRowProxy getGridRow();
Date getCreateDate();
RegistryProxy getRegistry();
Long getDataId();
}
它是GWT RequestFactory其中話費清單服務使用。
getRequestFactory().registryRow().list(registry.getCode(), paramsId).with("gridRow").fire(receiver);
它返回的數據,一切都很好,但是當我打開show_sql它正在做額外的選擇數據庫。類似的查詢:
select "all_columns" from RegistryRow where id = ?;
select "all_columns" from DataRow where id = ?;
這些查詢的執行次數與列表中的行數一樣多。我不知道如何擺脫這些對性能有影響的附加查詢。你知道爲什麼有額外的數據庫查詢? (我補充一點,在實體存在變數,看起來像這樣:
@JoinColumn(name = "T_DATA_ROWS_ID")
@NotNull
private DataRow gridRow;
,但並非全部)
更新1: 註釋是這樣的正是:
@OneToOne(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
@JoinColumn(name = "T_DATA_ROWS_ID")
@NotNull
private DataRow gridRow;
而且仍然在爲每一行進行查詢。
在代碼中,它看起來是這樣的: '@OneToOne(取= FetchType.EAGER,級聯= CascadeType.ALL ) @JoinColumn(name =「T_DATA_ROWS_ID」) @NotNull private DataRow gridRow;' – Caroline