Ormlite - 構造函數調用失敗時BaseDaoImpl擴展

Question

我有以下的表格 -

@DatabaseTable(tableName="b", daoClass=B_DaoImpl.class) 
public class B { 

    @DatabaseField 
    public String b1 ; 

    public B(){ 
    // For Ormlite 
    } 
} 

@DatabaseTable(tableName="a", daoClass=A_DaoImpl.class) 
public class A { 

    @DatabaseField 
    public String a1 ; 

    @DatabaseField(foreign=true) 
    public B b; 

    public A(){ 
    // For Ormlite 
    } 
} 

對於這些表，相關道和DaoImpl如下

public interface A_Dao extends Dao<A, String>{} 
public interface B_Dao extends Dao<B, String>{} 


public class B_DaoImpl extends BaseDaoImpl<User, String> implements B_Dao { 

    public B_DaoImpl(ConnectionSource connectionSource) throws SQLException { 
     super(connectionSource, B.class); 
    } 
} 

public class A_DaoImpl extends BaseDaoImpl<User, String> implements A_Dao { 

    public A_DaoImpl(ConnectionSource connectionSource) throws SQLException { 
     super(connectionSource, A.class); 
    } 
} 

數據庫幫手如下：

public class DatabaseHelperImpl extends OrmLiteSqliteOpenHelper implements DatabaseHelper { 

    private A_DaoImpl aDao = null; 
    private B_DaoImpl bDao = null; 

    public B_DaoImpl getBDao() throws SQLException { 
     if (bDao == null) { 
      bDao = getDao(B.class); 
     } 
     return bDao; 
    } 

    public A_DaoImpl getA() throws SQLException { 
     if (aDao == null) { 
      aDao = getDao(A.class); 
     } 
     return aDao; 
    } 
} 

現在，當我嘗試調用 -

ADao aDao = databaseHelper.getA(); 

它出現了錯誤，錯誤如下：

Could not call the constructor in class class A_DaoImpl 

現在，如果我沒有在A中的foriegn關鍵 - 即，如果不包含公衆B B，它工作正常。有什麼我在這裏失蹤？

非常感謝您提前。

Answer 1

我懷疑你的異常堆棧跟蹤結束時缺少原因消息。例如，如果我複製你上面的例子，我得到：

java.sql.SQLException: Could not call the constructor in class class 
     com.j256.ormlite.table.CustomDaoTest$A_DaoImpl 
    at com.j256.ormlite.misc.SqlExceptionUtil.create(SqlExceptionUtil.java:22) 
    ... 
Caused by: java.lang.reflect.InvocationTargetException 
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) 
    ... 
Caused by: java.lang.IllegalArgumentException: Foreign field class 
>>>>  com.j256.ormlite.table.CustomDaoTest$B does not have id field <<<<<< 
    at com.j256.ormlite.field.FieldType.configDaoInformation(FieldType.java:332) 
    ... 

因爲A具有B類的洋場，然後B需要有一個ID字段。外來字段需要標識字段。

我敢肯定A和B是你類的簡化版本，所以如果你發佈了更多的例外，包括所有的原因信息，我會適當地編輯我的答案。