问题描述
我想了解初始化JOOQ生成的DAO的最佳实践.现在,我正在使用以下方法初始化JOOQ生成的DAO.在以下情况下,StudentDao是JOOQ生成的.
I want to know Best practices for initilizing JOOQ generated DAO. Now,I am using following approach for initilization of JOOQ generated DAO. In following case StudentDao is JOOQ generated.
public class ExtendedStudentDAO extends StudentDao {
public ExtendedStudentDAO () {
super();
}
public ExtendedStudentDAO (Connection connection) {
Configuration configuration = DSL.using(connection,
JDBCUtils.dialect(connection)).configuration();
this.setConfiguration(configuration);
}
//adding extra methods to DAO using DSL
public String getStudentName(Long ID)
throws SQLException {
try (Connection connection = ServiceConnectionManager.getConnection()) {
DSLContext dslContext = ServiceConnectionManager
.getDSLContext(connection);
Record1<String> record = dslContext
.select(Student.Name)
.from(Student.Student)
.where(Student.ID
.equal(ID)).fetchOne();
if (record != null) {
return record.getValue(Student.Name);
}
return null;
}
}
}
我对使用上面的DAO感到怀疑,我的示例代码如下.
and I have doubt with using above DAO my example code is below.
try (Connection connection = ServiceConnectionManager.getConnection()) {
ExtendedStudentDAO extendedStudentDAO =new ExtendedStudentDAO(connection);
Student stud=new Student();
.....
....
//insert method is from Generated DAO
extendedStudentDAO.insert(stud);
//this method is added in extended class
extendedStudentDAO.getStudentName(12);
}
推荐答案
查看这种初始化有两种方法:
There are two ways to look at this kind of initialisation:
您的方法是正确的,但可能会被认为有点繁重.每次需要时,您都在创建一个新的DAO
.
Your approach is correct, but might be considered a bit heavy. You're creating a new DAO
every time you need it.
从jOOQ 3.7开始,DAO
是一个非常轻巧的对象.包裹Connection
的Configuration
也是一样.
As of jOOQ 3.7, a DAO
is a pretty lightweight object. The same is true for the Configuration
that wraps your Connection
.
一旦您的项目进行了开发(或在将来的jOOQ版本中),由于您的Configuration
初始化(或jOOQ的DAO
初始化)可能会变得越来越重,这可能不再成立.
Once your project evolves (or in future jOOQ versions), that might no longer be true, as your Configuration
initialisation (or jOOQ's DAO
initialisation) might become heavier.
但这是一个很小的风险,而且很容易解决:
But this is a small risk, and it would be easy to fix:
大多数人将为他们的应用程序只设置一个jOOQ Configuration
,并且在服务中的某个位置也只设置一个DAO
实例(每种DAO
类型).在这种情况下,您的Configuration
不得共享Connection
引用,而应通过 ConnectionProvider
SPI .就您而言,这似乎微不足道:
Most people will set up only a single jOOQ Configuration
for their application, and also only a single DAO
instance (per DAO
type), somewhere in a service. In this case, your Configuration
must not share the Connection
reference, but provide a Connection
to jOOQ via the ConnectionProvider
SPI. In your case, that seems trivial enough:
class MyConnectionProvider implements ConnectionProvider {
@Override
public Connection acquire() {
return ServiceConnectionManager.getConnection();
}
@Override
public void release(Connection connection) {
try {
connection.close();
}
catch (SQLException e) {
throw new DataAccessException("Error while closing", e);
}
}
}
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