CreateIfNecessaryTemplate (OpenNMS 29.0.10 API)

java.lang.Object
- org.opennms.netmgt.dao.support.UpsertTemplate<T,D>
- - org.opennms.netmgt.dao.support.CreateIfNecessaryTemplate<T,D>

```
public abstract class CreateIfNecessaryTemplate<T,D extends OnmsDao<T,?>>
extends UpsertTemplate<T,D>
```
Template for creating a row if and only if one doesn't already exists. This suffers from some of the same concurrency issues as described in the UpsertTemplate. See the detailed javadoc there for a description.

Author:

brozow

Field Summary
- Fields inherited from class org.opennms.netmgt.dao.support.UpsertTemplate
  m_dao, m_transactionManager

Constructor Summary

Constructors
Constructor	Description
`CreateIfNecessaryTemplate(org.springframework.transaction.PlatformTransactionManager transactionManager, D dao)`	Create a CreateIfNecessaryTemplate using the given transactionManager to create transactions.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`protected abstract T`	`doInsert()`	Override this method to insert a new object into the database.
`protected T`	`doUpdate(T dbObj)`	There is no need to update the object for this case as we just return the object found.
`protected abstract T`	`query()`	Override this method to execute the query that is used to determine if there is an existing object in the database

Methods inherited from class org.opennms.netmgt.dao.support.UpsertTemplate
execute

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - CreateIfNecessaryTemplate
```
public CreateIfNecessaryTemplate(org.springframework.transaction.PlatformTransactionManager transactionManager,
                                 D dao)
```
    Create a CreateIfNecessaryTemplate using the given transactionManager to create transactions.
- Method Detail
  - query
```
protected abstract T query()
```
    Description copied from class: UpsertTemplate
    
    Override this method to execute the query that is used to determine if there is an existing object in the database
    
    Specified by:
    
    query in class UpsertTemplate<T,D extends OnmsDao<T,?>>
  - doUpdate
```
protected T doUpdate(T dbObj)
```
    There is no need to update the object for this case as we just return the object found.
    
    Specified by:
    
    doUpdate in class UpsertTemplate<T,D extends OnmsDao<T,?>>
  - doInsert
```
protected abstract T doInsert()
```
    Description copied from class: UpsertTemplate
    
    Override this method to insert a new object into the database. This method will be called when the query method returns null. A DataIntegrityViolationException should be thrown if the insert has already occurred. (This is the normal exception thrown when to objects with the same id are inserted).
    
    Specified by:
    
    doInsert in class UpsertTemplate<T,D extends OnmsDao<T,?>>