如何定制EO的增加、修改、删除操作？

开发环境：JDeveloper 11.1.2.2.0 + Oracle XE Database 10gR2。

本实验基于《使用ADF实现基于Form的CRUD
（3）》

ADF-BC中的EO对象写入数据库的操作本来不需要我们关心，不用写任何代码，这是使用ADF-BC的好处之一。

但在实际开发中，有时需要在EO入库前做一些其它操作，比如设置默认属性值、设置Sequence值；有时需要在插入某个EO后做一些其它事情，比如再插入另一个EO对象。

这时，就需要定制EO的增加、修改、删除操作，以及定制提交入库前后的代码。

ADF-BC为定制化提供了优美的解决方案：

1. 定制EO的增加、修改、删除操作

（1）选中需要定制的EO，为其生成对应的Entity Object Java Class，勾上“Create”、“Remove”、“Data Manipulation Methods"。





（2）定制create、remove、doDML方法

protected void create(AttributeList attributeList) {
System.out.println("################### before create:");
super.create(attributeList);
System.out.println("################### after create:");
}

public void remove() {
System.out.println("################### before remove:");
super.remove();
System.out.println("################### after remove:");
}

protected void doDML(int operation, TransactionEvent e) {
if (operation == DML_INSERT) {
System.out.println("################### doDML before insert:");
super.doDML(operation, e);
System.out.println("################### doDML after insert:");
} else if (operation == DML_UPDATE) {
System.out.println("################### doDML before update:");
super.doDML(operation, e);
System.out.println("################### doDML after update:");
} else if (operation == DML_DELETE) {
System.out.println("################### doDML before delete:");
super.doDML(operation, e);
System.out.println("################### doDML after delete:");
}
}

doDML方法说明：

（1）根据不同的操作（增加、修改、删除），选择不同的逻辑分支。

super.doDML(operation, e); 就是EO自身的入库操作代码，除非你要彻底修改它的逻辑，否则不要修改。

（2）入库前的代码，写在super.doDML(operation, e);之前。

（3）入库后的代码，写在super.doDML(operation, e);之后。

（4）关于EO常用操作代码请参考《ADF-BC中EO常用操作代码之一：查询》系列文章。

2. 定制EO提交入库前后的代码

EO提交入库分为前后两个阶段：Post Phase和Commit Phase。

（1）Post Phase

验证标记为”invalid“的EO，所有新建的和修改的EO都被标记为”invalid“的EO。

验证定义在EO上的所有验证规则，包括定制的验证规则。

由于验证规则可能会修改EO数据，因此验证过程将反复执行多次，最多执行10次，直到EO被标记为”valid"。

最后，把标记为”valid"的EO提交到数据库。

（2）Commit Phase

提交事务，将EO改变的数据写入数据库。

public void postChanges(TransactionEvent transactionEvent) {
System.out.println("################### before postChanges:");
super.postChanges(transactionEvent);
System.out.println("################### after postChanges:");
}

public void beforeCommit(TransactionEvent transactionEvent) {
System.out.println("################### before commit:");
super.beforeCommit(transactionEvent);
}

public void beforeRollback(TransactionEvent transactionEvent) {
System.out.println("################### before rollback:");
super.beforeRollback(transactionEvent);
}

public void afterCommit(TransactionEvent transactionEvent) {
super.afterCommit(transactionEvent);
System.out.println("################### after commit:");
}

public void afterRollback(TransactionEvent transactionEvent) {
super.afterRollback(transactionEvent);
System.out.println("################### after rollback:");
}

3. 运行AM

（1）点击Insert





Console输出如下：

################### before create:

################### after create:

[67] **** refreshControl() for BindingContainer :AppModule_JobsView1_0PageDef

（2）成功Insert后，点击Commit





Console输出如下：

[68] INFO: No app _def_ in BindingContext for: adfFacesContext

[69] INFO: mDCRefMap lookup failed. Does the cpx have a dataControlUsages 'dc' entry? adfFacesContext

[70] INFO: No app _def_ in BindingContext for: adfFacesContext

[71] INFO: mDCRefMap lookup failed. Does the cpx have a dataControlUsages 'dc' entry? adfFacesContext

[72] OracleSQLBuilder: SAVEPOINT 'BO_SP'

################### before postChanges:

################### doDML before insert:

[73] OracleSQLBuilder Executing, Lock 2 DML on: JOBS (Insert)

[74] INSERT buf Jobs>#i SQLStmtBufLen: 300, actual=77

[75] INSERT INTO JOBS(JOB_ID,JOB_TITLE,MIN_SALARY,MAX_SALARY) VALUES (:1,:2,:3,:4)

[76] Insert binding param 1: 3344

[77] Insert binding param 2: 4444

[78] Insert binding param 3: 1

[79] Insert binding param 4: 2

################### doDML after insert:

################### after postChanges:

################### before commit:

################### after commit:

[80] JobsView1 notify COMMIT ...

（3）修改EO数据，并点击Commit

Console输出如下：

[81] OracleSQLBuilder: SAVEPOINT 'BO_SP'

################### before postChanges:

[82] OracleSQLBuilder Executing doEntitySelect on: JOBS (true)

[83] Built select: 'SELECT JOB_ID, JOB_TITLE, MIN_SALARY, MAX_SALARY FROM JOBS Jobs'

[84] Executing LOCK...SELECT JOB_ID, JOB_TITLE, MIN_SALARY, MAX_SALARY FROM JOBS Jobs WHERE JOB_ID=:1 FOR UPDATE NOWAIT

[85] Where binding param 1: 3344

################### doDML before update:

[86] OracleSQLBuilder Executing, Lock 2 DML on: JOBS (Update)

[87] UPDATE buf Jobs>#u SQLStmtBufLen: 255, actual=64

[88] UPDATE JOBS Jobs SET MIN_SALARY=:1,MAX_SALARY=:2 WHERE JOB_ID=:3

[89] Update binding param 1: 3

[90] Update binding param 2: 4

[91] Where binding param 3: 3344

################### doDML after update:

################### after postChanges:

################### before commit:

################### after commit:

[92] JobsView1 notify COMMIT ...

[93] EntityCache close prepared statement

（4）点击Delete





Console输出如下：

################### before remove:

[94] QueryCollection: afterRemove(0)

[95] ViewRowCache: removeReference, vr id = 3

################### after remove:

（5）成功Delete后，点击Commit





Console输出如下：

[96] OracleSQLBuilder: SAVEPOINT 'BO_SP'

################### before postChanges:

[97] OracleSQLBuilder Executing doEntitySelect on: JOBS (true)

[98] Built select: 'SELECT JOB_ID, JOB_TITLE, MIN_SALARY, MAX_SALARY FROM JOBS Jobs'

[99] Executing LOCK...SELECT JOB_ID, JOB_TITLE, MIN_SALARY, MAX_SALARY FROM JOBS Jobs WHERE JOB_ID=:1 FOR UPDATE NOWAIT

[100] Where binding param 1: 3344

################### doDML before delete:

[101] OracleSQLBuilder Executing, Lock 2 DML on: JOBS (Delete)

[102] DELETE buf Jobs>#u SQLStmtBufLen: 105, actual=37

[103] DELETE FROM JOBS Jobs WHERE JOB_ID=:1

[104] Where binding param 1: 3344

################### doDML after delete:

################### after postChanges:

################### before commit:

################### after commit:

[105] JobsView1 notify COMMIT ...

[106] EntityCache close prepared statement

4. 把删除操作变为修改操作

（1）重写remove方法和doDML方法

public void remove() {
setMinSalary(new Integer(-1));
setMaxSalary(new Integer(-1));
super.remove();
}

protected void doDML(int operation, TransactionEvent e) {
if (operation == DML_INSERT) {
System.out.println("################### doDML before insert:");
super.doDML(operation, e);
System.out.println("################### doDML after insert:");
} else if (operation == DML_UPDATE) {
System.out.println("################### doDML before update:");
super.doDML(operation, e);
System.out.println("################### doDML after update:");
} else if (operation == DML_DELETE) {
if (operation == DML_DELETE) {
operation = DML_UPDATE;
}
super.doDML(operation, e);
}
}

remove方法说明：这里必须把设置字段值的操作放到 super.remove();前面，否则运行时会抛出异常：“Attempt to access dead entity in Jobs, key=oracle.jbo.Key[123 ]"。

（2）运行AM，删除一条记录，并Commit

Console输出如下：

[81] QueryCollection: afterRemove(0)

[82] ViewRowCache: removeReference, vr id = 3

[83] OracleSQLBuilder: SAVEPOINT 'BO_SP'

################### before postChanges:

[84] OracleSQLBuilder Executing doEntitySelect on: JOBS (true)

[85] Built select: 'SELECT JOB_ID, JOB_TITLE, MIN_SALARY, MAX_SALARY FROM JOBS Jobs'

[86] Executing LOCK...SELECT JOB_ID, JOB_TITLE, MIN_SALARY, MAX_SALARY FROM JOBS Jobs WHERE JOB_ID=:1 FOR UPDATE NOWAIT

[87] Where binding param 1: 2232

[88] OracleSQLBuilder Executing, Lock 2 DML on: JOBS (Update)

[89] UPDATE buf Jobs>#u SQLStmtBufLen: 255, actual=64

[90] UPDATE JOBS Jobs SET MIN_SALARY=:1,MAX_SALARY=:2 WHERE JOB_ID=:3

[91] Update binding param 1: -1

[92] Update binding param 2: -1

[93] Where binding param 3: 2232

################### after postChanges:

################### before commit:

################### after commit:

[94] JobsView1 notify COMMIT ...

[95] EntityCache close prepared statement

查看数据库，被Delete的记录依然存在，只是MinSalary和MaxSalary字段的值为-1。

5. 运行页面form_crud.jsf

点击Delete，并确认提交后，发现数据被真的删除了，说明Delete Opertaion并没有调用remove方法。

从Console输出也能够看出来，因为没有打印出来自定义的语句，这不符合我的本来想法。

如果执行Delete Opertaion时没有调用remove方法，那remove方法就失去其意义了。

难道说，如果想调用remove方法，就必须通过程序明确调用EO的remove方法？比如：

public void deleteJob(String jobId) {
JobsImpl job = retrieveJobById(jobId);
if (job != null) {
job.remove();
try {
getTransaction().commit();
} catch (JboException ex) {
getTransaction().rollback();
throw ex;
}
}
}

Project 下载：ADF_Form_CRUD(CustomEO).7z
http://maping930883.blogspot.com/2010/04/adf058eo_03.html