我对接口(interface)的编码如下:
DAO 接口(interface):
public interface SampleTblDao extends BaseDao<SampleTbl> {
/**
*
* @param mapper
* @param sampleKey
* @return
* @throws DataAccessException
*/
public SampleTbl selectSampleTbl(SampleKey sampleKey) throws DataAccessException;
}
DAO 实现
public class SampleTblDaoImpl extends AbstractBaseDao<SampleTbl, SampleTblMapper> implements SampleTblDao {
public SampleTblDaoImpl() {
super(SampleTblMapper.class);
}
@Override
public SampleTbl selectSampleTbl(SampleKey sampleKey) throws DataAccessException {
return getSqlSession().getMapper(SampleTblMapper.class).selectSampleTbl(sampleKey);
}
}
业务逻辑接口(interface):
public interface SampleBusinessLogic {
/**
*
* @param sample
* @return
* @throws SampleException
*/
public Sample createSample(Sample sample) throws SampleException;
/**
*
* @param sample
* @return
* @throws SampleException
*/
public Sample updateSample(Sample sample) throws SampleException;
/**
* @param sampleKey
* @return
* @throws SampleException
*/
public Sample getSample(SampleKey sampleKey) throws SampleException;
}
业务逻辑实现:
public class SampleBusinessLogicImpl implements SampleBusinessLogic {
/**
* sample table dao
*/
@Autowired
@Qualifier(value = "sampleTblDao")
private SampleTblDao sampleTblDao;
@Override
@Transactional(rollbackFor = Exception.class)
public Sample createSample(Sample sample) throws SampleException {
try {
// sample table
createSampleTbl(sample.getSampleTbl());
} catch (Exception e) {
List < String > messageList = new ArrayList < String > ();
String message = "{createSample : " + "{itemId=" + sample.getSampleTbl().getItemId() + "}," + "{itemName=" + sample.getSampleTbl().getItemName() + "}}";
messageList.add("createShop system error");
throw new SampleException(message, messageList, e);
}
return sample;
}
@Override
@Transactional(rollbackFor = Exception.class)
public Sample updateSample(Sample sample) throws SampleException {
List < String > messageList = null;
String message = null;
try {
// global shop table
updateSampleTbl(sample.getSampleTbl());
} catch (IllegalDataException e) {
message = "{updateSample : " + "{itemId=" + sample.getSampleTbl().getItemId() + "}," + "{itemName=" + sample.getSampleTbl().getItemName() + "}}";
messageList = new ArrayList < String > ();
messageList.add("updateSample illegal data error");
throw new SampleException(message, messageList, e);
} catch (Exception e) {
message = "{updateSample : " + "{itemId=" + sample.getSampleTbl().getItemId() + "}," + "{itemName=" + sample.getSampleTbl().getItemName() + "}}";
messageList = new ArrayList < String > ();
messageList.add("updateSample system error");
throw new SampleException(message, messageList, e);
}
return sample;
}
@Override
@Transactional(rollbackFor = Exception.class, readOnly = true)
public Sample getSample(SampleKey sampleKey) throws SampleException {
Sample sample = new Sample();
String message = null;
List < String > messageList = null;
try {
sample.setSampleTbl(getSampleTbl(sampleKey));
} catch (DataNotFoundException e) {
message = "{getSample : " + "{itemId=" + sampleKey.getItemId() + "}}";
messageList = new ArrayList < String > ();
messageList.add("getSample data not found error");
throw new SampleException(message, messageList, e);
} catch (Exception e) {
message = "{getSample : " + "{itemId=" + sampleKey.getItemId() + "}}";
messageList = new ArrayList < String > ();
messageList.add("getSample system error");
throw new SampleException(message, messageList, e);
}
return sample;
}
/**
*
* @param sampleTbl
* @throws Exception
*/
private void createSampleTbl(SampleTbl sampleTbl) throws Exception {
sampleTbl.setItemId(new UUID().toString());
sampleTblDao.insert(sampleTbl);
}
/**
* @param sampleTbl
* @throws Exception
*/
private void updateSampleTbl(SampleTbl sampleTbl) throws Exception {
if (sampleTbl.isTransactionTarget(SampleTbl.class)) {
String message = null;
SampleKey sampleKey = new SampleKey();
sampleKey.setItemId(sampleTbl.getItemId());
SampleTbl sampleTblPre = sampleTblDao.selectSampleTbl(sampleKey);
if (sampleTblPre == null) {
// if sample table is empty
message = "{illegal data error:{sampleTblPre=null}}";
throw new IllegalDataException(message);
}
sampleTbl.setItemId(sampleTblPre.getItemId());
sampleTblDao.update(sampleTbl);
}
}
/**
* @param sampleKey
* @return
* @throws Exception
*/
private SampleTbl getSampleTbl(SampleKey sampleKey) throws Exception {
String message = "";
SampleTbl sampleTbl = sampleTblDao.selectSampleTbl(sampleKey);
if (sampleTbl == null) {
// if sample tbl is empty
message = "{data not found error:{SampleTbl=null}}";
throw new DataNotFoundException(message);
}
return sampleTbl;
}
public void setSampleTblDao(SampleTblDao sampleTblDao) {
this.sampleTblDao = sampleTblDao;
}
}
在应用程序上下文 XML 中，我按如下方式配置了 bean:
<bean id="sampleTblDao" class="com.rakuten.gep.sample.dao.impl.SampleTblDaoImpl" parent="baseDAO" scope="singleton">
<property name="namespace" value="com.rakuten.gep.sample.dao.mapper.SampleTblMapper" />
</bean>
<bean id="sampleBusinessLogic" class="com.rakuten.gep.sample.businesslogic.impl.SampleBusinessLogicImpl" scope="singleton"/>
<!-- and annocation based transaction is configured as follows -->
<tx:annotation-driven transaction-manager="trx-manager" proxy-target-class="true" />
<bean id="trx-manager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource"/>
</bean>
但在调试之后，我意识到在'SampleBusinessLogicImpl' 中的 Autowiring 字段'sampleTblDao' 始终为空。
有什么建议吗？
最佳答案
您正在使用 XML 配置内容并(部分)依赖注释。默认情况下，spring 忽略所有注释，如 @Autowired , @Inject之类的。要启用这些注释的处理，请使用 AutowiredAnnotationBeanPostProcessor 的实例和 CommonAnnotationBeanPostProcessor (后者用于@Resource等JSR-250注解处理)需要注册。
这可以手动完成或使用命名空间完成。
<context:annotation-config />
使用 <context:component-scan /> 时已经暗示人们想要使用注释进行配置以及 <context:annotation-config /> 的功能。已包含，因此无需再次添加。
关于java - Spring 3 : @Autowired dao fields are null in service beans with @Transactional annotation，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/21155010/