how can i inject an empty (new) arraylist of "double/string/object" in spring ?
public class Pack{
private List<String> names;
private List<Course> courses;
private List<double> prices;
private int comp;
}
xml file
<bean id="pack" class="com.classes.Pack">
<property name="compt" value="0" />
<property name="courses" ref="courses" />
<property name="prices" ref="prices" />
<property name="names" ref="names" />
</bean>
You can inject an empty list like this, however this is probably unnecessary, unless you're trying to setup an example template spring XML config perhaps.
<property name="courses">
<list></list>
</property>
Related
Entity:
package com.test.entity
#Entity
#Table(name="TEST_TABLE")
public class TestTable implements HasMapping, PrimaryKey<Long>, Serializable {
public static final String TABLE_NAME = "TEST_TABLE";
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
#Column(name="ID", nullable=false)
private Long id;
#Id
#Column(name="Name", nullable=false)
private String name;
#Temporal(value=TemporalType.TIMESTAMP)
#Column(name="CREATE_TIME", nullable=true)
#CreatedDate
private Date createTime;
#Column(name="CREATE_USER", nullable=true, length=32)
#CreatedBy
private String createUser;
#Temporal(value=TemporalType.TIMESTAMP)
#Column(name="LST_UPD_TIME", nullable=true)
#LastModifiedDate
private Date lstUpdTime;
#Column(name="LST_UPD_USER", nullable=true, length=32)
#LastModifiedBy
private String lstUpdUser;
#Column(name="JPA_VERSION", nullable=false)
#Version
private Integer jpaVersion;
......
}
QPath
package com.test.qpath
#Generated("com.mysema.query.codegen.EntitySerializer")
public class QTestTable extends EntityPathBase<TestTable> {
private static final long serialVersionUID = -1751805455;
public static final QTestTable testTable = new QTestTable("testTable");
public final NumberPath<Long> id = createNumber("id", Long.class);
public final DateTimePath<java.util.Date> createTime = createDateTime("createTime", java.util.Date.class);
public final StringPath createUser = createString("createUser");
public final NumberPath<Integer> jpaVersion = createNumber("jpaVersion", Integer.class);
public final DateTimePath<java.util.Date> lstUpdTime = createDateTime("lstUpdTime", java.util.Date.class);
public final StringPath lstUpdUser = createString("lstUpdUser");
public QTestTable(String variable) {
super(TestTable.class, forVariable(variable));
}
#SuppressWarnings("all")
public QTestTable(Path<? extends TestTable> path) {
super((Class)path.getType(), path.getMetadata());
}
public QTestTable(PathMetadata<?> metadata) {
super(TestTable.class, metadata);
}
......
}
Repository
package com.test.repos
public interface RTestTable extends JpaRepository<TestTable, Long>, QueryDslPredicateExecutor<TestTable> {
}
Service
package com.test.service
#Service
public class TestServiceR() {
#Autowired
private RTestTable rTestTable;
public void handler() {
long id = 1;
TestTable t = rTestTable.findone(id);
}
}
package com.test.service
#Service
public class TestServiceQuery() {
#Autowired
private RTestTable rTestTable;
#PersistenceContext
private EntityManager em;
private QTestTable qTestTable = QTestTable.testTable;
public void handler() {
long id = 1;
JPAQuery query = new JPAQuery(em);
TestTable t = query.from(qTestTable).where(qTestTable.id.eq(id)).singleResult(qTestTable);
}
}
spring config
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" destroy-method="close">
<property name="url" value="#{env.jdbcUrl}" />
<property name="username" value="#{env.jdbcUsername}" />
<property name="password" value="#{env.jdbcPassword}" />
<property name="initialSize" value="1" />
<property name="minIdle" value="#{env['jdbcMinIdle'] ?: 2 }" />
<property name="maxActive" value="#{env['jdbcMaxActive'] ?: 20}" />
<property name="minEvictableIdleTimeMillis" value="#{env['jdbcMinEvictableIdleTimeMillis'] ?: 1800000}" />
<property name="validationQuery" value="#{env['jdbcTestSql']}" />
<property name="testWhileIdle" value="#{env['jdbcTestWhileIdle']?: false}" />
<property name="testOnBorrow" value="#{env['jdbcTestOnBorrow']?: true}" />
<property name="testOnReturn" value="#{env['jdbcTestOnReturn']?: false}" />
<property name="poolPreparedStatements" value="false" />
<property name="maxPoolPreparedStatementPerConnectionSize" value="-1" />
<property name="filters" value="mergeStat,slf4j" />
<property name="connectionProperties" value="druid.stat.slowSqlMillis=1500;druid.stat.logSlowSql=true" />
<property name="timeBetweenLogStatsMillis" value="900000" />
</bean>
<bean id="emf"
class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="persistenceUnitName" value="default" />
<property name="packagesToScan">
<list>
<value>com.sunline.ccs.infrastructure.shared.model</value>
</list>
</property>
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
<property name="database" value="#{env['jpaDatabaseType']?:'DEFAULT'}" />
<property name="showSql" value="#{env['jpaShowSql']?:false}" />
</bean>
</property>
</bean>
<bean id="sessionFactory" factory-bean="emf" factory-method="getSessionFactory" />
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="emf" />
</bean>
<tx:annotation-driven mode="aspectj"
transaction-manager="transactionManager" />
<jpa:repositories base-package="com.test.repos" />
I test TestServiceR.handler() and TestServiceQuery.handler().
I think they don't start a transaction.
but class TestServiceR are start a transaction.
why? how can i set TestServiceR.handler() don't start a transaction.
TestServiceR calls RTestTable.findOne which extends JpaRepository, which is implemented by SimpleJpaRepository, which is annotated with #Transactional(readOnly = true). So, the transaction is started by SimpleJpaRepository.
Is there a particular reason why you are worried about the transaction, given that it does not affect the application adversely (at least not much)? See the comment history for this Spring Data JPA JIRA issue if you are not convinced.
If you still want to override the default behaviour, you can initialise JPA repositories as #EnableJpaRepositories(enableDefaultTransactions = false) (Java configuration) or <jpa:repositories enable-default-transactions="false" ... /> (XML configuration) to prevent the default implementation from creating transactions by default. See this Spring Data JPA JIRA issue for more details.
I have following configuration in application context
<jee:jndi-lookup id="dataSource" jndi-name="MY_DS" />
<context:load-time-weaver/>
<bean id="transactionManager" class="org.springframework.transaction.jta.WebLogicJtaTransactionManager" />
<tx:annotation-driven transaction-manager="transactionManager"/>
<bean
class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />
<bean id="emf"
class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="jtaDataSource" ref="dataSource" />
<property name="jpaVendorAdapter" ref="jpaVendorAdapter" />
<property name="persistenceUnitName" value="pu_TEST" />
</bean>
<bean id="jpaVendorAdapter"
class="org.springframework.orm.jpa.vendor.EclipseLinkJpaVendorAdapter">
<property name="database" value="ORACLE" />
<property name="showSql" value="true" />
</bean>
Now my DAO Class
#Repository
public class EmployeeDAO{
#PersistenceContext
private EntityManager em;
#Transactional
public void create(Employee entity) {
LOG.error("Enitity Manager:create" + em);
em.persist(entity);
// em.flush(); if i use flush it saves
}
}
Now when I save the entity it does not say give any error but no data is updated into db.
I do not wish to use flush as entitymanager is injected by spring and should perform flush at the end automatically which is not happening. correct my understanding.
Adding facade class may be issue is there, Does Propagation.REQUIRES_NEW has anything to do here?
#Transactional(propagation=Propagation.REQUIRES_NEW)
public void process(){
Employee e = factory.getEmployee();
employeeDao.create(e);
}
On Debug after create method call it shows employee got primary key populated that mean db call has made but at the end it is not persisted.
Please try either of the 3 :
1.Solution 1
Please call below code
em.joinTransaction();
just before
em.persistEntity(entity);
2.Solution 2
make attribute readOnly=false in #Transactional
3.Solution 3
Try manually adding bean EmployeeDAO in spring xml file
or else you can try below:
#Transactional(propagation=Propagation.REQUIRED)
My config:
<bean parent="cache-template">
<property name="name" value="yagoLabel" />
<property name="cacheMode" value="PARTITIONED" />
<property name="atomicityMode" value="TRANSACTIONAL" />
<property name="distributionMode" value="PARTITIONED_ONLY" />
<property name="backups" value="1" />
<property name="store">
<bean class="id.ac.itb.ee.lskk.lumen.yago.YagoLabelCacheStore" autowire="byType" init-method="init" />
</property>
<property name="writeBehindEnabled" value="true" />
<property name="writeBehindFlushSize" value="102380" />
<property name="writeBehindFlushFrequency" value="30000" />
<property name="writeBehindBatchSize" value="10240" />
<property name="swapEnabled" value="false" />
<property name="evictionPolicy">
<bean class="org.gridgain.grid.cache.eviction.lru.GridCacheLruEvictionPolicy">
<property name="maxSize" value="102400" />
</bean>
</property>
</bean>
And I start GridGain as follows:
My GridCacheStore implementation:
public class YagoLabelCacheStore extends GridCacheStoreAdapter<String, YagoLabel> {
private static final Logger log = LoggerFactory
.getLogger(YagoLabelCacheStore.class);
private DBCollection labelColl;
#GridSpringResource(resourceName="mongoDb")
private DB db;
#Inject
private GridGainSpring grid;
#PostConstruct
public void init() {
log.info("Grid is {}", grid);
labelColl = db.getCollection("label");
}
I start GridGain as follows:
String entityId = "Muhammad";
try (AnnotationConfigApplicationContext appCtx
= new AnnotationConfigApplicationContext(LumenConfig.class)) {
Grid grid = appCtx.getBean(Grid.class);
GridCache<String, YagoLabel> labelCache = YagoLabel.cache(grid);
log.info("Label for {}: {}", entityId, labelCache.get(entityId));
}
LumenConfig Spring configuration contains a DB bean named mongoDb.
However this throws NullPointerException because db is not injected properly. I tried #Inject GridGainSpring just for testing, and even GridGainSpring itself is not injected.
I also tried setting <property name="db" ref="mongoDb"/> in the GridGain Config XML but Spring complains cannot find the bean.
My workaround is to put it inside a public static field but that's soo hacky: https://github.com/ceefour/lumen-kb/blob/b8445fbebd227fb7ac337c758a60badb7ecd3095/cli/src/main/java/id/ac/itb/ee/lskk/lumen/yago/YagoLabelCacheStore.java
The way is to load the GridConfiguration using Spring, then pass it to GridGainSpring.start() :
// "classpath:" is required, otherwise it won't be found in a WAR
#ImportResource("classpath:id/ac/itb/ee/lskk/lumen/core/lumen.gridgain.xml")
#Configuration
public static class GridGainConfig {
#Inject
private ApplicationContext appCtx;
#Inject
private GridConfiguration gridCfg;
#Bean(destroyMethod="close")
public Grid grid() throws GridException {
return GridGainSpring.start(gridCfg, appCtx);
}
}
:-)
Let's say, I have a REST styled controller mapping
#RequestMapping(value="users", produces = {MediaType.APPLICATION_JSON_VALUE})
public List<User> listUsers(#ReqestParams Integer offset, #ReqestParams Integer limit, #ReqestParams String query) {
return service.loadUsers(query, offset, limit);
}
Serving JSON (or even XML) is not an issue, this is easy using ContentNegotation and MessageConverters
<bean id="contentNegotiationManager" class="org.springframework.web.accept.ContentNegotiationManagerFactoryBean">
<property name="favorPathExtension" value="true" />
<property name="favorParameter" value="false" />
<property name="ignoreAcceptHeader" value="false" />
<property name="mediaTypes" >
<value>
html=text/html
json=application/json
xml=application/xml
</value>
</property>
</bean>
Now, I need to add support for PDF. Naturally, I want to use (Spring) MVC + REST as much as possible. Most examples I have found implement this with an explicit definition not using REST style, e.g.
#RequestMapping(value="users", produces = {"application/pdf"})
public ModelAndView listUsersAsPdf(#ReqestParams Integer offset, #ReqestParams Integer limit, #ReqestParams String query) {
List<User> users = listUsers(offset, limit, query); // delegated
return new ModelAndView("pdfView", users);
}
That works, but is not very comfortable because for every alternate output (PDF, Excel, ...) I would add a request mapping.
I have already added application/pdf to the content negotation resolver; unfortunately any request with a suffix .pdf or the Accept-Header application/pdf were be responded with 406.
What is the ideal setup for a REST/MVC style pattern to integrate alternate output like PDF?
You can create a WEB-INF/spring/pdf-beans.xml like below.
<bean id="listofusers" class="YourPDFBasedView"/>
And your controller method will return view name as listofusers.
#RequestMapping(value="users")
public ModelAndView listUsersAsPdf(#ReqestParams Integer offset, #ReqestParams Integer limit, #ReqestParams String query) {
List<User> users = listUsers(offset, limit, query); // delegated
return new ModelAndView("listofusers", users);
}
And you can use contentNegotiationViewResolver in this way:
<bean class="org.springframework.web.servlet.view.XmlViewResolver">
<property name="order" value="1"/>
<property name="location" value="WEB-INF/spring/pdf-views.xml"/>
</bean>
<!--
View resolver that delegates to other view resolvers based on the content type
-->
<bean class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver">
<!-- All configuration is now done by the manager - since Spring V3.2 -->
<property name="contentNegotiationManager" ref="cnManager"/>
</bean>
<!--
Setup a simple strategy:
1. Only path extension is taken into account, Accept headers are ignored.
2. Return HTML by default when not sure.
-->
<bean id="cnManager" class="org.springframework.web.accept.ContentNegotiationManagerFactoryBean">
<property name="ignoreAcceptHeader" value="true"/>
<property name="defaultContentType" value="text/html" />
</bean>
For JSON: Create a generic JSON view resolver like below and register it as bean in context file.
public class JsonViewResolver implements ViewResolver {
/**
* Get the view to use.
*
* #return Always returns an instance of {#link MappingJacksonJsonView}.
*/
#Override
public View resolveViewName(String viewName, Locale locale) throws Exception {
MappingJacksonJsonView view = new MappingJacksonJsonView();
view.setPrettyPrint(true); // Lay the JSON out to be nicely readable
return view;
}
}
Same for XML:
public class MarshallingXmlViewResolver implements ViewResolver {
private Marshaller marshaller;
#Autowired
public MarshallingXmlViewResolver(Marshaller marshaller) {
this.marshaller = marshaller;
}
/**
* Get the view to use.
*
* #return Always returns an instance of {#link MappingJacksonJsonView}.
*/
#Override
public View resolveViewName(String viewName, Locale locale)
throws Exception {
MarshallingView view = new MarshallingView();
view.setMarshaller(marshaller);
return view;
}
}
and register above xml view resolver in context file like this:
<oxm:jaxb2-marshaller id="marshaller" >
<oxm:class-to-be-bound name="some.package.Account"/>
<oxm:class-to-be-bound name="some.package.Customer"/>
<oxm:class-to-be-bound name="some.package.Transaction"/>
</oxm:jaxb2-marshaller>
<!-- View resolver that returns an XML Marshalling view. -->
<bean class="some.package.MarshallingXmlViewResolver" >
<constructor-arg ref="marshaller"/>
</bean>
You can find more information at this link:
http://spring.io/blog/2013/06/03/content-negotiation-using-views/
Using all view resolver techniques, you can avoid writing duplicate methods in controller, such as one for xml/json, other for excel, other for pdf, another for doc, rss and all.
Knalli, if you replace #ResponseBody with ModelAndView(), you can achieve both the features.
Is there any reason you want to keep #ResponseBody ? I just want to know if I am missing anything, just want to learn.
Other option is to write HttpMessageConverters then:
Some samples are here.
Custom HttpMessageConverter with #ResponseBody to do Json things
http://www.javacodegeeks.com/2013/07/spring-mvc-requestbody-and-responsebody-demystified.html
This is working sample. I have configured contentnegotiationviewresolver for this, and give highest order. After that I have ResourceBundleViewResolver for JSTL and Tiles View, then XmlViewResolver for excelResolver, pdfResolver, rtfResolver. excelResolver, pdfResolver, rtfResolver. XmlViewResolver and ResourceBundleViewResolver works only with MAV only, but MappingJacksonJsonView and MarshallingView takes care for both MAV and #ResponseBody return value.
<bean id="contentNegotiatingResolver" class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver">
<property name="order"
value="#{T(org.springframework.core.Ordered).HIGHEST_PRECEDENCE}" />
<property name="mediaTypes">
<map>
<entry key="json" value="application/json" />
<entry key="xml" value="application/xml" />
<entry key="pdf" value="application/pdf" />
<entry key="xlsx" value="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet" />
<entry key="doc" value="application/msword" />
</map>
</property>
<property name="defaultViews">
<list>
<!-- JSON View -->
<bean class="org.springframework.web.servlet.view.json.MappingJacksonJsonView" />
<!-- XML View -->
<bean class="org.springframework.web.servlet.view.xml.MarshallingView">
<constructor-arg>
<bean id="jaxbMarshaller" class="org.springframework.oxm.jaxb.Jaxb2Marshaller">
<property name="classesToBeBound">
<list>
<value>Employee</value>
<value>EmployeeList</value>
</list>
</property>
</bean>
</constructor-arg>
</bean>
</list>
</property>
<property name="ignoreAcceptHeader" value="true" />
</bean>
<bean class="org.springframework.web.servlet.view.ResourceBundleViewResolver"
id="resourceBundleResolver">
<property name="order" value="#{contentNegotiatingResolver.order+1}" />
</bean>
<bean id="excelResolver" class="org.springframework.web.servlet.view.XmlViewResolver">
<property name="location">
<value>/WEB-INF/tiles/spring-excel-views.xml</value>
</property>
<property name="order" value="#{resourceBundleResolver.order+1}" />
</bean>
<bean id="pdfResolver" class="org.springframework.web.servlet.view.XmlViewResolver">
<property name="location">
<value>/WEB-INF/tiles/spring-pdf-views.xml</value>
</property>
<property name="order" value="#{excelResolver.order+1}" />
</bean>
<bean id="rtfResolver" class="org.springframework.web.servlet.view.XmlViewResolver">
<property name="location">
<value>/WEB-INF/tiles/spring-rtf-views.xml</value>
</property>
<property name="order" value="#{excelResolver.order+1}" />
</bean>
And our XMLViewResolver spring-pdf-views.xml looks like this.
<bean id="employees"
class="EmployeePDFView"/>
And EmployeePDFView will have code for generating pdf and writing pdf byte stream on Response object. This will resolve to rest url that will end with .pdf extension, and when you return MAV with "employees" id.
We have an application where we have used spring for IOC. We have the dataSource bean configured in applicationContext.xml and that is referenced in other bean definations.
The dataSource bean defination looks like:
<bean id="dbDataSource" class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close">
<property name="driverClassName" value="oracle.jdbc.driver.OracleDriver" />
<property name="url"
value="jdbc:oracle:oci:#TESTDB" />
<property name="username" value="TESTUSER" />
<property name="password" value="TESTPWD" />
<property name="initialSize" value="50" />
<property name="maxActive" value="40" />
<property name="maxIdle" value="10" />
<property name="minIdle" value="10" />
<property name="maxWait" value="-1" />
</bean>
<bean id="serviceDAO" class="com.test.impl.ServiceDAOImpl">
<property name="dataSource" ref="dbDataSource" />
</bean>
ServiceDAOImpl looks as follows:
public class ServiceDAOImpl implements ServiceDAO {
private JdbcTemplate jdbcTemplate;
public void setDataSource(DataSource dataSource) {
this.jdbcTemplate = new JdbcTemplate(dataSource);
}
#SuppressWarnings({ "rawtypes", "unchecked" })
public ValueObj readValue(String key) {
String query = "SELECT * FROM SERVICE_LOOKUP WHERE KEY=?";
/**
* Implement the RowMapper callback interface
*/
return (ValueObj) jdbcTemplate.queryForObject(query,
new Object[] { key }, new RowMapper() {
public Object mapRow(ResultSet resultSet, int rowNum)
throws SQLException {
return new ValueObj(resultSet.getString("KEY"),
resultSet.getString("VALUE"));
}
});
}
public ServiceDAOImpl() {
}
}
Now, at the server start up injection is happening fine and when we use the dataSource in serviceDAOImpl the connection is happening fine. But the very first time the database call is made it takes around 3 mins to get the response back. I think this is because the pool creation is done during the first call and we have set the parameter "initialSize" = 50 in applicationConext.xml.
So, to avoid this we need a way in which the pool can be created during the application startup itself and can be used directly.
Please suggest. Let me know if any clarification required.
Regards
Saroj
There's a work-around for this .You could force jdbcTemplate to use the
DB connection at startup. See the link here for detailed explanation .
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<constructor-arg index="0" ref="dataSource"/>
<constructor-arg index="1" value="false"/>
</bean>
The second constructor-arg is the lazy Init flag.
Aravind A's solution is the preffered one, but just in case you don't want to define an extra bean you can point spring to your DAO's init method:
<bean id="serviceDAO" class="com.test.impl.ServiceDAOImpl" init-method="init">
<property name="dataSource" ref="dbDataSource" />
</bean>
and then define ServiceDAOImpl.init() which calls some sql like SELECT 1 FROM SERVICE_LOOKUP LIMIT 1 or even better some noop like SELECT 1:
public class ServiceDAOImpl implements ServiceDAO {
public void init() {
String query = "SELECT 1 FROM SERVICE_LOOKUP LIMIT 1";
int i = jdbcTemplate.queryForInt(query);
}
}