[英]Spring dependency injection for a dynamic list from database
我是春天的新手。 我的問題是如何將從數據庫加載的值(來自db的業務單位的動態列表)注入另一個bean進行某些處理。
我正在從我的代碼中執行以下操作。
/*** Sample code Starts here ****/
/ *使用加載方法從數據庫加載業務單位* /
public class BusinessUnitDaoImpl implements BusinessUnitDao {
private JdbcTemplate jdbctemplate;
public BusinessUnitDaoImpl() {
super();
}
public BusinessUnitDaoImpl(DataSource ds) {
this.jdbctemplate=new JdbcTemplate(ds);
}
@Override
public List<BusinessUnit> load() {
String SQL = "select * from business_unit";
List<BusinessUnit> businessunits = jdbctemplate.query(SQL,
new BusinessUnitRowMapper());
return businessunits;
}
}
/ *業務單位行映射器* /
public class BusinessUnitRowMapper implements RowMapper<BusinessUnit> {
public BusinessUnitRowMapper() {
// TODO Auto-generated constructor stub
}
public BusinessUnit mapRow(ResultSet rs, int rowNum) throws SQLException {
BusinessUnit bunit = new BusinessUnit();
bunit.setBusinessUnitId(rs.getInt("business_unit_id"));
bunit.setBusinessUnitDesc(rs.getString("business_unit_desc"));
bunit.setCurrencyCode(rs.getString("currency_code"));
return bunit;
}
}
/ *業務單位VO * /
public class BusinessUnit {
private int businessUnitId;
private String businessUnitDesc;
private String currencyCode;
public BusinessUnit() {
super();
}
public int getBusinessUnitId() {
return businessUnitId;
}
public void setBusinessUnitId(int businessUnitId) {
this.businessUnitId = businessUnitId;
}
public String getBusinessUnitDesc() {
return businessUnitDesc;
}
public void setBusinessUnitDesc(String businessUnitDesc) {
this.businessUnitDesc = businessUnitDesc;
}
public String getCurrencyCode() {
return currencyCode;
}
public void setCurrencyCode(String currencyCode) {
this.currencyCode = currencyCode;
}
@Override
public String toString() {
return "BusinessUnit [businessUnitId=" + businessUnitId
+ ", businessUnitDesc=" + businessUnitDesc + ", currencyCode="
+ currencyCode + "]";
}
}
/ *一些服務,它調用dao來加載業務單元* /
public class HarmonyService {
private BusinessUnitDao budao;
private RequestDetails requestDetails;
public HarmonyService(BusinessUnitDao budao,RequestDetails requestDetails) {
this.budao=budao;
this.requestDetails=requestDetails;
}
public List<BusinessUnit> show() {
return budao.load();
}
public WFRequest getDetail(long requestId) {
return requestDetails.load(requestId);
}
}
Spring xml:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<context:property-placeholder location="file:${databaseConfiguration}"/>
<bean id="AmericasDataSource" class="dell.harmony.data.HarmonyBasicDataSource" destroy-method="close" >
<property name="url"><value>${HarmonyAmericasDb.url}</value></property>
<property name="driverClassName"><value>${HarmonyAmericasDb.driverClassName}</value></property>
<property name="username"><value>${HarmonyAmericasDb.username}</value></property>
<property name="password"><value>${HarmonyAmericasDb.password}</value></property>
<property name="removeAbandoned"><value>${HarmonyAmericasDb.removeAbandoned}</value></property>
<property name="initialSize"><value>${HarmonyAmericasDb.initialSize}</value></property>
<property name="maxActive"><value>${HarmonyAmericasDb.maxActive}</value></property>
</bean>
<bean id="EMEADataSource" class="dell.harmony.data.HarmonyBasicDataSource" destroy-method="close" >
<property name="url"><value>${HarmonyEMEADb.url}</value></property>
<property name="driverClassName"><value>${HarmonyEMEADb.driverClassName}</value></property>
<property name="username"><value>${HarmonyEMEADb.username}</value></property>
<property name="password"><value>${HarmonyEMEADb.password}</value></property>
<property name="removeAbandoned"><value>${HarmonyEMEADb.removeAbandoned}</value></property>
<property name="initialSize"><value>${HarmonyEMEADb.initialSize}</value></property>
<property name="maxActive"><value>${HarmonyEMEADb.maxActive}</value></property>
</bean>
<bean id="budao" class="test.dao.BusinessUnitDaoImpl">
<constructor-arg index="0"><ref bean="AmericasDataSource"/></constructor-arg>
</bean>
<bean id="requestdao" class="test.dao.RequestDetailImpl">
<constructor-arg index="0"><ref bean="AmericasDataSource"/></constructor-arg>
</bean>
<bean id="service" class="test.service.HarmonyService">
<constructor-arg index="0"><ref bean="budao"/></constructor-arg>
<constructor-arg index="1"><ref bean="requestdao"/></constructor-arg>
</bean>
</beans>
/ *測試彈簧的測試應用* /
public class MyApp {
public static void main(String args[]) {
ApplicationContext context =
new ClassPathXmlApplicationContext("Spring-All-Module.xml");
HarmonyService hservice = (HarmonyService) context.getBean("service");
System.out.println(hservice.show());
System.out.println(hservice.getDetail(13090000000001L));
}
}
/*** Sample code ends here ****/
題:
如果假設,我想從服務HarmonyService的加載方法中注入業務單位列表,該怎么做?
假設我有一個處理器類,類似下面的BatchProcessor。
public class BatchProcessor {
public List<BusinessUnit> proces(List<BusinessUnit> businessUnitList ) {
//do some processing here.
}
}
如何使用spring xml將動態創建的businessUnit注入到本地方法變量businessUnitList中(請用java代碼和spring xml更改解釋)。
此致,Raghu
我會采取上述答案。
正如我之前所說,我對春天很新。 我有一個想法,當我探索Stackoverflow另一個問題。
讓我們假設businessUnitList作為實例變量。
public class BatchProcessor {
public BatchProcessor(List<BusinessUnit> businessUnitList) {
this.businessUnitList=businessUnitList;
}
private List<BusinessUnit> businessUnitList;
public List<BusinessUnit> getBusinessUnitList() {
return businessUnitList;
}
public void setBusinessUnitList(List<BusinessUnit> businessUnitList) {
this.businessUnitList = businessUnitList;
}
public List<BusinessUnit> process() {
System.out.println("Started processing the business Units" + businessUnitList);
//do some processing
return this.businessUnitList;
}
從MyApp主程序,我可以做到這一點。
BatchProcessor bprocess = (BatchProcessor) context.getBean("bprocessor", hservice.show());
System.out.println(bprocess.process());
//context.getBean( “bprocessor”,hservice.show()); 在這里,我從hservice.show發送動態列表,它連接到數據庫並獲取業務單位列表。
現在再次,我將調用BatchProcessor的進程方法。
這是一種很好的做事方式嗎?
基本上當我們想要動態傳遞一個值時,我們需要使用參數調用contextbean。
我的Spring xml:
<!-- passing a dummy list to the constructor -->
<bean id="bprocessor" class="test.rules.BatchProcessor" scope="prototype">
<constructor-arg type="java.util.List">
<list>
<ref bean="bunit"/>
</list>
</constructor-arg>
我對嗎?
您可以在與HarmonyService
類似的行上HarmonyService
BatchProcessor
<bean id="service" class="test.service.BatchProcessor">
<constructor-arg index="0"><ref bean="budao"/></constructor-arg>
</bean>
然后在BatchProcessor
:
public class BatchProcessor {
private BusinessUnitDao budao;
public BatchProcessor(BusinessUnitDao dao) {
this.budao = dao;
}
public List<BusinessUnit> process() {
// process budao.load() list here
}
}
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