Java 数据库中动态列表的Spring依赖项注入

我是春天的新手。我的问题是如何将从数据库加载的值（来自db的业务单元动态列表）注入到另一个bean中进行一些处理

我正在从我的代码中执行以下操作

                               /*** Sample code Starts here ****/

/*使用Load方法从数据库加载业务单元*/

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;
    }
}

/*一些服务，它调用dao来加载业务单元*/

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);
    }

}

问题:

如果假设，我想从服务HarmonyService的load方法中注入业务单元列表，如何做到这一点

假设我有一个processorclass，类似下面的BatchProcessor

public class BatchProcessor {


          public List<BusinessUnit> proces(List<BusinessUnit> businessUnitList ) {
                 //do some processing here.

           }

}

//getBean（“bprocessor”，hsservice.show（））；这里我从hservice.show发送动态列表，它连接到数据库并获取业务单位列表

现在，我再次调用BatchProcessor的process方法

这是一种好的做事方式吗

基本上，当我们想要动态地传递一个值时，我们需要使用参数调用contextbean

我的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>

<!-- 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>

---

我说得对吗

您可以将

BatchProcessor

包装在与

HarmonyService

<bean id="service" class="test.service.BatchProcessor">
    <constructor-arg index="0"><ref bean="budao"/></constructor-arg>
</bean>

---

我建议改为使用Spring很棒的AOP特性在非容器管理的类上获得DI。这真的很简单，而且非常通用。@Jasperbluse:根据OP，他是Spring和DI的新手，所以我想他在学习基础知识之前不应该深入AOP。你不需要知道AOP就可以使用此功能-Spring会为你解决这个问题。最终结果是对非容器管理的类进行DI。这与使用“@Transactional”注释不需要了解AOP是同一回事，它也是基于AOP构建的。@Jasperbluse:如果基本知识不清楚，我不建议有人使用高级功能。但是我将把这个留给OP来适应AOP来做这个简单的事情。事实证明我看错了这个问题。我认为OP需要对从数据库发出的对象使用DI。所以你是100%对的，而我的建议是100%错的：）哦，对不起！：）

public class BatchProcessor {


          public List<BusinessUnit> proces(List<BusinessUnit> businessUnitList ) {
                 //do some processing here.

           }

}

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;
    }

BatchProcessor bprocess = (BatchProcessor) context.getBean("bprocessor", hservice.show());
System.out.println(bprocess.process());

<!-- 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>

<bean id="service" class="test.service.BatchProcessor">
    <constructor-arg index="0"><ref bean="budao"/></constructor-arg>
</bean>

public class BatchProcessor {
    private BusinessUnitDao budao;

    public BatchProcessor(BusinessUnitDao dao) {
        this.budao = dao;
    }

    public List<BusinessUnit> process() {
       // process budao.load() list here
    }
}