Question

在将一些Spring XML配置显式加载到GenericXmlApplicationContext对象时，我遇到了使SpEL工作的问题。

非常感谢您提供的任何帮助。这是我的POM文件：

<project xmlns="http://maven.apache.org/POM/4.0.0"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.example</groupId>
    <artifactId>minimal</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>
    <properties>
       <version.spring>3.2.6.RELEASE</version.spring>
    </properties>
    <dependencies>
       <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>${version.spring}</version>
       </dependency>
       <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${version.spring}</version>
       </dependency>
    </dependencies>
</project>

这里是Spring XML配置文件：

<?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"
    xmlns:p="http://www.springframework.org/schema/p"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-3.1.xsd">

    <bean id="defaultPerson" class="java.lang.String">
        <constructor-arg value="World!" />
    </bean>
    <bean id="greeter" class="com.example.Greeter">
        <property name="person" value="#{ getObject('specificPerson') != null ? getObject('specificPerson') : defaultPerson }"/>
    </bean>
</beans>

最后，我的Java代码

public class Greeter {
    private String person;

    public String sayHello() {
        return String.format("Hello %s", this.person);
    }

    public void setPerson(String person) {
        this.person = person;
    }
}


public class Main {

    public static void main(String[] args) {
        GenericApplicationContext parentContext = new GenericApplicationContext();

                parentContext.getBeanFactory().registerSingleton("specificPerson", "Dave");

        GenericXmlApplicationContext xmlContext = new GenericXmlApplicationContext();
        xmlContext.setParent(parentContext);

        // Load the beans
        xmlContext.load("xmlContext.xml");

        // GenericXmlApplicationContext lazy loads singletons by default and we need them instantiated.
        xmlContext.getBeanFactory().preInstantiateSingletons();

        Greeter greeter = (Greeter) xmlContext.getBean("greeter");

        System.out.println(String.format("Greeter says: [%s]", greeter.sayHello()));
    }
}

我希望看到

Greeter says: [Hello Dave]

但我看到了：

Greeter says: [Hello #{ getObject('specificPerson') != null ? getObject('specificPerson') : defaultPerson }]

知道为什么吗？非常感谢您的帮助 - 谢谢！

Answer 1

原来我需要添加对refresh()的调用。

在对象构建后添加对parentContext.refresh()和xmlContext.refresh()的调用解决了问题。希望其他人认为这有用！

使用GenericXmlApplicationContext时的Spring SpEL？

1 个答案: