Question

我有一个名为App.java的swing类，我有这个：

private EmployeeService employeeService;

public void setEmployeeService(EmployeeService employeeService) {
    this.employeeService = employeeService;
}

在我的applicationContext.xml中，我有这个：

<bean id="employeeDao" class="com.myapp.dao.EmployeeDaoImpl">
    <property name="dataSource" ref="dataSource" />
</bean>

<bean id="employeeService" class="com.myapp.service.EmployeeServiceImpl">
    <property name="employeeDao" ref="employeeDao" />
</bean>

<bean id="app" class="com.myapp.swing.App">
    <property name="employeeService" ref="employeeService" />
</bean>

当我运行App.java时，我收到employeeService为null的错误。为什么会这样？如果我直接从类中分配employeeService bean：

ConfigurableApplicationContext context = new ClassPathXmlApplicationContext("/spring/applicationContext.xml");
EmployeeService employeeService = (EmployeeService) context.getBean("employeeService");
employeeService.validateEmployeeNo(1234);
context.close();

...

我能够成功运行它。当我从applicationContext.xml注入它时，不是在App.java中连接employeeService吗？

Answer 1

除非您的App类是由Spring容器创建的，否则您将尝试访问任何服务的null。你是如何初始化你的App类的？

App myApp = new App();

或

App myApp = (App) context.getBean("app");

从主类访问时，service变量为null

1 个答案: