Java 通过传递构造函数args来实例化Spring bean？
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Spring bean instantiation by passing constructor args?
提问by user755806
I have below spring bean.
我有下面的春豆。
public class Employee2 {
private int id;
private String name;
private double salary;
public Employee2(int id, String name, double salary) {
this.id = id;
this.name = name;
this.salary = salary;
}
// some logic to call database using above values
}
Now i have below config in spring configuration file.
现在我在 spring 配置文件中有以下配置。
<bean id="emp2" class="com.basic.Employee2">
<constructor-arg name="id" value="" />
<constructor-arg name="name" value="" />
<constructor-arg name="salary" value="" />
</bean>
Now i cannot hard code the values in above config since they are dynamic.
现在我不能硬编码上面配置中的值，因为它们是动态的。
Now i am getting spring bean programmatically using below code. The bean scope is singelton.
现在我使用下面的代码以编程方式获取 spring bean。bean 范围是 singelton。
Employee2 emp = (Employee2)applicationContext.getBean("emp2");
Now how can i pass the values to Employee2 constructor?
现在如何将值传递给 Employee2 构造函数？
Thanks!
谢谢！
回答by Konstantin Yovkov
You can use the ApplicationContext#getBean(String name, Object ... params)method, which
您可以使用ApplicationContext#getBean(String name, Object ... params)方法，该方法
Allows for specifying explicit constructor arguments / factory method arguments, overriding the specified default arguments (if any) in the bean definition.
允许指定显式构造函数参数/工厂方法参数，覆盖 bean 定义中指定的默认参数（如果有）。
For example:
例如：
Integer param1 = 2;
String param2 = "test";
Double param3 = 3.4;
Employee2 emp =
(Employee2)applicationContext.getBean("emp2", param1, param2, param3);
Anyway, while this will possibly work, you should consider using Spring EL, as noted in one of the comments under the question.
无论如何，虽然这可能会奏效，但您应该考虑使用Spring EL，如问题下的评论之一所述。
