java - setter 在 Spring Framework #2 中如何工作？

Question

很抱歉收到此 article 的副本。我想评论它，但没有 50 分声誉我无法评论，所以...

我有

private boolean stopLoggingIntoDb;
....
  public void setStopLoggingIntoDb(String stopLoggingIntoDb) {  
    this.stopLoggingIntoDb = BooleanUtils.toBoolean(stopLoggingIntoDb.replaceAll("[^A-Za-z]", ""));
    logger.warn("Logging into SiebelMethodLogs is " + (!this.stopLoggingIntoDb ? "ON" : "OFF"));
}

和 XML

<bean id="siebelMethodProcessor" class="com.entities.utils.Logger">
    <property name="logService" ref="logService"/>
    <property name="stopLoggingIntoDb" value="${monitor.siebel.stopLogging}"/>
</bean>

在这种情况下，一切都好，但是如果我将setter方法中的属性从stopLoggingIntoDb更改为stopLog，并将XML中的属性名称也更改为stopLog或不更改，Spring说我无效属性'stopLoggingIntoDb'或Bean属性'stopLog ' 不可写。

因此，我的问题是 Spring 使用 setter 方法做什么？注入(inject)哪个值以及在获取注入(inject)时搜索哪个字段/属性？

Answer 1

正如 Spring Documentation 中的示例所示，name <property> 的属性元素必须与 setter 方法匹配。方法参数的名称和字段的名称并不重要。

Examples of dependency injection

The following example uses XML-based configuration metadata for setter-based DI. A small part of a Spring XML configuration file specifies some bean definitions:

<bean id="exampleBean" class="examples.ExampleBean">
    <!-- setter injection using the nested ref element -->
    <property name="beanOne">
        <ref bean="anotherExampleBean"/>
    </property>

    <!-- setter injection using the neater ref attribute -->
    <property name="beanTwo" ref="yetAnotherBean"/>
    <property name="integerProperty" value="1"/>
</bean>

<bean id="anotherExampleBean" class="examples.AnotherBean"/>
<bean id="yetAnotherBean" class="examples.YetAnotherBean"/>

public class ExampleBean {

    private AnotherBean beanOne;
    private YetAnotherBean beanTwo;
    private int i;

    public void setBeanOne(AnotherBean beanOne) {
        this.beanOne = beanOne;
    }

    public void setBeanTwo(YetAnotherBean beanTwo) {
        this.beanTwo = beanTwo;
    }

    public void setIntegerProperty(int i) {
        this.i = i;
    }

}

注意如何name="integerProperty"匹配到 setIntegerProperty()方法，即使参数名为 i该字段名为 i .