我学习了春天，我在init，destroy方法和构造函数部分中感到困惑
这是public class Car {
private Engine engine;
public Car(Engine engine){
System.out.println("Inside Car constructor");
this.engine = engine;
}
public void startCarEngine(){
engine.startEngine();
}
private void initEngine(){
System.out.println("heating up engine");
}
}
Engine.java这是public class Engine {
public Engine(){
System.out.println("Inside Engine constructor");
}
public void startEngine(){
System.out.println("Engine is starting...");
}
}
MessageBean.java这是public class MessagesBean {
private static final String HELLO_WORLD = "Hello World";
public MessagesBean(){
System.out.println("Printing " + HELLO_WORLD);
}
public void start(){
System.out.println("Step 2.Bean is starting");
}
}
Main class这是 AbstractApplicationContext abstractAppContext = new ClassPathXmlApplicationContext("spring-config.xml");
MessagesBean msgBean2 = abstractAppContext.getBean("msgBean", MessagesBean.class);
output这是我的 Printing Hello World
Step 2.Bean is starting
Inside Engine constructor
Inside Car constructor
heating up engine
MessageBean这是我的MessageBean Constructor
init我的问题是我在主课程中只调用<tr>
<td>Down payment $</td>
<td>
<input name="downpaymentpc" id="downpaymentpc" type="text" size="8" maxlength="8" onChange="javascript:downPaymentPcChanged(true);" value="<?php echo $min_fha_down_payment;?>" />%</td>
<td colspan="2">Or $
<input name="downpaymentamt" id="downpaymentamt" type="text" size="8" maxlength="8" onChange="javascript:downPaymentAmountChanged(true);" />
</td>
</tr>
并且它应该只调用<div class="col-md-2 padding-Zero">
<input name="downpaymentpc" id="downpaymentpc" type="text" class="txt" size="8" maxlength="8" onChange="javascript:downPaymentPcChanged(true);" value="<?php echo $min_fha_down_payment;?>" />
</div>
<div class="col-md-1 padding-lft">
<img src="Content/Images/percent.png" onclick="changeColor(event,this.src)" style="cursor:pointer" />
</div>
和<td>Monthly MIP </td>
<td>
<input name="monthlymippc" type="text" size="8" maxlength="8" onChange="javascript:monthlyMIPPcChanged(true)" />
%</td>
<td>Or $
<input name="monthlymipamt" type="text" size="8" maxlength="8" onChange="javascript:monthlyMIPAmountChanged(true)"/>
</td>
方法，但为什么另外两个bean构造函数和init方法是叫做或做错了什么？如果我对不同的bean有不同的init，destroy方法，并且我只想初始化/调用特定的bean（s）构造函数和init方法，该怎么办？
答案 0 :(得分：2)
默认情况下，spring beans会被急切地初始化，如果你想让它们懒得初始化，可以在bean定义中添加这个属性
lazy-init="true"