比如我们有下面的一个bean：
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import java.util.Date;
public class Customer {
Date date;
public Date getDate() {
return date;
}
public void setDate(Date date) {
this.date = date;
}
@Override
public String toString() {
return "Customer [date=" + date + "]";
}
}
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注意我们上面的bean中有一个Date，但是如果我们使用下面的配置：
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xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
<
bean
id="customer" class="com.mkyong.common.Customer">
<
property
name="date" value="2010-01-31" />
</
bean
>
</
beans
>
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然后我们尝试着运行的话
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public
class
App {
public
static
void
main(String[] args) {
ApplicationContext context =
new
ClassPathXmlApplicationContext(
"SpringBeans.xml"
);
Customer cust = (Customer) context.getBean(
"customer"
);
System.out.println(cust);
}
}
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会出现如下的错误：
Caused by: org.springframework.beans.TypeMismatchException: Failed to convert property value of type [java.lang.String] to required type [java.util.Date] for property 'date'; nested exception is java.lang.IllegalArgumentException: Cannot convert value of type [java.lang.String] to required type [java.util.Date] for property 'date': no matching editors or conversion strategy foun
在这里提供两种解决办法：
1. Factory bean
声明一个dateFormat的bean，然后引用。如下解决：
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xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
<
bean
id="dateFormat" class="java.text.SimpleDateFormat">
<
constructor-arg
value="yyyy-MM-dd" />
</
bean
>
<
bean
id="customer" class="com.mkyong.common.Customer">
<
property
name="date">
<
bean
factory-bean="dateFormat" factory-method="parse">
<
constructor-arg
value="2010-01-31" />
</
bean
>
</
property
>
</
bean
>
</
beans
>
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2. CustomDateEditor
我们声明一个CustomDateEditor，将String转换为Date对象。
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<
bean
id="dateEditor"
class="org.springframework.beans.propertyeditors.CustomDateEditor">
<
constructor-arg
>
<
bean
class="java.text.SimpleDateFormat">
<
constructor-arg
value="yyyy-MM-dd" />
</
bean
>
</
constructor-arg
>
<
constructor-arg
value="true" />
</
bean
>
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<
bean
class="org.springframework.beans.factory.config.CustomEditorConfigurer">
<
property
name="customEditors">
<
map
>
<
entry
key="java.util.Date">
<
ref
local="dateEditor" />
</
entry
>
</
map
>
</
property
>
</
bean
>
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完整的配置为：
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xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
<
bean
id="dateEditor"
class="org.springframework.beans.propertyeditors.CustomDateEditor">
<
constructor-arg
>
<
bean
class="java.text.SimpleDateFormat">
<
constructor-arg
value="yyyy-MM-dd" />
</
bean
>
</
constructor-arg
>
<
constructor-arg
value="true" />
</
bean
>
<
bean
class="org.springframework.beans.factory.config.CustomEditorConfigurer">
<
property
name="customEditors">
<
map
>
<
entry
key="java.util.Date">
<
ref
local="dateEditor" />
</
entry
>
</
map
>
</
property
>
</
bean
>
<
bean
id="customer" class="com.mkyong.common.Customer">
<
property
name="date" value="2010-02-31" />
</
bean
>
</
beans
>
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