jsf配置问题 Error performing conversion of value ' of type class java.lang.String to type class

managed-bean:UserBean

/**

*

*/

package com.joary.jsf;

/**

* @author Administrator

*

*/

public class UserBean {

private java.lang.String name;

private Friend friend;

public UserBean() {

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public Friend getFriend() {

return friend;

}

public void setFriend(Friend friend) {

this.friend = friend;

}

public String add(){

return "success";

}

}

//对应的配置文件

<managed-bean>

<managed-bean-name>userBean</managed-bean-name>

<managed-bean-class>com.joary.jsf.UserBean</managed-bean-class>

<managed-bean-scope>request</managed-bean-scope>

<managed-property>

<property-name>name</property-name>

<property-class>java.lang.String</property-class>

<value/>

<property-name>friend</property-name>

<property-class>com.joary.jsf.Friend</property-class>

<null-value/>

</managed-property>

</managed-property>

</managed-bean>

（此为正确的配置文件）

<managed-bean>

<managed-bean-name>userBean</managed-bean-name>

<managed-bean-class>com.joary.jsf.UserBean</managed-bean-class>

<managed-bean-scope>request</managed-bean-scope>

<managed-property>

<property-name>name</property-name>

<property-class>java.lang.String</property-class>

<value/>

<property-name>friend</property-name>

<property-class>com.joary.jsf.Friend</property-class>

<value/>

</managed-property>

</managed-bean>

（此为错误的配置文件）

问题应该是：如是类型是JSF不能自己从String为型中转换过来的话，vlaue值就必须得设置成null-value才行。