更新时间:2022-06-06 23:19:10
1. 数据传输:OGNL和类型转换
OGNL和struts2
OGNL:Object-Graph Navigation Language.
OGNL是集成进struts框架中比较强大的技术有助于数据传输和类型转换.OGNL由表达式语言和类型转换器组成.
内置类型转换器
用ognl表达式映射表单字段名到属性
<s:form action="Register">
<s:textfield name="user.username" label="Username"/>
<s:password name="user.password" label="Password"/>
<s:textfield name="user.portfolioName" label="Enter a name "/>
<s:textfield name="user.age" label="Enter your age as a double "/>
<s:textfield name="user.birthday" label="birthday. (mm/dd/yy)"/>
<s:submit/>
</s:form>
private User user;//get/set
User{
private String username;
private String password;
private String portfolioName;
private Double age;
private Date birthday;//get/set
内置类型转换器
List
private List lastNames ;
private List middleNames ;
不必预初始化集合.默认转换成字符串.
<s:textfield name="middleNames[0]" label="middleNames"/>
<s:textfield name="middleNames[1]" label="middleNames"/>
<s:textfield name="middleNames[2]" label="middleNames"/>
<s:textfield name="lastNames" label="lastNames"/>
<s:textfield name="lastNames" label="lastNames"/>
<s:textfield name="lastNames" label="lastNames"/>
若想显式指定数据类型,可通过属性文件的方式指定[XxxAction-conversion.properties].属性文件和Action类放在一起.
内置类型转换器
Map<String,String>
<s:textfield name="maidenNames.mary" label="Maiden Name"/>
<s:textfield name="maidenNames.jane" label="Maiden Name"/>
<s:textfield name="maidenNames.hellen" label="Maiden Name"/>
<s:textfield name="maidenNames['beth']" label="Maiden Name"/>
<s:textfield name="maidenNames['sharon']" label="Maiden Name"/>
<s:textfield name="maidenNames['martha']" label="Maiden Name"/>
private Map maidenNames ;
Map<String,User>
Element_myUsers=manning.utils.User
<s:textfield name="myUsers['chad'].username" label="names"/>
<s:textfield name="myUsers.chad.birthday" label="birthday"/>
private Map myUsers ;
自定义类型转换器
实现ognl.TypeConverter接口
继承类org.apache.struts2.util.StrutsTypeConverter.
public abstract Object convertFromString(Map context, String[] values,Class toClass);
public abstract String convertToString(Map context, Object o);
在字符串和Date对象间转换(续)
public class DateTypeConverter extends StrutsTypeConverter {
public Object convertFromString(Map context, String[] values, Class toClass) {
String date = values[0];
SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd");
return sdf.parse(date);
}
public String convertToString(Map context, Object o) {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd");
return sdf.format((Date)o);
}
}
配置自定义类型转换器
属性相关:
属性文件同action类放在一起, action中list map使用泛型定义,无需配置转换类型
private Date birthday;
[CustomConverterTest-conversion.properties]
birthday=manning.utils.DateTypeConverter
全局类型转换: 放在 src目录下
[classpath]/xwork-conversion.properties
manning.utils.Circle=manning.utils.DateTypeConverter
---------------- 实例 address 转换, 输入 aa-bb-cc 转为 Address-----------
address.java domain
注册提交Jsp, reg,jsp
action
地址转换器
OgnlAction-conversion.properties 转换类型配置, 放在action同目录,命名方式固定
xwork-conversion.properties 类型转换,全局配置文件,放在src目录下,命名固定