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
/**
* 地址类
*/
public class Address {
private String province;
private String city;
private String street;
public String getProvince() {
return province;
}
public void setProvince(String province) {
this.province = province;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public String getStreet() {
return street;
}
public void setStreet(String street) {
this.street = street;
}
public String toString() {
return province + "-" + city + "-" + street;
}
}
注册提交Jsp, reg,jsp
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>reg.jsp</title> </head> <body> <s:debug /> <s:form namespace="/ognl" action="OgnlAction_reg" method="post"> <s:textfield name="names" label="UserName" /> <s:textfield name="names" label="UserName" /> <s:textfield name="ages[0]" label="UserAge" /> <s:textfield name="ages[1]" label="UserAge" /> <s:textfield name="namesListNoGen" label="namesListNoGen" /> <s:textfield name="namesListNoGen" label="namesListNoGen" /> <s:textfield name="agesListNoGen[0]" label="agesListNoGen" /> <s:textfield name="agesListNoGen[1]" label="agesListNoGen" /> <s:textfield name="userList[0].name" label="userList[0].name" /> <s:textfield name="userList[1].name" label="userList[1].name" /> <s:textfield name="userList[0].age" label="userList[0].age" /> <s:textfield name="userList[1].age" label="userList[1].age" /> <s:textfield name="userMap[100].name" label="userMap[100].name" /> <s:textfield name="userMap[100].age" label="userMap[100].age" /> <s:textfield name="userMap[200].name" label="userMap[200].name" /> <s:textfield name="userMap[200].age" label="userMap[200].age" /> <s:textfield name="comAddress" label="comAddress"/> <s:submit /> </s:form> <s:property value="comAddress"/> <s:url includeContext="true" /> </body> </html>
action
/**
* OgnlAction
*/
public class OgnlAction extends ActionSupport {
private static final long serialVersionUID = -6933309304624396640L;
private String[] names = new String[2];
private Integer[] ages = new Integer[2];
/**
* 不带泛型的集合
*/
private List namesListNoGen ;
private List agesListNoGen ;
/* javabean集合 */
private List userList ;
/* map */
private Map userMap;
/* 公司地址 */
private Address comAddress ;
public Address getComAddress() {
return comAddress;
}
public void setComAddress(Address comAddress) {
this.comAddress = comAddress;
}
public List getUserList() {
return userList;
}
public void setUserList(List userList) {
this.userList = userList;
}
public Integer[] getAges() {
return ages;
}
public void setAges(Integer[] ages) {
this.ages = ages;
}
public String[] getNames() {
return names;
}
public void setNames(String[] names) {
this.names = names;
}
public String reg() {
return "success";
}
public String toRegView() {
System.out.println("toRegView");
return "loginView";
}
/**
* 保存数据,
*/
public String saveData(){
ServletActionContext.getRequest().setAttribute("username", "requestTom");
ServletActionContext.getRequest().getSession().setAttribute("username", "sessionTom");
ServletActionContext.getServletContext().setAttribute("username", "applicationTom");
ServletActionContext.getContext().getValueStack().set("username", "vsTom");
//
popUserList();
return "showView" ;
}
/**
* 组装用户集合
*/
private void popUserList(){
userList = new ArrayList<User>();
User u = null ;
for(int i = 0 ; i < 10 ; i ++){
u = new User();
u.setId(1 + i);
u.setName("tom" + i);
u.setAge(20 + i);
userList.add(u);
}
}
public List getNamesListNoGen() {
return namesListNoGen;
}
public void setNamesListNoGen(List namesListNoGen) {
this.namesListNoGen = namesListNoGen;
}
public List getAgesListNoGen() {
return agesListNoGen;
}
public void setAgesListNoGen(List agesListNoGen) {
this.agesListNoGen = agesListNoGen;
}
public Map getUserMap() {
return userMap;
}
public void setUserMap(Map userMap) {
this.userMap = userMap;
}
}
地址转换器
/**
* 地址类型转换器
*/
public class AddressConverter extends StrutsTypeConverter {
/**
* 将字符串转换成地址对象
*/
public Object convertFromString(Map context, String[] values, Class toClass) {
if(values != null && values.length > 0){
String str = values[0];
String[] ss = str.split("-");
if(ss != null && ss.length > 2){
Address a = new Address();
a.setProvince(ss[0]);
a.setCity(ss[1]);
a.setStreet(ss[2]);
return a ;
}
}
return null;
}
/**
* 将地址对象转换成字符串信息
*/
public String convertToString(Map context, Object o) {
if(o instanceof Address){
return o.toString();
}
return null;
}
}
OgnlAction-conversion.properties 转换类型配置， 放在action同目录，命名方式固定
Element_agesListNoGen=java.lang.Integer Element_userList=cn.itcast.struts2.model.User Element_userMap=cn.itcast.struts2.model.User Key_userMap=java.lang.Integer #comAddress=cn.itcast.struts2.ognl.AddressConverter
xwork-conversion.properties 类型转换，全局配置文件，放在src目录下，命名固定
cn.itcast.struts2.model.Address=cn.itcast.struts2.ognl.AddressConverter