一、通过ActionContext类获取
public class ActionContextDemo extends ActionSupport {
@Override
public String execute() throws Exception {
//获取ActionContext对象
ActionContext context = ActionContext.getContext();
//调用getParameters对象获取参数
Map<String, Object> map = context.getParameters();
//遍历打印map集合
for (String key : map.keySet()) {
String[] val = (String[]) map.get(key);
System.out.println(key + " : " + Arrays.toString(val));
}
return NONE;
}
}
二、通过ServletActionContext类获取request类然后获取
public class ServletActionContextDemo extends ActionSupport {
@Override
public String execute() throws Exception {
//获取request
HttpServletRequest request = ServletActionContext.getRequest();
//获取参数
String username = request.getParameter("username");
String password = request.getParameter("password");
String[] hobbies = request.getParameterValues("hobbies");
System.out.println(username + " : " + password + " : " + Arrays.toString(hobbies));
//操作域对象
//request域
HttpServletRequest request2 = ServletActionContext.getRequest();
request2.setAttribute("request", "hello request");
//获取session域
HttpSession session = request2.getSession();
session.setAttribute("session", "hello session");
//获取servletcontext域
ServletContext servletContext = request2.getServletContext();
servletContext.setAttribute("servletContext", "application");
return SUCCESS;
}
}
三、属性封装
定义私有的成员变量，变量名称与表单中name属性值一致
提供成员变量的get和set方法（实际上，在数据封装时，仅提供set方法即可。成员变量的属性名也不一定非得跟name属性值一致，但set方法跟的字段setXXX中的XXX必须跟name属性名的首字符大写一致）
public class DataPackagingAction extends ActionSupport {
private static final long serialVersionUID = 1L;
private String username;
private String password;
private String[] hobbies;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String[] getHobbies() {
return hobbies;
}
public void setHobbies(String[] hobbies) {
this.hobbies = hobbies;
}
@Override
public String execute() throws Exception {
System.out.println("属性驱动: " + username + " : " + password + " " + Arrays.toString(hobbies));
return NONE;
}
}
四、基于模型驱动的数据封装方法
1.让action类实现ModelDriven<T>接口
2.实现ModelDriven<T>接口中的getModel方法
3.在Action中创建私有的成员变量,并手动创建实体类
public class DataPackagingAction2 extends ActionSupport implements ModelDriven<User> {
private User user = new User();
@Override
public User getModel() {
return user;
}
@Override
public String execute() throws Exception {
System.out.println(user);
return NONE;
}
}
五、复杂数据的封装方法
1.封装数据到list集合中
第一步: 在action中声明list成员变量,并手动创建实体类;
第二部: 提供get和set方法;
第三部: 在jsp页面中,提供基于list作为值得name属性
public class ListAction extends ActionSupport {
private List<User> list = new ArrayList<User>();
public List<User> getList() {
return list;
}
public void setList(List<User> list) {
this.list = list;
}
@Override
public String execute() throws Exception {
for (int i = 0; i < list.size(); i ++) {
System.out.println(list.get(i));
}
return NONE;
}
}
在jsp页面中name属性的赋值规则
<form action="${pageContext.request.contextPath}/list.action" method="post">
username: <input type="text" name="list[0].username" /><br/>
password: <input type="password" name="list[0].password" /><br/>
hobby: <input type="checkbox" name="list[0].hobbies" value="basketball" />basketball
<input type="checkbox" name="list[0].hobbies" value="football" />football
<input type="checkbox" name="list[0].hobbies" value="badminton" />badminton
<hr/>
username: <input type="text" name="list[1].username" /><br/>
password: <input type="password" name="list[1].password" /><br/>
hobby: <input type="checkbox" name="list[1].hobbies" value="basketball" />basketball
<input type="checkbox" name="list[1].hobbies" value="football" />football
<input type="checkbox" name="list[1].hobbies" value="badminton" />badminton
<hr/>
<input type="submit" value="提交" />
</form>
2.封装数据到map集合中
第一步: 在action中声明map成员变量,并手动创建实体类;
第二部: 提供get和set方法;
第三部: 在jsp页面中,提供基于map作为值得name属性
public class MapAction extends ActionSupport {
private Map<String, User> map = new HashMap<String, User>();
public Map<String, User> getMap() {
return map;
}
public void setMap(Map<String, User> map) {
this.map = map;
}
@Override
public String execute() throws Exception {
for (String key : map.keySet()) {
System.out.println(key + " " + map.get(key));
}
return NONE;
}
}
在jsp页面中name属性的命名规则
<form action="${pageContext.request.contextPath}/map.action" method="post">
username: <input type="text" name="map['one'].username" /><br/>
password: <input type="password" name="map['one'].password" /><br/>
hobby: <input type="checkbox" name="map['one'].hobbies" value="basketball" />basketball
<input type="checkbox" name="map['one'].hobbies" value="football" />football
<input type="checkbox" name="map['one'].hobbies" value="badminton" />badminton
<hr/>
username: <input type="text" name="map['two'].username" /><br/>
password: <input type="password" name="map['two'].password" /><br/>
hobby: <input type="checkbox" name="map['two'].hobbies" value="basketball" />basketball
<input type="checkbox" name="map['two'].hobbies" value="football" />football
<input type="checkbox" name="map['two'].hobbies" value="badminton" />badminton
<hr/>
<input type="submit" value="提交" />
</form>
3.使用属性封装数据到对象中
第一步: 在action中声明实体类User的成员变量,可以不用实例化
第二步: 提供实体类的get和set方法
第三部: jsp中name属性基于实体类赋值
public class UserAction extends ActionSupport {
private static final long serialVersionUID = 1L;
//声明实体类
private User user;
//生成get和set方法
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
//数据打印
@Override
public String execute() throws Exception {
System.out.println("~~~~~~" + user);
return NONE;
}
}
jsp页面中name属性的命名规则
<form action="${pageContext.request.contextPath}/user.action" method="post">
username: <input type="text" name="user.username" /><br/>
password: <input type="password" name="user.password" /><br/>
hobby: <input type="checkbox" name="user.hobbies" value="basketball" />basketball
<input type="checkbox" name="user.hobbies" value="football" />football
<input type="checkbox" name="user.hobbies" value="badminton" />badminton
<hr/>
<input type="submit" value="提交" />
</form>