JavaWeb学习：Struts2的数据封装
获取页面表单数据的方式：根本是通过request对象的getParameterMap();
Map<String, String[]> map=request.getParameterMap();
但是如果能把这些数据封装到对象中，我们使用起来是不是方便些。
Struts2中Params拦截器提供了表单数据封装的几种方式
- 属性驱动：提供属性set方法（不常用）
- 属性驱动：页面中提供表达式
- 可以封装多个对象的数据
- 模型驱动：采用模型驱动方式（最常用）
- 只能封装一个对象的数据
一、属性驱动（属性set方法）
①、index.jsp
<form action="${pageContext.request.contextPath}/user1.action" method="post"> UserName:<input type="text" name="username" /><br /> password:<input type="password" name="password" /><br /> age:<input type="text" name="age" /><br /> birthday:<input type="text" name="birthday" /><br /> salary:<input type="text" name="salary" /><br /> <input type="submit" name="submit" /> </form>
②、User
public class User { private String username; private String password; private Integer age; private Date birthday; private Double salary; 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 Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } public Date getBirthday() { return birthday; } public void setBirthday(Date birthday) { this.birthday = birthday; } public Double getSalary() { return salary; } public void setSalary(Double salary) { this.salary = salary; } @Override public String toString() { return "User [username=" + username + ", password=" + password + ", age=" + age + ", birthday=" + birthday + ", salary=" + salary + "]"; } }
③、Action
public class User1Action extends ActionSupport { // 1、提供对应的属性 private String username; private String password; private Integer age; private Date birthday; private Double salary; // 2、提供属性对应的set方法 public void setUsername(String username) { this.username = username; } public void setPassword(String password) { this.password = password; } public void setAge(Integer age) { this.age = age; } public void setBirthday(Date birthday) { this.birthday = birthday; } public void setSalary(Double salary) { this.salary = salary; } @Override public String execute() throws Exception { // 3、接收数据: System.out.println(username); System.out.println(password); System.out.println(age); System.out.println(birthday); System.out.println(salary); return NONE; } }
④、struts_user.xml
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.5//EN" "http://struts.apache.org/dtds/struts-2.5.dtd"> <struts> <package name="strutsdemo2" extends="struts-default" namespace="/"> <action name="user1" class="com.xxx.web.action.user.User1Action"></action> </package> </struts>
⑤、struts.xml
<include file="com/xxx/web/action/user/struts_user.xml"></include>
二、属性驱动（页面提供表达式）
①、index.jsp
<form action="${pageContext.request.contextPath}/user2.action" method="post"> UserName:<input type="text" name="user.username" /><br /> password:<input type="password" name="user.password" /><br /> age:<input type="text" name="user.age" /><br /> birthday:<input type="text" name="user.birthday" /><br /> salary:<input type="text" name="user.salary" /><br /> <input type="submit" name="user.submit" /> </form>
②、Action
public class User2Action extends ActionSupport { // 1、私有属性对象变量 // 2、私有属性对象变量提供get、set方法 private User user; public User getUser() { return user; } public void setUser(User user) { this.user = user; } @Override public String execute() throws Exception { System.out.println(user); return NONE; } }
④、struts_user.xml
<action name="user2" class="com.xxx.web.action.user.User2Action"></action>
三、模型驱动
①、index.jsp
<form action="${pageContext.request.contextPath}/user2.action" method="post"> UserName:<input type="text" name="username" /><br /> password:<input type="password" name="password" /><br /> age:<input type="text" name="age" /><br /> birthday:<input type="text" name="birthday" /><br /> salary:<input type="text" name="salary" /><br /> <input type="submit" name="submit" /> </form>
②、Action
public class User3Action extends ActionSupport implements ModelDriven<User>{ // 1、implements ModelDriven<User> // 2、提供实例化对象 // 3、重写getModel方法 private User user=new User(); @Override public User getModel() { return user; } @Override public String execute() throws Exception { System.out.println(user); return NONE; } }
③、struts_user.xml
<action name="user3" class="com.xxx.web.action.user.User3Action"></action>
四、复杂数据结构（List） -- 以下的数据结构需要使用属性驱动（页面提供表达式）
public class ViewModel { private List<Product> products; public List<Product> getProducts() { return products; } public void setProducts(List<Product> products) { this.products = products; } }
①、index.jsp（products和ViewModel中的products一致）
<form action="${pageContext.request.contextPath}/product1.action" method="post"> ProductName:<input type="text" name="model.products[0].name" /><br /> ProductPrice:<input type="text" name="model.products[0].price" /><br /> ProductName:<input type="text" name="model.products[1].name" /><br /> ProductPrice:<input type="text" name="model.products[1].price" /><br /> ProductName:<input type="text" name="model.products[2].name" /><br /> ProductPrice:<input type="text" name="model.products[2].price" /><br /> <input type="submit" name="submit" /> </form>
②、Action （Action 的model 和index.jsp中model对应的）
public class Product1Action extends ActionSupport { private ViewModel model; public ViewModel getModel() { return model; } public void setModel(ViewModel model) { this.model = model; } @Override public String execute() throws Exception { for (Product product : model.getProducts()) { System.out.println(product); } return NONE; } }
③、struts_product.xml
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.5//EN" "http://struts.apache.org/dtds/struts-2.5.dtd"> <struts> <package name="strutsdemo3" extends="struts-default" namespace="/"> <action name="product1" class="com.xxx.web.action.product.Product1Action"></action> </package> </struts>
④、struts.xml
<include file="com/xxx/web/action/product/struts_product.xml"></include>
五、复杂数据结构（Map）
public class ViewModel { private Map<String,Product> map; public Map<String, Product> getMap() { return map; } public void setMap(Map<String, Product> map) { this.map = map; } }
①、index.jsp（map和ViewModel中的map一致）
<form action="${pageContext.request.contextPath}/product2.action" method="post"> ProductName:<input type="text" name="model.map['0'].name" /><br /> ProductPrice:<input type="text" name="model.map['0'].price" /><br /> ProductName:<input type="text" name="model.map['1'].name" /><br /> ProductPrice:<input type="text" name="model.map['1'].price" /><br /> ProductName:<input type="text" name="model.map['2'].name" /><br /> ProductPrice:<input type="text" name="model.map['2'].price" /><br /> <input type="submit" name="submit" /> </form>
②、Action
public class Product2Action extends ActionSupport { private ViewModel model; public ViewModel getModel() { return model; } public void setModel(ViewModel model) { this.model = model; } @Override public String execute() throws Exception { for (String key : model.getMap().keySet()) { System.out.println(key+" "+model.getMap().get(key)); } return NONE; } }
