struts2自学笔记

一. 建立我的第一个struts2工程

1. 创建JavaWeb动态工程

2. 导入struts2 jar包

3. 修改web.xml文件

```
<?xml version="1.0" encoding="UTF-8"?>

http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
struts2_3

Struts2

org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter



org.apache.struts2.dispatcher.FilterDispatcher
org.apache.struts2.dispatcher.FilterDispatcher

<filter-mapping>
    <filter-name>Struts2</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>
<filter-mapping>
    <filter-name>org.apache.struts2.dispatcher.FilterDispatcher</filter-name>
    <url-pattern>*.action</url-pattern>
</filter-mapping>

<welcome-file-list>
    <welcome-file>login.jsp</welcome-file>
</welcome-file-list>

```

4. 在src目录下创建struts.xml文件

    <?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
    <!--constant 配置用于开启动态方法调用 -->
    <constant name="struts.enable.DynamicMethodInvocation" value="true" />
    <package name="default" extends="struts-default" >
    <action name="login" class="struts2_deoml.LoginAction">
    <result name="success">/success.jsp</result>
    <result name="fail">/ShuChu.jsp</result>
    </action>
    </package>
</struts>

5.创建LoginAction.java

package struts2_deoml;
import com.opensymphony.xwork2.ActionSupport;
public class LoginAction extends ActionSupport{
    private static final long serialVersionUID = 1L;
     @Override
        public String execute() throws Exception {
            System.out.println("执行Action");
            return SUCCESS;
        }
}

6.jsp表单跳转配置

<form action="login" method="post">

7.创建其他相应的jsp页面，提交login.jsp中的表单即可运行成功。

二. Struts2方法调用的三种方式

1.指定method属性

<action name="UserMethod" class="struts2_deoml.UserMethodAction" method="add">
    <result name="add">/add_user.jsp</result>
</action>

2.动态方法调用(DMI)

jsp提交写法

<a href="User!add">添加用户</a>

struts.xml配置中必须设置这个常量才能保证正常使用动态方法调用

<constant name="struts.enable.DynamicMethodInvocation" value="true" />

struts.xml中action配置

<action name="User" class="struts2_deoml.UserAction">
    <result name="add">/add_user.jsp</result>
    <result name="update">/update_user.jsp</result>
</action>

UserAction.java

public class UserAction extends ActionSupport{
    private static final long serialVersionUID = 1L;
    //添加用户
    public String  add(){
        System.out.println("添加用户!!!!");
        return "add";
    }
}

3.通配符（推荐使用）

<action name="UserClMethod*" class="struts2_deoml.UserClMethodAction" method="{1}">
    <result name="{1}">/{1}_user.jsp</result>
</action>

<a href="UserClMethodadd">添加用户(通配符调用方法)</a>

三.Struts2接收参数的几种方式

1.在action里定义要接收的参数，并提供相应的set和get方法。

Action类：

//LoginAction.java
public class LoginAction extends ActionSupport{
    private static final long serialVersionUID = 1L;
    private String username;
    private String password;
     @Override
        public String execute() throws Exception {
            System.out.println("执行Action");
            System.out.println("username:" + username + "  password:" + password);
            return SUCCESS;
        }
        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;
        }
}

Jsp提交方式

<form action="login" name="form1" method="post">
用户：<input type="text" name="username"><br>
密码：<input type="password" name="password"><br>
<input type="submit" value="提交" > <input type="reset" value="清空" >
</form>

2.使用DomainModel

如果Action中属性过多，则可以Model保存为一个对象，并提供get和set
Model类：

public class User {
    private String username;
    private String password;
    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;
    }
}

Action类

public class LoginAction2 extends ActionSupport{
    private static final long serialVersionUID = 1L;
    User user = new User();
    @Override
    public String execute() throws Exception {
        System.out.println("执行LoginAction2");
        System.out.println("username:" + user.getUsername() + 
                "  password:" + user.getPassword());
        return SUCCESS;
    }
    public User getUser() {
        return user;
    }
    public void setUser(User user) {
        this.user = user;
    }
}

Jsp提交方式：

<form action="login2" name="form2" method="post">
用户：<input type="text" name="user.username"><br>
密码：<input type="password" name="user.password"><br>
<input type="submit" value="提交" > <input type="reset" value="清空" >
</form>

3.使用ModelDriven（模型驱动）

使用模型驱动模式时，Acton必须实现ModelDriven接口，实现该接口则必须实现getModel()方法，该方法用于把Action和与之对应的Model实例关联起来。
Model类同上。

Action类：

public class LoginAction3 extends ActionSupport implements ModelDriven<User>{
    private static final long serialVersionUID = 1L;
    User user = new User();
    @Override
    public String execute() throws Exception {
        System.out.println("执行LoginAction3");
        System.out.println("username:" + user.getUsername() + 
                "  password:" + user.getPassword());
        return SUCCESS;
    }
    public User getUser() {
        return user;
    }
    public void setUser(User user) {
        this.user = user;
    }
    public User getModel() {  
        return user;  
    } 
}

JSP提交方式：(这里提交既可以用 “对象.变量” 的方式提交，又可以直接用 “变量” 的方式提交)

<form action="login3" name="form3" method="post">
用户：<input type="text" name="user.username"><br>
密码：<input type="password" name="password"><br>
<input type="submit" value="提交" > <input type="reset" value="清空" >
</form>

4.使用request接收参数

此方法和传统的JSP页面接收参数一样，用request.getParameter("")方法。
Action类：

ActionContext context=ActionContext.getContext(); 
HttpServletRequest request = (HttpServletRequest)context.get(ServletActionContext.HTTP_REQUEST);
String username_2 = request.getParameter("username");
String password_2 = request.getParameter("password");
System.out.println("username：" + username_2 + "  password:" + password_2);

JSP 提交方式：

<s:form action="login3" method="post">
    <s:textfield name="username" label="用户名"/>
    <s:password name="password"  label="密码"/>
    <s:submit/>
</s:form>

5.使用ActionContext得到parameterMap获取参数

//方法二:在Action中使用ActionContext得到parameterMap获取参数:     
 ActionContext context=ActionContext.getContext();     
Map<?,?>  parameterMap=context.getParameters();              
String username[]=(String[])parameterMap.get("username");     
String password[]=(String[])parameterMap.get("password");          
System.out.println("username: " +username[0] + "password: " +password[0]);

JSP 提交方式：

<s:form action="login3" method="post">
    <s:textfield name="username" label="用户名"/>
    <s:password name="password"  label="密码"/>
    <s:submit/>
</s:form>

四.