Struts2核心流程图
1. Struts2 和 Struts1 对比
struts1:基于Servlet(ActionServlet),actionForm众多(类的爆炸),action单例(数据安全[线程安全]问题).
将所有任务的解决都集于一身.(不容易扩展和定制)
action位于控制层. extends Action{...}
action更struts1的action和原生servlet api(HttpServletRequest,HttpServlerResponse)绑定在一起,
因此不容易测试,需要部署到web容器中进行测试.
回显数据:struts-html.tld <html:checkbox> html:text
struts-bean.tld
struts-logic.tld
//
class CustomerAction extends DispatchAction{
public ActionForward save(ActionMapping ActionForm Request,Response){
}
public ActionForward update(ActionMapping ActionForm Request,Response){
}
}
<action-mappings>
<action path="/customerAction"
name="customerForm"
scope="request|session"
validate="true"
input="/xxx.jsp"
type="xxxx..CustomerAction"
parameter="method" />
http://xxx/sss/customerAction.do?method=save
struts2:基于filter,没有actionform,action(原型的,独占).
seperate aware:分离关注.解耦.(interceptor,拦截器).
action是模型层(接受参数+pojo).
action不需要和struts的action和原生servlet API(HttpServletRequest,HttpServlerResponse)耦合在一起.
所以更容易测试,不需要一定要部署到web环境中进行测试.
struts2是更加整洁的mvc框架(原因是采用了seperate aware技术,实现任务的拆解).
体验struts2：
1.创建web项目
2.引入struts2类库
${struts解压目录}/app/struts2-blank-2.1.8.1.war/web-inf/lib/*.jar
3.创建action.
package cn.itcast.struts2.action;
/**
* HelloWorldAction
*/
public class HelloWorldAction {
public String execute(){
System.out.println("hello world");
return null ;
}
}
4.创建struts配置文件.src/struts.xml
dtd:struts-core.jar/struts-2.1.7.dtd/30行
<?xml version="1.0"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.1.7//EN"
"http://struts.apache.org/dtds/struts-2.1.7.dtd">
<struts>
<package name="HelloWorldPkg" namespace="/helloworld">
<action name="HelloWorldAction" class="cn.itcast.struts2.action.HelloWorldAction" />
</package>
</struts>
5.配置struts2的过滤器web-inf/web.xml文件中
类:org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<filter>
<filter-name>action</filter-name>
<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>action</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
struts2包搜索顺序:
http://localhost:8085/lsn_struts2/helloworld/aaa/bbb/HelloWorldAction.action
http://localhost:8085/lsn_struts2/helloworld/aaa/bbb/
http://localhost:8085/lsn_struts2/helloworld/aaa/
http://localhost:8085/lsn_struts2/helloworld
list lst = .. ;
request.setAttribute("list",list); Map<String,Object>
request.getRequestDispatcher("/xxxx.jsp").forward(request,response);
HttpServletResponse.sendRedirect("/xx");
ContentType:
response.setContentType("text/html");
mime:
(HttpServletRequest)request.getAttribute("list");
request.setAttribute("list",list);
map:Sessoin (ServletContext)Application.setAttri
使用Token拦截器避免表单重复提交:
1.在jsp页面上使用<s:token />
2.在拦截器栈中加入token拦截器.
Google:
Web:异步执行.
2. 实例： 表单提交 ，校验，防重复提交，文件上传
web.xml 配置
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<filter>
<filter-name>action</filter-name>
<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>action</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping> <welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
struts.xml配置 包含模块 reg.xml
<?xml version="1.0"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.1.7//EN"
"http://struts.apache.org/dtds/struts-2.1.7.dtd">
<struts> <!-- 通过常量方式改变struts默认的属性配置, -->
<constant name="struts.action.extension" value="do" />
<!-- 设置开发模式,重新加载国际化资源文件和配置文件 -->
<constant name="struts.devMode" value="true" />
<!-- 动态方法调用 -->
<constant name="struts.enable.DynamicMethodInvocation" value="true" /> <package name="HelloWorldPkg" namespace="/helloworld" extends="struts-default">
<!-- 默认该包下默认的action引用,若该包没有要访问的action元素,则使用默认的action引用 -->
<default-action-ref name="HelloWorldAction" /> <!-- 设置默认的class引用,将摸个类作为默认的action类 -->
<default-class-ref class="cn.itcast.struts2.action.HelloWorldAction" /> <!-- 通过通配符的方式实现动态方法调用 -->
<action name="HelloWorldAction_*" class="cn.itcast.struts2.action.HelloWorldAction"
method="{1}">
<result name="success">/index.jsp</result>
<result name="save">/index.jsp</result>
<result name="update">/success.jsp</result>
</action> <!-- 没有类的action -->
<action name="ActionNoClass">
<result>/index.jsp</result>
</action>
</package>
<!-- 模块话编程,包含配置文件 -->
<include file="cn/itcast/struts2/action/reg.xml" />
</struts>
reg.xml 配置
<?xml version="1.0"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.1.7//EN"
"http://struts.apache.org/dtds/struts-2.1.7.dtd">
<struts>
<package name="RegPkg" namespace="/regns" extends="struts-default">
<action name="RegAction_*" class="cn.itcast.struts2.action.RegAction" method="{1}">
<result name="success">/reg/success.jsp</result>
<result name="error">/reg/error.jsp</result>
<result name="regView">/reg/reg.jsp</result>
<result name="input">/reg/reg.jsp</result>
<interceptor-ref name="defaultStack"> <!--动态方法调用，方式之一-->
<param name="validation.excludeMethods">input,back,cancel,toRegView</param>
</interceptor-ref>
</action>
</package>
</struts>
token.xml 防止重复提交 配置
<?xml version="1.0"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.1.7//EN"
"http://struts.apache.org/dtds/struts-2.1.7.dtd">
<struts>
<package name="TokenPkg" namespace="/token" extends="struts-default">
<action name="TokenAction_*" class="cn.itcast.struts2.token.TokenAction" method="{1}">
<result name="success">/token/success.jsp</result>
<result name="regView">/token/reg.jsp</result>
<!--无效令牌-->
<result name="invalid.token">/token/reg.jsp</result>
<result name="wait">/wait.jsp</result>
<!-- 如果指定了一个拦截器,则覆盖默认的配置,必须手动指定默认栈 -->
<interceptor-ref name="token">
<param name="excludeMethods">toRegView,findAllCustomers</param>
</interceptor-ref>
<interceptor-ref name="defaultStack" />
<!-- 执行等待拦截器 -->
<interceptor-ref name="execAndWait" />
</action>
</package>
</struts>
reg.jsp 表单提交 JSP， 使用struts-tags 标签，数据回显与校验
<%@ page language="java" contentType="text/html; charset=utf-8"%>
<%@taglib uri="/struts-tags" prefix="s"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>reg.jsp</title>
</head>
<body>
<s:debug />
<s:actionerror />
<s:form namespace="/regns" action="RegAction_reg" method="post" enctype="multipart/form-data">
<s:token /> <!--防止重复提交-->
<s:textfield name="name" label="UserName" />
<s:textfield name="age" label="UserAge" />
<s:file name="photo" label="UserPhoto" />
<s:submit />
</s:form>
</body>
</html>
RegAction.java 处理action
public class RegAction extends ActionSupport {
private static final long serialVersionUID = 2941355104469235318L;
private String name;
private Integer age;
/* 接受上传的文件 */
private File photo ;
/* 接受文件名称 */
private String photoFileName ;
/* 接受文件内容类型的 */
private String photoContentType ;
public String getPhotoFileName() {
return photoFileName;
}
public void setPhotoFileName(String photoFileName) {
this.photoFileName = photoFileName;
}
public String getPhotoContentType() {
return photoContentType;
}
public void setPhotoContentType(String photoContentType) {
this.photoContentType = photoContentType;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
/**
*
*/
public String reg(){
System.out.println("reg : " + name);
String dir = ServletActionContext.getServletContext().getRealPath("/upload");
String ext = photoFileName.substring(photoFileName.lastIndexOf("."));
long l = System.nanoTime();
File newFile = new File(dir,l + ext);
photo.renameTo(newFile);
return SUCCESS;
}
/**
* 达到注册页面, 动态方法调用之一， 使用SkipValidation标签掉过校验
*/
//@SkipValidation
public String toRegView(){
return "regView" ;
}
/**
* 动态方法调用之一，命名： validate + 要校验方法（Reg) == void validateReg() {}
*/
public void validate() {
if(name == null || name.length() == 0){
//国际化，getText会从配置文件获得message，配置文件名和类名一致，位置相同，RegAction.properties
addFieldError("name",getText("error.name.empty"));
}
}
public File getPhoto() {
return photo;
}
public void setPhoto(File photo) {
this.photo = photo;
}
}
RegAction.properties 国际化配置文件
error.name.empty=name is required!
error.name.age=age is required!
success.jsp 成功跳转JSP
<%@ page language="java" contentType="text/html; charset=utf-8"%>
<%@taglib uri="/struts-tags" prefix="s"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>index.jsp</title>
</head>
<body>
you input's name is <s:property value="name" />.<br>
you input's age is <s:property value="age" />.<br>
</body>
</html>
wait.jsp 等待页面
<%@ page language="java" contentType="text/html; charset=utf-8"%>
<%@taglib uri="/struts-tags" prefix="s"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>wait.jsp</title>
<meta http-equiv="refresh" content="2;url=<s:url/>"/>
</head>
<body>
处理中,请稍后....
</body>
</html>