JavaWeb -- Struts2，对比， 简单表单提交，校验，防重复提交， 文件上传

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>