Java后台处理框架之struts2学习总结

2022-05-01 16:25:56

最近我在网上了解到，在实际的开发项目中struts2的使用率在不断降低，取而代之的是springMVC。可能有很多的朋友看到这里就会说，那还不如不学struts2，直接学习springMVC算了。如果你急于忙着开发项目，这个想法没错。但是，我在这里想说一下的就是，框架其实是对基础代码的封装，对流行功能的优化，为了提高开发效率而存在的。好比武林大会上降龙十八掌，金钟罩，铁布衫，说到底大家还是要靠拳打脚踢的嘛。Struts2,springMVC就是各种招式，我们学习它，学的是招式，以便于更好的见招拆招。闲话不多扯，我来对我这几天的struts2学习做一次总结。

1.struts2防重复提交。

首先要在jsp提交页面导入<%@taglib prefix="s" uri="/struts-tags" %>

在这里有两种方法：一个是在要提交的表单里面嵌入标签<s:token></s:token>，如下：

<s:actionerror/>

<s:token></s:token>

姓名：<input type="text" name="student.name"/><br/>

年龄：<input type="text" name="student.age"/><br/>

</form>

接着，在项目src下配置struts.xml如下：

<result name="success">/success.jsp</result>

<result name="invalid.token">/student.jsp</result>

<interceptor-ref name="token"></interceptor-ref>

<interceptor-ref name="defaultStack"></interceptor-ref>

</action>

</package>

另一种方法是：直接在struts.xml中配置为无视重复提交(推荐使用这种方法)，如下

<result name="success">/success.jsp</result>

<interceptor-ref name="tokenSession"></interceptor-ref>

<interceptor-ref name="defaultStack"></interceptor-ref>

</action>

</package>

2.struts2过滤敏感词汇。比如在进行用户注册时，对用户提交的姓名进行过滤。

假如有个提交页面：

<s:form action="/validationAction" method="post">

<s:textfield name="name" label="姓名"></s:textfield>

<s:submit value="提交"></s:submit>

</s:form>

提交之后，在struts.xml(src直接目录下)中找到配置，

<result name="input">/validation.jsp</result>

<result name="success">/success.jsp</result>

</action>

</package>

此时，在包action下找到ValidationAction.java里面代码如下：

package action;

import java.util.Map;

import org.apache.struts2.components.ActionComponent;

import com.opensymphony.xwork2.ActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class ValidationAction extends ActionSupport{

/**

private static final long serialVersionUID = 1L;

private String name;

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

@Override

public String execute() throws Exception {

ActionContext actionComtext=ActionContext.getContext();

Map<String, Object> session=actionComtext.getSession();

session.put("name", name);

System.out.println("姓名："+name);

return SUCCESS;

}

配置文件为ValidationAction-validation.xml(不可随便命名，格式为xx-validation.xml)，代码如下：

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

<!DOCTYPE validators PUBLIC "-//Apache Struts//XWork Validator 1.0.2//EN" "http://struts.apache.org/dtds/xwork-validator-1.0.2.dtd">

<field-validator type="requiredstring">

<message>请输入姓名</message>

</field-validator>

<field-validator type="sensitive">

<message>有敏感词汇</message>

</field-validator>

</field>

</validators>

在上面的配置中，我们自定义了一个sensitive验证，在src目录下与struts平级的还得有一个配置文件validators.xml，代码如下：

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

<!DOCTYPE validators PUBLIC

"-//Apache Struts//XWork Validator Config 1.0//EN"

"http://struts.apache.org/dtds/xwork-validator-config-1.0.dtd">

</validators>

根据此配置找到包validators下的SensitiveWordValidators.java，代码如下：

package validators;

import com.opensymphony.xwork2.validator.ValidationException;

import com.opensymphony.xwork2.validator.validators.FieldValidatorSupport;

public class SensitiveWordValidators extends FieldValidatorSupport{

@Override

public void validate(Object object) throws ValidationException {

String fieldName=this.getFieldName();

String value=this.getFieldValue(fieldName, object).toString();//获取输入值

if(!check(value)){

this.addFieldError(fieldName, object);//返回页面提示有敏感词汇(此句话在ValidationAction-validation.xml中)

}

public boolean check(String value){

String sensitiveWords[]={"操","你妈","屌","尼玛","日","cao","艹"}; for(int i=0;i<sensitiveWords.length;i++){

if(value.indexOf(sensitiveWords[i])!=-1){

return false;

}

return true;

}

执行到这里之后，如果有敏感词汇，则直接返回页面提示有敏感词汇。没有敏感词汇的话，则跳转到success.jsp页面。(struts.xml中可知道)

3.Struts2实现文件上传与下载。Struts2实现文件上传是基于拦截器实现的，使用的是fileupload，文件上传大小、类型控制是在struts.xml中配置(src目录下)，默认上传最大为2M。

首先来总结单文件上传：假如有个上传页面，如下

<%@ page language="java" contentType="text/html; charset=UTF-8"

pageEncoding="UTF-8"%>

<%@taglib prefix="s" uri="/struts-tags" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title>单文件上传</title>

</head>

<body>

<s:fielderror></s:fielderror>

文件：<input type="file" name="java1234"/><br/>

</form>

</body>

</html>

struts.xml中配置如下：

<?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">

<result name="success">/success.jsp</result>

<result name="input">/fileupload.jsp</result>

<!-- <interceptor-ref name="fileUpload">用来进行上传文件限制，只能为图片和大小不超过81101b

<param name="allowedTypes">image/bmp,image/x-png,image/gif,image/jpg,image/jpeg</param>

</interceptor-ref>

<interceptor-ref name="defaultStack"></interceptor-ref> -->

</action>

</package>

</struts>

在action包下找到FileUploadAction.java，代码如下：

package action;

import java.io.File;

import org.apache.commons.io.FileUtils;

import com.opensymphony.xwork2.ActionSupport;

public class FileUploadAction extends ActionSupport {

/**

private static final long serialVersionUID = 1L;

private File java1234;// 文件

private String java1234FileName;//文件名，格式为提交页面name(java1234)+FileName

private String java1234ContentType;// 文件类型。格式为提交页面name(java1234)+ContentType

public File getJava1234() {

return java1234;

}

public void setJava1234(File java1234) {

this.java1234 = java1234;

}

public String getJava1234FileName() {

return java1234FileName;

}

public void setJava1234FileName(String java1234FileName) {

this.java1234FileName = java1234FileName;

}

public String getJava1234ContentType() {

return java1234ContentType;

}

public void setJava1234ContentType(String java1234ContentType) {

this.java1234ContentType = java1234ContentType;

}

@Override

public String execute() throws Exception {

System.out.println("文件名:" + java1234FileName);

System.out.println("文件类型:" + java1234ContentType);

String filePath="E:/"+java1234FileName;

File savePath=new File(filePath);

FileUtils.copyFile(java1234, savePath);

return SUCCESS;

}

上传成功则跳转到success.jsp页面，失败则继续留在原界面(struts.xml可知)

其次来总结多文件上传：多文件上传和单文件上传不同之处便是FileUploadAction.java中用数组来处理文件。代码如下：

package com.java1234.action;

import java.io.File;

import org.apache.commons.io.FileUtils;

import com.opensymphony.xwork2.ActionSupport;

public class FilesUploadAction extends ActionSupport{

/**

private static final long serialVersionUID = 1L;

private File[] java1234; // 文件

private String[] java1234FileName; // 文件名

private String[] java1234ContentType; // 文件类型

public File[] getJava1234() {

return java1234;

}

public void setJava1234(File[] java1234) {

this.java1234 = java1234;

}

public String[] getJava1234FileName() {

return java1234FileName;

}

public void setJava1234FileName(String[] java1234FileName) {

this.java1234FileName = java1234FileName;

}

public String[] getJava1234ContentType() {

return java1234ContentType;

}

public void setJava1234ContentType(String[] java1234ContentType) {

this.java1234ContentType = java1234ContentType;

}

@Override

public String execute() throws Exception {

for(int i=0;i<java1234.length;i++){

System.out.println("文件名："+java1234FileName[i]);

System.out.println("文件类型："+java1234ContentType[i]);

String filePath="C:/"+java1234FileName[i];

File saveFile=new File(filePath);

FileUtils.copyFile(java1234[i], saveFile);

}

return SUCCESS;

}

最后来总结文件下载：返回的是一个文件流

假如有个下载页面如下：

<%@ page language="java" contentType="text/html; charset=UTF-8"

pageEncoding="UTF-8"%>

<%@taglib prefix="s" uri="/struts-tags" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title>Insert title here</title>

</head>

<body>

</body>

</html>

struts.xml中配置为：

<param name="contentDisposition">attachment;filename=${fileName}</param>

</result>

</action>

</package>

根据配置找到action包下面的FileDownloadAction.java，代码如下：

package action;

import java.io.File;

import java.io.FileInputStream;

import java.io.InputStream;

import com.opensymphony.xwork2.ActionSupport;

public class FileDownloadAction extends ActionSupport{

/**

private static final long serialVersionUID = 1L;

private String fileName;

public String getFileName() throws Exception{

fileName=new String(fileName.getBytes(),"ISO8859-1");//解决乱码 return fileName;

}

public void setFileName(String fileName) {

this.fileName = fileName;

}

public InputStream getInputStream()throws Exception{

File file=new File("C:/美女1.jpg");//假设下载的为此文件

this.fileName="美女1号";//自己定义下载的文件名字,系统会补上文件后缀名无需自己添加

return new FileInputStream(file);//和上传不同，返回的是一个InputStream

}

4.struts2实现国际化。什么意思呢，就是根据浏览器语言环境，显示不同语言网页。不同国家地区访问网站，给出相应版本语言的网页。

直接先贴出struts.xml配置文件(src目录下)。如下：

<?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>

假如有这么一个登录网页和欢迎界面：注意<s:text name="xx"></s:text>

<%@ page language="java" contentType="text/html; charset=UTF-8"

pageEncoding="UTF-8"%>

<%@taglib prefix="s" uri="/struts-tags" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title>Insert title here</title>

</head>

<body>

<table>

<tr>

<td>

</td>

</tr>

<tr>

<td>

</td>

</tr>

<tr>

<td>

</td>

</tr>

</table>

</body>

</html>

欢迎网页：

<%@ page language="java" contentType="text/html; charset=UTF-8"

pageEncoding="UTF-8"%>

<%@taglib prefix="s" uri="/struts-tags" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title>Insert title here</title>

</head>

<body>

<s:text name="welcomeInfo">

<s:param>Jack</s:param>

</s:text>

</body>

</html>

此时，需要在src下配置properties文件相应的转换规则。此处配置三个properties文件，默认，英文，中文。其他国家的自己去搞，这里只展示三个。默认文件是必须的，文件名要和struts.xml中配置的一致。

Java1234.properties（src目录下）[默认文件]，采用Uicode编码，代码如下：

userName=\u7528\u6237\u540d

password=\u5bc6\u7801

welcomeInfo=\u6b22\u8fce{0}

Java1234_en_US.properties（src目录下）[英文]，采用Uicode编码，代码如下：

userName=userName

password=password

welcomeInfo=welcome{0}

Java1234_zh_CN.properties（src目录下）[中文]，采用Uicode编码，代码如下：

userName=\u7528\u6237\u540d

password=\u5bc6\u7801

welcomeInfo=\u6b22\u8fce{0}

5.struts2标签。Struts2标签是封装完全的，可以换几套皮肤。

数据标签：

①bean标签：

<s:bean name="com.java1234.model.Student" var="student">

<s:param name="name" value="'张三'"></s:param>

<s:param name="age" value="10"></s:param>

</s:bean>

<s:property value="#student.name"/>

<s:property value="#student.age"/>

②date标签：

<s:date name="#request.date" format="yyyy-MM-dd"/>

举例如下：

<%@ page language="java" contentType="text/html; charset=UTF-8"

pageEncoding="UTF-8"%>

<%@ page import="java.util.*" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<%@taglib prefix="s" uri="/struts-tags" %>

<html>

<head>

<title>Insert title here</title>

request.setAttribute("date",new Date());

</head>

<body>

${date }<br/>

当前日期：<s:date name="#request.date" format="yyyy-MM-dd"/>

</body>

</html>

③debug标签：

<s:debug></s:debug>

④include标签：

<s:include value="head.html"></s:include>

⑤property标签：

<%@ page language="java" contentType="text/html; charset=UTF-8"

pageEncoding="UTF-8"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<%@taglib prefix="s" uri="/struts-tags" %>

<html>

<head>

<title>Insert title here</title>

request.setAttribute("name","<font color=red>张三</font>");

</head>

<body>

<s:property value="#request.name" /><br/>

<s:property value="#request.name2" default="某某人"/><br/>

<s:property value="#request.name" default="某某人" escapeHtml="false"/><br/>

</body>

</html>

⑥set标签：

<s:set var="i" value="1"></s:set>

<s:property value="#i" /><br/>

<s:set var="a" value="'action范围的值'" scope="action"></s:set>

<s:set var="p" value="'page范围的值'" scope="page"></s:set>

<s:set var="r" value="'request范围的值'" scope="request"></s:set>

<s:set var="s" value="'session范围的值'" scope="session"></s:set>

<s:set var="app" value="'application范围的值'" scope="application"></s:set>

<s:property value="#a" /><br/>

<s:property value="#attr.p"/><br/>

<s:property value="#request.r"/><br/>

<s:property value="#session.s"/><br/>

<s:property value="#application.app"/><br/>

⑥url标签：

<s:url action="hello" namespace="/foreground" id="h">

<s:param name="name" value="'struts2'"></s:param>

</s:url>

<s:a href="%{h}">超链接</s:a>

<s:a action="hello" namespace="/foreground">

<s:param name="name" value="'struts2'"></s:param>

超链接2

</s:a>

控制标签：

Append标签(叠加标签)

<%@ page language="java" contentType="text/html; charset=UTF-8"

pageEncoding="UTF-8"%>

<%@ page import="com.java1234.model.Student" %>

<%@ page import="java.util.*" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<%@taglib prefix="s" uri="/struts-tags" %>

<html>

<head>

<title>Insert title here</title>

List<Student> studentList1=new ArrayList<Student>();

List<Student> studentList2=new ArrayList<Student>();

studentList1.add(new Student(1,"张三",10));

studentList1.add(new Student(3,"李四",20));

studentList2.add(new Student(5,"王五",30));

studentList2.add(new Student(7,"赵六",40));

request.setAttribute("studentList1",studentList1);

request.setAttribute("studentList2",studentList2);

</head>

<body>

<s:append var="studentList3">

<s:param value="#request.studentList1"></s:param>

<s:param value="#request.studentList2"></s:param>

</s:append>

<table>

<tr>

</tr>

<s:iterator value="studentList3" status="status">

<tr>

</tr>

</s:iterator>

</table>

</body>

</html>

generator标签(分割标签)

<s:generator separator="," val="'张三,李四,王五'" var="nameList"></s:generator>

<s:iterator value="#nameList">

<s:property/>

</s:iterator>

ifelse标签(判断标签)

<title>Insert title here</title>

int age=11;

request.setAttribute("age",age);

</head>

<body>

<s:if test="#request.age<20">

年龄小于20岁

</s:if>

<s:elseif test="#request.age==20">

年龄等于20岁

</s:elseif>

<s:else>

年龄大于20岁

</s:else>

</body>

UI标签：

<s:checkboxlist list="#{0: '游泳', 1:'唱歌 ',2:'跳舞'}" name="hobby" value="1" />

<s:form action="hello" method="post" namespace="/foreground">

<s:radio list="#{0: '男 ', 1:'女 '}" name="sex" value="0" />

<s:select list="#{0: '游泳', 1:'唱歌 ',2:'跳舞'}" name="hobby" value="1" multiple="true"/>

<s:textfield name="userName"></s:textfield><br/>

<s:password name="password"></s:password><br/>

<s:textarea name="desc"></s:textarea><br/>

其他标签：

<s:optiontransferselect label="选择你喜欢图书"

name="cnbook" leftTitle="中文图书" list="{'struts2权威指南','轻量级javaeye 企业应用空实战','ajax讲义'}"

doubleName="enBook" rightTitle="外文图书" doubleList="{'JavaScrip:The definitive Guide','export one-to-one'}" multiple="true"

addToLeftLabel="向左移动" addToRightLabel="向右移动" addAllToRightLabel="全部右移" addAllToLeftLabel="全部左移"

allowSelectAll="true" headerKey="cnKey" headerValue="选择图书" emptyOption="true" doubleHeaderKey="enKey"

doubleHeaderValue="选择外文图书" doubleMultiple="true" doubleEmptyOption="true" leftDownLabel="向下移动"

rightDownLabel="向下移动"

leftUpLabel="向上移动"

rightUpLabel="向上移动" >

</s:optiontransferselect>

<s:updownselect

list="#{0:'游泳', 1:'唱歌', 2:'跳舞'}"

name="hobby"

headerKey="-1"

headerValue="请选择"

emptyOption="true"

allowMoveUp="true"

allowMoveDown="true"

allowSelectAll="true"

moveUpLabel="Move Up"

moveDownLabel="Move Down"

　　selectAllLabel="Select All" />

6.struts2中用ognl(对象图导航语言)访问复杂对象，静态方法和静态属性(此功能太过于强大，请慎用。注意数据的安全性)

此处要获取静态方法和属性，必须为public。默认状态下，是不允许访问静态方法，因此要在struts.xml配置<constant name="struts.ognl.allowStaticMethodAccess" value="true"></constant>

在jsp页面访问代码如下：

<%@ page language="java" contentType="text/html; charset=UTF-8"

pageEncoding="UTF-8"%>

<%@taglib prefix="s" uri="/struts-tags" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title>Insert title here</title>

</head>

<body>

ognl获取静态属性：<s:property value="@com.java1234.comom.MyStatic@name"/><br />

ognl获取静态方法:<s:property value="@com.java1234.comom.MyStatic@print()"/>

</body>

</html>

获取对象代码如下：

<%@ page language="java" contentType="text/html; charset=UTF-8"

pageEncoding="UTF-8"%>

<%@taglib prefix="s" uri="/struts-tags" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title>Insert title here</title>

</head>

ognl获取对象值：

<s:property value="student.name"/><s:property value="student.age"/><br />

ognl获取list对象

<s:property value="students[0].name"/><s:property value="students[0].age"/><s:property value="students[1].name"/><s:property value="students[1].age"/><br />

ognl访问Map：<s:property value="studentMap['goodStudent'].name"/><s:property value="studentMap['goodStudent'].age"/><br/>

<s:property value="studentMap['badStudent'].name"/><s:property value="studentMap['badStudent'].age"/><br/>

</body>

</html>

7.struts2中的值的存储与获取

首先配置struts.xml,代码如下：

<?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">

<result name="success">success.jsp</result>

</action>

</package>

</struts>

配置接着找到action包下面的HelloAction.java,代码如下：

package com.java1234.action;

import java.util.Map;

import com.opensymphony.xwork2.ActionContext;

import com.opensymphony.xwork2.ActionSupport;

import com.opensymphony.xwork2.util.ValueStack;

public class HelloAction extends ActionSupport{

/**

private static final long serialVersionUID = 1L;

@Override

public String execute() throws Exception {

ActionContext actionContext=ActionContext.getContext();

//设置狭义上的值栈

ValueStack valueStack= actionContext.getValueStack();

valueStack.set("name", "女神(ValueStack)");

valueStack.set("age", 21);

//设置session中的值

Map<String, Object> session=actionContext.getSession();

session.put("name", "女神(session)");

session.put("age", 22);

//设置application中的值

Map<String, Object> application=actionContext.getApplication();

application.put("name", "女神(application)");

application.put("age", 23);

return SUCCESS;

}

现在怎么取值呢，代码如下：

<%@ page language="java" contentType="text/html; charset=UTF-8"

pageEncoding="UTF-8"%>

<%@taglib prefix="s" uri="/struts-tags" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title>Insert title here</title>

request.setAttribute("name", "女神(request)");

request.setAttribute("age", "24");

</head>

getValueStack's value is:<s:property value="name"/><s:property value="age"/><br />

getSession's value is:<s:property value="#session.name"/><s:property value="#session.age"/><br />

getApplication's value is:<s:property value="#application.name"/><s:property value="#application.age"/><br />

getRequest's value is:<s:property value="#request.name"/><s:property value="#request.age" /><br />

getAttr's value is:<s:property value="#attr.name" /><s:property value="age"/>

</body>

</html>

8.struts2中登录验证，也就是服务器端的验证了。在这里我要谈谈我对js登录验证和struts登录验证的联系和区别。一开始我学习到这里的时候很迷糊，我以前学习过js，很好用。为什么在这里还有学习登录验证呢。原来，struts2是服务器端验证。两种方式都是对用户身份进行验证，区别便是一个是客户端验证，一个是服务器验证。客户端验证也是就是js验证，反应速度很快，无需刷新页面，用户体验度很高。但是提升用户体验度的同时，也付出了安全性代价，js验证可以人为的跳过，使黑客能不经身份验证便访问服务器资源。服务器验证也就是这里的struts2验证，用户每次验证都要刷新页面，用户体验度不高，验证速度较慢，但是安全性高。所以验证最好的方式便是双重验证，至于为什么，想想很快就能明白了。

现在总结struts2登录验证,Struts2验证是基于拦截器的。

首先贴出struts.xml配置文件(src目录下),代码如下：

<?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">

<interceptor-stack name="myStack">

<interceptor-ref name="loginInterceptor"></interceptor-ref>

<interceptor-ref name="defaultStack"></interceptor-ref>

</interceptor-stack>

</interceptors>

<default-interceptor-ref name="myStack"></default-interceptor-ref>

<global-results>

<result name="error">error.jsp</result>

</global-results>

<result name="success">success.jsp</result>

<interceptor-ref name="defaultStack"></interceptor-ref>

</action>

<result name="success">success.jsp</result>

</action>

</package>

</struts>

当页面访问user后，找到UserAction.java,代码如下：

package com.java1234.action;

import java.util.Map;

import com.java1234.model.User;//放用户数据

import com.java1234.service.UserService;//登录具体的验证方法

import com.opensymphony.xwork2.ActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class UserAction extends ActionSupport{

/**

private static final long serialVersionUID = 1L;

private UserService userService=new UserService();

private User user;

private String error;

public User getUser() {

return user;

}

public void setUser(User user) {

this.user = user;

}

public String getError() {

return error;

}

public void setError(String error) {

this.error = error;

}

@Override

public String execute() throws Exception {

if(userService.login(user)){

ActionContext actionContext=ActionContext.getContext();

Map<String, Object> session=actionContext.getSession();

session.put("currentUser", user);

return SUCCESS;

}else{

this.error="用户名或密码错误";

return "error";

}

上面的代码意思为:如果验证通过，则把数据放到session中，如果没有通过则返回用户名或者密码错误。这里要说明的是，Useraction.java中为最后的验证，验证数据放在User.java中，验证方法放在UserService.java中。

现在贴出拦截器代码：

package com.java1234.interceptor;

import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionContext;

import com.opensymphony.xwork2.ActionInvocation;

import com.opensymphony.xwork2.interceptor.Interceptor;

public class LoginInterceptor implements Interceptor{

@Override

public void destroy() {

// TODO Auto-generated method stub

System.out.println("LoginInterceptor销毁");

}

@Override

public void init() {

// TODO Auto-generated method stub

System.out.println("LoginInterceptor初始化");

}

@Override

public String intercept(ActionInvocation invocation) throws Exception {

System.out.println("在Action执行之前");

ActionContext actionContext=invocation.getInvocationContext();

Map<String, Object> session=actionContext.getSession();

Object currentUser=session.get("currentUser");

String result=null;

if(currentUser!=null){

result=invocation.invoke();

}else{

HttpServletRequest request=(HttpServletRequest)invocation.getInvocationContext().get(ServletActionContext.HTTP_REQUEST);

request.setAttribute("error", "请先登录！");

result="error";

}

System.out.println("result:"+result);

return result;

}

上面的代码其实就是验证session是否为空，空的话提醒先登录，不能有后续的gril操作。注意，在程序运行的时候就已经初始化拦截器，在struts.xml可以知道，拦截器是放在user的前面的。还有要注意的就是，在struts.xml中<action name=”user”.....>中后面要添加上<interceptor-ref name="defaultStack"></interceptor-ref>,不然没法通过拦截器

在struts.xml还配置了一个全局error页面，

<global-results>

<result name="error">error.jsp</result>

</global-results>

这样只需一个就可以搞定所有的出错页面，不用再在每个<result>中写<result name=”error”>error.jsp</result>,error.jsp代码贴出来：

<%@ page language="java" contentType="text/html; charset=UTF-8"

pageEncoding="UTF-8"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title>Insert title here</title>

</head>

<body>

错误信息：${error } <a href="login.jsp">登录</a>

</body>

</html>

还有要说明的是，有四个包分别为：action、interceptor、model、service

action中写UserAction.java(最后的验证)，interceptor中写LoginInterceptor.java(判断session中是否为空)，空的话直接返回error，不为空则进行下一步操作

ActionContext actionContext=invocation.getInvocationContext();

Map<String, Object> session=actionContext.getSession();

Object currentUser=session.get("currentUser");

String result=null;

if(currentUser!=null){

result=invocation.invoke();//

}else{

HttpServletRequest request=(HttpServletRequest)invocation.getInvocationContext().get(ServletActionContext.HTTP_REQUEST);

request.setAttribute("error", "请先登录！");

result="error";

}

model中写User.java放用户数据

package com.java1234.model;

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;

}

Service中写UserService.java，判断登录方法：

package com.java1234.service;

import com.java1234.model.User;

public class UserService {

public boolean login(User user){

if("java1234".equals(user.getUserName())&&"123456".equals(user.getPassword())){

return true;

}else{

return false;

}

9.struts2处理多值传入(批量添加)

比如有个提交页面，添加多个学生：

<%@ page language="java" contentType="text/html; charset=UTF-8"

pageEncoding="UTF-8"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title>Insert title here</title>

</head>

<body>

<table>

<tr>

</tr>

<tr>

</tr>

<tr>

</tr>

<tr>

</td>

</tr>

</table>

</form>

</body>

</html>

struts.xml(src目录下)配置如下

<?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">

<result name="success">success.jsp</result>

<result name="error">false.jsp</result>

</action>

</package>

</struts>

根据配置找到StudentAction.java,代码如下：

package com.java1234.action;

import java.util.List;

import com.java1234.model.Student;//放数据，并重写toString方法

import com.opensymphony.xwork2.Action;

public class StudentAction implements Action {

private List<Student> students;

public List<Student> getStudents() {

return students;

}

public void setStudents(List<Student> students) {

this.students = students;

}

@Override

public String execute() throws Exception {

System.out.println("执行了Action的默认方法");

for (Student s : students) {

System.out.println(s);

}

return SUCCESS;

}

public void show() throws Exception {

System.out.println("执行了show的方法");

for (Student s : students) {

System.out.println(s);

}

再来举个例子，比如处理多选框值：

假如有个提交页面如下：

<%@ page language="java" contentType="text/html; charset=UTF-8"

pageEncoding="UTF-8"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title>Insert title here</title>

</head>

<body>

爱好：

<input type="checkbox" name="hobby" value="吃饭"/>吃饭

<input type="checkbox" name="hobby" value="睡觉"/>睡觉

<input type="checkbox" name="hobby" value="打豆豆"/>打豆豆

<input type="checkbox" name="hobby" value="数绵阳"/>数绵阳

</form>

</body>

</html>

struts.xml配置如下：

<?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">

<result name="success">success.jsp</result>

<result name="error">false.jsp</result>

</action>

</package>

</struts>

根据配置找到HobbyAction.java代码如下：

package com.java1234.action;

import com.opensymphony.xwork2.ActionSupport;

public class HobbyAction extends ActionSupport {

/**

private static final long serialVersionUID = 1L;

private String[] hobby;

public String[] getHobby() {

return hobby;

}

public void setHobby(String[] hobby) {

this.hobby = hobby;

}

@Override

public String execute() throws Exception {

System.out.println("执行了Action的默认方法");

if (hobby != null) {

for (String h : hobby) {

System.out.println(h);

}

return SUCCESS;

}

好了，以上便是我这几天所学struts2我认为应该总结的东西，还有很多细枝末节就不再累述了。学完了struts2感触最深的就是拦截器，功能很强大，能处理很多用户需求。但是使用struts2的时候要小心，会出现意想不到的情况，数据要保护好，异常也要处理得当。

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