一、Struts2 概述
Struts 翻译:支柱
Struts 是流行和成熟的基于 MVC 设计模式的 Web 应用程序框架
POJO(Plain Ordinary Java Object)简单的 Java 对象
MVC 模式
模型视图控制器
Model View Controller
工作原理图
二、Struts2 项目
项目结构
. ├── pom.xml └── src ├── main │ ├── java │ │ └── com │ │ └── mouday │ │ └── HelloWorldAction.java │ ├── resources │ │ └── struts.xml │ └── webapp │ ├── WEB-INF │ │ └── web.xml │ ├── hello.jsp │ └── index.html └── test └── java
1、配置文件
(1)pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0";xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.example</groupId>
<artifactId>java-demo-struts</artifactId>
<version>1.0-SNAPSHOT</version>
<build>
<plugins>
<!-- tomcat7插件 maven 命令 tomcat7:run 启动项目-->
<plugin>
<groupId>org.apache.tomcat.maven</groupId>
<artifactId>tomcat7-maven-plugin</artifactId>
<version>2.2</version>
<configuration>
<port>8080</port>
<path>/</path>
<uriEncoding>UTF-8</uriEncoding>
<!--添加忽略war包检查标签,则可以让tomcat7:run指令正常启动tomcat-->
<ignorePackaging>true</ignorePackaging>
<contextFile>src/main/webapp/WEB-INF/web.xml</contextFile>
<contextReloadable>true</contextReloadable>
</configuration>
</plugin>
</plugins>
</build>
<!-- https://mvnrepository.com/artifact/org.apache.struts/struts2-core -->
<dependencies>
<dependency>
<groupId>org.apache.struts</groupId>
<artifactId>struts2-core</artifactId>
<version>2.5.22</version>
</dependency>
<!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.1</version>
<scope>provided</scope>
</dependency>
</dependencies>
</project>
(2)src/main/webapp/WEB-INF/web.xml
<?xml version="1.0" encoding="utf-8" ?>
<web-app>
<display-name>Hello</display-name>
<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
</welcome-file-list>
</web-app>
(3)src/main/resources/struts.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="default" namespace="/" extends="struts-default">
<action name="HelloWorldAction" class="com.mouday.HelloWorldAction">
<result name="">/hello.jsp</result>
</action>
</package>
</struts>
2、Action
src/main/java/com/mouday/HelloWorldAction.java
package com.mouday;
import com.opensymphony.xwork2.ActionSupport;
public class HelloWorldAction extends ActionSupport {
@Override
public String execute() throws Exception {
System.out.println("hello action");
return SUCCESS;
}
}
3、视图文件
src/main/webapp/index.html
<!DOCTYPE html>
<html lang="en">
<body>
hi
</body>
</html>
4、访问测试
GET http://localhost:8080/
hi
GET http://localhost:8080/HelloWorldAction
hello action jsp
三、核心文件
web.xml
struts.xml
struts.properties 全局属性文件,自动加载
struts.properties 常用配置
# struts.xml改动后重新加载重载 默认 false
struts.configuration.xml.reload=true
# 打开开发模式 默认 false
struts.devMode=true
# 设置浏览器缓存静态页面 默认true
struts.serve.static.browserCache=false
# 被struts处理的请求后缀
struts.action.extension=action,do
# 服务器运行时端口号
struts.url.http.port=8080
四、深入 Struts2
1、访问 Servlet API 方式
- ActionContext
- 实现 Aware 接口
- ServletActionContext
2、Action 搜索顺序
逐级向上查找
3、动态方法调用
(1)指定 method 属性
package com.mouday;
import com.opensymphony.xwork2.ActionSupport;
public class HelloWorldAction extends ActionSupport {
@Override
public String execute() throws Exception {
System.out.println("hello action");
return SUCCESS;
}
public String add(){
System.out.println("add");
return SUCCESS;
}
}
struts.xml(简化)
<struts>
<package name="default" namespace="/" extends="struts-default">
<action name="add" class="com.mouday.HelloWorldAction" method="add">
<result name="">/add.jsp</result>
</action>
</package>
</struts>
访问结果
GET http://localhost:8080/add.action
add result
(2)感叹号方式(不推荐)
参考
struts2.5 使用感叹号和通配符实现动态方法调用无效的问题及解决!
配置文件
<?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="default" namespace="/" extends="struts-default">
<global-allowed-methods>regex:.*</global-allowed-methods>
<action name="HelloWorldAction" class="com.mouday.HelloWorldAction">
<result>/hello.jsp</result>
<result name="add">/add.jsp</result>
</action>
</package>
<constant name="struts.enable.DynamicMethodInvocation" value="true"/>
</struts>
GET http://localhost:8080/HelloWorldAction!add.action
add result
(3) 通配符方式
<?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="default" namespace="/" extends="struts-default">
<global-allowed-methods>regex:.*</global-allowed-methods>
<action name="_" method="{2}" class="com.mouday.{1}Action">
<result name="{2}">/{2}.jsp</result>
</action>
</package>
<constant name="struts.enable.DynamicMethodInvocation" value="true"/>
</struts>
GET http://localhost:8080/HelloWorldAction_add.action
add result
4、指定多个配置文件
<include file="helloworld.xml" />
配置示例
struts.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>
<include file="hello.xml"/>
<constant name="struts.enable.DynamicMethodInvocation" value="true"/>
<!-- 以防乱码-->
<constant name="struts.i18n.encoding" value="UTF-8"/>
</struts>
hello.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="default" namespace="/" extends="struts-default">
<global-allowed-methods>regex:.*</global-allowed-methods>
<action name="_" method="{2}" class="com.mouday.{1}Action">
<result name="{2}">/{2}.jsp</result>
</action>
</package>
</struts>
访问
GET http://localhost:8080/HelloWorld_add.action
add result
5、默认 Action
<?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="default" namespace="/" extends="struts-default">
<default-action-ref name="index" />
<action name="index">
<result>/error.jsp</result>
</action>
</package>
</struts>
访问
GET http://localhost:8080/xxxx.action
error jsp
6、Struts2 后缀
(1)struts.xml
<constant name="struts.action.extension" value="html" />
(2)struts.properties
struts.action.extension=action,do
(3)web.xml
<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter</filter-class>
<init-param>
<param-name>struts.action.extension</param-name>
<param-value>do</param-value>
</init-param>
</filter>
7、接收参数
(1)Action 属性
Action 类
package com.mouday;
import com.opensymphony.xwork2.ActionSupport;
public class LoginAction extends ActionSupport {
private String username;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
@Override
public String execute() throws Exception {
System.out.println(username);
return SUCCESS;
}
}
路由配置
<action name="login" class="com.mouday.LoginAction">
<result>/login.html</result>
</action>
表单页面
<form action="login.action" method="post">
<input type="text" name="username" />
<input type="submit" />
</form>
(2)Domain Model
新建 User 类
package com.mouday.bean;
public class User {
private String username;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
}
Action
package com.mouday.action;
import com.mouday.bean.User;
import com.opensymphony.xwork2.ActionSupport;
public class LoginAction extends ActionSupport {
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.getUsername());
return SUCCESS;
}
}
登录表单
<form action="login.action" method="post">
<input type="text" name="user.username" />
<input type="submit" />
</form>
(3)ModelDriven
Action
package com.mouday.action;
import com.mouday.bean.User;
import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.ModelDriven;
public class LoginAction extends ActionSupport implements ModelDriven<User> {
private User user = new User();
@Override
public String execute() throws Exception {
System.out.println(user.getUsername());
return SUCCESS;
}
public User getModel() {
return user;
}
}
表单
<form action="login.action" method="post">
<input type="text" name="username" />
<input type="submit" />
</form>
4)接收列表类型
User 类
package com.mouday.bean;
import java.util.List;
public class User {
private String username;
private List<String> list;
public List<String> getList() {
return list;
}
public void setList(List<String> list) {
this.list = list;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
}
Action
package com.mouday.action;
import com.mouday.bean.User;
import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.ModelDriven;
public class LoginAction extends ActionSupport implements ModelDriven<User> {
private User user = new User();
@Override
public String execute() throws Exception {
System.out.println(user.getUsername());
System.out.println(user.getList());
return SUCCESS;
}
public User getModel() {
return user;
}
}
表单
<form action="login.action" method="post">
<input type="text" name="username" />
<input type="text" name="list[0]" />
<input type="text" name="list[1]" />
<input type="submit" />
</form>
8、处理结果类型
Struts2 处理流程
用户请求
-> Stuts框架
-> 控制器Action
-> Stuts框架
-> 视图资源
result 如果省略 name,则默认是 success
<result name="success">/success.jsp</result>
<!-- 等价于 -->
<result>/success.jsp</result>
处理结果类型:
- SUCCESS 正确执行,默认视图
- NONE 正确执行,不返回视图
- ERROR 执行失败
- LOGIN 登录视图
- INPUT 参数输入界面
Action
package com.mouday.action;
import com.mouday.bean.User;
import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.ModelDriven;
public class LoginAction extends ActionSupport implements ModelDriven<User> {
private User user = new User();
@Override
public String execute() throws Exception {
System.out.println(user.getUsername());
System.out.println(user.getList());
return SUCCESS;
}
@Override
public void validate() {
if (user.getUsername() == null || "".equals(user.getUsername())
) {
addFieldError("username", "用户名不能为空");
}
}
public User getModel() {
return user;
}
}
配置
<?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="default" namespace="/" extends="struts-default">
<action name="login" class="com.mouday.action.LoginAction">
<result>/login.jsp</result>
<result name="input">/login.jsp</result>
</action>
</package>
</struts>
登录框
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
<form action="login.action" method="post">
<input type="text" name="username"/>
<!-- 显示错误提示 -->
<s:fielderror name="username"></s:fielderror>
<input type="text" name="list[0]"/>
<input type="text" name="list[1]"/>
<input type="submit" />
</form>
9、局部结果和全局结果
OGNL
<result name="">
<param name="location">resource</param>
</result>
</div>