struts2入门-白红宇

struts2的hello world

1、导包（自行导包）

2、配置web.xml文件

struts2基于拦截器，配置的第一步是在WEB-INF/web.xml中配置struts2拦截器。


    
      
     
      struts2
       
         
      
       index.html
          
      
       index.htm
          
      
       index.jsp
          
      
       default.html
          
      
       default.htm
          
      
       default.jsp
        
       
       
       	
      
       struts2
        	
      
       org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter
        
         
       	
      
       struts2
      	
      
       /*
        	  
      
    复制代码

3、配置struts.xml文件

4、写一个HelloAction类

public class HelloAction extends ActionSupport{    public String execute() {        System.out.println("hello world");        return "success";    }}复制代码

5、编写一个hello.jsp页面和index.jsp页面

hello.jsp

<%@ page language="java" contentType="text/html; charset=utf-8"    pageEncoding="utf-8"%>        
        struts2                    hello world        复制代码

index.jsp

<%@ page language="java" contentType="text/html; charset=utf-8"    pageEncoding="utf-8"%>        
        struts2                    hello struts        复制代码

6、测试

配置好后，就可以通过浏览器访问(根路径取决于项目配置)     http://127.0.0.1/strut2/hello.action    如果访问成功，jsp页面也会显示hello struts    http://127.0.0.1/strut2/hello.action     如果访问成功，控制台后打印 hello world，jsp页面也会显示hello world

7、补充（注解配置如下）

// 使用注解前必须导入 struts2-convention-plugin 包@ParentPackage("struts-default")public class HelloAction extends ActionSupport{    @Action(value="hello",results= {            @Result(name="success",location="/hello.jsp")    })    public String execute() {        System.out.println("hello world");        return "success";    }    }复制代码

struts2常量配置

动态方法调用

HelloAction

public class HelloAction extends ActionSupport{    public String execute() {        System.out.println("hello world");        return "success";    }        public String execute1() {        System.out.println("hello world1");        return "success";    }        public String execute2() {        System.out.println("hello world2");        return "success";    }}复制代码


    
    
    
    
     execute1,execute2,execute3
    
    
    	
     
      /hello.jsp
     
    
    
    	
     
      /hello.jsp
     
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Action的创建方式

//第一种方式public class HelloAction{}//第二种方式public class Test implements Action{    @Override    public String execute() throws Exception {        // TODO Auto-generated method stub        return null;    }}//第三种方式public class HelloAction extends ActionSupport{}复制代码

Action中result处理方式

Action获取servlet api

//获得原生的servlet作用域对象  方式一public class Action1 extends ActionSupport{    public String hello1() {        HttpServletRequest request=ServletActionContext.getRequest();        request.setAttribute("key", "value");        HttpSession session=request.getSession();        HttpServletResponse response=ServletActionContext.getResponse();        ServletContext servletContext=ServletActionContext.getServletContext();        return "success1";    }}//获得原生的servlet作用域对象  方式二public class Action1 extends ActionSupport implements ServletRequestAware,ServletResponseAware,ServletContextAware{    private HttpServletRequest request;    private HttpServletResponse response;    private ServletContext servletContext;    @Override    public void setServletRequest(HttpServletRequest request) {        this.request=request;        HttpSession session=request.getSession();    }    @Override    public void setServletResponse(HttpServletResponse response) {        this.response=response;    }    @Override    public void setServletContext(ServletContext servletContext) {        this.servletContext=servletContext;            }}//获得原生的ActionContext作用域对象(常用)  方式一public class Action1 extends ActionSupport{    public String hello2() {        Map
    
      request=(Map
     
      )ActionContext.getContext().get("request");        ActionContext context=ActionContext.getContext();        context.put("key", "value");        Map
      
        session=ActionContext.getContext().getSession();        session.put("key", "value");        Map
       
         application=ActionContext.getContext().getApplication();        return "success1";    }}//获得原生的ActionContext作用域对象(常用)  方式二public class Action1 extends ActionSupport implements RequestAware, SessionAware, ApplicationAware {    private Map
        
          request;    private Map
         
           session; private Map
          
            application; @Override public void setRequest(Map
           
             request) { this.request = request; } @Override public void setSession(Map
            
              session) { this.session = session; } @Override public void setApplication(Map
             
               application) { this.application = application; }}复制代码

struts2接收前台传过来的参数的方式

第一种方式：属性加载驱动

index.jsp

public class Action1{    private String name;    private Integer age;    private Date date;    //...省略getter/setter方法    public String hello1() {        System.out.println(name+"-"+age+"-"+date);        return "success1";    } }复制代码

第二种方式：对象加载驱动

index.jsp

Student.java

public class Student {    private Integer id;    private String name;    private Integer age;    private Date date;    //...省略getter/setter方法}复制代码

public class Action1{    private Student student;    //...省略getter/setter方法    public String hello1() {        System.out.println(student);        return "success1";    } }复制代码

第三种方式：ModelDriven模型驱动

index.jsp

public class Student {    private Integer id;    private String name;    private Integer age;    private Date date;    //...省略getter/setter方法}复制代码

public class Action1 implements ModelDriven
    
     {    private Student student=new Student();    public String hello1() {        System.out.println(student);        return "success1";    }    @Override    public Student getModel() {        return student;    } }复制代码

接收list集合

public class Action1{    private List
    
      list;    //...省略getter/setter方法    public String hello1() {        System.out.println(list);        return "success1";    }}复制代码

接收map集合

public class Action1{    private Map
    
      map;    //...省略getter/setter方法    public String hello1() {        System.out.println(map);        return "success1";    }}复制代码

值栈(ValueStack)

栈：先进后出

队列：先进先出

struts拦截器

StudentAction.java

public class StudentAction {    public String getAdd() {        System.out.println("add");        return "success";    }    public String getUpdate() {        System.out.println("update");        return "success";    }    public String getDel() {        System.out.println("del");        return "success";    }    public String getSelect() {        System.out.println("select");        return "success";    }}复制代码

MyInterceptor3.java

//自定义拦截器public class MyInterceptor3 extends MethodFilterInterceptor{    private static final long serialVersionUID = 1L;    @Override    protected String doIntercept(ActionInvocation invocation) throws Exception {        //前处理        System.out.println("before");        invocation.invoke();        //后处理        System.out.println("after");        //返回结果集，不执行后面的拦截器，直接给result处理结果集，跳转页面        return null;    }}复制代码


    
    	
     		
      		
      			
       			
       			
       				
        				
        					
         					
         					
         					
         					
         getDel,getSelect				
        				
        				
        			
       		
      		
      		
      		
      
       getAdd,getUpdate,getDel,getSelect
      	
     
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struts2的执行流程

用户请求前端控制器(StrutspreapredAndExecuteFilter)，它是一个 Filter，拦截用户的请求，根据用户请求的url调用Action

前端控制器(StrutsPrepareAndExecuteFilter)判定该请求是否是一个Struts2 请求(ActionMapper)

若该请求是一个Struts2请求，则前端控制器StrutsPrepareAndExecuteFilter 把请求的处理交给ActionProxy

ActionProxy创建一个ActionInvocation的实例，并进行初始化

ActionInvocation实例在调用 Action 的过程前后，涉及到相关拦截器（Intercepter）的调用。

Action 执行完毕，ActionInvocation 负责根据struts.xml中的配置找到对应的result，渲染结果。

执行各个拦截器 invocation.invoke() 之后的代码

把结果发送到客户端