准备
为后面测试示例编写代码及配置如下:
// com.zze.bean.User
package com.zze.bean;
import java.util.Date;
public class User {
private String name;
private Integer age;
private Date birthday;
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 Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
@Override
public String toString() {
return "User{" +
"name='" + name + '\'' +
", age=" + age +
", birthday=" + birthday +
'}';
}
}
<!-- struts.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
"http://struts.apache.org/dtds/struts-2.3.dtd">
<struts>
<constant name="struts.devMode" value="true"/>
<package name="test" extends="struts-default" namespace="/">
<action name="*" class="com.zze.action.{1}Action">
<result>/show.jsp</result>
</action>
</package>
</struts>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>v1:${requestScope.key}
v2:${sessionScope.key}
v3:${applicationScope.key}
Servlet API 的三种访问方式
在使用 Struts2 的过程中,会发现 Struts2 和 Servlet 的 API 是松耦合的。但在实际开发中,经常用到 Servlet 的 API,比如将信息保存到 session
中、使用 response
响应一些内容等等..,这些都涉及到对 Servlet 的 API 的访问。下面为三种方式使用的示例:
松耦合方式
// com.zze.action.Test1Action
package com.zze.action;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
import java.util.Arrays;
import java.util.Map;
public class Test1Action extends ActionSupport {
/**
* 解耦合方式
*/
@Override
public String execute() {
ActionContext context = ActionContext.getContext();
// 获取请求参数
Map<String, Object> parameters = context.getParameters();
for (String key : parameters.keySet()) {
String[] values = (String[]) parameters.get(key);
System.out.println(String.format("key:%s value:%s", key, Arrays.toString(values)));
}
// 存放参数到域对象
context.put("key", "value from context.put"); // request.setAttribute("key","value from context.put")
context.getSession().put("key", "value from context.getSession().put"); // session.setAttribute("key","value from context.getSession().put")
context.getApplication().put("key", "value from context.getApplication().put"); // application.setAttribute("key","value from context.getApplication().put")
return SUCCESS;
}
}
使用 ServletActionContext 直接访问
// com.zze.action.Test2Action
package com.zze.action;
import com.opensymphony.xwork2.ActionSupport;
import org.apache.struts2.ServletActionContext;
import javax.servlet.http.HttpServletRequest;
import java.util.Arrays;
import java.util.Map;
public class Test2Action extends ActionSupport {
@Override
public String execute() throws Exception {
// 获取原生 request 对象
HttpServletRequest request = ServletActionContext.getRequest();
Map<String, String[]> parameterMap = request.getParameterMap();
for (String key : parameterMap.keySet()) {
String[] values = (String[]) parameterMap.get(key);
System.out.println(String.format("key:%s value:%s", key, Arrays.toString(values)));
}
// 存放数据到域对象
request.setAttribute("key","value from request.setAttribute");
request.getSession().setAttribute("key","value from request.getSession().setAttribute");
// ServletActionContext.getServletContext()
request.getServletContext().setAttribute("key","value from request.getServletContext().setAttribute");
return super.execute();
}
}
接口注入的方式
// com.zze.action.Test3Action
package com.zze.action;
import com.opensymphony.xwork2.ActionSupport;
import org.apache.struts2.ServletActionContext;
import org.apache.struts2.interceptor.ServletRequestAware;
import org.apache.struts2.interceptor.ServletResponseAware;
import org.apache.struts2.util.ServletContextAware;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.Arrays;
import java.util.Map;
/**
* 接口注入的方式需要实现相应接口
*/
public class Test3Action extends ActionSupport implements ServletRequestAware, ServletResponseAware, ServletContextAware {
private HttpServletRequest request; // 接收注入的原生 request
private HttpServletResponse response; // 接收注入的原生 response
private ServletContext servletContext; // 接收注入的原生 servletContext
@Override
public String execute() throws Exception {
// 接收请求参数
Map<String, String[]> parameterMap = request.getParameterMap();
for (String key : parameterMap.keySet()) {
String[] values = (String[]) parameterMap.get(key);
System.out.println(String.format("key:%s value:%s", key, Arrays.toString(values)));
}
// 存放数据到域对象
request.setAttribute("key", "value from request.setAttribute");
request.getSession().setAttribute("key", "value from request.getSession().setAttribute");
servletContext.setAttribute("key", "value from servletContext.setAttribute");
return super.execute();
}
@Override
public void setServletRequest(HttpServletRequest request) {
this.request = request;
}
@Override
public void setServletResponse(HttpServletResponse response) {
this.response = response;
}
@Override
public void setServletContext(ServletContext context) {
this.servletContext = context;
}
}
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