struts2学习(3)struts2核心知识II
一、struts.xml配置:
1.分模塊配置方法:
比如某個系統多個模塊,我們把資產管理模塊和車輛管理模塊,分開,在總的struts.xml配置文件中include他們:
工程結構:
struts.xml配置:
<?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><include file="cheliang.xml"></include><include file="zichan.xml"></include> </struts>cheliang.xml:
<struts><package name="cheliang" namespace="/cheliang" extends="struts-default"><action name="cheliang" class="com.cy.action.CheLiangAction"><result name="success">${pageContext.request.contextPath}/success.jsp</result></action></package></struts> View Codezichan.xml:
<struts><package name="zichan" namespace="/zichan" extends="struts-default"><action name="zichan" class="com.cy.action.ZiChanAction"><result name="success">${pageContext.request.contextPath}/success.jsp</result></action></package></struts> View CodeCheLiangAction.java:
public class CheLiangAction extends ActionSupport{private static final long serialVersionUID = 1L;public String execute() throws Exception {System.out.println("執行了CheLiangAction Action的默認方法");return SUCCESS;} } View CodeZiChanAction.java:
public class ZiChanAction extends ActionSupport{private static final long serialVersionUID = 1L;public String execute() throws Exception {System.out.println("執行了CheLiangAction Action的默認方法");return SUCCESS;} } View Code測試:
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2.使用通配符:
?struts.xml:
<?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><package name="manage" namespace="/" extends="struts-default"><!-- method={1} 取到第一個通配符--><action name="student_*" class="com.cy.action.StudentAction" method="{1}"><result name="success">success.jsp</result></action><action name="grade_*" class="com.cy.action.GradeAction" method="{1}"><result name="success">success.jsp</result></action></package> </struts>com.cy.action.GradeAction.java:
package com.cy.action;import com.opensymphony.xwork2.ActionSupport;public class GradeAction extends ActionSupport{private String name;public String getName() {return name;}public void setName(String name) {this.name = name;}public String list()throws Exception{System.out.println("班級查找");name="班級查找";return SUCCESS;}public String add()throws Exception{System.out.println("班級添加");name="班級添加";return SUCCESS;}public String update()throws Exception{System.out.println("班級修改");name="班級修改";return SUCCESS;}public String delete()throws Exception{System.out.println("班級刪除");name="班級刪除";return SUCCESS;}} View Codecom.cy.action.StudentAction.java:
package com.cy.action;import com.opensymphony.xwork2.ActionSupport;public class StudentAction extends ActionSupport{private String name;public String getName() {return name;}public void setName(String name) {this.name = name;}public String list()throws Exception{System.out.println("學生查找");name="學生查找";return SUCCESS;}public String add()throws Exception{System.out.println("學生添加");name="學生添加";return SUCCESS;}public String update()throws Exception{System.out.println("學生修改");name="學生修改";return SUCCESS;}public String delete()throws Exception{System.out.println("學生刪除");name="學生刪除";return SUCCESS;}} View Codesuccess.jsp:
<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body>OK! ${name} </body> </html> View Codeindex.jsp:
<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body><h1>通配符</h1><a href="student_list" target="_blank">學生信息查詢</a> <a href="student_add" target="_blank">學生信息添加</a> <a href="student_update" target="_blank">學生信息修改</a> <a href="student_delete" target="_blank">學生信息刪除</a> <br/><br/><a href="grade_list" target="_blank">班級信息查詢</a> <a href="grade_add" target="_blank">班級信息添加</a> <a href="grade_update" target="_blank">班級信息修改</a> <a href="grade_delete" target="_blank">班級信息刪除</a> <br/></body> </html> View Code測試:
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3.上面的通配符配置方式還可以簡化:
struts.xml:
<struts><package name="manage" namespace="/" extends="struts-default"><action name="*_*" class="com.cy.action.{1}Action" method="{2}"><result name="success">success.jsp</result></action></package> </struts>因為{1}Action獲取到student/grade是小寫,index.jsp中改為大寫的:
index.jsp:
<body><h1>通配符</h1><a href="Student_list" target="_blank">學生信息查詢</a> <a href="Student_add" target="_blank">學生信息添加</a> <a href="Student_update" target="_blank">學生信息修改</a> <a href="Student_delete" target="_blank">學生信息刪除</a> <br/><br/><a href="Grade_list" target="_blank">班級信息查詢</a> <a href="Grade_add" target="_blank">班級信息添加</a> <a href="Grade_update" target="_blank">班級信息修改</a> <a href="Grade_delete" target="_blank">班級信息刪除</a> <br/></body>測試結果ok
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二、動態方法調用:
struts.enable.DynamicMethodInvocation,開啟動態方法調用,默認是false;上面的struts.xml修改為如下:
<struts><constant name="struts.enable.DynamicMethodInvocation" value="true" /><package name="manage" namespace="/" extends="struts-default"><action name="student" class="com.cy.action.StudentAction"><result name="success">success.jsp</result></action><action name="grade" class="com.cy.action.GradeAction"><result name="success">success.jsp</result></action></package> </struts>index.jsp:
<body><h1>動態方法調用</h1><a href="student!list" target="_blank">學生信息查詢</a> <a href="student!add" target="_blank">學生信息添加</a> <a href="student!update" target="_blank">學生信息修改</a> <a href="student!delete" target="_blank">學生信息刪除</a> <br/><br/><a href="grade!list" target="_blank">班級信息查詢</a> <a href="grade!add" target="_blank">班級信息添加</a> <a href="grade!update" target="_blank">班級信息修改</a> <a href="grade!delete" target="_blank">班級信息刪除</a> <br/></body> View Code測試:
三、Action生命周期
例子:
com.cy.action.HelloAction.java:
package com.cy.action;import com.opensymphony.xwork2.ActionSupport;public class HelloAction extends ActionSupport{/*** */private static final long serialVersionUID = 1L;public HelloAction() {System.out.println(this);}@Overridepublic String execute() throws Exception {// TODO Auto-generated method stubreturn SUCCESS;}} View Codestruts.xml:
<?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><package name="manage" namespace="/" extends="struts-default"><action name="hello" class="com.cy.action.HelloAction"><result name="success">success.jsp</result></action></package> </struts> View Code我們在每次請求hello鏈接的時候,產生HelloAction實例,實例的構造方法中打印了當前類對象;
測試結果:
多次訪問:http://localhost:8080/Struts2Chap01/hello
console:
證明了:
每次請求hello,都會產生一個新的HelloAction實例; 每次產生新的,保證安全點,但是每次都產生新的,感覺有點浪費,當并發量很大的時候,內存可能有問題; 等到以后spring管理struts的Action都是單例;HelloAction始終只有1個;(當然也可以多例)?
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轉載于:https://www.cnblogs.com/tenWood/p/7092246.html
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