前言1:java , tomcat設定 可以參考.
前面幾篇
前言2:struts2 架構
Struts2 的 Action 能夠相容
POJO
講白話一點就是什麼都不用繼承的 class 就能當 Action 用.
POJO類別簡單來說，就是單純的
Java類別，不帶有其他框架 API 呼叫，開發者可以以簡單不複雜的方式(不必實
作一些繁複的介面或繼承)來開發商業邏輯，減少與其他元件的耦合性.
action:Each URL is mapped to a specific action.
2. create dynamic web project
3. put structs2 lib to your web-inf\lib
4. create model =>HelloWorldAction.java
Struts 2 framework will create an object of HelloWorldAction.java,
and call execute method.
package com.tutorialspoint.struts2;
public class HelloWorldAction{
private String name;
private String age;
public String getAge() {
return age;
}
public void setAge(String age) {
this.age = age;
}
public String execute() throws Exception {
System.out.println(name+age);
return "success2";
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
5. create view under webContent=>HelloWorld.jsp
<s:property value="name"/> 會呼叫 HelloWorldAction.java的getname()
<%@ page contentType="text/html; charset=UTF-8" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>Hello World
</head>
<body>
Hello World,<s:property value="name">
age ,<s:property value="age">
</body>
</html>
6.create main page under webContent => index.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<html>
<head>
Hello World
</head>
<body>
Hello World From Struts2
Hello World From Struts2 Extend
Hello World From Struts2 Map
</body>
</html>
action = hello . mapping to HelloWorldAction class , use struts.xml to setting
7.create struts.xml under src/
/HelloWorld.jsp
/HelloWorld.jsp
/AccessDenied.jsp
/HelloWorldMap.jsp
/AccessDenied.jsp
The only requirement for actions in Struts2 is that there must be one no-argument method that returns either a String or Result object and must be a POJO. If the no-argument method is not specified, the default behavior is to use the execute() method.
8.create web.xml under webContent/web-inf
Struts 2
index.jsp
struts2
org.apache.struts2.dispatcher.FilterDispatcher
struts2
/*
9.enable detail log (先跳過)
10. [test] run your project
11. struts.properties file (if need, this will have default)
### When set to true, Struts will act much more friendly for developers
struts.devMode = true
### Enables reloading of internationalization files
struts.i18n.reload = true
### Enables reloading of XML configuration files
struts.configuration.xml.reload = true
### Sets the port that the server is run on
struts.url.http.port = 8080
create under web-inf/classes
Create Multiple Actions
_1. create HelloWorldActionExtendActionSupport.java
package com.tutorialspoint.struts2;
import com.opensymphony.xwork2.ActionSupport;
public class HelloWorldActionExtendActionSupport extends ActionSupport{
private String name;
public String execute() throws Exception {
if ("SECRET".equals(name))
{
return SUCCESS;
}else{
return ERROR;
}
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
_2. add content to struts.xml
/HelloWorld.jsp
/HelloWorld.jsp
/AccessDenied.jsp
/HelloWorldMap.jsp
/AccessDenied.jsp
ValueStack/OGNL Example
The Object-Graph Navigation Language (OGNL) is a powerful expression language that is used to reference and manipulate data on the ValueStack. OGNL also helps in data transfer and type conversion.
=1. create HelloWorldActionExtendActionMap.java
package com.tutorialspoint.struts2;
import java.util.*;
import com.opensymphony.xwork2.util.ValueStack;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
public class HelloWorldActionMap extends ActionSupport{
private String name;
public String execute() throws Exception {
ValueStack stack = ActionContext.getContext().getValueStack();
Map context = new HashMap();
context.put("key1", this.name);
context.put("key2", this.name);
stack.push(context);
System.out.println("Size of the valueStack: " + stack.size());
return "success";
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
=2. add content to struts.xml(同上)
=3. add HolloWorldMap.jsp
<%@ page contentType="text/html; charset=UTF-8" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<head>
Hello World
</head>
<body>
Entered value : <s:property value="name">
Value of key 1 : <s:property value="key1">
Value of key 2 : <s:property value="key2">
</body>
</html>
