Struts2的使用注解配置Action(零配置)
1.首先引入struts2注解的jar包:struts2-convention-plugin.jar
------------------------------第一种方式-------------------------------------
2.struts的配置
<?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> <package name="lxyPackage" extends="json-default" namespace="/"> <!-- S QLQ 增加的培训类别管理 --> <global-results> <result name="success" type="json"> <param name="root">response</param> </result> </global-results> </struts>
3.TestAnnotationAction.java(测试JSON,跳转,重定向三种方式)
package cn.xm.exam.action.trainContent; import java.util.HashMap; import java.util.Map; import org.apache.struts2.convention.annotation.Action; import org.apache.struts2.convention.annotation.Namespace; import org.apache.struts2.convention.annotation.ParentPackage; import org.apache.struts2.convention.annotation.Result; import org.apache.struts2.convention.annotation.Results; import org.springframework.context.annotation.Scope; import org.springframework.stereotype.Controller; import com.opensymphony.xwork2.ActionSupport; @Controller @Scope("prototype") // 多例 @Namespace("/") @Results({ @Result(name = "tiaozhuan", location = "/view/testPerson/outEmployeeAllot.jsp"), @Result(name = "redirect", type = "redirect", location = "/view/testPerson/outEmployeeAllot.jsp") }) @ParentPackage("lxyPackage") // 属于哪个package public class TestAnnotationAction extends ActionSupport { private Map response; @Action("/test1") public String test1() { response = new HashMap(); response.put("hello", "hello"); return SUCCESS; } @Action("/test2") public String test2() { return "tiaozhuan"; } @Action("/test3") public String test3() { return "redirect"; } public Map getResponse() { return response; } public void setResponse(Map response) { this.response = response; } }
4.测试:
(1)测试返回JSON
(2)测试转发
(3)测试重定向
访问: http://localhost/Exam/test3.action
------------------------------第二种方式(注解返回JSON、跳转、重定向)-------------------------------------
pom.xml依赖:
<dependency> <groupId>org.apache.struts</groupId> <artifactId>struts2-convention-plugin</artifactId> <version>2.3.24</version> </dependency> <dependency> <groupId>org.apache.struts</groupId> <artifactId>struts2-core</artifactId> <version>2.3.24</version> </dependency> <dependency> <groupId>org.apache.struts</groupId> <artifactId>struts2-json-plugin</artifactId> <version>2.3.24</version> </dependency>
struts.xml配置
<?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.i18n.encoding" value="utf-8"></constant> <constant name="devMode" value="true"></constant> <constant name="struts.enable.DynamicMethodInvocation" value="true" /> <!-- 配置拦截的后缀 --> <constant name="struts.action.extension" value="action,do" /> <package name="default" extends="json-default"></package> </struts>
测试代码:
package cn.qlq.action; import org.apache.struts2.convention.annotation.Action; import org.apache.struts2.convention.annotation.Namespace; import org.apache.struts2.convention.annotation.ParentPackage; import org.apache.struts2.convention.annotation.Result; import com.opensymphony.xwork2.ActionSupport; import com.opensymphony.xwork2.Preparable; @Namespace("/") @ParentPackage("default") public class FirstAction extends ActionSupport implements Preparable { private static final long serialVersionUID = 1L; private String test; @Override public void prepare() throws Exception { System.out.println("这是所有方法前的处理"); } @Action(value = "test", results = { @Result(name = "success1", location = "/index2.jsp", type = "redirect") , @Result(name = "error", location = "/index2.jsp") , @Result(name = "success" ,type = "json" , params = {"root","test"}) }) @Override public String execute() throws Exception { test = "test"; return super.execute(); } public String getTest() { return test; } public void setTest(String test) { this.test = test; } }
注意:
@Result的type值默认为dispatcher(转发)。
如果普通页面跳转和重定向,不需要指定ParentPackage属性。
如果需要返回JSON,需要指定ParentPackage属性,否则找不到JSON结果类型,params = {"root","test"}是将test属性作为JSON返回前台,如果不指定参数会将所有带get、set的属性以JSON形式返回前台。
如果希望某些属性不被转为JSON返回前台,可以:
@JSON(serialize=false)//不被序列化
补充:
网上说注解配置必须继承ActionSupport,经过测试不继承ActionSupport也是可以的。上面的是单独的没和spring整合的注解配置,发现是多例模式,每次请求都会创建Action对象。
------------------------------第三种:和spring整合的注解----------------
pom配置:
<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/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>cn.xm</groupId> <artifactId>jwxt</artifactId> <packaging>war</packaging> <version>1.0-SNAPSHOT</version> <name>jwxt Maven Webapp</name> <url>http://maven.apache.org</url> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.9</version> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>servlet-api</artifactId> <version>2.5</version> <scope>provided</scope> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>jsp-api</artifactId> <version>2.0</version> <scope>provided</scope> </dependency> <!-- 调试过程中自己加的包依赖包 --> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-api</artifactId> <version>2.0-rc1</version> </dependency> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-core</artifactId> <version>2.0-rc1</version> </dependency> <!--EL和JSTL --> <dependency> <groupId>taglibs</groupId> <artifactId>standard</artifactId> <version>1.1.2</version> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> <dependency> <groupId>org.apache.struts</groupId> <artifactId>struts2-convention-plugin</artifactId> <version>2.3.24</version> </dependency> <dependency> <groupId>org.apache.struts</groupId> <artifactId>struts2-core</artifactId> <version>2.3.24</version> </dependency> <dependency> <groupId>org.apache.struts</groupId> <artifactId>struts2-json-plugin</artifactId> <version>2.3.24</version> </dependency> <!-- slf4j 依赖包 --> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>1.7.25</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>1.7.5</version> </dependency> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-api</artifactId> <version>2.0-rc1</version> </dependency> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-core</artifactId> <version>2.0-rc1</version> </dependency> <dependency> <groupId>org.apache.struts</groupId> <artifactId>struts2-spring-plugin</artifactId> <version>2.3.24</version> </dependency> </dependencies> <build> <!-- 配置了很多插件 --> <plugins> <!-- 编译插件 --> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.5.1</version> <configuration> <source>1.7</source> <target>1.7</target> <encoding>UTF-8</encoding> </configuration> </plugin> </plugins> </build> </project>
spring配置:
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd "> <!-- 扫描Action基本包 --> <context:component-scan base-package="cn.qlq.action"></context:component-scan> </beans>
struts配置:
<?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.i18n.encoding" value="utf-8"></constant> <constant name="devMode" value="true"></constant> <constant name="struts.enable.DynamicMethodInvocation" value="true" /> <constant name="" value="true" /> <!-- 配置拦截的后缀 --> <constant name="struts.action.extension" value="action,do" /> <!-- 与spring整合 --> <constant name="struts.objectFactory" value="spring"></constant> <package name="default" extends="json-default"></package> </struts>
web.xml配置:
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5"> <display-name>Struts</display-name> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> <!-- spring --> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:applicationContext.xml</param-value> </context-param> <!-- struts --> <filter> <filter-name>struts2</filter-name> <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class> </filter> <filter-mapping> <filter-name>struts2</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> </web-app>
测试:
package cn.qlq.action; import org.apache.struts2.convention.annotation.Action; import org.apache.struts2.convention.annotation.Namespace; import org.apache.struts2.convention.annotation.ParentPackage; import org.apache.struts2.convention.annotation.Result; import org.springframework.context.annotation.Scope; import org.springframework.stereotype.Controller; import com.opensymphony.xwork2.ActionSupport; @Namespace("/") @ParentPackage("default") @Controller("firstAction") @Scope("singleton") public class FirstAction extends ActionSupport{ private String test; public FirstAction() { System.out.println("-----------无参构造方法---------"); } @Action(value = "test", results = { @Result(name = "success1", location = "/index2.jsp", type = "redirect"), @Result(name = "error", location = "/index2.jsp"), @Result(name = "success", type = "json", params = { "root", "test" }) }) public String execute() throws Exception { test = "test"; return "success"; } public String getTest() { return test; } public void setTest(String test) { this.test = test; } }
发现上面无论我们写不写@Controller都可以生成Action对象,写不写scope都是多例模式,即使写成单例也是多例。
补充:有时候我们希望简化配置,不想每个方法都写一对Action注解,如下:(先结果写在类注解上,然后每个方法只写对应的Action的value即可)
package cn.qlq.action; import java.util.HashMap; import java.util.Map; import org.apache.struts2.convention.annotation.Action; import org.apache.struts2.convention.annotation.Namespace; import org.apache.struts2.convention.annotation.ParentPackage; import org.apache.struts2.convention.annotation.Result; import org.apache.struts2.convention.annotation.Results; import org.springframework.stereotype.Controller; import com.opensymphony.xwork2.ActionSupport; @Namespace("/") @ParentPackage("default") @Controller("firstAction") @Results({ @Result(name = "redirect", location = "/index2.jsp", type = "redirect"), @Result(name = "forward", location = "/index.jsp"), @Result(name = "json", type = "json", params = { "root", "responseMap" }) }) public class FirstAction extends ActionSupport { private Map<String, Object> responseMap = new HashMap<String, Object>(); public FirstAction() { System.out.println("-----------无参构造方法---------"); } @Action(value = "getJson1") public String getJson1() { try { Thread.sleep(2 * 1000); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } responseMap.put("str1", "str1"); return "json"; } @Action(value = "getJson2") public String getJson2() { try { Thread.sleep(2 * 1000); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } responseMap.put("str2", "str2"); return "json"; } @Action(value = "redirect") public String redirect() { try { Thread.sleep(2 * 1000); } catch (InterruptedException e) { e.printStackTrace(); } responseMap.put("redirect", "redirect"); return "redirect"; } @Action(value = "forward") public String forward() { try { Thread.sleep(2 * 1000); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } responseMap.put("forward", "forward"); return "forward"; } public Map<String, Object> getResponseMap() { return responseMap; } public void setResponseMap(Map<String, Object> responseMap) { this.responseMap = responseMap; } }
结果:
控制台:(证明Action是多例的,每个请求都会创建新的Action)
有时候我们也希望方法上的注解覆盖类上的注解,例如:
package cn.qlq.action; import java.util.HashMap; import java.util.Map; import org.apache.struts2.convention.annotation.Action; import org.apache.struts2.convention.annotation.Namespace; import org.apache.struts2.convention.annotation.ParentPackage; import org.apache.struts2.convention.annotation.Result; import org.apache.struts2.convention.annotation.Results; import org.springframework.stereotype.Controller; import com.opensymphony.xwork2.ActionSupport; @Namespace("/") @ParentPackage("default") @Controller("firstAction") @Results({ @Result(name = "redirect", location = "/index2.jsp", type = "redirect"), @Result(name = "forward", location = "/index.jsp"), @Result(name = "json", type = "json", params = { "root", "responseMap" }) }) public class FirstAction extends ActionSupport { private Map<String, Object> responseMap = new HashMap<String, Object>(); public FirstAction() { System.out.println("-----------无参构造方法---------"); } @Action(value = "getJson1") public String getJson1() { try { Thread.sleep(2 * 1000); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } responseMap.put("str1", "str1"); return "json"; } @Action(value = "getJson2") public String getJson2() { try { Thread.sleep(2 * 1000); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } responseMap.put("str2", "str2"); return "json"; } // 希望返回是json的时候还是页面跳转 @Action(value = "getJson3", results = { @Result(name = "json", location = "/index.jsp") }) public String getJson3() { try { Thread.sleep(2 * 1000); } catch (InterruptedException e) { e.printStackTrace(); } responseMap.put("str3", "str3"); return "json"; } @Action(value = "redirect") public String redirect() { try { Thread.sleep(2 * 1000); } catch (InterruptedException e) { e.printStackTrace(); } responseMap.put("redirect", "redirect"); return "redirect"; } @Action(value = "forward") public String forward() { try { Thread.sleep(2 * 1000); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } responseMap.put("forward", "forward"); return "forward"; } public Map<String, Object> getResponseMap() { return responseMap; } public void setResponseMap(Map<String, Object> responseMap) { this.responseMap = responseMap; } }
测试:
总结:方法上的结果返回的定义优先级别高于类级别的返回结果定义,所以我们可以在配置中采用此方式简化一些配置。