spring-自动加载配置文件\使用属性文件注入

在上一篇jsf环境搭建的基础上 , 加入spring框架 , 先看下目录结构

src/main/resources 这个source folder 放置web项目所需的主要配置,打包时,会自动打包到WEB-INF下

首先看下pom.xml,需要引入一些依赖项:

 <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/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>yjmyzz</groupId>
     <artifactId>jsf-web</artifactId>
     <version>1.0</version>
     <packaging>war</packaging>

     <dependencies>
         <!-- 单元测试 -->
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
             <version>4.7</version>
             <scope>test</scope>
         </dependency>

         <!-- jsf -->
         <dependency>
             <groupId>org.jboss.spec.javax.faces</groupId>
             <artifactId>jboss-jsf-api_2.1_spec</artifactId>
             <version>2.1.19.1.Final-redhat-1</version>
             <scope>compile</scope>
         </dependency>

         <!-- spring -->
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-context</artifactId>
             <version>4.0.2.RELEASE</version>
         </dependency>

         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-web</artifactId>
             <version>4.0.2.RELEASE</version>
         </dependency>

         <!-- servlet支持 -->
         <dependency>
             <groupId>javax.servlet</groupId>
             <artifactId>servlet-api</artifactId>
             <version>2.5</version>
         </dependency>

     </dependencies>

     <build>
         <plugins>
             <plugin>
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>3.1</version>
                 <configuration>
                     <source>1.7</source>
                     <target>1.7</target>
                 </configuration>
             </plugin>
             <plugin>
                 <artifactId>maven-war-plugin</artifactId>
                 <version>2.3</version>
                 <configuration>
                     <warSourceDirectory>webapp</warSourceDirectory>
                     <failOnMissingWebXml>false</failOnMissingWebXml>
                 </configuration>
             </plugin>
         </plugins>
     </build>
 </project>

pom.xml

1. 自动加载配置文件

在web项目中,可以让spring自动加载配置文件(即上图中的src/main/resouces/spring下的xml文件),WEB-INF/web.xml中参考以下设置:

 <?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_3_0.xsd" id="WebApp_ID" version="3.0">
      <display-name>jsf-web</display-name>

      <welcome-file-list>
        <welcome-file>index.html</welcome-file>
      </welcome-file-list>

     <listener>
      <listener-class>
        org.springframework.web.context.ContextLoaderListener
       </listener-class>
     </listener>  

     <context-param>
      <param-name>contextConfigLocation</param-name>
       <param-value>
        classpath*:spring/applicationContext-*.xml
       </param-value>
     </context-param>    

 </web-app>

web.xml

解释一下: classpath*:spring/applicationContext-*.xml 这里表示将加载classpath路径下 spring目录下的所有以applicationContext-开头的xml文件 , 通常为了保持配置文件的清爽 , 我们会把配置分成多份 : 比如 applicationContext-db.xml 用来配置DataSource , applicationContext-cache.xml用来配置缓存...等等.

2.代码中如何取得ApplicationContext实例

 package yjmyzz.utils;

 import javax.faces.context.FacesContext;
 import javax.servlet.ServletContext;

 import org.springframework.context.ApplicationContext;
 import org.springframework.web.context.support.WebApplicationContextUtils;

 public class ApplicationContextUtils {

     public static ApplicationContext getApplicationContext() {
         ServletContext context = (ServletContext) FacesContext
                 .getCurrentInstance().getExternalContext().getContext();
         ApplicationContext appctx = WebApplicationContextUtils
                 .getRequiredWebApplicationContext(context);

         return appctx;
     }

     public static <T> T getBean(Class<T> t) {
         return getApplicationContext().getBean(t);
     }
 }

ApplicationContextUtils

有了这个工具类 , 就可以方便的取得注入的Bean

3. 使用properties文件注入

为了演示注入效果,先定义一个基本的Entity类

 package yjmyzz.entity;

 import java.io.Serializable;

 public class ProductEntity implements Serializable {

     private static final long serialVersionUID = -2055674628624266800L;
     /*
      * 产品编码
      */
     private String productNo;

     /**
      * 产品名称
      */
     private String productName;

     /**
      * 产品ID
      */
     private Long productId;

     public String getProductNo() {
         return productNo;
     }

     public void setProductNo(String productNo) {
         this.productNo = productNo;
     }

     public String getProductName() {
         return productName;
     }

     public void setProductName(String productName) {
         this.productName = productName;
     }

     public Long getProductId() {
         return productId;
     }

     public void setProductId(Long productIdLong) {
         this.productId = productIdLong;
     }

     @Override
     public String toString() {
         return productId + "/" + productNo + "/" + productName;
     }

 }

ProductEntity

然后在applicationContext-beans.xml中配置以下内容:

 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

     <bean id="propertyConfigurer"
         class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
         <property name="locations">
             <list>
                 <value>classpath:properties/*.properties</value>
             </list>
         </property>
     </bean>

     <bean id="productEntity" class="yjmyzz.entity.ProductEntity">
         <property name="productId" value="${product.id}" />
         <property name="productNo" value="${product.no}" />
         <property name="productName" value="${product.name}" />
         <!-- <property name="productId">
             <bean class="java.lang.Long">
                 <constructor-arg index="0" value="${product.id}" />
             </bean>
         </property>
          -->
     </bean>
 </beans>

spring配置文件

注:classpath:properties/*.properties表示运行时 , spring容器会自动加载classpath\properties目录下的所有以.properties后缀结尾的文件 ,  我们在src/main/resources/properties/下放置一个product.properties属性文件 , 内容如下:

 product.id=3
 product.no=n95
 product.name=phone

product.properties

该文件被spring自动加载后 , 就可以用里面定义的属性值 , 为Bean做setter属性注入 , 即配置文件中的<property name="productId" value="${product.id}" />

4.验证注入是否成功

在HomeController里 ,  向Spring容器要一个Bean ,  显示下它的属性:

 package yjmyzz.controller;

 import javax.faces.bean.ManagedBean;

 import yjmyzz.entity.ProductEntity;
 import yjmyzz.utils.ApplicationContextUtils;

 @ManagedBean(name = "Home")
 public class HomeController {

     public String sayHello() {

         ProductEntity product = ApplicationContextUtils
                 .getBean(ProductEntity.class);

         return product.toString();
     }

 }

HomeController

index.xhtml里仍然跟上篇相同:

 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 <html xmlns="http://www.w3.org/1999/xhtml"
       xmlns:h="http://java.sun.com/jsf/html"
       xmlns:f="http://java.sun.com/jsf/core"
       xmlns:ui="http://java.sun.com/jsf/facelets"> 

 <h:head>
     <title>jsf-web</title>
 </h:head>
 <body>
     <h1>
         #{Home.sayHello()}

     </h1>
 </body>
 </html>

index.xhtml

最后部署到jboss上 , 运行截图如下: