spring-自動加載配置文件\使用屬性文件注入

在上一篇jsf環境搭建的基礎上 , 加入spring框架 , 先看下目錄結構

src/main/resources 這個source folder 放置web項目所需的主要配置,打包時,會自動打包到WEB-INF下

首先看下pom.xml,需要引入一些依賴項:

<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>
        <!-- 單元測試 -->
        <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>

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1. 自動加載配置文件

在web項目中,可以讓spring自動加載配置文件(即上圖中的src/main/resouces/spring下的xml文件),WEB-INF/web.xml中參考以下設置:

<?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>

解釋一下: classpath*:spring/applicationContext-*.xml 這里表示將加載classpath路徑下 spring目錄下的所有以applicationContext-開頭的xml文件 , 通常為了保持配置文件的清爽 , 我們會把配置分成多份 : 比如 applicationContext-db.xml 用來配置DataSource , applicationContext-cache.xml用來配置緩存...等等.

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2.代碼中如何取得ApplicationContext實例

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);
    }
}

?有了這個工具類 , 就可以方便的取得注入的Bean

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3. 使用properties文件注入

為了演示注入效果,先定義一個基本的Entity類

package yjmyzz.entity;

import java.io.Serializable;

public class ProductEntity implements Serializable {

    private static final long serialVersionUID = -2055674628624266800L;
    /*
     * 產品編碼
     */
    private String productNo;

    /**
     * 產品名稱
     */
    private String productName;

    /**
     * 產品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;
    }

}

然后在applicationContext-beans.xml中配置以下內容:

<?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>

注:classpath:properties/*.properties表示運行時 , spring容器會自動加載classpath\properties目錄下的所有以.properties后綴結尾的文件 ,? 我們在src/main/resources/properties/下放置一個product.properties屬性文件 , 內容如下:

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

該文件被spring自動加載后 , 就可以用里面定義的屬性值 , 為Bean做setter屬性注入 , 即配置文件中的<property name="productId" value="${product.id}" />

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4.驗證注入是否成功

在HomeController里 ,? 向Spring容器要一個Bean ,? 顯示下它的屬性:

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();
    }

}

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>

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最后部署到jboss上 , 運行截圖如下:

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