Spring入门，使用Maven进行管理

一，使用maven创建项目原型

mvn archetype:generate

进入交互模式创建项目原型，根据网速不同，跳出设置选项的时间不定

第一个选项

直接Enter即可，表示使用默认值502，后面的如法炮制，直到设置我们需要的groupId，artifactId，version为止。

我的设置为：

groupId：com.yxl.springdemo

artifactId：springdemo

version：1.0-SNAPSHOT（也就是默认值）

使用tree展示原型目录结构：

二，编辑源代码

　　首先创建一个bean类，在com/yxl/springdemo目录下新建HelloBean.java。

 package com.yxl.springdemo;
 
 public class HelloBean
 {
     private String helloword;
 
     public void setHelloword(String helloword)
     {
         this.helloword = helloword;
     }
     public String getHelloword()
     {
         return helloword;
     }
 }

　　在com/yxl/springdemo目录下新建SpringDemo.java。

 package com.yxl.springdemo;
 
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.support.ClassPathXmlApplicationContext;
 import org.springframework.context.support.FileSystemXmlApplicationContext;
 
 public class SpringDemo
 {
     public static void main(String[] args)
     {
         //ApplicationContext ctx = new ClassPathXmlApplicationContext("beans-config.xml");
         ApplicationContext ctx = new FileSystemXmlApplicationContext("beans-config.xml");
         HelloBean hello = (HelloBean)ctx.getBean("helloBean");
         System.out.println(hello.getHelloword());
     }
 }

　　重新编辑pom.xml，解决依赖关系，并生成可执行jar包。

 <?xml version = "1.0" encoding = "UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0"
      xmlns:xsi="http://www.w3.org/4.1.2.RELEASE1/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>com.yxl.springdemo</groupId>
   <artifactId>springdemo</artifactId>
   <version>1.0-SNAPSHOT</version>
   <packaging>jar</packaging>
 
   <name>springdemo</name>
   <url>http://maven.apache.org</url>
 
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
   </properties>
 
   <dependencies>
     <dependency>
         <groupId>org.springframework</groupId>
         <artifactId>spring-core</artifactId>
         <version>4.1.2.RELEASE</version>
     </dependency>
     <dependency>
         <groupId>org.springframework</groupId>
         <artifactId>spring-context</artifactId>
         <version>4.1.2.RELEASE</version>
     </dependency>
     <dependency>
         <groupId>org.springframework</groupId>
         <artifactId>spring-context-support</artifactId>
         <version>4.1.2.RELEASE</version>
     </dependency>
     <dependency>
         <groupId>org.springframework</groupId>
         <artifactId>spring-beans</artifactId>
         <version>4.1.2.RELEASE</version>
     </dependency>
     <dependency>
         <groupId>org.springframework</groupId>
         <artifactId>spring-aop</artifactId>
         <version>4.1.2.RELEASE</version>
     </dependency>
     <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>
       <version>4.7</version>
       <scope>test</scope>
     </dependency>
   </dependencies>
 
 <build>
     <plugins>
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-shade-plugin</artifactId>
         <version>2.3</version>
         <executions>
           <execution>
             <phase>package</phase>
             <goals>
               <goal>shade</goal>
             </goals>
             <configuration>
               <transformers>
                 <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                   <manifestEntries>
                     <Main-Class>com.yxl.springdemo.SpringDemo</Main-Class>
                     <Build-Number>123</Build-Number>
                   </manifestEntries>
                 </transformer>
               </transformers>
             </configuration>
           </execution>
         </executions>
       </plugin>
     </plugins>
   </build>
 
 </project>

　　在项目主目录springdemo（不是包目录）下新建beans-config.xml，配置bean属性。

 <?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.xsd">
 
     <bean id = "helloBean"
         class = "com.yxl.springdemo.HelloBean">
         <property name = "helloword">
             <value>Hello, World</value>
         </property>
     </bean>
 </beans>

在这里我犯过的一个错误就是xml文件第一行的?与xml之间插入了一个空格，然后运行程序就会抛出异常。

三，编译并运行结果

mvn clean compile
mvn clean package
java -jar target/sprintdemo-1.0-SNAPSHOT.jar

结果：

注意，执行java -jar target/springdemo-1.0-SNAPSHOT.jar时，配置文件必须在当前目录下。比如我是在项目根目录下执行这条语句，所以beans-config.xml也被放置在项目根目录springdemo中，如果在target中执行该包文件，执行时会抛出异常。