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。