IDEA搭建第一个Spring案例，基于Maven实现

迈不过友情╰ 2023-07-21 13:26 1阅读 0赞

> Spring框架的主要核心就是DI（依赖注入）和AOP（面向切面编程），用Bean来管理对象，从而实现了松耦合，提高了灵活性，现在对于Spring的学习主要有xml方式和注解方式，可能 注解方式用到的比较多，也比较的方便。下面我们使用xml和注解的方式来写第一个Spring程序！

# 一、xml的方式 #

*  项目引用Maven坐标

<dependencies>
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>3.8.1</version>
                <scope>test</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-context</artifactId>
                <version>4.2.6.RELEASE</version>
            </dependency>
            
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-aop</artifactId>
                <version>4.2.6.RELEASE</version>
            </dependency>
            
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-beans</artifactId>
                <version>4.2.6.RELEASE</version>
            </dependency>
            
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-context</artifactId>
                <version>4.2.6.RELEASE</version>
            </dependency>
    
            
            <dependency>
                <groupId>commons-logging</groupId>
                <artifactId>commons-logging</artifactId>
                <version>1.1</version>
            </dependency>
            
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-expression</artifactId>
                <version>4.2.6.RELEASE</version>
            </dependency>
        </dependencies>

*  Hello

public class Hello { 
        public void hellos(){ 
            System.out.println("hello Spring");
        }
    }

*  applicationContex.xml

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xmlns:util="http://www.springframework.org/schema/util"
           xsi:schemaLocation="
           http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
           http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd">
           
    	
        <bean id="hello" class="com.itt.entity.Hello">
    
        </bean>
    </beans>

*  AppTest

public static void main(String[] args) { 
          ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
          Hello hello = applicationContext.getBean("hello", Hello.class);
          hello.hellos();
    }

**注 意：**

管理配置文件的两个类：

ClassPathXmlApplicationContext:用于加载**classPath**(类路径、src)下的指定的xml。

FileSystemXmlApplicationContext ：用于加载**指定盘符**下的xml。

*  运行结果：

![在这里插入图片描述][20200403214739881.png_pic_center]

# 二、注解方式 #

*  项目引用Maven坐标

*  Person

package com.itt.entity;
    
    public class Person { 
    
        private String name;
        private Integer age;
    
        public String getName() { 
            return name;
        }
    
        public void setName(String name) { 
            this.name = name;
        }
    
        public Integer getAge() { 
            return age;
        }
    
        public void setAge(Integer age) { 
            this.age = age;
        }
    
        @Override
        public String toString() { 
            return "Person{" +
                    "name='" + name + '\'' +
                    ", age=" + age +
                    '}';
        }
    
        public Person() { 
        }
    
        public Person(String name, Integer age) { 
            this.name = name;
            this.age = age;
        }
    }

*  MyConfig

//告诉Spring这是一个配置类
    @Configuration
    public class MyConfig { 
    
        //给容器中注册一个bean并赋值，默认按类名访问（注意：小写类名）
        @Bean
        public Person person(){ 
            return new Person("zs",18);
        }
    }

*  APPTest

public static void main(String[] args) { 
       	//AnnotationConfigApplicationContext：注解扫描配置对应的配置类
         ApplicationContext applicationContext = new AnnotationConfigApplicationContext(MyConfig.class);
         //从容器中取出对应的Bean对象
         Person person = applicationContext.getBean("Person", Person.class);
         System.out.println(person);
    }

*  运行结果

![在这里插入图片描述][2020040322053322.png_pic_center]

[20200403214739881.png_pic_center]: /images/20230528/2279babfd19a4ce39d58b64b6c5669c6.png
[2020040322053322.png_pic_center]: /images/20230528/0c377e18ede4418fae25fe9f6c93ad8d.png