Spring基础知识（2）- 创建 Spring 程序

本文将在 Windows 下使用 IntelliJ IDEA 和 Apache Maven 创建一个简单的 Spring 程序。在开始之前，确保已经正确搭建了 Spring 开发环境，如何搭建 Spring 开发环境见：Spring基础知识（1）- Spring简介、Spring体系结构和开发环境配置

Windows版本 : Windows 10 Home (20H2)

IntelliJ IDEA：Community Edition for Windows 2020.1.4

Apache Maven：3.8.1

1. 在 IDEA 上创建 Maven Quickstart 项目

    1) 运行 IDEA

        点击菜单 New 创建 Project：

        New Project -> Project Type: Maven -> Project SDK: 1.8 -> Check "Create from archtype" -> select "org.apache.maven.archtypes:maven-archtype-quickstart" -> Next

            Name: SpringBasic
            GroupId: com.example
            ArtifactId: SpringBasic

        -> Finish

    2) 生成的项目目录结构和文件

3) App.java 代码

1         package com.example;
2 
3         public class App {
4             public static void main( String[] args ) {
5                 System.out.println( "Hello World!" );
6             }
7         }

4) AppTest.java 代码

 1         package com.example;
 2 
 3         import static org.junit.Assert.assertTrue;
 4 
 5         import org.junit.Test;
 6 
 7         public class AppTest {
 8 
 9             @Test
10             public void shouldAnswerWithTrue() {
11                 assertTrue( true );
12             }
13         }

5) pom.xml 代码

 1         <?xml version="1.0" encoding="UTF-8"?>
 2 
 3         <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 5         <modelVersion>4.0.0</modelVersion>
 6 
 7         <groupId>com.example</groupId>
 8         <artifactId>SpringBasic</artifactId>
 9         <version>1.0-SNAPSHOT</version>
10 
11         <name>SpringBasic</name>
12         <!-- FIXME change it to the project's website -->
13         <url>http://www.example.com</url>
14 
15         <properties>
16             <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
17             <maven.compiler.source>1.7</maven.compiler.source>
18             <maven.compiler.target>1.7</maven.compiler.target>
19         </properties>
20 
21         <dependencies>
22             <dependency>
23             <groupId>junit</groupId>
24             <artifactId>junit</artifactId>
25             <version>4.11</version>
26             <scope>test</scope>
27             </dependency>
28         </dependencies>
29 
30         <build>
31             <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
32             <plugins>
33                 <!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle -->
34                 <plugin>
35                 <artifactId>maven-clean-plugin</artifactId>
36                 <version>3.1.0</version>
37                 </plugin>
38                 <!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
39                 <plugin>
40                 <artifactId>maven-resources-plugin</artifactId>
41                 <version>3.0.2</version>
42                 </plugin>
43                 <plugin>
44                 <artifactId>maven-compiler-plugin</artifactId>
45                 <version>3.8.0</version>
46                 </plugin>
47                 <plugin>
48                 <artifactId>maven-surefire-plugin</artifactId>
49                 <version>2.22.1</version>
50                 </plugin>
51                 <plugin>
52                 <artifactId>maven-jar-plugin</artifactId>
53                 <version>3.0.2</version>
54                 </plugin>
55                 <plugin>
56                 <artifactId>maven-install-plugin</artifactId>
57                 <version>2.5.2</version>
58                 </plugin>
59                 <plugin>
60                 <artifactId>maven-deploy-plugin</artifactId>
61                 <version>2.8.2</version>
62                 </plugin>
63                 <!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle -->
64                 <plugin>
65                 <artifactId>maven-site-plugin</artifactId>
66                 <version>3.7.1</version>
67                 </plugin>
68                 <plugin>
69                 <artifactId>maven-project-info-reports-plugin</artifactId>
70                 <version>3.0.0</version>
71                 </plugin>
72             </plugins>
73             </pluginManagement>
74         </build>
75         </project>

2. 编译运行

    1) 可以选择 Java SDK 版本

        在IDE项目列表 -> External Libraries -> <1.8>, 在 "<1.8>" 上点击鼠标右键跳出菜单，选择 Open Library Settings 菜单项，跳出对话框。

        在对话框上 Platform Settings -> SDKS 选择或添加 <1.8>

            Name: 1.8
            JDK home path: select 1.8 SDK or download a SDK

    2) Run App.main()

        Open App.java, click mouse right button, select Run "App.main()"

    3) Edit Configurations

        Click "+" add new configuration -> Select "Application"
            Name: SpringBasic
            Main class: com.example.App
-> Apply / OK

　 Click Run "SpringBasic"

        　　Hello World!

3. 导入 Spring, log4j, slf4j 依赖包

访问 http://www.mvnrepository.com/，查询 Spring, log4j, slf4j

  本文选择了 Spring 4.3.9.RELEASE、log4j 1.2.17、slf4j 1.7.36， log4j 和 slf4j 用于把 Spring 输出的 log 信息保存到 log 文件。

    修改 pom.xml，添加 Spring 依赖：

        <project ... >
            ...

            <dependencies>
                ...
                
                <dependency>
                    <groupId>org.slf4j</groupId>
                    <artifactId>slf4j-api</artifactId>
                    <version>1.7.36</version>
                </dependency>
                
                <dependency>
                    <groupId>org.slf4j</groupId>
                    <artifactId>slf4j-log4j12</artifactId>
                    <version>1.7.36</version>
                    <type>pom</type>
                    <scope>test</scope>
                </dependency>
                
                <dependency>
                    <groupId>log4j</groupId>
                    <artifactId>log4j</artifactId>
                    <version>1.2.17</version>
                </dependency>

                
                <dependency>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-core</artifactId>
                    <version>4.3.9.RELEASE</version>
                </dependency>

                
                <dependency>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-context</artifactId>
                    <version>4.3.9.RELEASE</version>
                </dependency>

                
                <dependency>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-beans</artifactId>
                    <version>4.3.9.RELEASE</version>
                </dependency>

                
                <dependency>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-jdbc</artifactId>
                    <version>4.3.9.RELEASE</version>
                </dependency>

                ...
            </dependencies>

            ...
        </project>

    在IDE中项目列表 -> 点击鼠标右键 -> Maven -> Reload Project

4. 创建/修改 Java 类

在 src/main/java/com/example 目录下，内容如下：

 1         package com.example;
 2 
 3         import org.springframework.context.ApplicationContext;
 4         import org.springframework.context.support.ClassPathXmlApplicationContext;
 5 
 6         public class App {
 7             public static void main(String[] args) {
 8 
 9                 // System.out.println( "Hello World!" );
10                 
11                 ApplicationContext context1 = new ClassPathXmlApplicationContext("spring-beans.xml");
12                 Test01 obj1 = context1.getBean("Test01", Test01.class);
13                 obj1.getMessage();
14             }
15         }
16 
17         class Test01 {
18             private String message;
19             
20             public void setMessage(String message) {
21                 this.message = message;
22             }
23 
24             public void getMessage() {
25                 System.out.println("Message: " + message);
26             }
27         }

5. 创建 Spring 配置文件 spring-beans.xml

　　在 src/main/resources 目录下，创建 spring-beans.xml (通常命名为 applicationContext.xml，不强制要求)，内容如下：

 1         <?xml version="1.0" encoding="UTF-8"?>
 2         <beans xmlns="http://www.springframework.org/schema/beans"
 3                 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4                 xmlns:context="http://www.springframework.org/schema/context"
 5                 xsi:schemaLocation="http://www.springframework.org/schema/beans
 6                                 http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
 7                                 http://www.springframework.org/schema/context
 8                                 http://www.springframework.org/schema/context/spring-context-4.0.xsd" >
 9 
10             <bean id="Test01" class="com.example.Test01">
11                 <property name="message" value="Test01 Hello World!" />
12             </bean>
13 
14         </beans>

*注：src/main/resources 目录不存在，先创建这个目录，再添加 spring-beam.xml (下文如遇到目录不存在，自行创建)

6. 创建 log4j.properties 文件

    在 src/main/resources 目录下，创建 log4j.properties，内容如下：

       # Define the root logger with appender file
       log4j.rootLogger = DEBUG, FILE

       # Define the file appender
       log4j.appender.FILE=org.apache.log4j.FileAppender
       # Set the name of the file
       log4j.appender.FILE.File=d:\\temp\\spirng-basic_log4j.txt

       # Set the immediate flush to true (default)
       log4j.appender.FILE.ImmediateFlush=true

       # Set the threshold to debug mode
       log4j.appender.FILE.Threshold=debug

       # Set the append to false, overwrite
       log4j.appender.FILE.Append=false

       # Define the layout for file appender
       log4j.appender.FILE.layout=org.apache.log4j.PatternLayout
       log4j.appender.FILE.layout.conversionPattern=%m%n

7. 运行

    参考 "2. 编译运行"

    运行 App.java，IDEA 控制台中显示信息如下:

        Message: Test01 Hello World!

posted @ 2022-03-03 20:25 垄山小站阅读(153) 评论(0) 编辑收藏举报

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