maven学习笔记之(五)maven模块化ssm项目建立

Bertha 。 2022-10-23 08:03 127阅读 0赞

## 引言 ##

在实际开发项目的过程中，由于项目业务量比较庞大，所以我们通常会分工协作，将整个项目按照模块或者按照业务进行模块拆分，然后每个模块进行单独开发，最终惊奇整合后形成一个完整的项目，那如何进行拆分和组合呢？下面我们将进一步剖析maven的整个工程项目。

## maven工程的继承 ##

在面向java编程的世界中，类之间是可以相互继承的，通过继承关系，子类可以引用父类中的非私有变量，这样做的好处就是避免了大量的重复代码，同理maven工程之间也可以继承，子工程继承父工程后，就可以使用在父工程中引入的依赖，**maven工程继承的目的是为了消除重复依赖。**  
父类工程会有自己的pom文件，最为关键的是pom文件需要打包成pom形式。  
![在这里插入图片描述][20210309152448578.png]  
而子工程需要继承父工程，要引入parent标签

<parent>
            <artifactId>maven_parents</artifactId>
            <groupId>org.example</groupId>
            <version>1.0-SNAPSHOT</version>
            <relativePath>../pom.xml</relativePath>
       </parent>

## maven工程的聚合 ##

聚合是在maven父工程的pom.xml中设置的，以使用标签将其他maven工程聚合到一起，聚合的目的是为了进行统一操作和管理。  
maven 父工程聚合。

<groupId>org.example</groupId>
        <artifactId>maven_parents</artifactId>
        <packaging>pom</packaging>
        <version>1.0-SNAPSHOT</version>
        <modules>
            <module>maven_dao</module>
            <module>maven_service</module>
            <module>maven_web</module>
            <module>maven_domain</module>
        </modules>

通过聚合和拆封的简单操作，我们就可以完成maven工程分模块开发。

## maven 分块开发案例 ##

### 案例目录结构 ###

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3h1ZXNoYW5mZWl0aWFu_size_16_color_FFFFFF_t_70]  
domain 、dao、 web 、service均需要继承自parents。

### maven\_parents ###

1.  在maven\_parents中我们需要对各自身的打包方式以及项目聚合进行管理。
2.  其中最为重要的一项内容是我们需要对jar包进行锁定，防止jar包依赖冲突。
3.  引入编译相关的插件，需要在设定编码以及jdk版本。  
    pom.xml

<?xml version="1.0" encoding="UTF-8"?>
    <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>org.example</groupId>
        <artifactId>maven_parents</artifactId>
        <packaging>pom</packaging>
        <version>1.0-SNAPSHOT</version>
        <modules>
            <module>maven_dao</module>
            <module>maven_service</module>
            <module>maven_web</module>
            <module>maven_domain</module>
        </modules>
    
        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <maven.compiler.source>1.8</maven.compiler.source>
            <maven.compiler.target>1.8</maven.compiler.target>
            <spring.version>5.0.5.RELEASE</spring.version>
            <springmvc.version>5.0.5.RELEASE</springmvc.version>
            <mybatis.version>3.4.5</mybatis.version>
        </properties>
    
    
        <dependencyManagement>
            <dependencies>
                
                <dependency>
                    <groupId>org.mybatis</groupId>
                    <artifactId>mybatis</artifactId>
                    <version>${mybatis.version}</version>
                </dependency>
                
                <dependency>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-webmvc</artifactId>
                    <version>${springmvc.version}</version>
                </dependency>
                
                <dependency>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-context</artifactId>
                    <version>${spring.version}</version>
                </dependency>
                <dependency>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-core</artifactId>
                    <version>${spring.version}</version>
                </dependency>
                <dependency>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-aop</artifactId>
                    <version>${spring.version}</version>
                </dependency>
                <dependency>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-web</artifactId>
                    <version>${spring.version}</version>
                </dependency>
                <dependency>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-expression</artifactId>
                    <version>${spring.version}</version>
                </dependency>
                <dependency>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-beans</artifactId>
                    <version>${spring.version}</version>
                </dependency>
                <dependency>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-aspects</artifactId>
                    <version>${spring.version}</version>
                </dependency>
                <dependency>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-context-support</artifactId>
                    <version>${spring.version}</version>
                </dependency>
                <dependency>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-test</artifactId>
                    <version>${spring.version}</version>
                </dependency>
                <dependency>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-jdbc</artifactId>
                    <version>${spring.version}</version>
                </dependency>
                <dependency>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-tx</artifactId>
                    <version>${spring.version}</version>
                </dependency>
            </dependencies>
        </dependencyManagement>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.1</version>
                    <configuration>
                        <source>1.8</source>
                        <target>1.8</target>
                        <encoding>UTF-8</encoding>
                    </configuration>
                </plugin>
            </plugins>
        </build>
    </project>

### maven\_domain ###

#### pom.xml ####

#### User ####

public class User { 
        private Date birthday;
        private String username;
        private String password;
        private String sex;
    
        public User() { 
        }
    
        public User(Date birthday, String username, String password, String sex) { 
            this.birthday = birthday;
            this.username = username;
            this.password = password;
            this.sex = sex;
        }
    
        public Date getBirthday() { 
            return birthday;
        }
    
        public void setBirthday(Date birthday) { 
            this.birthday = birthday;
        }
    
        public String getUsername() { 
            return username;
        }
    
        public void setUsername(String username) { 
            this.username = username;
        }
    
        public String getPassword() { 
            return password;
        }
    
        public void setPassword(String password) { 
            this.password = password;
        }
    
        public String getSex() { 
            return sex;
        }
    
        public void setSex(String sex) { 
            this.sex = sex;
        }
    
        @Override
        public String toString() { 
            return "User{" +
                    "birthday=" + birthday +
                    ", username='" + username + '\'' +
                    ", password='" + password + '\'' +
                    ", sex='" + sex + '\'' +
                    '}';
        }
    }

### maven\_dao ###

#### maven\_dao目录结构 ####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3h1ZXNoYW5mZWl0aWFu_size_16_color_FFFFFF_t_70 1]  
maven\_dao中需要对jar包依赖真正的导入进来，

#### pom.xml ####

<?xml version="1.0" encoding="UTF-8"?>
    <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">
        <parent>
            <artifactId>maven_parents</artifactId>
            <groupId>org.example</groupId>
            <version>1.0-SNAPSHOT</version>
            <relativePath>../pom.xml</relativePath>
        </parent>
        <modelVersion>4.0.0</modelVersion>
        <artifactId>maven_dao</artifactId>
        <packaging>jar</packaging>
    
        <dependencies>
            <dependency>
                <groupId>org.example</groupId>
                <artifactId>maven_domain</artifactId>
                <version>1.0-SNAPSHOT</version>
            </dependency>
    
            
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-webmvc</artifactId>
            </dependency>
            
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-context</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-core</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-aop</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-web</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-expression</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-beans</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-aspects</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-context-support</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-test</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-jdbc</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-tx</artifactId>
            </dependency>
            
            <dependency>
                <groupId>org.mybatis</groupId>
                <artifactId>mybatis</artifactId>
            </dependency>
            <dependency>
                <groupId>org.mybatis</groupId>
                <artifactId>mybatis-spring</artifactId>
                <version>1.3.1</version>
            </dependency>
            
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>5.1.32</version>
            </dependency>
            
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>druid</artifactId>
                <version>1.0.9</version>
            </dependency>
    
            
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.12</version>
            </dependency>
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>servlet-api</artifactId>
                <version>2.5</version>
                <scope>provided</scope>
            </dependency>
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>jsp-api</artifactId>
                <version>2.0</version>
                <scope>provided</scope>
            </dependency>
            
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>jstl</artifactId>
                <version>1.2</version>
            </dependency>
            
            <dependency>
                <groupId>commons-logging</groupId>
                <artifactId>commons-logging</artifactId>
                <version>1.2</version>
            </dependency>
            <dependency>
                <groupId>org.slf4j</groupId>
                <artifactId>slf4j-log4j12</artifactId>
                <version>1.7.7</version>
            </dependency>
        </dependencies>
    </project>

#### dao接口 ####

public interface UserDao { 
        User findUserById(int id);
    }

#### 资源文件 ####

##### UserDao.xml #####

<?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
    <mapper namespace="com.feitian.dao.UserDao" >
        <select id="findUserById" parameterType="int" resultType="com.feitian.domain.User">
            select * from user where id = #{id}
        </select>
    </mapper>

##### 数据库配置文件 #####

jdbc.driver=com.mysql.jdbc.Driver
    jdbc.url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf8
    jdbc.username=root
    jdbc.password=root

##### 日志配置文件 #####

### direct log messages to stdout ###
    log4j.appender.stdout=org.apache.log4j.ConsoleAppender
    log4j.appender.stdout.Target=System.err
    log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
    log4j.appender.stdout.layout.ConversionPattern=%d{ ABSOLUTE} %5p %c{ 1}:%L - %m%n
    
    ### direct messages to file mylog.log ###
    log4j.appender.file=org.apache.log4j.FileAppender
    log4j.appender.file.File=c:/mylog.log
    log4j.appender.file.layout=org.apache.log4j.PatternLayout
    log4j.appender.file.layout.ConversionPattern=%d{ ABSOLUTE} %5p %c{ 1}:%L - %m%n
    
    ### set log levels - for more verbose logging change 'info' to 'debug' ###
    log4j.rootLogger=debug, stdout

##### applicationContext-Dao #####

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" 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 http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
    
        
        <context:property-placeholder location="classpath:jdbc.properties"/>
    
        
        <context:component-scan base-package="com.feitian.dao"/>
    
        
        <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
            <property name="driverClassName" value="${jdbc.driver}"/>
            <property name="url" value="${jdbc.url}"/>
            <property name="username" value="${jdbc.username}"/>
            <property name="password" value="${jdbc.password}"/>
         </bean>
        
        <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
            <property name="dataSource" ref="dataSource"/>
            <property name="typeAliasesPackage" value="com.feitian.domain"/>
        </bean>
    
        <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
            <property name="basePackage" value="com.feitian.dao"/>
        </bean>
    </beans>

### maven\_service ###

#### maven\_service模块目录 ####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3h1ZXNoYW5mZWl0aWFu_size_16_color_FFFFFF_t_70 2]

#### pom文件 ####

#### applicationContext-service.xml ####

#### service接口及其实现类 ####

##### service interface #####

public interface UserService { 
        User findUserById(int id);
    }

##### service interface implements #####

@Service
    @Transactional
    public class UserServiceImpl  implements UserService { 
        @Autowired
        public UserDao userDao;
    
    
        @Override
        public User findUserById(int id) { 
            return userDao.findUserById(id);
        }
    }

### maven\_web ###

#### maven\_web目录结构 ####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3h1ZXNoYW5mZWl0aWFu_size_16_color_FFFFFF_t_70 3]

#### pom.xml文件 ####

#### spring-mvc.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:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
    
        
        <context:component-scan base-package="com.feitian.controller"/>
    
        
        <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
            <property name="prefix" value="/WEB-INF/jsp/"/>
            <property name="suffix" value=".jsp"/>
        </bean>
    
        
        <mvc:annotation-driven/>
        
        <mvc:default-servlet-handler/>
        
        <context:annotation-config />
    </beans>

#### controller ####

@Controller
    @RequestMapping("/user")
    public class UserController { 
        @Autowired
        private UserService userService;
    
        @RequestMapping("/findUserById/{id}")
        public String findUserById( @PathVariable("id") int id, Model model ){ 
                User user = userService.findUserById(id);
                model.addAttribute("user",user);
                return  "user";
        }
    }

#### web.xml ####

<?xml version="1.0" encoding="UTF-8"?>
    <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" version="4.0">
        <context-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath*:applicationContext*.xml</param-value>
        </context-param>
        <listener>
            <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
        </listener>
    
        
        <listener>
            <listener-class>org.springframework.web.util.IntrospectorCleanupListener</listener-class>
        </listener>
        <servlet>
            <servlet-name>DispatcherServlet</servlet-name>
            <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
            <init-param>
                <param-name>contextConfigLocation</param-name>
                <param-value>classpath:spring-mvc.xml</param-value>
            </init-param>
            <load-on-startup>20</load-on-startup>
        </servlet>
        <servlet-mapping>
            <servlet-name>DispatcherServlet</servlet-name>
            <url-pattern>/</url-pattern>
        </servlet-mapping>
        
        <filter>
            <filter-name>CharacterEncoding</filter-name>
            <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
            <init-param>
                <param-name>encoding</param-name>
                <param-value>UTF-8</param-value>
            </init-param>
        </filter>
        <filter-mapping>
            <filter-name>CharacterEncoding</filter-name>
            <url-pattern>/*</url-pattern>
        </filter-mapping>
    </web-app>

notes: *此处值得一提的是当分块后的监听器加载的路径需要发生变化，否则会报错，如无法穿件service 或者 controller bean，需要将原来context-param中的classpath:xxx改成classpath:xxx.*\*

#### jsp页面 ####

<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
    <html>
    <head>
        <title>Title</title>
    </head>
    <body>
        <h1>${ user.username}</h1><br/>
        <h1>${ user.password}</h1><br/>
        <h1>${ user.birthday}</h1><br/>
    </body>
    </html>

最后运行成功  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3h1ZXNoYW5mZWl0aWFu_size_16_color_FFFFFF_t_70 4]

[20210309152448578.png]: /images/20221023/de0eda35893f44c3acdfdd298e7ffbe4.png
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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3h1ZXNoYW5mZWl0aWFu_size_16_color_FFFFFF_t_70 1]: /images/20221023/76fa26281bbc43ce8df764a524c1e9d2.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3h1ZXNoYW5mZWl0aWFu_size_16_color_FFFFFF_t_70 2]: /images/20221023/abf05faabef94c1c8ba6c713cd288ffb.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3h1ZXNoYW5mZWl0aWFu_size_16_color_FFFFFF_t_70 3]: /images/20221023/ba999d154f2448dda11e1d61b301369f.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3h1ZXNoYW5mZWl0aWFu_size_16_color_FFFFFF_t_70 4]: /images/20221023/47b88ae1a3f7425e93dbcf8340983f34.png