使用SSM搭建一个简单的crud项目

使用SSM完成增删查改

前端使用到的技术：ajax，json，bootstrap等

完整项目地址：点这里GitHub

项目地址，可以在线访问

这一章节主要搭建SSM的环境。

---

SpringMVC

SpringMVC是Web层的框架，当浏览器发送请求，前端控制器(DispatcherServlet)接收到请求后，根据处理器映射器(HandlerMapping)查找url对应的Handler，之后再调用处理器适配器(HandlerAdapter)来执行对应的Handler，这时候Handler会返回一个带有逻辑视图以及模型数据的ModelAndView给HandlerAdpater并再次返回给DispatcherServlet，前端控制器调用视图解析器对ModelAndView进行视图渲染，并且向前端相应处理结果。

1.pom.xml添加依赖(依赖先添加这么多先，有需要用到在添加)

<?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.train</groupId>
    <artifactId>MySSM</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>

    <name>MySSM Maven Webapp</name>
    <!-- FIXME change it to the project's website -->
    <url>http://www.example.com</url>

    <properties>
        <!-- 设置项目编码编码 -->
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>
    <dependencies>
        <!--数据库驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.46</version>
        </dependency>
        <!--数据库连接池-->
        <dependency>
            <groupId>c3p0</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.1.2</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.5</version>
        </dependency>
        <dependency>
            <groupId>jstl</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>
        <!-- JSTL实现包 -->
        <dependency>
            <groupId>org.apache.taglibs</groupId>
            <artifactId>taglibs-standard-impl</artifactId>
            <version>1.2.5</version>
        </dependency>
        <!-- 单元测试 -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
        <!-- JSON -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.9.0</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.9.0</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.9</version>
        </dependency>
        <!-- mybatis/spring整合包 -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>1.3.0</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.1.9.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>5.1.9.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.1.9.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>5.0.6.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>5.0.6.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.0.6.RELEASE</version>
        </dependency>
        <!--    日志包-->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
<!--        分页插件-->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
            <version>5.1.2</version>
        </dependency>
    </dependencies>
</project>

2.在web.xml中配置前端控制器

<!DOCTYPE web-app PUBLIC
        "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
        "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
    <display-name>Archetype Created Web Application</display-name>

    <!--启动spring容器-->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:applicationContext.xml</param-value>
    </context-param>

    <!--字符编码过滤器-->
    <filter>
        <filter-name>characterEncodingFilter</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>
        <init-param>
            <param-name>forceRequestEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
        <init-param>
            <param-name>forceResponseEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>characterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

<!--    ContextLoaderListener监听器的作用就是启动Web容器时，自动装配ApplicationContext的配置信息-->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <servlet>
        <servlet-name>DispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <!-- contextConfigLocation配置springmvc加载的配置文件（配置处理映射器、适配器等等）
            如果不配置contextConfigLocation 默认加载的是/WEB-INF/servlet名称-servlet.xml(springmvc-servlet.xml
            -->
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:springmvc.xml</param-value>
        </init-param>
        <!--标记容器是否在启动的时候就加载这个servlet。-->
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>DispatcherServlet</servlet-name>
        <!-- / 表示对所有请求进行解析-->
        <url-pattern>/</url-pattern>
    </servlet-mapping>

</web-app>

3.在resources/springmvc.xml配置注解扫描和视图解析器

视图解析器的作用：

 <!--开启注解扫描, 只扫描controller注解-->
    <context:component-scan base-package="org.train" use-default-filters="false">
        <!--只扫描控制器-->
        <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    </context:component-scan>
    <!--配置视图解析器-->
    <bean id="InternalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/views/" />
        <property name="suffix" value=".jsp" />
    </bean>
    <!--将springmvc不能处理的请求交给tomcat-->
    <mvc:default-servlet-handler/>
    <!--开启springmvc注解的支持
       该注解会自动注册RequestMappingHandlerMapping与RquestMappingHandlerAdapter两个Bean
       是@Controllers注解分发请求所必需的
-->
    <mvc:annotation-driven/>

4.检测springmvc前端控制器是否生效，配置两个页面和一个controller类

4.1:index.jsp页面，服务器启动就会加载这个页面

<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<%@taglib  uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<html>
<body>
<h2>Hello World!</h2>
<%--使用EL表达式pageContext获取当前项目名--%>
<a href="${pageContext.request.contextPath}/findBook_All">查询所有</a>
<a href="${pageContext.request.contextPath}/addBook">添加书籍</a>
<form action="" method="post">
    <input type="hidden" name="_method" value="findbook">
</form>

</body>
</html>

4.2:list.jsp。看看视图解析器有没有生效，生效就会跳转到这个页面

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h3>永不放弃的心，将有贯穿黑暗的力量</h3>
</body>
</html>

4.3：controller类的编写

package org.train.ssm.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class BookController {

    @RequestMapping("/findBook_All")
    public String findBook_All(){
        System.out.println("hahaha");
        return "list";
    }
}

springmvc搭建好了

5.创建数据库和表

CREATE TABLE books(
book_id INT(11) NOT NULL AUTO_INCREMENT,
book_name VARCHAR(255) NOT NULL,
book_author VARCHAR(255) NOT NULL,
book_price FLOAT(25) NOT NULL,
book_publisher VARCHAR(255) NOT NULL,
PRIMARY KEY(book_id)
)

INSERT INTO books(
		      book_name,
		      book_author,
		      book_price,
		      book_publisher
)VALUES(
	'三国演义',
	'罗贯中',
	99.9,
	'清华大学出版社'

),
(
'红楼梦',
'曹雪芹',
88.8,
'北京大学出版社'
),
(
'西游记',
'吴承恩',
77.7,
'上海交通大学出版社'
),
(
'水浒传',
'施耐庵',
66.6,
'四川大学出版社'
);

6.创建POJO实体类

package org.train.ssm.bean;

import java.io.Serializable;

public class Book  implements Serializable {
    private Integer bookId;
    private String bookName;
    private Float bookPrice;
    private String bookPublisher;

    public Integer getBookId() {
        return bookId;
    }

    public void setBookId(Integer bookId) {
        this.bookId = bookId;
    }

    public String getBookName() {
        return bookName;
    }

    public void setBookName(String bookName) {
        this.bookName = bookName;
    }

    public Float getBookPrice() {
        return bookPrice;
    }

    public void setBookPrice(Float bookPrice) {
        this.bookPrice = bookPrice;
    }

    public String getBookPublisher() {
        return bookPublisher;
    }

    public void setBookPublisher(String bookPublisher) {
        this.bookPublisher = bookPublisher;
    }

    @Override
    public String toString() {
        return "Book{" +
                "bookId=" + bookId +
                ", bookName='" + bookName + '\'' +
                ", bookPrice=" + bookPrice +
                ", bookPublisher='" + bookPublisher + '\'' +
                '}';
    }
}

7.Spring整合Mybatis

首先创建dao层的包(放置DAO数据交互层处理类)，service层的包(放置代理对象)

8.在resources创建资源文件

8.1 mybatis的全局配置文件 (SqlMapConfig.xml)

8.2 Spring的资源配置文件(applicationContext.xml)

8.3 Mapper映射文件(sqlmap/Mapper.xml)

8.4 数据库连接文件(db.properties)

8.5 日志系统配置文件(log4j.properties)

9.编写Spring的配置文件

配置数据库连接信息

jdbc.jdbcUrl=jdbc:mysql://localhost:3306/booksdb?useUnicode=true&characterEncoding=utf8
jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.user=root
jdbc.password=12345

加载数据库连接文件"db.properties"中的数据，建立数据源

配置spring的xml文件applicationContext.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:context="http://www.springframework.org/schema/context"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       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">

<!--    扫描所有的包注解，但不包含Controller注解-->
    <context:component-scan base-package="org.train">
        <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    </context:component-scan>
<!--    加载db.properties配置文件-->
    <context:property-placeholder location="classpath:db.properties"></context:property-placeholder>
<!--    配置数据源-->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
    <property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property>
    <property name="driverClass" value="${jdbc.driverClass}"></property>
    <property name="user" value="${jdbc.user}"></property>
    <property name="password" value="${jdbc.password}"></property>
</bean>
<!--配置和mybatis的整合

    设置sqlSessionFactory的bean实现类为mybatis与spring整合jar包中的
    SqlSessionFactoryBean类，在其中需要注入两个参数，一个是mybatis的
    全局配置文件，一个是上面的配置的数据源bean
-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!--        加载mybatis配置文件-->
        <property name="configLocation" value="classpath:SqlMapConfig.xml"></property>
<!--            加载数据源-->
        <property name="dataSource" ref="dataSource"></property>
<!--        加载mybatis的映射文件-->
        <property name="mapperLocations" value="classpath:sqlmap/*xml"></property>
    </bean>

<!--    扫描配置器，将mybatis的接口实现加入到ioc容器中-->
   <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
       <property name="basePackage" value="org.train.ssm.dao"></property>
   </bean>

</beans>

10.编写mybatis的全局配置文件SqlMapConfig.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!--    开启驼峰命名法-->
    <settings>
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    </settings>
<!--    配置别名
    每一个在package org.train.ssm.bean中的Java Bean，在没有注解的情况下，会
    使用Bean的首字母小写的非限定类名来作为他的别名
-->
    <typeAliases>
        <package name="org.train.ssm.bean"/>
    </typeAliases>
</configuration>

注意： 有了spring托管数据源，在mybatis的全局配置中，只需要注重性能化配置

11.编写Mapper映射文件

<?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="org.train.ssm.dao.BookMapper">
<!--    resultType本应该使用Book的全类名，但是我们已经在
        mybatis的全局配置文件中使用了别名
        id为接口的方法名字-->
    <select id="findBooks" resultType="book">
        select * from books
    </select>

    <insert id="addBook" useGeneratedKeys="true" keyProperty="book_id">
        insert into books
        (book_id,book_name,book_price,book_author,book_publisher)
        values
        (null,#{bookName},#{bookPrice},#{bookAuthor},#{bookPublisher})
    </insert>
</mapper>

12.配置日志文件

# Set root category priority to INFO and its only appender to CONSOLE.
#log4j.rootCategory=INFO, CONSOLE            debug   info   warn error fatal
log4j.rootCategory=INFO, CONSOLE, LOGFILE

# Set the enterprise logger category to FATAL and its only appender to CONSOLE.
log4j.logger.org.apache.axis.enterprise=INFO, CONSOLE

# CONSOLE is set to be a ConsoleAppender using a PatternLayout.
log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern=%d{ISO8601} %-6r [%15.15t] %-5p %30.30c %x - %m\n

# LOGFILE is set to be a File appender using a PatternLayout.
log4j.appender.LOGFILE=org.apache.log4j.FileAppender
log4j.appender.LOGFILE.File=d:\axis.log
log4j.appender.LOGFILE.Append=true
log4j.appender.LOGFILE.layout=org.apache.log4j.PatternLayout
log4j.appender.LOGFILE.layout.ConversionPattern=%d{ISO8601} %-6r [%15.15t] %-5p %30.30c %x - %m\n

估计很多人都没有看过日志的属性，这里简单说一下日志文件的介绍

日志输出等级有5级，当有bug发生时，你控制台没有显示异常信息，那可能就是你日志等级太高了，可以调低，说不定可以很容易的看到bug产生的原因。

  		debug("调试");
        info("信息");
        warn("警告");
        error("错误");
        fatal("致命错误")
        等级越往下越高

如果需要了解更多的信息，可以自行百度

13.编写dao层和service层

dao层

public interface BookMapper {
    //查询所有书籍
    List<Book> findBooks();
    //添加书籍
    Boolean addBook(Book book);
}

service层

@Service
public class BookService {
    @Autowired
    BookMapper bookMapper;

    public List<Book> findBooks(){
        return bookMapper.findBooks();
    }

    public Boolean addBook(Book book){

        return bookMapper.addBook(book);
    }
}

14.改进controller层

@Controller
public class BookController {

    @Autowired
    BookService bookService;

    @RequestMapping("/findBook_All")
    public String findBook_All() throws UnsupportedEncodingException {
        List<Book> books = bookService.findBooks();
        for (Book book:books){
            System.out.println(book);
        }
        return "list";
    }

    @RequestMapping("/addBook")
    public String addBook(){
        Book book = new Book(null,"天龙八部",55.5f,"清华大学出版社","金庸");
        bookService.addBook(book);
        return "list";
    }
}

查询方法和添加方法都没有问题，到这里SSM环境就搭建完成了。

当然还有很多的细节需要改动。

我的SSM的增删查改就先完成了一部分，接下来就是前端可以在我的GitHub上看。