Spring＋Mybatis＋Velocity项目搭建

一、开发工具

JDK 1.8.0_91
Intellij IDEA 15.0.6
Mysql 5.5.44
Maven 3

二、新建工程

新建Maven工程，不选Create from archtype提供的工程模版，为了学习从头开始配置工程，点击next设置工程坐标，然后一路到finish。
```
<groupId>red.itech</groupId>
<artifactId>blogDemo</artifactId>
<version>1.0-SNAPSHOT</version>
```

如果使用git开发，可以新建.gitignore文件，使git忽略idea自动生成的文件（.ignore插件可以帮助生成.gitignore），项目git初始化

# Created by .ignore support plugin (hsz.mobi)
.gitignore
### OSX template
*.DS_Store
    
# IntelliJ project files
.idea
*.iml
out
target
gen### Java template
*.class
    
# Package Files #
*.jar
*.war
*.ear

三、Spring MVC

编辑pom.xml添加Spring MVC、servlet依赖如下：

<dependencies>
    <!-- spring -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-core</artifactId>
        <version>4.3.3.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>4.3.3.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-web</artifactId>
        <version>4.3.3.RELEASE</version>
    </dependency>

    <!-- jsp -->
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>servlet-api</artifactId>
        <version>3.0-alpha-1</version>
    </dependency>
</dependencies>

增加Spring MVC框架支持

添加完成后对目录结构做一定调整，将web目录移到src/main下并重命名为webapp，调整后结构如下：
修改web.xml

web.xml的作用是配置Spring的DispatcherServlet，DispatcherServlet作为前端控制器，用于用户接口与Servlet间的映射。在web.xml的代码中,org.springframework.web.servlet.DispatcherServlet的实例名称为dispatcher，DispatcherServlet会从dispatcher－servlet.xml文件中加载应用上下文。

修改servlet-mapping中的url-pattern为/表示dispatcher会处理所有请求。

修改dispatcher-servlet.xml

xmlns:mvc="http://www.springframework.org/schema/mvc"   //mvc注解需要
<mvc:annotation-driven/>   //注解驱动
<context:component-scan base-package="red.itech.blog.controller"/>  //自动扫描@Controller注册为beans
//xsi:schemaLocation中添加
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd  //通配符的匹配很全面, 但无法找到元素 'mvc:annotation-driven' 的声明

实现控制器

package red.itech.blog.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
* Created by you on 16/9/28.
*/

@Controller
public class BlogController {

@RequestMapping(value = "/home", method = RequestMethod.GET)
    public void homePage(HttpServletResponse response) throws IOException{
        response.getWriter().print("<h1>Welcome to my Blog!</h1>");
        response.flushBuffer();
    }
}

启动Web服务

修改index.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
    <body>
        <%response.sendRedirect("home"); %>
    </body>
</html>

配置maven构建过程

<packaging>war</packaging>   //打包格式
<build>
    <finalName>blog</finalName>   //生成文件名
</build>

配置运行tomcat

home

四、velocity支持（velocity使前后端分离）

添加velocity库支持

在pom.xml中添加velocity、velocity-tools、spring-context-support依赖如下：

<dependency>
    <groupId>org.apache.velocity</groupId>
    <artifactId>velocity</artifactId>
    <version>1.7</version>
</dependency>
<dependency>
    <groupId>org.apache.velocity</groupId>
    <artifactId>velocity-tools</artifactId>
    <version>2.0</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context-support</artifactId>
    <version>4.3.3.RELEASE</version>
</dependency>

增加velocity视图解析

在dispatcher-servlet.xml中配置velocity视图解析器如下：

<bean id="velocityConfigure" class="org.springframework.web.servlet.view.velocity.VelocityConfigurer">
    <property name="resourceLoaderPath" value="/WEB-INF/templates/"/>
    <property name="velocityProperties">
        <props>
            <prop key="input.encoding">utf-8</prop>
            <prop key="output.encoding">utf-8</prop>
        </props>
    </property>
</bean>
<bean id="velocityViewResolver" class="org.springframework.web.servlet.view.velocity.VelocityViewResolver">
    <property name="suffix" value=".vm"/>
    <property name="contentType" value="text/html;charset=utf-8"/>
</bean>

修改控制器代码

控制器的作用是根据请求调用BLL的Service进行处理，获得处理结果后，将模型对象与逻辑视图返回。代码如下：

package red.itech.blog.controller;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

import javax.servlet.http.HttpServletRequest;

/**
* Created by you on 16/9/28.
*/

@Controller
public class BlogController {
    @RequestMapping(value = "/home", method = RequestMethod.GET)
    public String homePage(HttpServletRequest request, Model model){
        //1.调用BLL层的服务接口
        //2.设置模型数据
        model.addAttribute("username", "someone");
        //3.返回逻辑视图名称
        return "welcome";
    }
}

创建模版文件WEB-INF/templates/welcome.vm，测试视图解析器如下

page

五、mybatis支持，mybatis是一种SQL－mapping的ORM实现，将结果转化为POJO(使用mybatis-generator简化实现)

添加mybatis依赖

<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>3.3.0</version>
</dependency>
<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis-spring</artifactId>
    <version>1.2.3</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.17</version>
</dependency>
<dependency>
    <groupId>commons-dbcp</groupId>
    <artifactId>commons-dbcp</artifactId>
    <version>1.2.2</version>
</dependency>

配置数据库源

修改applicationContext.xml加入dataSource

<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
    <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
    <property name="url" value="jdbc:mysql://127.0.0.1:3306/blog"/>
    <property name="username" value="root"/>
    <property name="password" value="xxxxxx"/>
</bean>

<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <property name="dataSource" ref="dataSource"/>
    <property name="mapperLocations" value="classpath*:red/itech/blog/**/dal/**/*Mapper*.xml"/>
</bean>

<bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
    <constructor-arg index="0" ref="sqlSessionFactory"/>
</bean>

<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
    <property name="annotationClass" value="javax.annotation.Resource"></property>
    <property name="basePackage" value="red.itech.blog.***.dal.mapper"/>
</bean>

修改mybatis-generator配置文件(放置到resource目录下)，如下

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
"http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>
    <context id="base_resource" targetRuntime="MyBatis3">
        <property name="suppressDate" value="true"/>
        <!-- 是否去除自动生成的注释 true：是 ： false:否 -->
        <property name="suppressAllComments" value="true"/>
        <property name="useActualColumnNames" value="false"/>
        <!--数据库链接URL，用户名、密码 -->
        <jdbcConnection
                connectionURL="jdbc:mysql://127.0.0.1:3306/blog?useUnicode=true&amp;characterEncoding=UTF-8"
        driverClass="org.gjt.mm.mysql.Driver" password="xxx" userId="xxx"/>
        <javaTypeResolver>
            <property name="forceBigDecimals" value="true"/>
        </javaTypeResolver>
        <!-- 生成模型的包名和位置 -->
        <javaModelGenerator targetPackage="red.itech.blog.dal.model" targetProject="src/main/java">
            <property name="enableSubPackages" value="true"/>
            <property name="trimStrings" value="true"/>
        </javaModelGenerator>
        <!-- 生成映射文件的包名和位置 -->
        <sqlMapGenerator targetPackage="red.itech.blog.dal.mapper" targetProject="src/main/resources">
            <property name="enableSubPackages" value="true"/>
        </sqlMapGenerator>
        <!-- 生成DAO的包名和位置 -->
        <javaClientGenerator targetPackage="red.itech.blog.dal.mapper" targetProject="src/main/java"
                     type="XMLMAPPER">
            <property name="enableSubPackages" value="true"/>
        </javaClientGenerator>
        <table domainObjectName="User" tableName="user">
            <generatedKey column="id" sqlStatement="JDBC"/>
        </table>
    </context>
</generatorConfiguration>

生成POJO对象文件与映射

在pom.xml中添加mybatis-generator插件如下：

<build>
    <finalName>blog</finalName>
    <plugins>
        <plugin>
            <groupId>org.mybatis.generator</groupId>
            <artifactId>mybatis-generator-maven-plugin</artifactId>
            <version>1.3.2</version>
            <configuration>
                <overwrite>true</overwrite>
            </configuration>
            <dependencies>
                <dependency>
                    <groupId>org.mybatis.generator</groupId>
                    <artifactId>mybatis-generator-core</artifactId>
                    <version>1.3.2</version>
                </dependency>
                <!-- 数据库驱动 -->
                <dependency>
                    <groupId>mysql</groupId>
                    <artifactId>mysql-connector-java</artifactId>
                    <version>5.1.17</version>
                </dependency>
            </dependencies>
        </plugin>
    </plugins>
</build>

在项目目录下执行：

mvn -Dmybatis.generator.overwrite=true -Dmybatis.generator.configurationFile=src/main/resources/generatorConfig.xml mybatis-generator:generate

实现Service层（接口与实现）

根据业务逻辑实现相应逻辑代码，简化控制器层
修改控制器代码

Spring＋Mybatis＋Velocity项目搭建

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