IDEA+maven搭建前后端分离ssm环境

第一次搭建ssm前后端分离环境的时候遇到了很多坑，一天下来我充分体验到什么叫做面向配置编程了。

第一步：使用IDEA构建maven项目，并配置Tomcat

这里我就不细说了，搭建之后如下图

第二步：在pom.xml中导入相关依赖

<groupId>com.hsy.sms</groupId>
  <artifactId>u_sms</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>war</packaging>

  <!-- 用来设置版本号 -->
  <properties>
    <srping.version>4.2.4.RELEASE</srping.version>
    <mybatis.version>3.2.8</mybatis.version>
    <slf4j.version>1.7.12</slf4j.version>
    <log4j.version>1.2.17</log4j.version>
    <druid.version>1.0.9</druid.version>
  </properties>
  <!-- 用到的jar包 -->
  <dependencies>
    <!-- 单元测试 -->
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <!-- 表示开发的时候引入，发布的时候不会加载此包 -->
      <scope>test</scope>
    </dependency>

    <!-- spring框架包 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>${srping.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-core</artifactId>
      <version>${srping.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-oxm</artifactId>
      <version>${srping.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>${srping.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>${srping.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aop</artifactId>
      <version>${srping.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>${srping.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context-support</artifactId>
      <version>${srping.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-expression</artifactId>
      <version>${srping.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-orm</artifactId>
      <version>${srping.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-web</artifactId>
      <version>${srping.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>${srping.version}</version>
    </dependency>
    <!-- spring框架包 -->
    <!-- mybatis框架包 -->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>${mybatis.version}</version>
    </dependency>
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis-spring</artifactId>
      <version>1.2.2</version>
    </dependency>
    <!-- mybatis框架包 -->
    <!-- 数据库驱动 -->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.35</version>
    </dependency>
    <!-- 导入dbcp的jar包，用来在applicationContext.xml中配置数据库 -->
    <dependency>
      <groupId>commons-dbcp</groupId>
      <artifactId>commons-dbcp</artifactId>
      <version>1.4</version>
    </dependency>
    <!-- jstl标签类 -->
    <dependency>
      <groupId>jstl</groupId>
      <artifactId>jstl</artifactId>
      <version>1.2</version>
    </dependency>
    <!-- log -->
    <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>${log4j.version}</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-api</artifactId>
      <version>${slf4j.version}</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-log4j12</artifactId>
      <version>${slf4j.version}</version>
    </dependency>
    <!-- 连接池 -->
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid</artifactId>
      <version>${druid.version}</version>
    </dependency>

      <!--加入对json转换-->
    <!-- JSON: jackson -->
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-annotations</artifactId>
      <version>2.5.0</version>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-core</artifactId>
      <version>2.5.0</version>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-databind</artifactId>
      <version>2.5.0</version>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.jr</groupId>
      <artifactId>jackson-jr-all</artifactId>
      <version>2.5.0</version>
    </dependency>
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>fastjson</artifactId>
      <version>1.2.46</version>
    </dependency>
  </dependencies>

  <build>
    <!-- java编译插件,如果maven的设置里配置好jdk版本就不用 -->
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.2</version>
        <configuration>
          <source>1.8</source>
          <target>1.8</target>
          <encoding>UTF-8</encoding>
        </configuration>
      </plugin>
    </plugins>

    <!--打包配置文件-->
      <resources>
          <resource>
              <directory>srcmain
esources</directory>
              <includes>
                  <include>**/*.properties</include>
                  <include>**/*.xml</include>
                  <include>**/*.tld</include>
              </includes>
              <filtering>false</filtering>
          </resource>
          <resource>
              <directory>srcmainjava</directory>
              <excludes>
                  <exclude>**/*.java</exclude>
              </excludes>
          </resource>
      </resources>
  </build>

第二步：配置框架底层的配置文件

1、创建log4j.properties

# Global logging configuration
log4j.rootLogger=DEBUG, stdout
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

2、创建jdbc.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/u_sms?characterEncoding=utf-8
jdbc.username=root
jdbc.password=root
#定义初始连接数
initialSize=0    
#定义最大连接数
maxActive=20    
#定义最大空闲
maxIdle=20    
#定义最小空闲
minIdle=1    
#定义最长等待时间
maxWait=60000

3、创建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:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context"
	   xsi:schemaLocation="http://www.springframework.org/schema/beans
                        http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
                        http://www.springframework.org/schema/tx
                        http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

	<!-- 加载properties文件 -->
	<bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
		<property name="location" value="classpath:jdbc.properties"/>
	</bean>

	<!-- 配置数据源 -->
	<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>

	<!-- mybatis和spring完美整合，不需要mybatis的配置映射文件 -->
	<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
		<property name="dataSource" ref="dataSource"/>
		<!-- 扫描model包 -->
		<property name="typeAliasesPackage" value="com.hsy.sms.entity"/>
		<!-- 扫描sql配置文件:mapper需要的xml文件-->
		<property name="mapperLocations" value="classpath:mapper/*.xml"/>
	</bean>

	<!-- Mapper动态代理开发，扫描dao接口包-->
	<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
		<!-- 注入sqlSessionFactory -->
		<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
		<!-- 给出需要扫描Dao接口包 -->
		<property name="basePackage" value="com.hsy.sms.mapper"/>
	</bean>

	<!-- 事务管理 -->
	<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
		<!--数据库连接池-->
		<property name="dataSource" ref="dataSource"/>
	</bean>
</beans>

4、创建springmvc.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:p="http://www.springframework.org/schema/p"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd">

	<!-- 配置@controller扫描包 -->
	<context:component-scan base-package="com.hsy.sms" />

	 <!--使用Annotation自动注册Bean,扫描@Controller和@ControllerAdvice-->
	<context:component-scan base-package="com.hsy.sms.handler" use-default-filters="false">
		<!-- base-package 如果多个，用“,”分隔 -->
		<context:include-filter type="annotation" expression="org.springframework.stereotype.Controller" />
		<!--控制器增强，使一个Contoller成为全局的异常处理类，类中用@ExceptionHandler方法注解的方法可以处理所有Controller发生的异常-->
		<context:include-filter type="annotation" expression="org.springframework.web.bind.annotation.ControllerAdvice" />
	</context:component-scan>
	<!-- 配置注解驱动，相当于同时使用最新处理器映射跟处理器适配器,对json数据响应提供支持 -->
	<mvc:annotation-driven />


	<!-- 输出对象转JSON支持 -->
	<bean
			class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
		<property name="messageConverters">
			<list>
				<bean
						class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
					<property name="supportedMediaTypes">
						<list>
							<value>text/html;charset=UTF-8</value>
							<value>text/plain;charset=UTF-8</value>
							<value>application/json;charset=UTF-8</value>
						</list>
					</property>
				</bean>
			</list>
		</property>
	</bean>

	<!-- 配置视图解析器 -->
	<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix" value="/WEB-INF/jsp/"/>
		<property name="suffix" value=".jsp"/>
	</bean>
</beans>

5、配置web.xml文件

<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_3_1.xsd"
         version="3.1">


  <!-- 注册ServletContext监听器，创建容器对象，并且将ApplicationContext对象放到Application域中 -->
  <listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>

  <!-- 指定spring核心配置文件 -->
  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:spring/applicationContext.xml</param-value>
  </context-param>

  <!-- 解决乱码的过滤器 -->
  <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>forceEncoding</param-name>
      <param-value>true</param-value>
    </init-param>
  </filter>
  <filter-mapping>
    <filter-name>CharacterEncodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>
 
  <!-- 配置前端控制器 -->
  <servlet>
    <servlet-name>springmvc</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

    <!-- 指定配置文件位置和名称 如果不设置,默认找/WEB-INF/<servlet-name>-servlet.xml -->
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:spring/springmvc.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
    <async-supported>true</async-supported>
  </servlet>

  <servlet-mapping>
    <servlet-name>springmvc</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>
</web-app>

5、在mapper中创建UserMapper.xml文件

在创建映射文件之前，先将先决条件搭建好

这里用User举个栗子

package com.hsy.sms.entity;
public class User {
    private Integer uid;
    private String uname;
    private String pwd_id;
    private Integer groupid;
///setter/getter
}

数据库如下

创建Usermapper.java

package com.hsy.sms.mapper;
import com.hsy.sms.entity.User;
public interface UserMapper {
    /**
     * 通过id获取用户基本信息
     * @param uid
     * @return
     */
    User getUserById(Integer uid);
}

<mapper namespace="com.hsy.sms.mapper.UserMapper">
	<select id="getUserById" parameterType="int" resultType="com.hsy.sms.entity.User">
		SELECT
		  `uid`,
		  `uname`,
		  `pwd_id`,
		  `groupid`
		FROM `t_test`
		WHERE
		uid = #{uid}
	</select>
</mapper>

    创建完成目录结构如下
![](https://img2018.cnblogs.com/blog/1426931/201910/1426931-20191018215416492-1749701699.png)

第三步：编辑java代码测试

1、创建UserService

package com.hsy.sms.service;
import com.hsy.sms.entity.User;
import org.springframework.stereotype.Service;
@Service
public interface UserService {
    /**
     * 通过id获取用户基本信息
     * @param uid
     * @return
     */
    User getUserById(Integer uid);
}

2、创建UserServiceImpl实现类

package com.hsy.sms.service.impl;

import com.hsy.sms.mapper.UserMapper;
import com.hsy.sms.entity.User;
import com.hsy.sms.service.UserService;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;

@Service("userService")
public class UserServiceImpl implements UserService {

    @Resource
    private UserMapper userDao;

    @Override
    public User getUserById(Integer uid) {
        return userDao.getUserById(uid);
    }
}

3、创建UserController编写login接口

package com.hsy.sms.controller;

import com.hsy.sms.entity.User;
import com.hsy.sms.service.UserService;
import com.hsy.sms.util.JSON;
import com.hsy.sms.util.OutputJson;
import com.hsy.sms.util.ReturnFormat;
import com.sun.javafx.collections.MappingChange;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.ModelAndView;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@Controller
@RequestMapping("/user")
public class UserController {

    @Autowired
    private UserService userService;

    @RequestMapping(value = "/login", method = RequestMethod.POST,consumes="application/x-www-form-urlencoded")
    @ResponseBody
    public Object selectUser(@RequestParam(value="uid") int uid, @RequestParam(value="password") String pwd_id) throws Exception {
        //根据用户的uid获取用户
        User user = userService.getUserById(uid);
        if(user != null $$ user.getPwd_id().equals(pwd_id)){
            return user;

        }
        return "";
    }
}

使用ajax测试成功