一、如何利用idea创建一个maven web项目？

1、file -- new -- project

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2、选择maven的web模板

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3、一些配置

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一直点next，这样一个空的web工程就创建好了

4、创建好的web工程目录结构

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5、补齐缺失的目录文件夹（看图操作）

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6、引入必要的依赖

6.1、引入springmvc的pom依赖

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.7</maven.compiler.source>
    <maven.compiler.target>1.7</maven.compiler.target>
    <spring.version>4.0.6.RELEASE</spring.version>
  </properties>

  <dependencies>
    <!-- servlet -->
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>servlet-api</artifactId>
      <version>2.5</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>3.1.0</version>
    </dependency>

    <!-- Spring framework -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-core</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-web</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>${spring.version}</version>
      <exclusions>
        <exclusion>
          <artifactId>spring-web</artifactId>
          <groupId>org.springframework</groupId>
        </exclusion>
      </exclusions>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context-support</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jms</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>${spring.version}</version>
      <scope>test</scope>
    </dependency>

    <!-- spring aop start -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aop</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aspects</artifactId>
      <version>${spring.version}</version>
      <exclusions>
        <exclusion>
          <artifactId>aspectjweaver</artifactId>
          <groupId>org.aspectj</groupId>
        </exclusion>
      </exclusions>
    </dependency>
    <dependency>
      <groupId>org.aspectj</groupId>
      <artifactId>aspectjrt</artifactId>
      <version>1.6.11</version>
    </dependency>
    <dependency>
      <groupId>org.aspectj</groupId>
      <artifactId>aspectjweaver</artifactId>
      <version>1.6.11</version>
    </dependency>
    <dependency>
      <groupId>cglib</groupId>
      <artifactId>cglib</artifactId>
      <version>2.1_3</version>
      <exclusions>
        <exclusion>
          <artifactId>asm</artifactId>
          <groupId>asm</groupId>
        </exclusion>
      </exclusions>
    </dependency>
    <!-- spring aop end --> 

6.2、引入jackson依赖，没有这个jackson，使用@ResponseBody注解会报416错误

 <!-- jackson -->
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-core</artifactId>
      <version>2.9.3</version>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-databind</artifactId>
      <version>2.9.3</version>
      <exclusions>
        <exclusion>
          <artifactId>jackson-annotations</artifactId>
          <groupId>com.fasterxml.jackson.core</groupId>
        </exclusion>
      </exclusions>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-annotations</artifactId>
      <version>2.9.3</version>
    </dependency>

    <!-- fast json 依赖 -->
    <dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.28</version>
    </dependency>

6.3、如何引入本地jar包依赖

6.3.1 jar包一定要放在WEB-INf下的lib目录下，否则会报NoClassDefFoundError（这个是编译正常，运行时找不到正确的jar包）

6.3.2 pom依赖的正确写法

 <!-- 添加串口通信 -->
    <dependency>
      <groupId>org.rxtx</groupId>
      <artifactId>rxtx</artifactId>
      <version>2.2</version>
      <scope>system</scope>
      <systemPath>${basedir}/src/main/webapp/WEB-INF/lib/rxtx-2.2.jar</systemPath>
    </dependency>

7、web.xml的配置

7.1 添加springmvcfilter，所有请求都交给spring容器处理

 <!-- springmvc -->
  <servlet>
    <servlet-name>springmvc</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>
        classpath:spring/spring-mvc-servlet.xml
      </param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>springmvc</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>

7.2 如果要使用applicationContext.getBean(beanName)的方式获取bean要添加如下配置

 <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:spring/spring-mvc-servlet.xml</param-value>
  </context-param>


  <!-- 添加spring上下文 -->
  <listener>
    <listener-class>com.shangda.message.listener.SuperContextLoaderListener</listener-class>
  </listener>

注：spring/spring-mvc-servlet.xml这个文件在下图目录下

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