超市管理系统总结篇二(准备工作补充)

1.maven的pom.xml导入所需的依赖

<?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>com.xia</groupId>
  <artifactId>smbms</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>war</packaging>

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

  <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>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>

    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>4.0.1</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/javax.servlet.jsp/javax.servlet.jsp-api -->
    <dependency>
      <groupId>javax.servlet.jsp</groupId>
      <artifactId>javax.servlet.jsp-api</artifactId>
      <version>2.3.3</version>
    </dependency>
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>jsp-api</artifactId>
      <version>2.0</version>
      <scope>provided</scope>
    </dependency>

    <dependency>
      <groupId>taglibs</groupId>
      <artifactId>standard</artifactId>
      <version>1.1.2</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/javax.servlet.jsp.jstl/jstl-api -->
    <dependency>
      <groupId>javax.servlet.jsp.jstl</groupId>
      <artifactId>jstl-api</artifactId>
      <version>1.2</version>
    </dependency>
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.19</version>
    </dependency>
    <dependency>
      <groupId>org.junit.jupiter</groupId>
      <artifactId>junit-jupiter</artifactId>
      <version>RELEASE</version>
      <scope>compile</scope>
    </dependency>

<!--   阿里JSON-->
    <!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>fastjson</artifactId>
      <version>1.2.41</version>
    </dependency>

  </dependencies>

  <build>
    <finalName>smbms</finalName>
    <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
      <plugins>
        <plugin>
          <artifactId>maven-clean-plugin</artifactId>
          <version>3.1.0</version>
        </plugin>
        <!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_war_packaging -->
        <plugin>
          <artifactId>maven-resources-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.8.0</version>
        </plugin>
        <plugin>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>2.22.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-war-plugin</artifactId>
          <version>3.2.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-install-plugin</artifactId>
          <version>2.5.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-deploy-plugin</artifactId>
          <version>2.8.2</version>
        </plugin>
      </plugins>
    </pluginManagement>
  </build>
</project>

2.在web.xml中注册servlet

<?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"
         metadata-complete="true">
  <!--配置web应用的初始化 参数-->
  <context-param>
    <param-name>url</param-name>
    <param-value>jdbc:mysql://3306:mysql</param-value>
  </context-param>

    <filter>
        <filter-name>Encoding</filter-name>
        <filter-class>com.xia.filter.CharacterEncoding</filter-class>
    </filter>
 <filter-mapping>
   <filter-name>Encoding</filter-name>
   <url-pattern>/*</url-pattern>
 </filter-mapping>
    <filter>
        <filter-name>SysFilter</filter-name>
        <filter-class>com.xia.filter.SysFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>SysFilter</filter-name>
        <url-pattern>/jsp/*</url-pattern>
    </filter-mapping>

<!--   //设置欢迎界面-->
    <welcome-file-list>
        <welcome-file>login.jsp</welcome-file>
    </welcome-file-list>

<!-- 登录-->
    <servlet>
        <servlet-name>UserServlet</servlet-name>
        <servlet-class>com.xia.servlet.UserServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>UserServlet</servlet-name>
        <url-pattern>/login.do</url-pattern>
    </servlet-mapping>

<!-- 注销用户-->
    <servlet>
        <servlet-name>Loginout</servlet-name>
        <servlet-class>com.xia.servlet.Loginout</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>Loginout</servlet-name>
        <url-pattern>/jsp/logout.do</url-pattern>
    </servlet-mapping>
<!--  修改密码-->
    <servlet>
        <servlet-name>PwdServlet</servlet-name>
        <servlet-class>com.xia.servlet.PwdServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>PwdServlet</servlet-name>
        <url-pattern>/jsp/user.do</url-pattern>
    </servlet-mapping>
<!--    默认session过期时间-->
      <session-config>
          <session-timeout>30</session-timeout>
      </session-config>
</web-app>

3.过滤器，编码预处理，注销后拦截

package com.xia.filter;

import javax.servlet.*;
import java.io.IOException;

public class CharacterEncoding  implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        servletRequest.setCharacterEncoding("utf-8");
        servletResponse.setCharacterEncoding("utf-8");
        filterChain.doFilter(servletRequest,servletResponse);
    }

    @Override
    public void destroy() {

    }
}

package com.xia.filter;

import com.xia.util.Constants;

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

public class SysFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {

        HttpServletRequest servletRequest1 = (HttpServletRequest) servletRequest;
        HttpServletResponse servletResponse1 = (HttpServletResponse) servletResponse;
        if (servletRequest1.getSession().getAttribute(Constants.USER_SESSION) == null) {
            servletResponse1.sendRedirect(servletRequest1.getContextPath()+"/login.jsp");
        }
        filterChain.doFilter(servletRequest,servletResponse);
    }
        @Override
    public void destroy() {

    }
}