Maven(父子模块)+myBatis+分页（pagehelper）项目案例
第一步：搭建Maven项目
首先是父模块：Demo-parent
然后是子模块：Demo-entity,Demo-dao,Demo-service,Demo-web
在Demo-web层添加Web目录。
第二步：父模块的pom.xml文件里，如下：
1 <?xml version="1.0" encoding="UTF-8"?> 2 <project xmlns="http://maven.apache.org/POM/4.0.0" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> 5 <modelVersion>4.0.0</modelVersion> 6 7 <groupId>com.nf</groupId> 8 <artifactId>mvnBatis-parent</artifactId> 9 <packaging>pom</packaging> 10 <version>1.0-SNAPSHOT</version> 11 <modules> 12 <module>mvnBatis-entity</module> 13 <module>mvnBatis-dao</module> 14 <module>mvnBatis-service</module> 15 <module>mvnBatis-web</module> 16 </modules> 17 18 <properties> 19 <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> 20 <maven.compiler.encoding>UTF-8</maven.compiler.encoding> 21 <java.version>1.8</java.version> 22 <maven.compiler.source>1.8</maven.compiler.source> 23 <maven.compiler.target>1.8</maven.compiler.target> 24 25 <javax.servlet.version>3.1.0</javax.servlet.version> 26 <mysql.version>8.0.11</mysql.version> 27 <jstl.version>1.2</jstl.version> 28 <myBatis.version>3.4.6</myBatis.version> 29 <pagehelper.version>5.1.2</pagehelper.version> 30 </properties> 31 32 <dependencyManagement> 33 <dependencies> 34 <dependency> 35 <groupId>javax.servlet</groupId> 36 <artifactId>javax.servlet-api</artifactId> 37 <version>${javax.servlet.version}</version> 38 </dependency> 39 40 <dependency> 41 <groupId>mysql</groupId> 42 <artifactId>mysql-connector-java</artifactId> 43 <version>${mysql.version}</version> 44 </dependency> 45 46 <dependency> 47 <groupId>javax.servlet</groupId> 48 <artifactId>jstl</artifactId> 49 <version>${jstl.version}</version> 50 </dependency> 51 52 <dependency> 53 <groupId>org.mybatis</groupId> 54 <artifactId>mybatis</artifactId> 55 <version>${myBatis.version}</version> 56 </dependency> 57 58 <dependency> 59 <groupId>com.github.pagehelper</groupId> 60 <artifactId>pagehelper</artifactId> 61 <version>${pagehelper.version}</version> 62 </dependency> 63 64 65 </dependencies> 66 </dependencyManagement> 67 68 <build> 69 <plugins> 70 <plugin> 71 <artifactId>maven-war-plugin</artifactId> 72 <version>3.2.0</version> 73 <configuration> 74 <warSourceDirectory>web</warSourceDirectory> 75 </configuration> 76 </plugin> 77 </plugins> 78 </build> 79 80 </project>
第三步：
3.1 写实体层代码
1 package entity; 2 3 import java.math.BigDecimal; 4 5 public class UserInfo { 6 private Integer id; 7 private String username; 8 private Integer gender; 9 private BigDecimal salary; 10 private Integer did; 11 12 @Override 13 public String toString() { 14 return "UserInfo{" + 15 "id=" + id + 16 ", username='" + username + '\'' + 17 ", gender=" + gender + 18 ", salary=" + salary + 19 ", did=" + did + 20 '}'; 21 } 22 23 public Integer getId() { 24 return id; 25 } 26 27 public void setId(Integer id) { 28 this.id = id; 29 } 30 31 public String getUsername() { 32 return username; 33 } 34 35 public void setUsername(String username) { 36 this.username = username; 37 } 38 39 public Integer getGender() { 40 return gender; 41 } 42 43 public void setGender(Integer gender) { 44 this.gender = gender; 45 } 46 47 public BigDecimal getSalary() { 48 return salary; 49 } 50 51 public void setSalary(BigDecimal salary) { 52 this.salary = salary; 53 } 54 55 public Integer getDid() { 56 return did; 57 } 58 59 public void setDid(Integer did) { 60 this.did = did; 61 } 62 }
3.2 dao层代码
3.2.1 dao包：接口UserInfoDao 和 实现类UserInfoDaoImpl
1 package dao; 2 3 import entity.UserInfo; 4 import org.apache.ibatis.annotations.Param; 5 6 import java.util.List; 7 import java.util.Map; 8 9 public interface UserInfoDao { 10 List<UserInfo> getAll(Map<String,Object> map, @Param("pageNum") int pageNum, @Param("pageSize") int pageSize); 11 }
1 package dao; 2 3 import entity.UserInfo; 4 import org.apache.ibatis.session.SqlSession; 5 import util.SqlSessionFactoryUtil; 6 7 import java.util.List; 8 import java.util.Map; 9 10 public class UserInfoDaoImpl implements UserInfoDao { 11 @Override 12 public List<UserInfo> getAll(Map<String, Object> map, int pageNum, int pageSize) { 13 try(SqlSession sqlSession= SqlSessionFactoryUtil.sqlSession(true)){ 14 UserInfoDao userInfoDao=sqlSession.getMapper(UserInfoDao.class); 15 List<UserInfo> userInfos=userInfoDao.getAll(map,pageNum,pageSize); 16 return userInfos; 17 } 18 } 19 }
注意：接口里的@ Param是必须的，原因：java代码在idea里编译时，参数名会消失，@Param可解决此问题。参数在sql语句会用，在后面的java代码也是会用到的。
3.2.2 util包：SqlSessionFactoryUtil辅助类
1 package util; 2 3 import org.apache.ibatis.io.Resources; 4 import org.apache.ibatis.session.SqlSession; 5 import org.apache.ibatis.session.SqlSessionFactory; 6 import org.apache.ibatis.session.SqlSessionFactoryBuilder; 7 8 import java.io.IOException; 9 import java.io.InputStream; 10 11 public class SqlSessionFactoryUtil { 12 private static final String RESOURCE="config.xml"; 13 private static final SqlSessionFactory FACTORY; 14 15 static { 16 InputStream inputStream=null; 17 try { 18 inputStream= Resources.getResourceAsStream(RESOURCE); 19 } catch (IOException e) { 20 e.printStackTrace(); 21 } 22 FACTORY=new SqlSessionFactoryBuilder().build(inputStream); 23 } 24 25 public static SqlSessionFactory sqlSessionFactory(){ 26 return FACTORY; 27 } 28 29 public static SqlSession sqlSession(boolean autocommit){ 30 return FACTORY.openSession(autocommit); 31 } 32 }
3.2.3 资源文件resource :config.xml 和 mapper.xml
1 <?xml version="1.0" encoding="UTF-8" ?> 2 <!DOCTYPE configuration 3 PUBLIC "-//mybatis.org//DTD Config 3.0//EN" 4 "http://mybatis.org/dtd/mybatis-3-config.dtd"> 5 <configuration> 6 <plugins> 7 <plugin interceptor="com.github.pagehelper.PageInterceptor"> 8 <property name="helperDialect" value="mysql"/> 9 <property name="supportMethodsArguments" value="true"/> 10 </plugin> 11 </plugins> 12 <environments default="def"> 13 <environment id="def"> 14 <transactionManager type="JDBC"></transactionManager> 15 <dataSource type="POOLED"> 16 <property name="driver" value="com.mysql.cj.jdbc.Driver"/> 17 <property name="url" value="jdbc:mysql://localhost:3306/nf?serverTimezone=Asia/Shanghai&useSSL=false"/> 18 <property name="username" value="root"/> 19 <property name="password" value="123456"/> 20 </dataSource> 21 </environment> 22 </environments> 23 <mappers> 24 <mapper resource="mapper.xml"/> 25 </mappers> 26 </configuration>
1 <?xml version="1.0" encoding="UTF-8" ?> 2 <!DOCTYPE mapper 3 PUBLIC "-//mybatis.org//DTD Config 3.0//EN" 4 "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> 5 <mapper namespace="dao.UserInfoDao"> 6 <select id="getAll" resultType="entity.UserInfo"> 7 select * from userinfo 8 </select> 9 </mapper>
3.3 pom.xml文件
1 <?xml version="1.0" encoding="UTF-8"?> 2 <project xmlns="http://maven.apache.org/POM/4.0.0" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> 5 <parent> 6 <artifactId>Demo-parent</artifactId> 7 <groupId>com.nf</groupId> 8 <version>1.0-SNAPSHOT</version> 9 </parent> 10 <modelVersion>4.0.0</modelVersion> 11 12 <artifactId>Demo-dao</artifactId> 13 14 <dependencies> 15 <dependency> 16 <groupId>com.nf</groupId> 17 <artifactId>Demo-entity</artifactId> 18 <version>1.0-SNAPSHOT</version> 19 </dependency> 20 21 <dependency> 22 <groupId>mysql</groupId> 23 <artifactId>mysql-connector-java</artifactId> 24 </dependency> 25 26 <dependency> 27 <groupId>org.mybatis</groupId> 28 <artifactId>mybatis</artifactId> 29 </dependency> 30 </dependencies> 31 32 33 </project>
第四步：
写service层代码
4.1 先写接口然后写实现类 UserInfoService 和 UserInfoServiceImpl
1 package service; 2 3 import entity.UserInfo; 4 import java.util.List; 5 import java.util.Map; 6 7 public interface UserInfoService { 8 List<UserInfo> getAll(Map<String,Object> map,int pageNum,int pageSize); 9 }
1 package service; 2 3 import dao.UserInfoDao; 4 import dao.UserInfoDaoImpl; 5 import entity.UserInfo; 6 7 import java.util.List; 8 import java.util.Map; 9 10 public class UserInfoServiceImpl implements UserInfoService { 11 UserInfoDao uid=new UserInfoDaoImpl(); 12 @Override 13 public List<UserInfo> getAll(Map<String, Object> map, int pageNum, int pageSize) { 14 return uid.getAll(map,pageNum,pageSize); 15 } 16 }
4.2 service里的pom.xml
1 <?xml version="1.0" encoding="UTF-8"?> 2 <project xmlns="http://maven.apache.org/POM/4.0.0" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> 5 <parent> 6 <artifactId>Demo-parent</artifactId> 7 <groupId>com.nf</groupId> 8 <version>1.0-SNAPSHOT</version> 9 </parent> 10 <modelVersion>4.0.0</modelVersion> 11 12 <artifactId>Demo-service</artifactId> 13 14 <dependencies> 15 <dependency> 16 <groupId>com.nf</groupId> 17 <artifactId>Demo-dao</artifactId> 18 <version>1.0-SNAPSHOT</version> 19 </dependency> 20 </dependencies> 21 22 23 </project>
第五步：
5.1 写servlet控制类：servlet_getAll
1 package action; 2 3 import com.github.pagehelper.Page; 4 import com.github.pagehelper.PageInfo; 5 import entity.UserInfo; 6 import service.UserInfoService; 7 import service.UserInfoServiceImpl; 8 9 import javax.servlet.ServletException; 10 import javax.servlet.annotation.WebServlet; 11 import javax.servlet.http.HttpServlet; 12 import javax.servlet.http.HttpServletRequest; 13 import javax.servlet.http.HttpServletResponse; 14 import java.io.IOException; 15 16 @WebServlet("/getAll") 17 public class Servlet_getAll extends HttpServlet { 18 @Override 19 protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { 20 UserInfoService uis=new UserInfoServiceImpl(); 21 int pageNum=getPageNum(req); 22 23 Page<UserInfo> userInfoPage= (Page<UserInfo>) uis.getAll(null,pageNum,4); 24 PageInfo<UserInfo> userInfoPageInfo=new PageInfo<>(userInfoPage,7); 25 26 req.setAttribute("userinfos",userInfoPageInfo); 27 req.getRequestDispatcher("show.jsp").forward(req,resp); 28 } 29 30 public static int getPageNum(HttpServletRequest req){ 31 int pageNum=1; 32 try{ 33 pageNum=Integer.valueOf(req.getParameter("page")); 34 }catch (Exception e){ 35 pageNum=1; 36 } 37 return pageNum; 38 } 39 }
5.2 添加web构面
快捷键 Ctrl+Shift+Alt+S 进入项目配置页面，为Demo-web层添加web构面
5.3 在里面添加show.jsp页面
1 <%-- 2 Created by IntelliJ IDEA. 3 User: Administrator 4 Date: 2018/9/5 0005 5 Time: 23:08 6 To change this template use File | Settings | File Templates. 7 --%> 8 <%@ page contentType="text/html;charset=UTF-8" language="java" %> 9 <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> 10 <html> 11 <head> 12 <title>Title</title> 13 </head> 14 <body> 15 <table border="1" align="center" width="80%"> 16 <tr> 17 <th>编号</th> 18 <th>姓名</th> 19 <th>性别</th> 20 <th>工资</th> 21 <th>部门</th> 22 </tr> 23 <c:forEach items="${userinfos.list}" var="u"> 24 <tr> 25 <td>${u.id}</td> 26 <td>${u.username}</td> 27 <td>${u.gender}</td> 28 <td>${u.salary}</td> 29 <td>${u.did}</td> 30 </tr> 31 </c:forEach> 32 </table> 33 <p align="center"> 34 <a href="getAll?page=1">首页</a> 35 <a href="getAll?page=${userinfos.prePage}">上一页</a> 36 <c:forEach items="${userinfos.navigatepageNums}" var="pageNum"> 37 <a href="getAll?page=${pageNum}">${pageNum}</a> 38 </c:forEach> 39 <a href="getAll?page=${userinfos.nextPage}">下一页</a> 40 <a href="getAll?page=${userinfos.pages}">尾页</a> 41 </p> 42 </body> 43 </html>
5.4 web层的pom.xml文件
1 <?xml version="1.0" encoding="UTF-8"?> 2 <project xmlns="http://maven.apache.org/POM/4.0.0" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> 5 <parent> 6 <artifactId>Demo-parent</artifactId> 7 <groupId>com.nf</groupId> 8 <version>1.0-SNAPSHOT</version> 9 </parent> 10 <modelVersion>4.0.0</modelVersion> 11 12 <artifactId>Demo-web</artifactId> 13 <packaging>war</packaging> 14 15 <dependencies> 16 <dependency> 17 <groupId>com.nf</groupId> 18 <artifactId>Demo-service</artifactId> 19 <version>1.0-SNAPSHOT</version> 20 </dependency> 21 <dependency> 22 <groupId>javax.servlet</groupId> 23 <artifactId>jstl</artifactId> 24 </dependency> 25 <dependency> 26 <groupId>com.github.pagehelper</groupId> 27 <artifactId>pagehelper</artifactId> 28 </dependency> 29 <dependency> 30 <groupId>javax.servlet</groupId> 31 <artifactId>javax.servlet-api</artifactId> 32 </dependency> 33 </dependencies> 34 35 36 </project>
第六步：
maven项目执行clean 和 package 生命周期，在父模块打包形成war包，
然后编辑运行配置即可。
