SpringMVC+Hibernate+Maven+MySQL实现增删改查的一个小Demo

来源：互联网发布：恒扬数据副总经理编辑：程序博客网时间：2024/06/09 14:50

写在前面

工作过的项目用的是非常老旧的框架：Spring + Hibernate + DWR，DAO 层的绝大多数现成的方法基本还是内部老前辈们写的，什么 queryList、queryMap、querySingleObj 乱七八糟的，平时都是直接拿来用，也是方便

最近闲下来，就了解一下当下(其实也不是)比较主流的框架，SSH 好像都比较少了，目前大都是 SpringMVC 了来着，持久层要么是 Hibernate，要么是 MyBatis，因为好歹用过 Hibernate，所以先学着写了个小 demo 熟悉下这个框架

项目结构

Eclipse 新建一个 Dynamic Web Project，然后转成的 Maven Project

项目结构

数据库表

随便建一张 book 表：

CREATE TABLE `book` (  `id` int(6) NOT NULL AUTO_INCREMENT,  `book_name` varchar(20) DEFAULT NULL,  `book_author` varchar(20) DEFAULT NULL,  PRIMARY KEY (`id`)) ENGINE=InnoDB AUTO_INCREMENT=20 DEFAULT CHARSET=utf8;

主要代码配置

0. pom.xml

<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>BookDemo</groupId>    <artifactId>BookDemo</artifactId>    <version>1.0.0</version>    <packaging>war</packaging>    <build>        <finalName>BookDemo</finalName>        <sourceDirectory>src</sourceDirectory>        <plugins>            <plugin>                <artifactId>maven-compiler-plugin</artifactId>                <version>3.6.1</version>                <configuration>                    <source>1.8</source>                    <target>1.8</target>                </configuration>            </plugin>            <plugin>                <artifactId>maven-war-plugin</artifactId>                <version>3.0.0</version>                <configuration>                    <warSourceDirectory>WebContent</warSourceDirectory>                </configuration>            </plugin>        </plugins>    </build>    <properties>        <spring.version>4.1.5.RELEASE</spring.version>        <hibernate.version>4.3.8.Final</hibernate.version>        <mysql.version>5.1.40</mysql.version>        <junit-version>4.11</junit-version>        <servlet-api-version>3.1.0</servlet-api-version>        <jsp-version>2.1</jsp-version>        <jstl-version>1.2</jstl-version>    </properties>    <dependencies>        <dependency>            <groupId>org.springframework</groupId>            <artifactId>spring-core</artifactId>            <version>${spring.version}</version>        </dependency>        <dependency>            <groupId>org.springframework</groupId>            <artifactId>spring-context</artifactId>            <version>${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>        </dependency>        <dependency>            <groupId>org.springframework</groupId>            <artifactId>spring-orm</artifactId>            <version>${spring.version}</version>        </dependency>        <dependency>            <groupId>org.springframework</groupId>            <artifactId>spring-test</artifactId>            <version>${spring.version}</version>            <scope>test</scope>        </dependency>        <!-- Hibernate 4 dependencies -->        <dependency>            <groupId>org.hibernate</groupId>            <artifactId>hibernate-core</artifactId>            <version>${hibernate.version}</version>        </dependency>        <dependency>            <groupId>org.hibernate</groupId>            <artifactId>hibernate-c3p0</artifactId>            <version>${hibernate.version}</version>        </dependency>        <!--MYSQL Connector -->        <dependency>            <groupId>mysql</groupId>            <artifactId>mysql-connector-java</artifactId>            <version>${mysql.version}</version>        </dependency>        <!-- Servlet and JSP -->        <dependency>            <groupId>javax.servlet</groupId>            <artifactId>javax.servlet-api</artifactId>            <version>${servlet-api-version}</version>        </dependency>        <dependency>            <groupId>javax.servlet.jsp</groupId>            <artifactId>jsp-api</artifactId>            <version>${jsp-version}</version>            <scope>provided</scope>        </dependency>        <!-- JSTL dependency -->        <dependency>            <groupId>jstl</groupId>            <artifactId>jstl</artifactId>            <version>${jstl-version}</version>        </dependency>        <!-- JUnit -->        <dependency>            <groupId>junit</groupId>            <artifactId>junit</artifactId>            <version>${junit-version}</version>            <scope>test</scope>        </dependency>    </dependencies></project>

1. web.xml

<?xml version="1.0" encoding="UTF-8"?><web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"    xmlns="http://java.sun.com/xml/ns/javaee"    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"    version="3.0">    <display-name>Archetype Created Web Application</display-name>    <welcome-file-list>        <welcome-file>index.jsp</welcome-file>    </welcome-file-list>    <context-param>        <param-name>contextConfigLocation</param-name>        <param-value>/WEB-INF/bookDemo-servlet.xml</param-value>    </context-param>    <listener>        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>    </listener>    <servlet>        <servlet-name>bookDemo</servlet-name>        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>        <load-on-startup>1</load-on-startup>    </servlet>    <servlet-mapping>        <servlet-name>bookDemo</servlet-name>        <url-pattern>/</url-pattern>    </servlet-mapping>    <!-- 编码过滤器 -->    <filter>        <filter-name>SpringEncodingFilter</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>SpringEncodingFilter</filter-name>        <url-pattern>/*</url-pattern>    </filter-mapping></web-app>

2. applicationContext.xml(bookDemo-servlet.xml)

<beans xmlns="http://www.springframework.org/schema/beans"    xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context"    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:tx="http://www.springframework.org/schema/tx"    xsi:schemaLocation="        http://www.springframework.org/schema/beans             http://www.springframework.org/schema/beans/spring-beans.xsd        http://www.springframework.org/schema/mvc        http://www.springframework.org/schema/mvc/spring-mvc.xsd        http://www.springframework.org/schema/context        http://www.springframework.org/schema/context/spring-context.xsd        http://www.springframework.org/schema/tx        http://www.springframework.org/schema/tx/spring-tx.xsd">    <context:component-scan base-package="com.priest.book" />    <bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping" />    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter" />    <bean        class="org.springframework.web.servlet.view.InternalResourceViewResolver">        <property name="prefix" value="/WEB-INF/views/" />        <property name="suffix" value=".jsp" />    </bean>    <!--配置数据源 -->    <bean id="dataSource"        class="org.springframework.jdbc.datasource.DriverManagerDataSource">        <property name="driverClassName" value="com.mysql.jdbc.Driver" />        <property name="url" value="jdbc:mysql://127.0.0.1:3306/springmvc_demo?useUnicode=true&amp;characterEncoding=UTF-8" />        <property name="username" value="root" />        <property name="password" value="mysql" />    </bean>    <!--配置hibernate -->    <bean id="sessionFactory"        class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">        <property name="dataSource" ref="dataSource"></property>        <property name="hibernateProperties">            <props>                <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>                <prop key="hibernate.show_sql">true</prop>                <prop key="hibernate.format_sql">true</prop>            </props>        </property>        <property name="packagesToScan" value="com.priest.book.model"></property>    </bean>    <bean id="txManager"        class="org.springframework.orm.hibernate4.HibernateTransactionManager">        <property name="sessionFactory" ref="sessionFactory"></property>    </bean>    <tx:annotation-driven transaction-manager="txManager" /></beans>

3. BookVO.java

import java.io.Serializable;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.GenerationType;import javax.persistence.Id;import javax.persistence.Table;@Entity@Table(name = "book")public class BookVO implements Serializable{    private static final long serialVersionUID = 1L;    @Id    @GeneratedValue(strategy = GenerationType.AUTO)    private int id;    @Column(name="book_name")    private String bookName;    @Column(name="book_author")    private String bookAuthor;    public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public String getBookName() {        return bookName;    }    public void setBookName(String bookName) {        this.bookName = bookName;    }    public String getBookAuthor() {        return bookAuthor;    }    public void setBookAuthor(String bookAuthor) {        this.bookAuthor = bookAuthor;    }}

4. IBookDao.java

import java.util.List;import com.priest.book.model.BookVO;public interface IBookDao {    public void saveOrUpdateBook(BookVO book);    public List<BookVO> getBooks();    public BookVO getBookById(int id);    public void deleteBookById(int id);}

5. BookDaoImpl.java

import java.util.List;import org.hibernate.SQLQuery;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.jdbc.object.SqlQuery;import org.springframework.stereotype.Repository;import com.priest.book.model.BookVO;@Repositorypublic class BookDaoImpl implements IBookDao {    @Autowired    private SessionFactory sessionFactory;    @Override    public void saveOrUpdateBook(BookVO book) {        Session session = sessionFactory.getCurrentSession();        session.saveOrUpdate(book);    }    @Override    public List<BookVO> getBooks() {        Session session = sessionFactory.getCurrentSession();        SQLQuery query = session.createSQLQuery("select * from book").addEntity(BookVO.class);        List<BookVO> list = query.list();        //List<BookVO> list = session.createQuery(" from BookVO ").list();        return list;    }    @Override    public BookVO getBookById(int id) {        Session session = sessionFactory.getCurrentSession();        BookVO book = new BookVO();//      SQLQuery query = session.createSQLQuery("select * from book where id = ?").addEntity(BookVO.class);//      query.setInteger(0, id);//      List<BookVO> result = query.list();//      if(result != null && result.size() > 0) {//          book = result.get(0);//      }        book = (BookVO) session.get(BookVO.class, id);        return book;    }    @Override    public void deleteBookById(int id) {        Session session = sessionFactory.getCurrentSession();//      SQLQuery query = session.createSQLQuery(" delete from book where id = ? ").addEntity(BookVO.class);//      query.setInteger(0, id);//      query.executeUpdate();        BookVO book = (BookVO) session.get(BookVO.class, id);        session.delete(book);    }}

6. IBookService.java

import java.util.List;import com.priest.book.model.BookVO;public interface IBookService {    public void saveOrUpdateBook(BookVO book);    public List<BookVO> getBooks();    public BookVO getBookById(int id);    public void deleteBookById(int id);}

7. BookServiceImpl.java

import java.util.List;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;import org.springframework.transaction.annotation.Transactional;import com.priest.book.dao.IBookDao;import com.priest.book.model.BookVO;@Service@Transactionalpublic class BookServiceImpl implements IBookService {    @Autowired    private IBookDao bookDao;    @Override    public void saveOrUpdateBook(BookVO book) {        bookDao.saveOrUpdateBook(book);    }    @Override    public List<BookVO> getBooks() {        return bookDao.getBooks();    }    @Override    public BookVO getBookById(int id) {        return bookDao.getBookById(id);    }    @Override    public void deleteBookById(int id) {        bookDao.deleteBookById(id);    }}

8. BookController.java

import java.util.List;import javax.servlet.http.HttpServletRequest;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Controller;import org.springframework.ui.Model;import org.springframework.web.bind.annotation.ModelAttribute;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.servlet.ModelAndView;import com.priest.book.model.BookVO;import com.priest.book.service.IBookService;@Controller@RequestMapping("/book")public class BookController {    @Autowired    private IBookService bookService;    @RequestMapping(value= {"/bookList","/"}, method = RequestMethod.GET)    public ModelAndView listAllBooks(ModelAndView model) {        List<BookVO> books = bookService.getBooks();        model.addObject("bookList", books);        model.setViewName("books");        return model;    }    //另一种写法//  @RequestMapping(value= {"/bookList","/"}, method = RequestMethod.GET)//  public String listAllBooks(Model model) {//      List<BookVO> books = bookService.getBooks();//      //      model.addAttribute("bookList", books);//      //      return "books";//  }    @RequestMapping(value = "/newBook", method = RequestMethod.GET)    public ModelAndView newBook(ModelAndView model) {        BookVO book = new BookVO();        model.addObject("book", book);        model.setViewName("addOrUpdateBook");        return model;    }    @RequestMapping(value = "saveOrUpdateBook", method = RequestMethod.POST)    public ModelAndView saveOrUpdateBook(@ModelAttribute BookVO book) {        bookService.saveOrUpdateBook(book);        return new ModelAndView("operationSuccess");    }    @RequestMapping(value = "modifyBook", method = RequestMethod.GET)    public ModelAndView modifyBook(HttpServletRequest request) {        int id = Integer.parseInt(request.getParameter("id"));        BookVO book = bookService.getBookById(id);        ModelAndView model = new ModelAndView("addOrUpdateBook");        model.addObject("book", book);        return model;    }    @RequestMapping(value = "deleteBook", method = RequestMethod.GET)    public ModelAndView deleteBook(HttpServletRequest request) {        int id = Integer.parseInt(request.getParameter("id"));        bookService.deleteBookById(id);        return new ModelAndView("operationSuccess");    }}

9. books.jsp

<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>书</title></head><body>    <table border="1">        <tr>            <th>ID</th>            <th>书名</th>            <th>作者</th>            <th>操作</th>        </tr>        <c:forEach items="${bookList}" var="book">            <tr>                <td>${book.id}</td>                <td>${book.bookName}</td>                <td>${book.bookAuthor}</td>                <td><a href="<c:url value='/book/modifyBook?id=${book.id}' />">编辑</a>                    <a href="<c:url value='/book/deleteBook?id=${book.id}' />">删除</a>                </td>            </tr>        </c:forEach>    </table>    <br />    <a href="<c:url value='/book/newBook' />">添加图书</a></body></html>

10. addOrUpdateBook.jsp

<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%><%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>新增/修改图书</title></head><body>    <h3>新增/修改图书</h3>    <form:form action="saveOrUpdateBook" method="post" modelAttribute="book">        <table>            <form:hidden path="id" />            <tr>                <td>书名：</td>                <td><form:input path="bookName" /></td>            </tr>            <tr>                <td>作者：</td>                <td><form:input path="bookAuthor" /></td>            </tr>            <tr>                <td><input type="submit" value="保存" /></td>            </tr>        </table>    </form:form></body></html>

11. operationSuccess.jsp

<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>书</title></head><body>    操作成功！<br/>    <a href="<c:url value='/book/bookList' />">返回列表</a></body></html>

运行结果

新打开的页面：

列表页

操作的页面：

操作页

操作完成：

操作完成

返回列表：

返回列表

遇到的问题

0. jar包使用异常

第一个最头大的问题当属引入了 jar 包，类中引用一直提示找不到的问题，在我上一篇博客中讲了这个问题

1. jstl 获取对象属性

在 jsp 中本来可以使用 对象.属性 的方式取得内容，就像这样：

<c:forEach items="${bookList}" var="book">    <tr>        <td>${book.id}</td>        <td>${book.bookName}</td>        <td>${book.bookAuthor}</td>    </tr></c:forEach>

在写代码的过程中，由于一个地方的失误：

包路径写错

把 model 的包路径写错了，导致：

返回object对象列表

查到的对象不能绑定为 BookVO，而是 Object，这样的话在 jstl 中使用对象.属性的时候就报错了

虽然是自己的一个小失误，除了配置中修改错误，映射正确的 VO 类外，这时候还可以使用下标的方式取的内容：

<c:forEach items="${bookList}" var="book">    <tr>        <td>${book[0]}</td>        <td>${book[1]}</td>        <td>${book[2]}</td>    </tr></c:forEach>

2. 乱码

项目中有几个地方要注意编码：

MySQL 数据库的配置
.xml 配置文件中数据源链接
jsp 页面的编码

最后参考学习，在 web.xml 中添加了 spring 的编码过滤器：

<filter>    <filter-name>SpringEncodingFilter</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>SpringEncodingFilter</filter-name>    <url-pattern>/*</url-pattern></filter-mapping>

3. 主键自增

一开始只在代码里给 VO 类注解了 ID 是自增，调用保存的时候报错：

java.sql.SQLException: Field 'id' doesn't have a default value

查询后发现是数据库里忘记给主键设置自增导致的

最后

参考学习：

http://javawebtutor.com/articles/spring/spring-mvc-hibernate-crud-example.php

https://howtodoinjava.com/spring/spring-mvc/spring-mvc-hello-world-example/

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