Spring 通过使用jdbcTemplate和org.springframework.jdbc.core和相关包中的相关类,使使用 JDBC 变得容易。有关JdbcTemplate 基础知识的介绍性教程,请参阅:Spring JDBC 模板简单示例。本教程通过演示如何在Spring MVC应用程序中集成JdbcTemplate来进一步。本教程中的示例应用程序管理如下所示的联系人列表:示例应用程序是使用以下软件/技术开发的(当然,您可以使用较新的版本):

- 爪哇 7
- 日食开普勒
- 弹簧框架 4.0
- JSTL 1.2
- MySQL 数据库 5.5
- 马文 3
1. 创建 MySQL 数据库
执行以下 MySQL 脚本以创建名为contactdb的数据库和一个名为contact 的表:
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create database contactdb;
CREATE TABLE `contact` (
`contact_id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(45) NOT NULL,
`email` varchar(45) NOT NULL,
`address` varchar(45) NOT NULL,
`telephone` varchar(45) NOT NULL,
PRIMARY KEY (`contact_id`)
) ENGINE=InnoDB AUTO_INCREMENT=25 DEFAULT CHARSET=utf8
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2. 在 Eclipse 中创建 Maven 项目
建议使用spring-mvc-archetype来创建项目(参见:在一分钟内使用 Maven 和 Eclipse 创建 Spring MVC 项目)。以下是项目的最终结构:

pom.xml文件中的以下 XML 部分用于向项目添加依赖项配置:
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<properties>
<java.version>1.7</java.version>
<spring.version>4.0.3.RELEASE</spring.version>
<cglib.version>2.2.2</cglib.version>
</properties>
<dependencies>
<!-- Spring core & mvc -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</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>${spring.version}</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<!-- CGLib for @Configuration -->
<dependency>
<groupId>cglib</groupId>
<artifactId>cglib-nodep</artifactId>
<version>${cglib.version}</version>
<scope>runtime</scope>
</dependency>
<!-- Servlet Spec -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>javax.servlet.jsp-api</artifactId>
<version>2.3.1</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>jstl</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
</dependencies>
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3. 编码模型类
模型类 -Contact.java- 非常简单:
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package net.codejava.spring.model;
public class Contact {
private int id;
private String name;
private String email;
private String address;
private String telephone;
public Contact() {
}
public Contact(String name, String email, String address, String telephone) {
this.name = name;
this.email = email;
this.address = address;
this.telephone = telephone;
}
// getters and setters
}
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此类只是将表联系人中的一行映射到普通的旧 Java 对象 (POJO) -Contact。
4. 编码 DAO 类
ContactDAO接口定义了对联系人表执行 CRUD 操作的方法:
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package net.codejava.spring.dao;
import java.util.List;
import net.codejava.spring.model.Contact;
/**
* Defines DAO operations for the contact model.
* @author www.codejava.net
*
*/
public interface ContactDAO {
public void saveOrUpdate(Contact contact);
public void delete(int contactId);
public Contact get(int contactId);
public List<Contact> list();
}
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这是一个实现 -ContactDAOImpl.java:
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package net.codejava.spring.dao;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
import javax.sql.DataSource;
import net.codejava.spring.model.Contact;
import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.ResultSetExtractor;
import org.springframework.jdbc.core.RowMapper;
/**
* An implementation of the ContactDAO interface.
* @author www.codejava.net
*
*/
public class ContactDAOImpl implements ContactDAO {
private JdbcTemplate jdbcTemplate;
public ContactDAOImpl(DataSource dataSource) {
jdbcTemplate = new JdbcTemplate(dataSource);
}
@Override
public void saveOrUpdate(Contact contact) {
// implementation details goes here...
}
@Override
public void delete(int contactId) {
// implementation details goes here...
}
@Override
public List<Contact> list() {
// implementation details goes here...
}
@Override
public Contact get(int contactId) {
// implementation details goes here...
}
}
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请注意声明JdbcTemplate的开头部分,并且通过构造函数注入数据源对象:
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private JdbcTemplate jdbcTemplate;
public ContactDAOImpl(DataSource dataSource) {
jdbcTemplate = new JdbcTemplate(dataSource);
}
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现在,让我们看一下每种方法的实现细节。插入或更新新联系人:
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public void saveOrUpdate(Contact contact) {
if (contact.getId() > 0) {
// update
String sql = "UPDATE contact SET name=?, email=?, address=?, "
+ "telephone=? WHERE contact_id=?";
jdbcTemplate.update(sql, contact.getName(), contact.getEmail(),
contact.getAddress(), contact.getTelephone(), contact.getId());
} else {
// insert
String sql = "INSERT INTO contact (name, email, address, telephone)"
+ " VALUES (?, ?, ?, ?)";
jdbcTemplate.update(sql, contact.getName(), contact.getEmail(),
contact.getAddress(), contact.getTelephone());
}
}
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请注意,如果联系人对象的 ID 大于零,请更新它;否则就是插入。注意:为了提高代码可读性,可以使用NamedParameterJdbcTemplate,而不是使用问号 (?) 作为占位符。您也可以使用SimpleJdbcInsert类,该类使用起来更方便。删除联系人:
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public void delete(int contactId) {
String sql = "DELETE FROM contact WHERE contact_id=?";
jdbcTemplate.update(sql, contactId);
}
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列出所有联系人:
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public List<Contact> list() {
String sql = "SELECT * FROM contact";
List<Contact> listContact = jdbcTemplate.query(sql, new RowMapper<Contact>() {
@Override
public Contact mapRow(ResultSet rs, int rowNum) throws SQLException {
Contact aContact = new Contact();
aContact.setId(rs.getInt("contact_id"));
aContact.setName(rs.getString("name"));
aContact.setEmail(rs.getString("email"));
aContact.setAddress(rs.getString("address"));
aContact.setTelephone(rs.getString("telephone"));
return aContact;
}
});
return listContact;
}
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请注意,使用RowMapper将结果集中的行映射到 POJO 对象。为了更方便,你可以像这样使用BeanPropertyRowMapper类:
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public List<Contact> list() {
String sql = "SELECT * FROM Contact";
return jdbcTemplate.query(sql, BeanPropertyRowMapper.newInstance(Contact.class));
}
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确保 Contact 类声明的字段名称与数据库表中的列名称完全匹配。使用BeanPropertyRowMapper更方便,但性能比使用RowMapper 慢。获取特定联系人:
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public Contact get(int contactId) {
String sql = "SELECT * FROM contact WHERE contact_id=" + contactId;
return jdbcTemplate.query(sql, new ResultSetExtractor<Contact>() {
@Override
public Contact extractData(ResultSet rs) throws SQLException,
DataAccessException {
if (rs.next()) {
Contact contact = new Contact();
contact.setId(rs.getInt("contact_id"));
contact.setName(rs.getString("name"));
contact.setEmail(rs.getString("email"));
contact.setAddress(rs.getString("address"));
contact.setTelephone(rs.getString("telephone"));
return contact;
}
return null;
}
});
}
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请注意使用ResultSetExtractor将单行提取为 POJO。你也可以像这样使用BeanPropertyRowMapper类:
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public Contact get(int contactId) {
String sql = "SELECT * FROM Contact WHERE id=" + contactId;
return jdbcTemplate.queryForObject(sql, BeanPropertyRowMapper.newInstance(Contact.class));
}
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它大大简化了代码,但换来的是性能降低。
5. 编码弹簧MVC配置
基于Java的类和注释用于配置这个Spring MVC应用程序。下面是MvcConfiguration类的代码:
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package net.codejava.spring.config;
import javax.sql.DataSource;
import net.codejava.spring.dao.ContactDAO;
import net.codejava.spring.dao.ContactDAOImpl;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
@Configuration
@ComponentScan(basePackages="net.codejava.spring")
@EnableWebMvc
public class MvcConfiguration extends WebMvcConfigurerAdapter{
@Bean
public ViewResolver getViewResolver(){
InternalResourceViewResolver resolver = new InternalResourceViewResolver();
resolver.setPrefix("/WEB-INF/views/");
resolver.setSuffix(".jsp");
return resolver;
}
@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
registry.addResourceHandler("/resources/**").addResourceLocations("/resources/");
}
@Bean
public DataSource getDataSource() {
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setDriverClassName("com.mysql.jdbc.Driver");
dataSource.setUrl("jdbc:mysql://localhost:3306/contactdb");
dataSource.setUsername("root");
dataSource.setPassword("P@ssw0rd");
return dataSource;
}
@Bean
public ContactDAO getContactDAO() {
return new ContactDAOImpl(getDataSource());
}
}
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请注意,getDataSource() 方法返回一个配置的数据源Bean。您可能需要根据您的环境更改数据库 URL、用户名和密码。getContactDAO()方法返回ContactDAO接口的实现,该接口是ContactDAOImpl类。此 Bean 将被注入到控制器类中,如下所述。
6. 配置 Spring MVC 调度程序 Servlet
要为我们的Java Web应用程序启用Spring MVC,请更新Web部署描述符文件(web.xml),如下所示:
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<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<display-name>SpringMvcJdbcTemplate</display-name>
<context-param>
<param-name>contextClass</param-name>
<param-value>
org.springframework.web.context.support.AnnotationConfigWebApplicationContext
</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<servlet>
<servlet-name>SpringDispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextClass</param-name>
<param-value>
org.springframework.web.context.support.AnnotationConfigWebApplicationContext
</param-value>
</init-param>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>net.codejava.spring</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>SpringDispatcher</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<session-config>
<session-timeout>30</session-timeout>
</session-config>
</web-app>
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7. 编码弹簧控制器类
HomeController类的框架:
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public class HomeController {
@Autowired
private ContactDAO contactDAO;
// handler methods go here...
}
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请注意,我们使用@Autowired注释让 Spring 自动将ContactDAO实现的实例注入到这个控制器中。每个处理程序方法都使用此contactDAO对象来执行必要的 CRUD 操作。让我们看看每种方法的实现细节。列出所有联系人的处理程序方法(也用作主页):
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@RequestMapping(value="/")
public ModelAndView listContact(ModelAndView model) throws IOException{
List<Contact> listContact = contactDAO.list();
model.addObject("listContact", listContact);
model.setViewName("home");
return model;
}
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显示新联系人表单的处理程序方法:
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@RequestMapping(value = "/newContact", method = RequestMethod.GET)
public ModelAndView newContact(ModelAndView model) {
Contact newContact = new Contact();
model.addObject("contact", newContact);
model.setViewName("ContactForm");
return model;
}
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插入/更新联系人的处理程序方法:
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@RequestMapping(value = "/saveContact", method = RequestMethod.POST)
public ModelAndView saveContact(@ModelAttribute Contact contact) {
contactDAO.saveOrUpdate(contact);
return new ModelAndView("redirect:/");
}
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删除联系人的处理程序方法:
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@RequestMapping(value = "/deleteContact", method = RequestMethod.GET)
public ModelAndView deleteContact(HttpServletRequest request) {
int contactId = Integer.parseInt(request.getParameter("id"));
contactDAO.delete(contactId);
return new ModelAndView("redirect:/");
}
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用于检索特定联系人的详细信息以进行编辑的处理程序方法:
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@RequestMapping(value = "/editContact", method = RequestMethod.GET)
public ModelAndView editContact(HttpServletRequest request) {
int contactId = Integer.parseInt(request.getParameter("id"));
Contact contact = contactDAO.get(contactId);
ModelAndView model = new ModelAndView("ContactForm");
model.addObject("contact", contact);
return model;
}
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8. 编码联系人列表页面(主页)
以下是主页.jsp页面的源代码,其中显示联系人列表以及用于创建新联系人、编辑和删除联系人的操作链接。
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<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Contact Manager Home</title>
</head>
<body>
<div align="center">
<h1>Contact List</h1>
<h3><a href="/newContact">New Contact</a></h3>
<table border="1">
<th>No</th>
<th>Name</th>
<th>Email</th>
<th>Address</th>
<th>Telephone</th>
<th>Action</th>
<c:forEach var="contact" items="${listContact}" varStatus="status">
<tr>
<td>${status.index + 1}</td>
<td>${contact.name}</td>
<td>${contact.email}</td>
<td>${contact.address}</td>
<td>${contact.telephone}</td>
<td>
<a href="/editContact?id=${contact.id}">Edit</a>
<a href="/deleteContact?id=${contact.id}">Delete</a>
</td>
</tr>
</c:forEach>
</table>
</div>
</body>
</html>
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请注意,此 JSP 页使用 JSTL 和 EL 表达式。
9. 编码联系表格页面
联系人表单页面 (ContactForm.jsp) 显示用于创建新联系人或更新旧联系人的详细信息。这是它的完整源代码:
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<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>New/Edit Contact</title>
</head>
<body>
<div align="center">
<h1>New/Edit Contact</h1>
<form:form action="saveContact" method="post" modelAttribute="contact">
<table>
<form:hidden path="id"/>
<tr>
<td>Name:</td>
<td><form:input path="name" /></td>
</tr>
<tr>
<td>Email:</td>
<td><form:input path="email" /></td>
</tr>
<tr>
<td>Address:</td>
<td><form:input path="address" /></td>
</tr>
<tr>
<td>Telephone:</td>
<td><form:input path="telephone" /></td>
</tr>
<tr>
<td colspan="2" align="center"><input type="submit" value="Save"></td>
</tr>
</table>
</form:form>
</div>
</body>
</html>
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请注意,此 JSP 页使用 Spring 窗体标记将窗体的值绑定到模型对象。要测试应用程序,您可以在方便时下载 Eclipse 项目或部署附加的 WAR 文件。
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| [可部署的 WAR 文件] | 5521 千字节 |
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| [Eclipse-Maven 项目] | 27 千字节 |


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