用springmvc和hibernate实现简单增删改查

      前段时间学习了下springmvc+hibernate.用这个框架实现了增删改查，想把学习的东西贴出来，和大家一起交流。由于之前没有学过什么框架之类的东西，在学习时遇到了很多困难，学的也很慢。

      我学先看的是hibernate，hibernate主要是用在数据持久层，用来把数据持久化，建立java实体bean与数据库中表的对应。利用hibernate操作数据库时就有很多封装好了的方法，很方便调用。再学的是spring，知道它是作为一个容器在使用，以及ioc和aop，不过我这里基本没有用到aop，没有涉及到切面的编程。在学springmvc时，以为它就是spring，根本没有想这是一个基于MVC的框架，框架这东西之前我是一直都不理解。后来靠给我讲了下，这个框架里面最重要的就是分层，它的模型层就是与数据库打交道的，控制层是不与数据打交道的，是在业务层的基础上进行控制，而业务层是实现模型层的一些方法，最后是用视图层进行显示，搞清楚逻辑关系是很重要的。

直接贴代码：

实体类：student.java

package com.xl.entity;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.SequenceGenerator;
import javax.persistence.Table;

@Entity
@Table(name="student")
public class Student {
	@Id
	@SequenceGenerator(name="seq_student",sequenceName="seq_student")
	@GeneratedValue(strategy=GenerationType.SEQUENCE,generator="seq_student")
	@Column(length=20)
	private Integer id;
	@Column(length=50)
	private String name;
	@Column(length=20)
	private Integer age;
	@Column(length=50)
	private String course;
	
	public Student(){}
	public Student(Integer id,String name,String course,Integer age){
		this.id=id;
		this.age=age;
		this.name=name;
		this.course=course;
	}
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public Integer getAge() {
		return age;
	}
	public void setAge(Integer age) {
		this.age = age;
	}
	public String getCourse() {
		return course;
	}
	public void setCourse(String course) {
		this.course = course;
	}

}

 IStudentDao.java

package com.xl.dao;

import java.util.List;

import com.xl.entity.Student;

public interface IStudentDao {
	public void addStudent(Student stu);

	public List<Student> getAllStudents();

	public Student getStudentById(Integer id);

	public void delStudent(Integer id);

	public void update(Student stu);
}

 StudentService.java

package com.xl.service;

import java.util.List;

import javax.annotation.Resource;

import org.hibernate.SessionFactory;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import com.xl.dao.IStudentDao;
import com.xl.entity.Student;
@Service
@Transactional
public class StudentService implements IStudentDao {

	@Resource 
	private SessionFactory sessionFactory;
	
	
	public void addStudent(Student stu) {
		sessionFactory.getCurrentSession().persist(stu);
	}

	@SuppressWarnings("unchecked")
	public List<Student> getAllStudents() {
		return sessionFactory.getCurrentSession().createQuery("from Student order by id").list();
	}

	public Student getStudentById(Integer id) {
		return (Student) sessionFactory.getCurrentSession().get(Student.class, id);
	}

	public void delStudent(Integer id) {
		sessionFactory.getCurrentSession().delete(sessionFactory.getCurrentSession().load(Student.class, id));
	}

	public void update(Student stu) {
		sessionFactory.getCurrentSession().update(stu);
	}

}

 StudentController.java

package com.xl.controller;

import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.util.List;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;

import com.xl.dao.IStudentDao;
import com.xl.entity.Student;
@Controller
@RequestMapping("/student")
public class StudentController {
	@Resource 
	private IStudentDao studentService;
	
	/**
	 * 获取学生列表 在首页显示
	 * @param req
	 * @param rep
	 * @return
	 */
	@RequestMapping("/stu")
	public String tostu(HttpServletRequest req,HttpServletResponse rep){
		List<Student> students=studentService.getAllStudents();
		req.setAttribute("studentlist", students);
		return "stu";
	}
	/**
	 * 根据获取的id删除对应的学生信息
	 * @param req
	 * @param rep
	 * @param id
	 * @return
	 */
	@RequestMapping("/del")
	public String del(HttpServletRequest req,HttpServletResponse rep,Integer id){
		studentService.delStudent(id);
		List<Student> students=studentService.getAllStudents();
		req.setAttribute("studentlist", students);
		return "stu";
	}
	/**
	 * 在增加学生信息时候 这里要注意编码
	 * 要先判断名字，年龄是否为空。也可以用ajax,对于更新就不是用这方法
	 * @param name
	 * @param age
	 * @param course
	 * @param req
	 * @param rep
	 * @return
	 */
	@RequestMapping("/add")
	public String add(String name,Integer age,String course,
			HttpServletRequest req,HttpServletResponse rep){
		try {
			rep.setContentType("text/html;charset=utf-8");			
			Student student=null;
			student = new Student(null,URLDecoder.decode(name,"utf-8"),URLDecoder.decode(course,"utf-8"),age);			
			
			studentService.addStudent(student);
			List<Student> students=studentService.getAllStudents();
			req.setAttribute("studentlist", students);
			return "stu";
			//printWriter.write("qq".getBytes());
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}

	}
	/**
	 * 根据传来的id取出student在页面中显示出来，与update分开
	 * @param req
	 * @param id
	 * @return
	 */
	@RequestMapping("/toUpdate")
	public String toUpdate(HttpServletRequest req,Integer id){
			//查找要更新的数据
		    Student student=studentService.getStudentById(id);
		   //放入作用域
			req.setAttribute("student", student);
			return "update";
	}
	
	/**
	 * 类似于删除，根据传来的student。直接用StudentService里的update方法更新
	 * @param student
	 * @param req
	 * @param rep
	 */

	@RequestMapping("/update")
	public String update(Student student,HttpServletRequest req,HttpServletResponse rep){
		try{
			System.out.println("12121212");
			rep.setContentType("text/html;charset=utf-8");
			Student newstudent=null;
			newstudent=new Student(student.getId(),URLDecoder.decode(student.getName(),"utf-8"),
					URLDecoder.decode(student.getCourse(),"utf-8"),student.getAge());
			studentService.update(newstudent);
			
			List<Student> students=studentService.getAllStudents();
			req.setAttribute("studentlist", students);
			return "stu";
		}catch(Exception e){
			e.printStackTrace();
			return null;
		}
	}
}

 配置文件

beans.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" 
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
       xmlns:context="http://www.springframework.org/schema/context" 
       xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="
						http://www.springframework.org/schema/beans
						http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
						http://www.springframework.org/schema/context
						http://www.springframework.org/schema/context/spring-context-3.2.xsd
						http://www.springframework.org/schema/tx 
						http://www.springframework.org/schema/tx/spring-tx-3.2.xsd"
>
  
  <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
	<property name="driverClass" value="oracle.jdbc.driver.OracleDriver"></property>
	<property name="jdbcUrl" value="jdbc:oracle:thin:@localhost:1521:orcl"/>
	<property name="user" value="scott"/>
	<property name="password" value="xuli"/>
	<property name="initialPoolSize" value="5"></property>
	<property name="minPoolSize" value="5"></property>
	<property name="maxPoolSize" value="15"/>
	<property name="checkoutTimeout" value="1000"/> 	
</bean>
<!-- 配置sessionfactory -->
<bean id="sessionFactory"  class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
       <property name="dataSource" ref="dataSource"/>     
       <property name="hibernateProperties">
		    <value>
		        hibernate.dialect=org.hibernate.dialect.OracleDialect
		        hibernate.hbm2ddl.auto=update
		        hibernate.show_sql=true
		        hibernate.format_sql=false		              	   
		      </value>
	     </property>
	     <property name="configLocations">
	       <list>
	         <value>
	           classpath*:config/hibernate.cfg.xml	         
	         </value>	       
	       </list>     
	     </property>
</bean>     
    <!-- 配置事务管理器 -->
<bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager">
    <property name="sessionFactory" ref="sessionFactory" />
</bean>

<tx:annotation-driven transaction-manager="transactionManager"/>
	<!-- 自动扫描(自动注入) -->
<context:component-scan base-package="com.xl" />

</beans>

 hibernate.hbm.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
		"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
		"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
   <session-factory>   
      <mapping class="com.xl.entity.Student"/>
   </session-factory>
    
</hibernate-configuration>

Springmvc-servlet.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans 
http://www.springframework.org/schema/beans/spring-beans-3.2.xsd 
http://www.springframework.org/schema/context 
http://www.springframework.org/schema/context/spring-context-3.2.xsd 
http://www.springframework.org/schema/mvc 
http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd">

	<!-- 自动扫描controller包下的所有类，使其认为spring mvc的控制器 -->
	<context:component-scan base-package="com.xl.controller" />	
	<!-- 对模型视图名称的解析，即在模型视图名称添加前后缀 -->
	<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" 
	p:prefix="/" p:suffix=".jsp" />
</beans>

 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" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
  <display-name>zx</display-name>
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath*:config/beans.xml</param-value>
  </context-param>
  <listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>
  <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*:config/Springmvc-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>
  <filter>
    <filter-name>openSessionInViewFilter</filter-name>
    <filter-class>org.springframework.orm.hibernate4.support.OpenSessionInViewFilter</filter-class>
    <init-param>
      <param-name>singleSession</param-name>
      <param-value>true</param-value>
    </init-param>
  </filter>
  <filter-mapping>
    <filter-name>openSessionInViewFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>
  
  <filter>
       <filter-name>characterEncodingFilter</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>characterEncodingFilter</filter-name>
      <url-pattern>/*</url-pattern>
 </filter-mapping>
</web-app>

      最后的效果是：

      在学习过程中也遇到很多低级的问题，如果是像我这样的新手的话，刚开始可能都会遇到，第一个就是jar包问题，我在前面几天调试的时候经常报的错就是jar包冲突或是缺少jar包，第二个就是配置文件的问题，总是搞不清楚怎么配，只是去复制粘贴别人的配置文件，自己又不是很懂，刚开始时程序都跑不起来。再有的一些问题基本就是一些细节性的问题，比如编码问题等。

      只是很简单的一个实现，像分页，插入日志等都没有做，我也不是很会，还在继续学习中，水平有限，还望轻喷。