Java学习之道：org.springframework.jdbc.core.JdbcTemplate

古城微笑少年丶 2021-09-30 01:30 286阅读 0赞

先看applicationContext.xml配置文件：   
  
  
<?xml version="1.0" encoding="UTF-8"?>   
<beans xmlns="http://www.springframework.org/schema/beans"   
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">   
  
    <bean id="springDSN"   
        class="org.springframework.jdbc.datasource.DriverManagerDataSource">   
        <property name="driverClassName"   
            value="com.microsoft.jdbc.sqlserver.SQLServerDriver">   
        </property>   
        <property name="url"   
            value="jdbc:microsoft:sqlserver://localhost:1433;databasename=bbs">   
        </property>   
        <property name="username" value="sa"></property>   
        <property name="password" value="sa"></property>   
    </bean>   
  
    <bean id="jdbcTemplate"   
        class="org.springframework.jdbc.core.JdbcTemplate" abstract="false"   
        lazy-init="false" autowire="default" dependency-check="default">   
        <property name="dataSource">   
            <ref bean="springDSN" />   
        </property>   
    </bean>   
</beans>    
  
在看SpringUtil类   
  
  
package com.r.dao;   
  
import org.springframework.context.ApplicationContext;   
import org.springframework.context.support.ClassPathXmlApplicationContext;   
  
  
public final class SpringUtil \{   
  
    private static ApplicationContext  ctx = new ClassPathXmlApplicationContext("applicationContext.xml");   
      
    public static Object getBean(String beanName)\{   
         return ctx.getBean(beanName);   
    \}      
\}    
  
  
  
  
  
最后看DAO:   
  
  
import java.math.BigDecimal;   
import java.util.ArrayList;   
import java.util.Iterator;   
import java.util.List;   
import java.util.Map;   
  
import org.springframework.jdbc.core.JdbcTemplate;   
  
import com.r.vo.Book;   
  
public class BookDao \{   
  
    private JdbcTemplate jdbcT = (JdbcTemplate) SpringUtil   
            .getBean("jdbcTemplate");   
  
    public List findALL() \{   
        String sql = "select \* from BookInfo";   
        return jdbcT.queryForList(sql);          
    \}   
  
    public List<Book> findALLBooks() \{   
        List<Book> books = new ArrayList<Book>();;   
        String sql = "select \* from BookInfo";   
        List list = jdbcT.queryForList(sql);   
        Iterator iterator = list.iterator();   
        Book book = null;   
        while (iterator.hasNext()) \{   
            Map map4book = (Map) iterator.next();   
            book = new Book();   
            book.setBid((Integer) map4book.get("bid"));   
            book.setBookName((String)map4book.get("bookName"));   
            book.setBookType((String)map4book.get("bookType"));          
            book.setBookPic(((BigDecimal)map4book.get("bookPic")).doubleValue() );              
            book.setCount((Integer) map4book.get("count"));   
            books.add(book);   
        \}   
        return books;   
    \}      
    public int delete(int bid)\{   
        String sql = "delete from BookInfo where bid =?";   
        return jdbcT.update(sql, new Object\[\]\{bid\});   
    \}       
    public static void main(String\[\] args) \{          
        List<Book> books = new BookDao().findALLBooks();;   
        for(Book book:books)\{   
            System.out.println(book.getBid()+","+book.getBookName()+","+book.getBookType());   
        \}   
    \}   
\}    
  
  
  
细心你，会发现JdbcTemplate的实例中有一系列的方法如：queryForXXX,update,delete大大简化了JDBC操作。   
  
当然,还可以再进一步的优化一下,就是通过依赖注入，直接把jdbcTemplate注入到dao类的jdbcT字段。