spring dao之jdbc
spring提供的dao(数据访问对象)支持主要的目的是便于以标准的方式使用不同的数据访问技术， 如jdbc，hibernate或者jdo等。它不仅可以让你方便地在这些持久化技术间切换， 而且让你在编码的时候不用考虑处理各种技术中特定的异常。
为了便于以一种一致的方式使用各种数据访问技术，如jdbc、jdo和hibernate， spring提供了一套抽象dao类供你扩展。这些抽象类提供了一些方法，通过它们你可以 获得与你当前使用的数据访问技术相关的数据源和其他配置信息。
dao支持类：
jdbcdaosupport - jdbc数据访问对象的基类。 需要一个datasource，同时为子类提供 jdbctemplate。
hibernatedaosupport - hibernate数据访问对象的基类。 需要一个sessionfactory，同时为子类提供 hibernatetemplate。也可以选择直接通过 提供一个hibernatetemplate来初始化， 这样就可以重用后者的设置，例如sessionfactory， flush模式，异常翻译器（exception translator）等等。
jdodaosupport - jdo数据访问对象的基类。 需要设置一个persistencemanagerfactory， 同时为子类提供jdotemplate。
jpadaosupport - jpa数据访问对象的基类。 需要一个entitymanagerfactory，同时 为子类提供jpatemplate。
本节主要讨论sping对jdbcdaosupport的支持。
下面是个例子：
drop table if exists user; /*==============================================================*/ /* table: user */ /*==============================================================*/ create table user ( id bigint auto_increment not null, name varchar(24), age int, primary key (id) );
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public class user {
private integer id;
private string name;
private integer age;
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;
}
}
/**
* created by intellij idea.<br>
* <b>user</b>: leizhimin<br>
* <b>date</b>: 2008-4-22 15:34:36<br>
* <b>note</b>: dao接口
*/
public interface iuserdao {
public void insert(user user);
public user find(integer id);
}
import javax.sql.datasource;
import java.sql.connection;
import java.sql.sqlexception;
/**
* created by intellij idea.<br>
* <b>note</b>: 基类dao，提供了数据源注入
*/
public class basedao {
private datasource datasource;
public datasource getdatasource() {
return datasource;
}
public void setdatasource(datasource datasource) {
this.datasource = datasource;
}
public connection getconnection() {
connection conn = null;
try {
conn = datasource.getconnection();
} catch (sqlexception e) {
e.printstacktrace();
}
return conn;
}
}
/**
* created by intellij idea.<br>
* <b>user</b>: leizhimin<br>
* <b>date</b>: 2008-4-22 15:36:04<br>
* <b>note</b>: dao实现
*/
public class userdao extends basedao implements iuserdao {
public jdbctemplate getjdbctemplate(){
return new jdbctemplate(getdatasource());
}
public void insert(user user) {
string name = user.getname();
int age = user.getage().intvalue();
// jdbctemplate.update("insert into user (name,age) "
// + "values('" + name + "'," + age + ")");
string sql = "insert into user(name,age) values(?,?)";
getjdbctemplate().update(sql,new object[]{name,age});
}
public user find(integer id) {
list rows = getjdbctemplate().queryforlist(
"select * from user where id=" + id.intvalue());
iterator it = rows.iterator();
if (it.hasnext()) {
map usermap = (map) it.next();
integer i = new integer(usermap.get("id").tostring());
string name = usermap.get("name").tostring();
integer age = new integer(usermap.get("age").tostring());
user user = new user();
user.setid(i);
user.setname(name);
user.setage(age);
return user;
}
return null;
}
}
<?xml version="1.0" encoding="utf-8"?>
<!doctype beans public "-//spring/dtd bean/en"
"http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
<bean id="datasource"
class="org.apache.commons.dbcp.basicdatasource" singleton="true">
<property name="driverclassname">
<value>com.mysql.jdbc.driver</value>
</property>
<property name="url">
<value>jdbc:mysql://localhost:3306/springdb</value>
</property>
<property name="username">
<value>root</value>
</property>
<property name="password">
<value>leizhimin</value>
</property>
</bean>
<bean id="basedao" class="com.lavasoft.springnote.ch05_jdbc03_temp.basedao" abstract="true">
<property name="datasource">
<ref bean="datasource"/>
</property>
</bean>
<bean id="userdao"
class="com.lavasoft.springnote.ch05_jdbc03_temp.userdao" parent="basedao">
</bean>
</beans>
import org.springframework.context.applicationcontext;
import org.springframework.context.support.filesystemxmlapplicationcontext;
/**
* created by intellij idea.<br>
* <b>user</b>: leizhimin<br>
* <b>date</b>: 2008-4-22 15:59:18<br>
* <b>note</b>: 测试类，客户端
*/
public class springdaodemo {
public static void main(string[] args) {
applicationcontext context = new filesystemxmlapplicationcontext("d:\\_spring\\src\\com\\lavasoft\\springnote\\ch05_jdbc03_temp\\bean-jdbc-temp.xml");
user user = new user();
user.setname("hahhahah");
user.setage(new integer(22));
iuserdao userdao = (iuserdao) context.getbean("userdao");
userdao.insert(user);
user = userdao.find(new integer(1));
system.out.println("name: " + user.getname());
}
}
运行结果：
log4j:warn no appenders could be found for logger (org.springframework.core.collectionfactory). log4j:warn please initialize the log4j system properly. name: jdbctemplate process finished with exit code 0
spring dao之hibernate
hibernatedaosupport - hibernate数据访问对象的基类。 需要一个sessionfactory，同时为子类提供 hibernatetemplate。也可以选择直接通过 提供一个hibernatetemplate来初始化， 这样就可以重用后者的设置，例如sessionfactory， flush模式，异常翻译器（exception translator）等等。
本节主要讨论sping对hibernatetemplate的支持。
下面是个例子：
drop table if exists user; /*==============================================================*/ /* table: user */ /*==============================================================*/ create table user ( id bigint auto_increment not null, name varchar(24), age int, primary key (id) );
/**
* created by intellij idea.<br>
* <b>note</b>: hiberante实体类
*/
public class user {
private integer id;
private string name;
private integer age;
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;
}
}
<?xml version="1.0" encoding="utf-8"?>
<!doctype hibernate-mapping
public "-//hibernate/hibernate mapping dtd 3.0//en"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="com.lavasoft.springnote.ch06_hbm_02detx.user"
table="user">
<id name="id" column="id">
<generator class="native"/>
</id>
<property name="name" column="name"/>
<property name="age" column="age"/>
</class>
</hibernate-mapping>
/**
* created by intellij idea.<br>
* <b>user</b>: leizhimin<br>
* <b>date</b>: 2008-4-23 15:37:43<br>
* <b>note</b>: dao接口
*/
public interface iuserdao {
public void insert(user user);
public user find(integer id);
}
import org.hibernate.sessionfactory;
import org.springframework.orm.hibernate3.hibernatetemplate;
/**
* created by intellij idea.<br>
* <b>user</b>: leizhimin<br>
* <b>date</b>: 2008-4-23 15:15:55<br>
* <b>note</b>: dao实现
*/
public class userdao implements iuserdao {
private hibernatetemplate hibernatetemplate;
public void setsessionfactory(sessionfactory sessionfactory) {
this.hibernatetemplate =new hibernatetemplate(sessionfactory);
}
public void insert(user user) {
hibernatetemplate.save(user);
system.out.println("所保存的user对象的id:"+user.getid());
}
public user find(integer id) {
user user =(user) hibernatetemplate.get(user.class, id);
return user;
}
}
<?xml version="1.0" encoding="utf-8"?>
<!doctype beans public "-//spring/dtd bean/en"
"http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
<bean id="datasource"
class="org.springframework.jdbc.datasource.drivermanagerdatasource">
<property name="driverclassname">
<value>com.mysql.jdbc.driver</value>
</property>
<property name="url">
<value>jdbc:mysql://localhost:3306/springdb</value>
</property>
<property name="username">
<value>root</value>
</property>
<property name="password">
<value>leizhimin</value>
</property>
</bean>
<bean id="sessionfactory"
class="org.springframework.orm.hibernate3.localsessionfactorybean"
destroy-method="close">
<property name="datasource">
<ref bean="datasource"/>
</property>
<property name="mappingresources">
<list>
<value>com/lavasoft/springnote/ch06_hbm_02protx/user.hbm.xml</value>
</list>
</property>
<property name="hibernateproperties">
<props>
<prop key="hibernate.dialect">
org.hibernate.dialect.mysqldialect
</prop>
</props>
</property>
</bean>
<bean id="userdao" class="com.lavasoft.springnote.ch06_hbm_02protx.userdao">
<property name="sessionfactory">
<ref bean="sessionfactory"/>
</property>
</bean>
</beans>
import org.springframework.context.applicationcontext;
import org.springframework.context.support.filesystemxmlapplicationcontext;
/**
* created by intellij idea.<br>
* <b>note</b>: 测试类、客户端
*/
public class springhibernatedemo {
public static void main(string[] args) {
applicationcontext context =new filesystemxmlapplicationcontext("d:\\_spring\\src\\com\\lavasoft\\springnote\\ch06_hbm_02protx\\bean-hbm_tx.xml");
// 建立dao物件
iuserdao userdao = (iuserdao) context.getbean("userdao");
user user = new user();
user.setname("caterpillar");
user.setage(new integer(30));
userdao.insert(user);
user = userdao.find(new integer(1));
system.out.println("name: " + user.getname());
}
}
运行结果：
log4j:warn no appenders could be found for logger (org.springframework.core.collectionfactory). log4j:warn please initialize the log4j system properly. 所保存的user对象的id:18 name: jdbctemplate process finished with exit code 0
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