1) 搭建數據庫環境
1、安裝數據庫(MySQL 5.0.24), 用戶: root,密碼: (空) 。2、建庫piscesdb。
3、建表address:
create table address (
addressID int not null,
city varchar(55) not null,
street varchar(55) NOT NULL,
zip varchar(8) NOT NULL,
PRIMARY KEY (addressID)
);
insert into address values (1, "深圳", "坂田市場", "518001");
insert into address values (2, "深圳", "坂田路口", "518002");
insert into address values (3, "深圳", "四季花城", "518003");
4、建表userinfo:
create table userinfo (
userID int not null, /** 用戶id */
username varchar(20) not null, /** 姓名 */
birthday datetime null, /** 出生日期 */
sex varchar(8) not null, /** 性別 */
addressID int not null, /** 地址id */
PRIMARY KEY (userID)
);
insert into userinfo values (1, "張金雄", null, "male", 1);
insert into userinfo values (2, "李某某", null, "male", 2);
insert into userinfo values (3, "王某某", '2006-08-10', "female", 3);
insert into userinfo values (4, "陳某某", '2006-08-12', "male", 3);
2) 獲取額外的jar包
下載JPA的實現類, 去https://glassfish.dev.java.net/downloads/persistence/JavaPersistence.html下載GlassFish v1 FCS branch版本,進行安裝後得到toplink-essentials.jar,toplink-essentials-agent.jar 兩個包,將這兩個包和mysql的驅動包加入到項目的classpath路徑中去。
3) 開發環境
JDK: jdk 6.0 beta2 (JDK 5.0 也可以)IDE: NetBeans 5.0 中文版
二、開發
1) 創建實體Entity類
1、地址類 Address :* Address.java
*/
package org.pisces.persist;
import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
/**
*
* @author kamhung
*/
@Entity
public class Address implements Serializable {
//地址id, 不能爲空, 必須唯一
@Id
@Column(name = "addressid", unique=true, nullable=false)
private int addressid;
//城市, 不能爲空
@Column(name = "city", nullable=false)
private String city;
//街道, 不能爲空
@Column(name = "street", nullable=false)
private String street;
//郵政編碼, 不能爲空
@Column(name = "zip", nullable=false)
private String zip;
public Address() {
}
public Address(int addressid) {
this.setAddressid(addressid);
}
public int getAddressid() {
return this.addressid;
}
public void setAddressid(int addressid) {
this.addressid = addressid;
}
public String getCity() {
return this.city;
}
public void setCity(String city) {
this.city = city;
}
public String getStreet() {
return street;
}
public void setStreet(String street) {
this.street = street;
}
public String getZip() {
return this.zip;
}
public void setZip(String zip) {
this.zip = zip;
}
@Override
public int hashCode() {
return this.addressid;
}
@Override
public boolean equals(Object object) {
if (!(object instanceof Address)) return false;
final Address other = (Address)object;
return this.addressid == other.addressid;
}
@Override
public String toString() {
return "Address[addressid=" + getAddressid() + ", city='" + getCity() + "', street='" + getStreet() + "', zip='" + getZip() +"']";
}
}
2、用戶類 UserInfo:
* UserInfo2.java
*/
package org.pisces.persist;
import java.io.Serializable;
import java.sql.Timestamp;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;
import static javax.persistence.CascadeType.*;
/**
*
* @author kamhung
*/
@Entity
public class UserInfo implements Serializable {
//用戶id, 不能爲空, 必須唯一
@Id
@Column(name = "userid", unique=true, nullable=false)
private int userid;
//用戶名, 不能爲空
@Column(name = "userName", nullable=false)
private String userName;
//性別, 不能爲空
@Column(name = "sex", nullable=false)
private String sex;
//出生日期, 可以爲空
@Column(name = "birthday")
private Timestamp birthday;
//地址, 不能爲空
//PERSIST 表示更新、新增UserInfo數據時會同時更新、新增Address的數據
//REMOVE 表示從數據庫刪除UserInfo會同時刪除Address表中對應的數據
@OneToOne(cascade={PERSIST, REMOVE})
@JoinColumn(name = "addressID", nullable=false)
private Address address;
public UserInfo() {
}
public UserInfo(int userid) {
this.setUserid(userid);
}
@Override
public int hashCode() {
return this.getUserid();
}
@Override
public boolean equals(Object object) {
if (!(object instanceof UserInfo)) return false;
final UserInfo other = (UserInfo)object;
return this.userid == other.userid;
}
@Override
public String toString() {
return "UserInfo[userid=" + this.userid + ", userName='" + userName + "', sex='" + sex
+ "', birthday=" + birthday + ", address=" + address + "]";
}
public int getUserid() {
return userid;
}
public void setUserid(int userid) {
this.userid = userid;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public Timestamp getBirthday() {
return birthday;
}
public void setBirthday(Timestamp birthday) {
this.birthday = birthday;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
}
2) 創建配置文件persistence.xml
在項目src文件夾下創建一個META-INF文件夾(有就不用創建了), META-INF文件夾下建一個persistence.xml文件, 內容爲:<persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
<!-- transaction-type 可選值有: JTA、RESOURCE_LOCAL ;
在Java EE 環境下默認值爲JTA, 在Java SE 環境下默認值爲RESOURCE_LOCAL;
如果值爲JTA的話, 則必須要指定<jta-data-source>的值 -->
<persistence-unit name="piscesPU" transaction-type="RESOURCE_LOCAL">
<description>這是piscesPU持久化單元的一個簡單描述</description>
<!-- 指明javax.persistence.spi.PersistenceProvider 的實現類, 一般來說該節點可以省略 -->
<provider>oracle.toplink.essentials.ejb.cmp3.EntityManagerFactoryProvider</provider>
<!-- 在Java SE環境下必須定義所有的實體Entity類, 也可以用 <mapping-file> 或<jar-file> 節點代替 -->
<class>org.pisces.persist.UserInfo</class>
<!--
//可以定義jndi資源代替properties節點中的數據庫配置,
//但是在調用Persistence.createEntityManagerFactory方法前必須保證此資源已經注入程序中.
<jta-data-source>jdbc/persist</jta-data-source>
-->
<!-- properties節點是用來定義各種JPA實現包所定義的屬性配置 -->
<!-- 下面列舉的是toplink實現包中可以配置的部分屬性 -->
<properties>
<!-- 數據庫連接配置, JDBC驅動 -->
<property name="toplink.jdbc.driver" value="com.mysql.jdbc.Driver"/>
<!-- 數據庫連接配置,URL -->
<property name="toplink.jdbc.url" value="jdbc:mysql://localhost:3306/piscesdb"/>
<!-- 數據庫連接配置, 用戶名 -->
<property name="toplink.jdbc.user" value="root"/>
<!-- 數據庫連接配置, 密碼 -->
<property name="toplink.jdbc.password" value=""/>
<!-- 數據庫連接池配置, 可寫的連接池的最大連接數, 默認爲 10 -->
<property name="toplink.jdbc.write-connections.max" value="10"/>
<!-- 數據庫連接池配置, 可寫的連接池的最大連接數, 默認爲 5 -->
<property name="toplink.jdbc.write-connections.min" value="5"/>
<!-- 數據庫連接池配置, 只讀的連接池的最大連接數, 默認爲 2 -->
<property name="toplink.jdbc.read-connections.max" value="2"/>
<!-- 數據庫連接池配置, 只讀的連接池的最大連接數, 默認爲 2 -->
<property name="toplink.jdbc.read-connections.min" value="2"/>
<!-- 數據庫連接池配置, 只讀的連接池是否可以共享, 默認爲 false -->
<property name="toplink.jdbc.read-connections.shared" value="false"/>
<!-- 是否綁定所有jdbc屬性, 默認爲 true -->
<property name="toplink.jdbc.bind-parameters" value="true"/>
<!-- 緩衝配置, 以下三個屬性值爲默認設置;
可以 default改爲entity名(@Entity註釋中的name屬性值)或者類名來指定該entity的緩衝配置, 如:
<property name="toplink.cache.size.org.pisces.persist.UserInfo" value="2"/>
<property name="toplink.cache.type.org.pisces.persist.UserInfo" value="SoftWeak"/>
<property name="toplink.cache.shared.org.pisces.persist.UserInfo" value="true"/>
-->
<property name="toplink.cache.size.org.pisces.persist.UserInfo" value="2"/>
<!-- 緩衝配置, 緩衝大小, 默認爲 1000 -->
<property name="toplink.cache.size.default" value="1000"/>
<!-- 緩衝配置, 緩衝類型, 可選值爲{ Weak、SoftWeak、HardWeak、Full、NONE }, 不區分大小, 默認爲 SoftWeak -->
<property name="toplink.cache.type.default" value="SoftWeak"/>
<!-- 緩衝配置, 是否共享緩衝, 默認爲 false -->
<property name="toplink.cache.shared.default" value="false"/>
<!-- 日誌配置, 日誌級別, 默認值爲java.util.logging.Level在系統中的值 -->
<property name="toplink.logging.level" value="SEVERE"/>
<!-- 日誌配置, 日誌是否記錄當前時間, 默認爲 true -->
<property name="toplink.logging.timestamp" value="true"/>
<!-- 日誌配置, 日誌是否記錄當前線程名, 默認爲 true -->
<property name="toplink.logging.thread" value="true"/>
<!-- 日誌配置, 日誌是否記錄當前會話名, 默認爲 true -->
<property name="toplink.logging.session" value="true"/>
<!-- 日誌配置, 日誌是否記錄異常堆棧, 默認爲 true -->
<property name="toplink.logging.exceptions" value="true"/>
<!-- 目標數據庫類型, 截至目前爲止可選值爲{ Auto、Oracle、Attunity、Cloudscape、Database、DB2、DB2Mainframe
、 DBase、Derby、HSQL、Informix、JavaDB、MySQL4、PostgreSQL、SQLAnyWhere、 SQLServer、Sybase、TimesTen },
不區分大小, 默認爲 Auto, 即 TopLink自動匹配對應的數據庫類型 -->
<property name="toplink.target-database" value="Auto"/>
<!-- 指定會話名稱, 默認爲系統自動產生唯一性名稱-->
<property name="toplink.session-name" value="pisces_session_name"/>
<!-- 設置是否爲weaving, 默認爲 true -->
<property name="toplink.weaving" value="true"/>
<!-- 指定目標應用服務器類型, 截至目前爲止可選值爲{ None、OC4J_10_1_3、SunAS9 }(以後可能會擴展其他值的),
在 Java SE環境下值爲 None, 不區分大小, 默認爲 None -->
<property name="toplink.target-server" value="None"/>
<!-- 指定實現 oracle.toplink.essentials.tools.sessionconfiguration.DescriptorCustomizer 的類名,
toplink.descriptor.customizer. 爲前綴, 後面跟entity名(@Entity註釋中的name屬性值)或者entity類名,
該類中的customize方法在執行 了所有的屬性(除了 toplink.session.customizer 之外)後運行, 如:
<property name="toplink.descriptor.customizer.org.pisces.persist.UserInfo" value="org.pisces.persist.SimpleDescriptorCustomizer"/>
<property name="toplink.descriptor.customizer.org.pisces.persist.Address" value="org.pisces.persist.SimpleDescriptorCustomizer"/>
-->
<!-- 指定實現 oracle.toplink.essentials.tools.sessionconfiguration.SessionCustomizer 的類名,
該類中的customize方法在執行了所有的屬性後運行, 如:
<property name="toplink.session.customizer" value="org.pisces.persist.SimpleSessionCustomizer"/>
-->
</properties>
</persistence-unit>
</persistence>
3) 創建Entity的管理類
* SimpleManager.java
*/
package org.pisces.persist;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
/**
*
* @author kamhung
*/
public class SimpleManager {
private SimpleManager(){
//do nothing
}
/**
* 刪除用戶id=6的數據
*/
public static void delete() {
final EntityManagerFactory emf =Persistence.createEntityManagerFactory("piscesPU");
final EntityManager em =emf.createEntityManager();
//找不到數據的話這裏會拋異常
UserInfo info =em.find(UserInfo.class, 6);
try {
em.getTransaction().begin();
em.remove(info);
em.getTransaction().commit();
} finally {
em.close();
}
}
/**
* 修改用戶id=6的數據
*/
public static void update() {
final EntityManagerFactory emf =Persistence.createEntityManagerFactory("piscesPU");
final EntityManager em =emf.createEntityManager();
//找不到數據的話這裏會拋異常
UserInfo info =em.find(UserInfo.class, 6);
info.setUserName("哈哈");
info.getAddress().setStreet("坂田2");
try {
em.getTransaction().begin();
//自動將info更新到數據庫
em.getTransaction().commit();
} finally {
em.close();
}
}
/**
* 查詢所有用戶數據
*/
public static void query() {
final EntityManagerFactory emf =Persistence.createEntityManagerFactory("piscesPU");
long s =System.currentTimeMillis();
//數據庫連接失敗這裏會拋出異常
final EntityManager em =emf.createEntityManager();
long e =System.currentTimeMillis();
System.out.println("連接數據庫耗時: " + (e-s) + "毫秒" );
//獲取數據
@SuppressWarnings("unchecked")
List<UserInfo> list =em.createQuery("SELECT a FROM UserInfo a").getResultList();
int i=0;
for(UserInfo info : list) {
System.out.println("第" + (++i) + "個值爲: " + info);
}
em.close();
}
/**
* 創建用戶id=6的一條數據, 地址id=6
*/
public static void create() {
final EntityManagerFactory emf =Persistence.createEntityManagerFactory("piscesPU");
final EntityManager em =emf.createEntityManager();
UserInfo info =new UserInfo(6);
info.setSex("male");
info.setUserName("張某某");
info.setBirthday(new java.sql.Timestamp(System.currentTimeMillis()));
Address naddr =new Address(6);
naddr.setCity("深圳");
naddr.setStreet("坂田");
naddr.setZip("518000");
info.setAddress(naddr);
try {
em.getTransaction().begin();
em.persist(info);
em.getTransaction().commit();
} finally {
em.close();
}
}
}
三、運行
1、 編寫main函數:* Main.java
*/
package org.pisces;
import org.pisces.persist.SimpleManager;
/**
*
* @author kamhung
*/
public class Main {
/**
* 主函數
*/
public static void main(String[] args) throws Throwable {
SimpleManager.query();
SimpleManager.create();
System.out.println("新增一條數據後進行查詢");
SimpleManager.query();
SimpleManager.update();
System.out.println("修改一條數據後進行查詢");
SimpleManager.query();
SimpleManager.delete();
System.out.println("刪除一條數據後進行查詢");
SimpleManager.query();
}
}
2、 運行結果如下:
連接數據庫耗時: 1000毫秒
第1個值爲: UserInfo[userid=1, userName='張金雄', sex='male', birthday=null, address=Address[addressid=1, city='深圳', street='坂田市場', zip='518001']]
第2個值爲: UserInfo[userid=2, userName='李某某', sex='male', birthday=null, address=Address[addressid=2, city='深圳', street='坂田路口', zip='518002']]
第3個值爲: UserInfo[userid=3, userName='王某某', sex='female', birthday=2006-08-10 00:00:00.0, address