1. 程式人生 > >[學習筆記] 在Eclipse中使用Hibernate,並建立第一個Demo工程,資料庫為Oracle XE

[學習筆記] 在Eclipse中使用Hibernate,並建立第一個Demo工程,資料庫為Oracle XE

前文參考:Oracle 11g xe 在windows安裝

在Eclipse中使用Hibernate

安裝 Hibernate Tools 外掛

https://tools.jboss.org/downloads/

Add the following URL to your Eclipse 4.13 (2019-09) installation, via:

Help > Install New Software… > Work with:

http://download.jboss.org/jbosstools/photon/stable/updates/

Then select the individual features that you want to install:

點選Next

點選Next
同意相關協議,點選Finish .

則會開始下載安裝。

視網路速度,可能需要幾分鐘到十幾分鐘的時間才能完成安裝。

最後會提示重啟Eclipse才能生效。

在Eclipse中新建Hibernate應用

File->New -> Java Project

點選Finish

專案結構圖

在Eclipse中新建使用者庫

此時下面顯示了已經建立的使用者庫列表

我們要新增Hibernate的依賴庫,因此點選使用者庫

Hibernate_4.3.5_final

選擇jar檔案

專案結構圖

繼續配置Hibernate

最後自動形成 如下的檔案內容:[本例使用oracle資料庫]

Oracle 11g xe 在windows安裝請看如下連結:

Oracle 11g xe 在windows安裝

hibernate.cfg.xml

 <?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <property name="hibernate.connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
        <property name="hibernate.connection.password">123456</property>
        <property name="hibernate.connection.url">jdbc:oracle:thin:@localhost:1521:xe</property>
        <property name="hibernate.connection.username">test</property>
        <property name="hibernate.default_schema">test</property>
        <property name="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</property>
    </session-factory>
</hibernate-configuration>

再增加幾個屬性

配置檔案更新後的內容如下: 注意要去掉name屬性 更改

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
                                         "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
 <session-factory >
  <property name="hibernate.connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
  <property name="hibernate.connection.password">123456</property>
  <property name="hibernate.connection.url">jdbc:oracle:thin:@localhost:xe:orcl</property>
  <property name="hibernate.connection.username">test</property>
  <property name="hibernate.default_schema">test</property>
  <property name="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</property>
  <property name="hibernate.show_sql">true</property>
  <!-- 第一次載入hibernate時根據model類會自動建立起表的結構(前提是先建立好資料庫),以後載入hibernate時根據 model類自動更新表結構,即使表結構改變了但表中的行仍然存在不會刪除以前的行。要注意的是當部署到伺服器後,表結構是不會被馬上建立起來的,是要等 應用第一次執行起來後才會。 -->
  <property name="hibernate.hbm2ddl.auto">update</property> 
  <property name="hibernate.format_sql">true</property>
  <property name="hibernate.default_entity_mode">pojo</property>
 </session-factory>
</hibernate-configuration>

繼續完善工程Hibernate_demo_001

新建一個包:mytest001.demo

在包mytest001.demo之下新建一個PO類: Emp

package mytest001.demo;

public class Emp {
    // 員工的標識屬性
    private Integer id;
    // 姓名
    private String name;
    // 年齡
    private Integer age;
    // 工資 (分)
    private Integer salary;

    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 Integer getSalary() {
        return salary;
    }

    public void setSalary(Integer salary) {
        this.salary = salary;
    }

    @Override
    public String toString() {
        return "Emp [id=" + id + ", name=" + name + ", age=" + age + ", salary=" + salary + "]";
    }
}

此刻此PO Emp.java 尚不具備持久化能力。下面為其添加註解。

@Entity 註解宣告該類是一個Hibernate持久化類
@Table 指定該類對映的表,對應的資料庫表名是T_EMP
@Id 指定該類的標識屬性,對映到資料庫的主鍵列
@GeneratedValue(strategy=GenerationType.SEQUENCE) 指定了主鍵生成策略,由於本文使用Oracle Database, 因此指定了使用 SEQUENCE

在hibernate.cfg.xml中增加持久化對映類名

增加一個新類:EmpManager,用於管理員工。

package mytest001.demo;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.Service;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;


public class EmpManager {

    public static void main(String[] args)  throws Exception  {
         
    //例項化配置
    Configuration configuration  = new Configuration()
            //不帶引數則預設載入hibernate.cfg.xml
            .configure();
    
    ServiceRegistry serviceRegistry = new ServiceRegistryBuilder()
            .applySettings(configuration.getProperties()).build();
    SessionFactory sFactory = configuration.buildSessionFactory(serviceRegistry);
    
    //建立session 
    Session session = sFactory.openSession();
    
    //開始事務
    Transaction tx = session.beginTransaction();
    //建立員工物件
    Emp emp = new Emp();
    // 設定員工資訊
    emp.setAge(28);
    emp.setName("scott");
    emp.setSalary(10000);
    session.save(emp);
    // 提交事務
    tx.commit();
    session.close();
    sFactory.close();
            
    
    }

}

最後配置檔案的內容:hibernate.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
                                         "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
 <session-factory >
  <property name="hibernate.connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
  <property name="hibernate.connection.password">123456</property>
  <property name="hibernate.connection.url">jdbc:oracle:thin:@localhost:1521:xe</property>
  <property name="hibernate.connection.username">test</property>
  <property name="hibernate.default_schema">test</property>
  <property name="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</property>
  <property name="hibernate.show_sql">true</property>
  <!-- 第一次載入hibernate時根據model類會自動建立起表的結構(前提是先建立好資料庫),以後載入hibernate時根據 model類自動更新表結構,即使表結構改變了但表中的行仍然存在不會刪除以前的行。要注意的是當部署到伺服器後,表結構是不會被馬上建立起來的,是要等 應用第一次執行起來後才會。 -->
  <property name="hibernate.hbm2ddl.auto">update</property> 
  <property name="hibernate.format_sql">true</property>
  <property name="hibernate.default_entity_mode">pojo</property>
  <mapping class="mytest001.demo.Emp"/>
 </session-factory>
</hibernate-configuration>

Emp.java

package mytest001.demo;

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

@Entity
@Table(name="T_EMP")
public class Emp {
    // 員工的標識屬性
    @Id
    @GeneratedValue(strategy=GenerationType.SEQUENCE)
    private Integer id;
    // 姓名
    private String name;
    // 年齡
    private Integer age;
    // 工資 (分)
    private Integer salary;

    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 Integer getSalary() {
        return salary;
    }

    public void setSalary(Integer salary) {
        this.salary = salary;
    }

    @Override
    public String toString() {
        return "Emp [id=" + id + ", name=" + name + ", age=" + age + ", salary=" + salary + "]";
    }
}

最後的工程結構如下:

執行EmpManger

十一月 23, 2019 8:50:47 上午 org.hibernate.annotations.common.reflection.java.JavaReflectionManager <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {4.0.4.Final}
十一月 23, 2019 8:50:47 上午 org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {4.3.5.Final}
十一月 23, 2019 8:50:47 上午 org.hibernate.cfg.Environment <clinit>
INFO: HHH000206: hibernate.properties not found
十一月 23, 2019 8:50:47 上午 org.hibernate.cfg.Environment buildBytecodeProvider
INFO: HHH000021: Bytecode provider name : javassist
十一月 23, 2019 8:50:47 上午 org.hibernate.cfg.Configuration configure
INFO: HHH000043: Configuring from resource: /hibernate.cfg.xml
十一月 23, 2019 8:50:47 上午 org.hibernate.cfg.Configuration getConfigurationInputStream
INFO: HHH000040: Configuration resource: /hibernate.cfg.xml
十一月 23, 2019 8:50:47 上午 org.hibernate.cfg.Configuration doConfigure
INFO: HHH000041: Configured SessionFactory: null
十一月 23, 2019 8:50:47 上午 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
WARN: HHH000402: Using Hibernate built-in connection pool (not for production use!)
十一月 23, 2019 8:50:47 上午 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH000401: using driver [oracle.jdbc.driver.OracleDriver] at URL [jdbc:oracle:thin:@localhost:1521:xe]
十一月 23, 2019 8:50:47 上午 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH000046: Connection properties: {user=test, password=****}
十一月 23, 2019 8:50:47 上午 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH000006: Autocommit mode: false
十一月 23, 2019 8:50:47 上午 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
INFO: HHH000115: Hibernate connection pool size: 20 (min=1)
十一月 23, 2019 8:50:48 上午 org.hibernate.dialect.Dialect <init>
INFO: HHH000400: Using dialect: org.hibernate.dialect.Oracle10gDialect
十一月 23, 2019 8:50:48 上午 org.hibernate.engine.transaction.internal.TransactionFactoryInitiator initiateService
INFO: HHH000399: Using default transaction strategy (direct JDBC transactions)
十一月 23, 2019 8:50:48 上午 org.hibernate.hql.internal.ast.ASTQueryTranslatorFactory <init>
INFO: HHH000397: Using ASTQueryTranslatorFactory
十一月 23, 2019 8:50:48 上午 org.hibernate.tool.hbm2ddl.SchemaUpdate execute
INFO: HHH000228: Running hbm2ddl schema update
十一月 23, 2019 8:50:48 上午 org.hibernate.tool.hbm2ddl.SchemaUpdate execute
INFO: HHH000102: Fetching database metadata
十一月 23, 2019 8:50:48 上午 org.hibernate.tool.hbm2ddl.SchemaUpdate execute
INFO: HHH000396: Updating schema
十一月 23, 2019 8:50:48 上午 org.hibernate.tool.hbm2ddl.DatabaseMetadata getTableMetadata
INFO: HHH000262: Table not found: T_EMP
十一月 23, 2019 8:50:48 上午 org.hibernate.tool.hbm2ddl.DatabaseMetadata getTableMetadata
INFO: HHH000262: Table not found: T_EMP
十一月 23, 2019 8:50:48 上午 org.hibernate.tool.hbm2ddl.DatabaseMetadata getTableMetadata
INFO: HHH000262: Table not found: T_EMP
十一月 23, 2019 8:50:48 上午 org.hibernate.tool.hbm2ddl.SchemaUpdate execute
INFO: HHH000232: Schema update complete
Hibernate: 
    select
        test.hibernate_sequence.nextval 
    from
        dual
Hibernate: 
    insert 
    into
        test.T_EMP
        (age, name, salary, id) 
    values
        (?, ?, ?, ?)
十一月 23, 2019 8:50:48 上午 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl stop
INFO: HHH000030: Cleaning up connection pool [jdbc:oracle:thin:@localhost:1521:xe]

到資料庫中查詢表:(這個表會被自動建立)
select * from t_emp;

如果再次執行會增加新的記錄。

至此,本文完成