Hibernate學習手記（1）--搭建環境

搭建環境：

Eclipse3.4

Build Path Configeration: 建立 hibernate 庫，并加進外部類包：

基本的有 hibernate3 以及 hibernate-distribution-3.3.2.GA/lib/required 目錄下的全部類包

還有 hibernate-annotations ， hibernate-commons-annotations ， ejb3-persistence

日志系統的： slf4j-nop-1.5.11 和 slf4j-api-1.5.11

測試系統的： junit-4.8.2

Hibernate 可以通過 XML 解析或 annotations 标注對實體對象進行映射，實作用面向對象的方式操作資料庫。

Hibernate 基本配置：

Hibernate.cfg.xml 檔案：（注意該檔案最好不要私自改名，且要放在項目的根目錄下）

最主要的聲明部分：

< hibernate-configuration >

    < session-factory >

        <!-- Database connection settings -->

        < property name = "connection.driver_class" >

                com.microsoft.sqlserver.jdbc.SQLServerDriver

        </ property >

        < property name = "connection.url" >

             jdbc:sqlserver://localhost :1433;databaseName=Test

        </ property >

        < property name = "connection.username" > username </ property >

         < property name = "connection.password" > *************

        </ property >

        <!-- JDBC connection pool (use the built-in) -->

        < property name = "connection.pool_size" > 1 </ property >

        <!-- SQL dialect -->

        < property name = "dialect" >

                   org.hibernate.dialect.SQLServerDialect

        </ property >

        <!-- Enable Hibernate's automatic session context management -->

        < property name = "current_session_context_class" >

                     Thread

        </ property >

        <!-- Disable the second-level cache  -->

        < property name = "cache.provider_class" >

              org.hibernate.cache.NoCacheProvider

        </ property >

        <!-- Echo all executed SQL to stdout -->

        < property name = "show_sql" > true </ property >

        <!-- Drop and re-create the database schema on startup -->

        < property name = "hbm2ddl.auto" > update </ property >

        <!—-format the sql-->

        <property name="format_sql">true</property>

        <!-- 實體映射對象 -->

        < mapping resource = "com/Test/Demo.hbm.xml" />

       < mapping class = "com.Test.Demo" />

        <!-- 以上聲明為 XML 映射方式，下面為 annotations 映射方式的聲明 -->

       < mapping class = "com.Test.T" />

    </ session-factory >

</ hibernate-configuration >

XML 解析方式：

  對象映射檔案 Demo.hbm.xml ，命名規則一般把被映射的類的類名作為最頂級的名再加上字尾 .hbm.xml ， 并與被映射的類放在同一個包裡 。

< hibernate-mapping >

  < class name = "com.Test.Demo" table = "[dbo].[T]" >

         < id name = "id" column = "id" type = "java.lang.Integer" >

            < generator class = "native" />

         </ id >

         < property name = "name" column = "name" />

         < property name = "no" column = "no" />

  </ class >

</ hibernate-mapping >

Annotations 注析方式：

package com.Test;

import javax.persistence.Column;

import javax.persistence.Entity;

import javax.persistence.Id;

import javax.persistence.Table;

@Entity

@Table(name="_T")

public class T {

    private int id;

    @Id

    public int getId() {

       return id;

    }

    public void setId(int id) {

       this.id = id;

    }

    @Column(name="_name")

    public String getName() {

       return Name;

    }

    public void setName(String name) {

       Name = name;

    }

    public int getNo() {

       return no;

    }

    public void setNo(int no) {

       this.no = no;

    }

    private String Name;

    private int no;

}

Junit 測試

使用 Junit 進行對象映射的測試，同時驗證資料庫裡的資料

package com.TestHibernate; // 測試包命名規則，一般為 Test+ 被測試的項目名

import org.hibernate.Session;

import org.hibernate.SessionFactory;

import org.hibernate.cfg.AnnotationConfiguration;

import org.junit.After;

import org.junit.Before;

import org.junit.Test;

import static org.junit.Assert.*;

import static org.hamcrest.CoreMatchers.*;

//assertThat 和 is 斷言要用到的外部類包

import com.Test.T;

import junit.framework.TestCase;

public class TestT extends TestCase {

    Session session ;

    SessionFactory sf ;

    T t ;

    @Before

    public void setUp() throws Exception {

         AnnotationConfiguration cfg =

                     new AnnotationConfiguration();

         sf = cfg.configure().buildSessionFactory();

         session = sf .openSession();

         session .beginTransaction();

         t = new T();

    }

    @After

    public void tearDown() throws Exception {

        session .close();

        sf .close();

    }

    @Test

    public void testT() {

       int x= 3;

       String y = "x" ;

       int z = 11;

       t .setId(x);

       t .setName(y);

       t .setNo(z);

       session .save( t );

       session .getTransaction().commit();

       assertThat (x,is ( t .getId()));

       assertThat (y,is ( t .getName()));

       assertThat (z,is ( t .getNo()));      

    }

}