我们上次讲到如何在Eclipse中创建Maven项目了，我们接下来来看看Maven用到了什么。 我们下面用maven开发一个简单的用户信息管理系统，我们就直接使用上一次创建的user-core来做这个系统。 我们在cn.edu.hpu.user.model包下创建一个user类 其中内容

package cn.edu.hpu.user.model;public class User {    private int id;    private String username;    private String password;    private String nickname;	public int getId() {		return id;	}	public void setId(int id) {		this.id = id;	}	public String getUsername() {		return username;	}	public void setUsername(String username) {		this.username = username;	}	public String getPassword() {		return password;	}	public void setPassword(String password) {		this.password = password;	}	public String getNickname() {		return nickname;	}	public void setNickname(String nickname) {		this.nickname = nickname;	}    }

我们要存储对象至数据库，就需要使用hibernate，那么我们就需要在POM配置文件中去引入它，因为我们不知道该怎么去写相应的配置参数，所以我们要登录mvnrepository.com，利用中央仓库的搜索引擎去找到我们需要的jar包，点击相应jar包可以找到配置参数：

我们把提供的配置拷贝至我们的pom文件中：

    	
     
      org.hibernate
     	
     
      hibernate-entitymanager
     	
     
      4.1.10.Final
     
    

然后我们的项目的环境中就有了这个jar包 其实是maven从网络中心仓库下载至我们本地仓库中的： hibernate引入后，然后修改我们的user，给它加上注解：

package cn.edu.hpu.user.model;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.Id;import javax.persistence.Table;@Entity@Table(name="t_user")public class User {    private int id;    private String username;    private String password;    private String nickname;    public User() {	super();    }        public User(String username, String password, String nickname) {	super();	this.username = username;	this.password = password;	this.nickname = nickname;    }	    public User(int id, String username, String password, String nickname){	super();	this.id = id;	this.username = username;	this.password = password;	this.nickname = nickname;    }    @Id    @GeneratedValue	public int getId() {		return id;	}	public void setId(int id) {		this.id = id;	}	public String getUsername() {		return username;	}	public void setUsername(String username) {		this.username = username;	}	public String getPassword() {		return password;	}	public void setPassword(String password) {		this.password = password;	}	public String getNickname() {		return nickname;	}	public void setNickname(String nickname) {		this.nickname = nickname;	}    }

然后我们在pom中加上mysql的数据库连接驱动：

    	
     
      mysql
     	
     
      mysql-connector-java
     	
     
      5.1.24
     
    

然后是log4j的：

    	
     
      log4j
     	
     
      log4j
     	
     
      1.2.17
     
    

然后接下来写hibernate的配置文件:

    
    	
     	      		
      
       root
      		
      
       1234
      		
      
       com.mysql.jdbc.Driver
      		
      
       jdbc:mysql://localhost:3306/maven_user
      				
      		
      
       true
      				
      	    
      
       org.hibernate.dialect.MySQL5Dialect
      	    		
      		
      		
      		
      
       update
      		
      
       true
      		
      
       true
      		
      		
      	
     
    

以及log4j配置文件：

log4j.appender.stdout=org.apache.log4j.ConsoleAppenderlog4j.appender.stdout.Target=System.outlog4j.appender.stdout.layout=org.apache.log4j.PatternLayoutlog4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p [%t] %c{1}:%L - %m%nlog4j.rootLogger=warn, stdout, Rlog4j.logger.cn.edu.hpu=debuglog4j.appender.R=org.apache.log4j.DailyRollingFileAppenderlog4j.appender.R.File=F:/tax/UserSys.loglog4j.appender.R.layout=org.apache.log4j.PatternLayoutlog4j.appender.R.layout.ConversionPattern=%d [%t] %5p  %c - %m%n

现在我们完成了所有配置，接下来写HibernateUtil来获取SessionFactory：

package cn.edu.hpu.user.util;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.boot.registry.StandardServiceRegistryBuilder;import org.hibernate.cfg.Configuration;import org.hibernate.service.ServiceRegistry;public class HibernateUtil {		private final static SessionFactory FACTORY = buildSessionFactory();	private static SessionFactory buildSessionFactory() {	Configuration cfg=new Configuration().configure();	ServiceRegistry serviceRegistry =  new ServiceRegistryBuilder().applySettings(cfg.getProperties()).buildServiceRegistry();	SessionFactory factory=cfg.buildSessionFactory(serviceRegistry);		return factory;	}	public static SessionFactory getFactory() {		return FACTORY;	}		public static Session openSession(){		return FACTORY.openSession();	}		public static void close(Session session){		if(session!=null) session.close();	}	}

接下来我们来编写Dao层： IUserDao:

package cn.edu.hpu.user.dao;import cn.edu.hpu.user.model.User;public interface IUserDao {	public void add(User user);	public User loadUsername(String username);}

UserDao:

package cn.edu.hpu.user.dao;import org.hibernate.Session;import cn.edu.hpu.user.model.User;import cn.edu.hpu.user.util.HibernateUtil;public class UserDao implements IUserDao {	public void add(User user) {		Session session = null;		try {			session=HibernateUtil.openSession();			session.beginTransaction();			session.save(user);			session.getTransaction().commit();		} catch (Exception e) {			e.printStackTrace();		}finally{			HibernateUtil.close(session);		}	}	public User loadUsername(String username) {		Session session = null;		User user=null;		try {			session=HibernateUtil.openSession();			user=(User) session.createQuery("from User where username=?")						.setParameter(0, username).uniqueResult();		} catch (Exception e) {			e.printStackTrace();		}finally{			HibernateUtil.close(session);		}		return user;	}}

由于我们接下来要隔离数据库进行操作，所以需要dbunit工具类，我们在pom中导入它:

    	
     
      dbunit
     	
     
      dbunit
     	
     
      2.2
     
    

测试不要和hibernate的Connection混用，我们使用原始的JDBC的链接： DbUtil:

package cn.edu.hpu.user.util;import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;public class DbUtil {	// 定义MySQL的数据库驱动程序	public static final String DBDRIVER = "org.gjt.mm.mysql.Driver" ;	//定义mysql的数据库连接地址：	public static final String DBDURL = "jdbc:mysql://localhost:3306/maven_user" ;	//mysql数据库的连接用户名	public static final String DBUSER = "root" ;	//mysql数据库的连接密码	public static final String DBPASS = "1234" ;		static{			try {			Class.forName(DBDRIVER);		} catch (ClassNotFoundException e) {			// TODO Auto-generated catch block			e.printStackTrace();		}	}		public static Connection getConnection(){		Connection conn=null;		try {			conn=DriverManager.getConnection(DBDURL,DBUSER,DBPASS);		} catch (SQLException e) {			// TODO Auto-generated catch block			e.printStackTrace();		}		return conn;	}		public static void close(ResultSet rs,Statement st,Connection conn){				try {								if(rs!=null){				rs.close();				}				if(st!=null){					st.close();				}				if(conn!=null){					conn.close();				}		} catch (SQLException e) {			// TODO Auto-generated catch block			e.printStackTrace();		}			} 		public static void close(Statement st,Connection conn){		close(null,st,conn);	}}

接下来编写AbstractDbUnitTestCase和EntitiesHelper两个测试用类 AbstractDbUnitTestCase:

package cn.edu.hpu.user.util;import java.io.File;import java.io.FileWriter;import java.io.IOException;import java.io.InputStream;import java.sql.SQLException;import org.dbunit.DatabaseUnitException;import org.dbunit.database.DatabaseConnection;import org.dbunit.database.IDatabaseConnection;import org.dbunit.database.QueryDataSet;import org.dbunit.dataset.DataSetException;import org.dbunit.dataset.IDataSet;import org.dbunit.dataset.xml.FlatXmlDataSet;import org.dbunit.operation.DatabaseOperation;import org.junit.AfterClass;import org.junit.Assert;import org.junit.BeforeClass;public class AbstractDbUnitTestCase {	public static IDatabaseConnection dbunitCon;	private File tempFile;		@BeforeClass	public static void init() throws Exception{		dbunitCon = new DatabaseConnection(DbUtil.getConnection());	}		protected IDataSet createDataSet(String tname)throws DataSetException,IOException{		InputStream is=AbstractDbUnitTestCase					   .class					   .getClassLoader().getResourceAsStream("dbunit_xml/"+tname+"xml");		Assert.assertNotNull("dbunit的基本数据文件不存在！", is);		return new FlatXmlDataSet(is);	}		protected void backupAllTable() throws SQLException,IOException,DataSetException{		IDataSet ds=dbunitCon.createDataSet();		writeBackupFile(ds);	}	private void writeBackupFile(IDataSet ds) throws IOException, DataSetException {		tempFile=File.createTempFile("back","xml");		FlatXmlDataSet.write(ds, new FileWriter(tempFile));	}		protected void backupCustomTable(String [] tname)throws DataSetException, SQLException, IOException{		QueryDataSet ds=new QueryDataSet(dbunitCon);		for(String str:tname){			ds.addTable(str);		}		writeBackupFile(ds);	}		protected void backupOneTable(String tname)throws DataSetException, SQLException, IOException{		backupCustomTable(new String[]{tname});	}		protected void resumeTable() throws IOException, DatabaseUnitException, SQLException{		IDataSet ds=new FlatXmlDataSet(tempFile);		DatabaseOperation.CLEAN_INSERT.execute(dbunitCon,ds);	}		@AfterClass	public static void destory(){		try {			if(dbunitCon!=null) dbunitCon.close();		} catch (SQLException e) {			e.printStackTrace();		}			}}

EntitiesHelper:

package cn.edu.hpu.user.util;import org.junit.Assert;import cn.edu.hpu.user.model.User;public class EntitiesHelper {	private static User baseUser=new User(1,"admin","123","管理员");		public static void assertUser(User expected,User actual){		Assert.assertNotNull(expected);		Assert.assertEquals(expected.getId(), actual.getId());		Assert.assertEquals(expected.getUsername(), actual.getUsername());		Assert.assertEquals(expected.getPassword(), actual.getPassword());		Assert.assertEquals(expected.getNickname(), actual.getNickname());	}		public static void assertUser(User expected){		assertUser(expected,baseUser);	}}

然后我们写一下user的文件t_user.xml，将其放入src/test/resource中

然后开始写测试类：

package cn.edu.hpu.user.dao;import java.io.IOException;import java.sql.SQLException;import org.dbunit.DatabaseUnitException;import org.dbunit.dataset.DataSetException;import org.dbunit.dataset.IDataSet;import org.dbunit.operation.DatabaseOperation;import org.junit.After;import org.junit.Assert;import org.junit.Before;import org.junit.Test;import cn.edu.hpu.user.model.User;import cn.edu.hpu.user.util.AbstractDbUnitTestCase;import cn.edu.hpu.user.util.EntitiesHelper;public class TestUserDao extends AbstractDbUnitTestCase{   private IUserDao userDao;      @Before   public void setUp() throws DataSetException, SQLException, IOException{	   userDao =new UserDao();	   backupOneTable("t_user");   }      @Test   public void testLoad() throws IOException, DatabaseUnitException, SQLException{	   IDataSet ds=createDataSet("t_user"); 	   DatabaseOperation.TRUNCATE_TABLE.execute(dbunitCon, ds);	   	   User tu=userDao.loadUsername("admin");	   EntitiesHelper.assertUser(tu);   }      @Test   public void testAdd() throws IOException, DatabaseUnitException, SQLException{	   IDataSet ds=createDataSet("t_user");	   DatabaseOperation.TRUNCATE_TABLE.execute(dbunitCon, ds);	   	   User user=new User("admin","123","管理员");	   userDao.add(user);	   Assert.assertTrue(user.getId()>0);	   	   User tu=userDao.loadUsername("admin");	   EntitiesHelper.assertUser(tu,user);   }      @After   public void tearDown() throws IOException, DatabaseUnitException, SQLException{	   resumeTable();   }   }

然后我们鼠标右键点击项目，然后选择Run As...，然后选择Maven Build: 我们输入两个指令(clean test)，现清空，然后再测试: 结果在控制台中显示，target文件夹中的测试报告中也有(如果出错了，点击txt有结果，点击下面Junit的txt文件会跳转至Junit测试台):

我们算是完成了项目中一部分模块了，下一次我们将写下一个模块，日志模块。

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