1、按照javaweb项目的要求逐步建立搭建起机构，具体的类包有：model 、db、dao、test;

具体的架构详见下图：

2、根据搭建的项目架构新建数据库test和数据库表t_userinfo并且添加对应的测试数据; (这里我使用的是绿色版的数据库，具体的下载地址：http://pan.baidu.com/s/1mg88YAc)

具体的建立数据库操作详见下图：

3、编写包中的各种类代码，具体参考代码如下：

UserInfo.java

/** * FileName: UserInfo.java * @Description: TODO封装对象的信息 * Copyright: personage * Company personage * @author: gaoxing * @version V1.0 * Createdate: 2014-5-25 下午2:26:41 * * Modification History: * Date Author Version Discription * ----------------------------------------------------------------------------------- * 2014-5-25 GX 1.0 1.0 * Why & What is modified: <修改原因描述> */package com.org.user.model; /** * @ClassName: UserInfo * @Description:TODO封装对象的信息 * @author: gaoxing * @date: 2014-5-25 下午2:26:41 */public class UserInfo { private int userid; private String username; private String password; /** * @Title: UserInfo * @Description: TODO(描述这个方法的作用) * @param: @param userid * @param: @param username * @param: @param password * @throws */ public UserInfo(int userid, String username, String password) { super(); this.userid = userid; this.username = username; this.password = password; } /** * @Title: UserInfo * @Description: TODO无参的构造方法 * @param: * @throws */public UserInfo() { super();} 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 String getPassword() { return password; } public void setPassword(String password) { this.password = password; } }

UserInfoDBManger.java

/** * FileName: UserInfoDBManger.java * @Description: TODO 连接数据库的操作 * Copyright: personage * Company personage * @author: gaoxing * @version V1.0 * Createdate: 2014-5-25 下午2:47:38 * * Modification History: * Date Author Version Discription * ----------------------------------------------------------------------------------- * 2014-5-25 GX 1.0 1.0 * Why & What is modified: <修改原因描述> */package com.org.user.db; import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.SQLException; import com.mysql.jdbc.Connection;import com.mysql.jdbc.PreparedStatement; /** * @ClassName: UserInfoDBManger * @Description:TODO连接数据库的操作 * @author: gaoxing * @date: 2014-5-25 下午2:47:38 */public class UserInfoDBManger { private static Connection conn = null; private PreparedStatement ps = null; private ResultSet rs = null; public static Connection getConn() { String url = "jdbc:mysql://localhost:3306/test"; try { Class.forName("com.mysql.jdbc.Driver"); try { conn = (Connection) DriverManager.getConnection(url, "root", "mysql"); } catch (SQLException e) { System.out.println(e.getMessage()); } } catch (ClassNotFoundException e) { System.out.println(e.getMessage()); } return conn; } public void close() { try { rs.close(); ps.close(); conn.close(); } catch (SQLException e) { e.getMessage(); } } }

UserInfoDao.java

/** * FileName: UserInfoDao.java * @Description: TODO 处理通过数据库的连接进行操作对象信息 * Copyright: personage * Company personage * @author: gaoxing * @version V1.0 * Createdate: 2014-5-25 下午2:36:09 * * Modification History: * Date Author Version Discription * ----------------------------------------------------------------------------------- * 2014-5-25 GX 1.0 1.0 * Why & What is modified: <修改原因描述> */package com.org.user.dao; import java.sql.ResultSet;import java.sql.SQLException;import java.util.ArrayList;import java.util.List; import com.mysql.jdbc.Connection;import com.mysql.jdbc.PreparedStatement;import com.org.user.db.UserInfoDBManger;import com.org.user.model.UserInfo; /** * @ClassName: UserInfoDao * @Description:TODO处理通过数据库的连接进行操作对象信息 * @author: gaoxing * @date: 2014-5-25 下午2:36:09 */public class UserInfoDao { Connection conn=null; PreparedStatement ps=null; ResultSet rs=null; public List<UserInfo> find(){ List<UserInfo> list=new ArrayList<UserInfo>(); String sql="select * from t_userinfo "; conn=UserInfoDBManger.getConn(); try { ps=(PreparedStatement) conn.prepareStatement(sql); rs=ps.executeQuery(); while (rs.next()) { UserInfo ui=new UserInfo(); ui.setUserid(rs.getInt(1)); ui.setUsername(rs.getString(2)); ui.setPassword(rs.getString(3)); list.add(ui); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return list; }}

UserInfoTest.java

/** * FileName: UserInfoTest.java * @Description: TODO测试dao包的方法 * Copyright: personage * Company personage * @author: gaoxing * @version V1.0 * Createdate: 2014-5-25 下午5:43:03 * * Modification History: * Date Author Version Discription * ----------------------------------------------------------------------------------- * 2014-5-25 GX 1.0 1.0 * Why & What is modified: <修改原因描述> */package com.org.user.test; import static org.junit.Assert.*; import java.util.List; import org.junit.AfterClass;import org.junit.BeforeClass;import org.junit.Test; import com.org.user.dao.UserInfoDao;import com.org.user.model.UserInfo; /** * @ClassName: UserInfoTest * @Description:TODO 测试dao包的方法 * @author: gaoxing * @date: 2014-5-25 下午5:43:03 */public class UserInfoTest { /** * @Title: setUpBeforeClass * @Description: TODO(描述这个方法的作用) * @param: @throws java.lang.Exception * @return: void * @throws */ @BeforeClass public static void setUpBeforeClass() throws Exception { } /** * @Title: tearDownAfterClass * @Description: TODO(描述这个方法的作用) * @param: @throws java.lang.Exception * @return: void * @throws */ @AfterClass public static void tearDownAfterClass() throws Exception { } /** * Test method for {@link com.org.user.dao.UserInfoDao#find()}. */ @Test public void testFind() { UserInfoDao udao=new UserInfoDao(); List<UserInfo> list=udao.find(); for (int i = 0; i < list.size(); i++) { UserInfo ui=list.get(i); System.out.println("名称: "+ui.getUsername()+"密码: "+ui.getPassword()); } } }

4、在编写好类内容之后，在搭建项目过程中要加入辅助的JUnit的测试包junit.jar，同时也要导入数据库的连接mysq-connector-java-5.1.7-bin.jar sqljdbc.jar,这样才可以连接到数据库；

5、所有的工作做好之后，就可以启动服务进行运行了查看结果了，如果在JUnit测试台和控制台出现如下结果就表示项目运行成功了。

以上就是小编为大家带来的java实现连接mysql数据库单元测试查询数据的实例代码全部内容了，希望大家多多支持~