java项目单独使用mybatis的小例子

朋友让我帮他写几个接口，因为比较简单，使用jdbc编程，后来发现数据库字段和实体类中对象属性不能实现映射，我使用mybatis框架。我使用httpClient的post方式来测试接口，项目所需包如下：



目录结构：



在src创建数据库配置文件mysql.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf8
jdbc.username=root
jdbc.password=123456

创建实体对象Goods

package pojo;
import java.math.BigDecimal;
public class Goods {
private String goodCode;
private String barCode;
private String nsUrl;
private String categoryTitle;
private String title;
private String remark;
private Integer reserve;
private Integer packge;
private BigDecimal price;
private String dicount;
private BigDecimal discountPrice;
private Integer carCount;
public String getGoodCode() {
return goodCode;
}
public void setGoodCode(String goodCode) {
this.goodCode = goodCode;
}
public String getBarCode() {
return barCode;
}
public void setBarCode(String barCode) {
this.barCode = barCode;
}
public String getNsUrl() {
return nsUrl;
}
public void setNsUrl(String nsUrl) {
this.nsUrl = nsUrl;
}
public String getCategoryTitle() {
return categoryTitle;
}
public void setCategoryTitle(String categoryTitle) {
this.categoryTitle = categoryTitle;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getRemark() {
return remark;
}
public void setRemark(String remark) {
this.remark = remark;
}
public Integer getReserve() {
return reserve;
}
public void setReserve(Integer reserve) {
this.reserve = reserve;
}
public Integer getPackge() {
return packge;
}
public void setPackge(Integer packge) {
this.packge = packge;
}
public BigDecimal getPrice() {
return price;
}
public void setPrice(BigDecimal price) {
this.price = price;
}
public String getDicount() {
return dicount;
}
public void setDicount(String dicount) {
this.dicount = dicount;
}
public BigDecimal getDiscountPrice() {
return discountPrice;
}
public void setDiscountPrice(BigDecimal discountPrice) {
this.discountPrice = discountPrice;
}
public Integer getCarCount() {
return carCount;
}
public void setCarCount(Integer carCount) {
this.carCount = carCount;
}

}

创建GoodsMapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org/DTD Mapper 3.0" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="mapper.GoodsMapper">
<!-- 自定义返回结果集 -->
<resultMap id="goodsMap" type="Goods">
<id property="goodCode" column="goodCode" javaType="java.lang.String"></id>
<result property="barCode" column="barCode" javaType="java.lang.String"></result>
<result property="nsUrl" column="nsUrl" javaType="java.lang.String"></result>
<result property="categoryTitle" column="categoryTitle" javaType="java.lang.String"></result>
<result property="title" column="title" javaType="java.lang.String"></result>
<result property="remark" column="remark" javaType="java.lang.String"></result>
<result property="reserve" column="reserve" javaType="java.lang.Integer"></result>
<result property="packge" column="packge" javaType="java.lang.Integer"></result>
<result property="price" column="price" javaType="java.math.BigDecimal"></result>
<result property="dicount" column="dicount" javaType="java.lang.String"></result>
<result property="discountPrice" column="discountPrice" javaType="java.math.BigDecimal"></result>
<result property="carCount" column="carCount" javaType="java.lang.Integer"></result>
</resultMap>
<select id="selectAllGoods" resultMap="goodsMap">
select * from goods
</select>

<select id="selectRecommendGoods" resultMap="goodsMap">
select * from goods limit 0,4;
</select>
</mapper>

创建接口GoodsMapper.java

package mapper;
import java.util.List;
import pojo.Goods;

public interface GoodsMapper {
public List<Goods> selectAllGoods() throws Exception;
public List<Goods> selectRecommendGoods() throws Exception;
}

mybatis.cfg.xml配置

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!-- 引入外部配置文件 -->
<properties resource="mysql.properties"></properties>
<!-- 为JAVA Bean起类别名 -->
<typeAliases >
<!-- 别名方式1，一个一个的配置 type中放置的是类的全路径，alias中放置的是类别名
<typeAliase type="com.cy.mybatis.beans.UserBean" alias="UserBean"/>-->
<!-- 别名方式2，自动扫描，将JAVA类的类名作为类的类别名 -->
<package name="pojo"/>
</typeAliases>

<!-- 配置mybatis运行环境 -->
<environments default="cybatis">
<environment id="cybatis">
<!-- type="JDBC" 代表使用JDBC的提交和回滚来管理事务 -->
<transactionManager type="JDBC" />
<!-- mybatis提供了3种数据源类型，分别是：POOLED,UNPOOLED,JNDI -->
<!-- POOLED 表示支持JDBC数据源连接池 -->
<!-- UNPOOLED 表示不支持数据源连接池 -->
<!-- JNDI 表示支持外部数据源连接池 -->
<dataSource type="POOLED">
<property name="driver" value="${jdbc.driver}" />
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />
</dataSource>
</environment>
</environments>
<mappers>
<!-- 告知映射文件方式1，一个一个的配置
<mapper resource="com/cy/mybatis/mapper/UserMapper.xml"/>-->
<!-- 告知映射文件方式2，自动扫描包内的Mapper接口与配置文件 -->
<package name="mapper"/>
</mappers>
</configuration>

数据库连接工具类DBTools

package until;
import java.io.Reader;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

public class DBTools {
public static SqlSessionFactory sessionFactory;
static {
try {
// 使用MyBatis提供的Resources类加载mybatis的配置文件
Reader reader = Resources.getResourceAsReader("mybatis.cfg.xml");
// 构建sqlSession的工厂
sessionFactory = new SqlSessionFactoryBuilder().build(reader);
} catch (Exception e) {
e.printStackTrace();
}
}
// 创建能执行映射文件中sql的sqlSession
public static SqlSession getSession() {
return sessionFactory.openSession();
}
}

selectGoods.java 代码（servlet接口）

package test;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.ibatis.session.SqlSession;
import mapper.GoodsMapper;
import net.sf.json.JSONArray;
import pojo.Goods;
import until.DBTools;

/**
* Servlet implementation class TestSvrvlet
*/
@WebServlet("/getAllGoods")
public class selectGoods extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse
*      response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
try {
out.println(selectAllGoods());
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse
*      response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
try {
out.println(selectAllGoods());
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

/**
* 整合mybatis后查询商品方法
*
* @return
*/
private String selectAllGoods() {
JSONArray jr = new JSONArray();
SqlSession session = DBTools.getSession();
GoodsMapper mapper = session.getMapper(GoodsMapper.class);
try {
List<Goods> goodsList = mapper.selectAllGoods();
System.out.println(goodsList.toString());
jr = JSONArray.fromObject(goodsList);
session.commit();
} catch (Exception e) {
e.printStackTrace();
session.rollback();
}
System.out.println("jr" + jr);
return jr.toString();
}
}

TestHttpClient.java

package test;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.ParseException;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

public class TestHttpClient {
public void postGoods() {
// 创建默认的httpClient实例.
CloseableHttpClient httpclient = HttpClients.createDefault();
// 创建httppost
HttpPost httppost = new HttpPost("http://localhost:8080/test/getAllGoods");
UrlEncodedFormEntity uefEntity = null;
try {
httppost.setEntity(uefEntity);
CloseableHttpResponse response = httpclient.execute(httppost);
try {
HttpEntity entity = response.getEntity();
if (entity != null) {
System.out.println("--------------------------------------");
System.out.println("Response content: " + EntityUtils.toString(entity, "UTF-8"));
System.out.println("--------------------------------------");
}
} finally {
response.close();
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e1) {
e1.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
// 关闭连接,释放资源
try {
httpclient.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}

//测试方法
public static void main(String[] args) {
TestHttpClient httpte = new TestHttpClient();
httpte.postGoods();
}
}

控制台输出内容

--------------------------------------
Response content: [{"carCount":0,"dicount":"","categoryTitle":"","remark":"很好","goodCode":"10000","packge":0,"discountPrice":0,"title":"笔记本","price":3000,"nsUrl":"","barCode":"1111","reserve":0},{"carCount":0,"dicount":"","categoryTitle":"","remark":"一般","goodCode":"10001","packge":0,"discountPrice":0,"title":"杯子","price":2500,"nsUrl":"","barCode":"4444","reserve":0},{"carCount":0,"dicount":"","categoryTitle":"","remark":"还可以","goodCode":"10002","packge":0,"discountPrice":0,"title":"水壶","price":20,"nsUrl":"","barCode":"2222","reserve":0},{"carCount":0,"dicount":"","categoryTitle":"","remark":"不错","goodCode":"10003","packge":0,"discountPrice":0,"title":"雨伞","price":30,"nsUrl":"","barCode":"3333","reserve":0},{"carCount":0,"dicount":"","categoryTitle":"","remark":"质量上好","goodCode":"10004","packge":0,"discountPrice":0,"title":"纸巾","price":5,"nsUrl":"","barCode":"5555","reserve":0},{"carCount":0,"dicount":"","categoryTitle":"","remark":"垃圾","goodCode":"10005","packge":0,"discountPrice":0,"title":"手机","price":3000,"nsUrl":"","barCode":"6666","reserve":0}]

--------------------------------------

数据库，goods表



测试成功，整个流程跑通