java專案單獨使用mybatis的小例子
阿新 • • 發佈：2019-02-10
朋友讓我幫他寫幾個介面，因為比較簡單，使用jdbc程式設計，後來發現數據庫欄位和實體類中物件屬性不能實現對映，我使用mybatis框架。我使用httpClient的post方式來測試介面，專案所需包如下：
目錄結構：
在src建立資料庫配置檔案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建立實體物件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; } }
建立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"> <!-- 自定義返回結果集 --> <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>
建立介面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>
<!-- 引入外部配置檔案 -->
<properties resource="mysql.properties"></properties>
<!-- 為JAVA Bean起類別名 -->
<typeAliases >
<!-- 別名方式1，一個一個的配置 type中放置的是類的全路徑，alias中放置的是類別名
<typeAliase type="com.cy.mybatis.beans.UserBean" alias="UserBean"/>-->
<!-- 別名方式2，自動掃描，將JAVA類的類名作為類的類別名 -->
<package name="pojo"/>
</typeAliases>
<!-- 配置mybatis執行環境 -->
<environments default="cybatis">
<environment id="cybatis">
<!-- type="JDBC" 代表使用JDBC的提交和回滾來管理事務 -->
<transactionManager type="JDBC" />
<!-- mybatis提供了3種資料來源型別，分別是：POOLED,UNPOOLED,JNDI -->
<!-- POOLED 表示支援JDBC資料來源連線池 -->
<!-- UNPOOLED 表示不支援資料來源連線池 -->
<!-- JNDI 表示支援外部資料來源連線池 -->
<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>
<!-- 告知對映檔案方式1，一個一個的配置
<mapper resource="com/cy/mybatis/mapper/UserMapper.xml"/>-->
<!-- 告知對映檔案方式2，自動掃描包內的Mapper介面與配置檔案 -->
<package name="mapper"/>
</mappers>
</configuration>資料庫連線工具類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類載入mybatis的配置檔案
Reader reader = Resources.getResourceAsReader("mybatis.cfg.xml");
// 構建sqlSession的工廠
sessionFactory = new SqlSessionFactoryBuilder().build(reader);
} catch (Exception e) {
e.printStackTrace();
}
}
// 建立能執行對映檔案中sql的sqlSession
public static SqlSession getSession() {
return sessionFactory.openSession();
}
}selectGoods.java 程式碼（servlet介面）
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後查詢商品方法
*
* @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() {
// 建立預設的httpClient例項.
CloseableHttpClient httpclient = HttpClients.createDefault();
// 建立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 {
// 關閉連線,釋放資源
try {
httpclient.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
//測試方法
public static void main(String[] args) {
TestHttpClient httpte = new TestHttpClient();
httpte.postGoods();
}
}控制檯輸出內容
--------------------------------------
Response content: [{"carCount":0,"dicount":"","categoryTitle":"","remark":"很好","goodCode":"10000","packge":0,"discountPrice":0,"title":"筆記本","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":"還可以","goodCode":"10002","packge":0,"discountPrice":0,"title":"水壺","price":20,"nsUrl":"","barCode":"2222","reserve":0},{"carCount":0,"dicount":"","categoryTitle":"","remark":"不錯","goodCode":"10003","packge":0,"discountPrice":0,"title":"雨傘","price":30,"nsUrl":"","barCode":"3333","reserve":0},{"carCount":0,"dicount":"","categoryTitle":"","remark":"質量上好","goodCode":"10004","packge":0,"discountPrice":0,"title":"紙巾","price":5,"nsUrl":"","barCode":"5555","reserve":0},{"carCount":0,"dicount":"","categoryTitle":"","remark":"垃圾","goodCode":"10005","packge":0,"discountPrice":0,"title":"手機","price":3000,"nsUrl":"","barCode":"6666","reserve":0}]
--------------------------------------資料庫，goods表
測試成功，整個流程跑通