记录一次TestNg+MyBatis中的SqlSession出现的问题，问题虽然解决了但尚未明白问题原因

问题：

   TestNg测试端项目结构：

几个主要文件的内容：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.course">
    <!-- 获取登录接口case -->
    <select id="loginCase" parameterType="Integer" resultType="com.course.model.LoginCase">
        SELECT * FROM loginCase
        WHERE id = #{id};
    </select>
    <!--添加用户接口case-->
    <select id="addUserCase" parameterType="Integer" resultType="com.course.model.AddUserCase">
        select * from addUserCase where id=#{id};
    </select>
    <!-- 获取用户信息case -->
    <select id="getUserInfoCase" parameterType="Integer" resultType="com.course.model.GetUserInfoCase">
        SELECT * FROM getUserInfoCase
        WHERE id = #{id};
    </select>
    <!-- 获取用户列表case -->
    <select id="getUserListCase" parameterType="Integer" resultType="com.course.model.GetUserListCase">
        <!-- SQL语句 -->
        select * from getUserListCase where id=#{id};
    </select>
    <!-- 更新/删除用户信息case -->
    <select id="updateUserInfoCase" parameterType="Integer" resultType="com.course.model.UpdateUserInfoCase">
        select * from updateUserInfoCase where id = #{id};
    </select>

    <!--添加用户接口-->
    <select id="addUser" parameterType="com.course.model.AddUserCase" resultType="com.course.model.User">
        select * from user
        where userName=#{userName}
        and password=#{password}
        and sex=#{sex}
        and age=#{age}
        and permission=#{permission}
        and isDelete=#{isDelete};
    </select>
    <!-- 获取用户信息 -->
    <select id="getUserInfo" parameterType="com.course.model.GetUserInfoCase" resultType="com.course.model.User">
        select * from user WHERE
        id=#{userId};
    </select>

    <!--获取用户列表-->
    <select id="getUserList" parameterType="com.course.model.GetUserListCase" resultType="com.course.model.User">
        <!-- SQL语句 -->
        select * from user
        <trim prefix="WHERE" prefixOverrides="and">
            <if test="null != userName and '' !=userName">
                AND userName=#{userName}
            </if>
            <if test="null != sex and '' !=sex">
                AND sex=#{sex}
            </if>
            <if test="null != age and '' !=age">
                AND age=#{age}
            </if>
        </trim>
        ;
    </select>
    <!--获取更新后的数据-->
    <select id="getUpdateUserInfo" parameterType="com.course.model.UpdateUserInfoCase" resultType="com.course.model.User">
        select * from user
        <trim prefix="WHERE" prefixOverrides="and">
            <if test="null != userName and '' !=userName">
                AND userName=#{userName}
            </if>
            <if test="null != sex and '' !=sex">
                AND sex=#{sex}
            </if>
            <if test="null != age and '' !=age">
                AND age=#{age}
            </if>
            <if test="null != permission and '' !=permission">
                AND permission=#{permission}
            </if>
            <if test="null != isDelete and '' !=isDelete">
                AND isDelete=#{isDelete}
            </if>
        </trim>
        And id = #{userId};
    </select>

    <insert id="insertUser" parameterType="com.course.model.User">
        INSERT INTO USER(userName, password, sex, age, permission, isDelete)
        VALUES(#{userName}, #{password}, #{sex}, #{age}, #{permission}, #{isDelete})
    </insert>
</mapper>

<?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">
<!-- 注意configuration中的标签有一定的顺序
properties, settings, typeAliases, typeHandlers, objectFactory, objectWrapperFactory,
reflectorFactory, plugins, environments, databaseIdProvider, mappers
-->
<configuration>
    <!-- 设置log记录sql语句 -->
    <settings>
        <setting name="logImpl" value="STDOUT_LOGGING"/>
    </settings>
    <!-- 注册对象的空间命名 -->
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <!-- 1.加载数据库驱动 -->
                <property name="driver" value="com.mysql.jdbc.Driver" />
                <!-- 2.数据库连接地址 -->
                <property name="url" value="jdbc:mysql://localhost:3306/course12?characterEncoding=utf8&amp;useSSL=false" />
                <!-- 3.数据库用户 -->
                <property name="username" value="root" />
                <!-- 4.数据库密码 -->
                <property name="password" value="yxh1990" />
            </dataSource>
        </environment>
    </environments>
    <!-- 注册映射文件：java对象与数据库之间的xml文件路径 -->
    <mappers>
        <mapper resource="mapper/SQLMapper.xml" />
    </mappers>

</configuration>

package com.course.utils;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.Reader;

public class DatabaseUtil {

    public static SqlSession getSqlSession() throws IOException {
        // 获取配置的资源文件
        Reader reader = Resources.getResourceAsReader("databaseConfig.xml");

        SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(reader);
        // sqlSession就是能够执行配置文件中的sql语句
        SqlSession sqlSession = factory.openSession();
        return sqlSession;
    }
}

 GetUserInfoTest中运行过程描述：

1.通过DataBaseUtil获取一个SqlSession session=DatabaseUtil.getSqlSession()，

2.session通过映射文件获取getuserinfocase表第一行内容并封装到GetUserInfoCase实体中

3.使用HttpClient发送请求访问getUserInfo接口（参数为GetUserInfoCase），返回查询的结果

4.session通过映射文件和参数查询获取user表中的user信息

GetUserInfoTest.java 

package com.course.cases;

import com.course.config.TestConfig;
import com.course.model.GetUserInfoCase;
import com.course.model.User;
import com.course.utils.DatabaseUtil;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.util.EntityUtils;
import org.apache.ibatis.session.SqlSession;
import org.json.JSONArray;
import org.json.JSONObject;
import org.testng.Assert;
import org.testng.annotations.Test;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class GetUserInfoTest {

    @Test(dependsOnGroups = "loginTrue", description = "获取userId为1的用户信息")
    public void getUserInfo() throws IOException, InterruptedException {
        SqlSession session = DatabaseUtil.getSqlSession();
        GetUserInfoCase getUserInfoCase = session.selectOne("getUserInfoCase", 1);
        System.out.println(getUserInfoCase.toString());
        System.out.println(TestConfig.getUserInfoUrl);

        //下边为写完接口的代码
        JSONArray resultJson = getJsonResult(getUserInfoCase);

        User user = session.selectOne(getUserInfoCase.getExpected(), getUserInfoCase);
        System.out.println("自己查询数据库获取用户信息："+user.toString());

        List userList = new ArrayList();
        userList.add(user);
        JSONArray jsonArray = new JSONArray(userList);
        System.out.println("获取用户信息："+jsonArray.toString());
        System.out.println("调用接口获取用户信息："+resultJson.toString());
        Assert.assertEquals(jsonArray.toString(), resultJson.toString());
    }

    private JSONArray getJsonResult(GetUserInfoCase getUserInfoCase) throws IOException {
        HttpPost post = new HttpPost(TestConfig.getUserInfoUrl);
        JSONObject param = new JSONObject();
        param.put("id", getUserInfoCase.getUserId());
        // 设置请求头信息 设置header
        post.setHeader("content-type", "application/json");
        //将参数信息添加到方法中
        StringEntity entity = new StringEntity(param.toString(), "utf-8");
        post.setEntity(entity);
        //设置cookies
        TestConfig.defaultHttpClient.setCookieStore(TestConfig.store);
        //声明一个对象来进行响应结果的存储
        String result;
        //执行post方法
        HttpResponse response = TestConfig.defaultHttpClient.execute(post);
        //获取响应结果
        result = EntityUtils.toString(response.getEntity(), "utf-8");
        System.out.println("调用接口result："+result);
        JSONArray jsonArray = new JSONArray(result);
        System.out.println(jsonArray.toString());
        return jsonArray;
    }
}

 AddUserTest中运行过程描述：

1.通过DataBaseUtil获取一个SqlSession session=DatabaseUtil.getSqlSession()，

2.session通过映射文件获取adduserinfocase表第一行内容并封装到AddUserInfoCase实体中

3.使用HttpClient发送请求访问getUserInfo接口（参数为AddUserInfoCase），接口将信息插入user表

4.session通过映射文件和参数查询获取user表中的user信息（？此处无法查询到user，user为null） 

AddUserTest.java

package com.course.cases;

import com.course.config.TestConfig;
import com.course.model.AddUserCase;
import com.course.model.User;
import com.course.utils.DatabaseUtil;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.util.EntityUtils;
import org.apache.ibatis.session.SqlSession;
import org.json.JSONObject;
import org.testng.Assert;
import org.testng.annotations.Test;

import java.io.IOException;
import java.util.Random;

public class AddUserTest {

    @Test(dependsOnGroups = "loginTrue", description = "添加用户接口")
    public void addUser() throws IOException, InterruptedException {
        SqlSession session = DatabaseUtil.getSqlSession();
        AddUserCase addUserCase = session.selectOne("addUserCase", 1);
        // 将查询到的addUserCase中的userName更新，防止每次都要删除user表中的记录
        addUserCase.setUserName(addUserCase.getUserName()+ new Random().nextInt());
        System.out.println(addUserCase.toString());
        System.out.println(TestConfig.addUserUrl);

        // 发送请求，获取结果
        String result = getResult(addUserCase);
        System.out.println("异步结果"+result);
        //验证返回结果
        /* 此处需要新建一个SqlSession才能查询新增的user，不然无法查询结果 */
        //SqlSession session1 = DatabaseUtil.getSqlSession();
        User user = session.selectOne("addUser", addUserCase);
        System.out.println(user.toString());

        Assert.assertEquals(addUserCase.getExpected(), result);
    }

    private String getResult(AddUserCase addUserCase) throws IOException {
        HttpPost post = new HttpPost(TestConfig.addUserUrl);
        JSONObject param = new JSONObject();
        param.put("userName", addUserCase.getUserName());
        param.put("password", addUserCase.getPassword());
        param.put("sex", addUserCase.getSex());
        param.put("age", addUserCase.getAge());
        param.put("permission", addUserCase.getPermission());
        param.put("isDelete", addUserCase.getIsDelete());

        // 设置头信息
        post.setHeader("content-type", "application/json");
        StringEntity entity = new StringEntity(param.toString(), "utf-8");
        post.setEntity(entity);

        // 设置cookies
        TestConfig.defaultHttpClient.setCookieStore(TestConfig.store);
        String result;  //存放返回结果
        HttpResponse response = TestConfig.defaultHttpClient.execute(post);

        result = EntityUtils.toString(response.getEntity(), "utf-8");

        System.out.println(result);

        return result;
    }
}

如何解决上面user为null的情况？目前发现两种解决方法：

1.重新建一个SqlSession查询数据库就好了，SqlSession session1 = DatabaseUtil.getSqlSession();

2.修改SqlSession sqlSession = factory.openSession();为SqlSession sqlSession = factory.openSession(true);

package com.course.utils;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.Reader;

public class DatabaseUtil {

    public static SqlSession getSqlSession() throws IOException {
        // 获取配置的资源文件
        Reader reader = Resources.getResourceAsReader("databaseConfig.xml");

        SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(reader);
        // sqlSession就是能够执行配置文件中的sql语句
        SqlSession sqlSession = factory.openSession();
        return sqlSession;
    }
}

但是目前不理解，同样的为啥GetUserTest.java中没有出现该问题，在AddUserTest.java中出现问题