编辑日报内容...

1.今日完成

编写Mybatis连接数据库：

（1）配置mybatis-config.xml文件

<?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>

    <typeAliases>

      <package name="cn.jnshu.pojo"/>

    </typeAliases>

    <environments default="development">

        <environment id="development">

            <transactionManager type="JDBC"/>

            <dataSource type="POOLED">

            <property name="driver" value="cn.mysql.jdbc.Driver"/>

            <property name="url" value="jdbc:mysql://localhost:3306/students?characterEncoding=UTF-8"/>

            <property name="username" value="root"/>

            <property name="password" value="root"/>

            </dataSource>

        </environment>

    </environments>

    <mappers>

        <mapper resource="cn/jnshu/students/mapper/StudentsMapper.xml"/>

        <mapper class="cn.jnshu.students.mapper.StudentsMapper.java"/>  

    </mappers>

</configuration>

（2）配置文件StudentsMapper.xml

<?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="StudentsMapper">

   <insert id="addStudents" parameterType="Students" >

       insert into students (name,qq,school) values (#{name},#{qq},#{school})    

   </insert>

   <delete id="deleteStudentsById" parameterType="int" >

       delete from students where id= #{id}   

   </delete>

   <select id="getStudentsById" parameterType="int" resultType="Students">

       select * from   students  where id= #{id}    

   </select>

   <update id="updateStudentsById" parameterType="Students" >

       update students set ( name=#{name},qq=#{qq},school=#{school} ) where id=#{id}    

   </update>

   <select id="listStudents" resultType="Students">

       select * from   students      

   </select>    

</mapper>

（3）Mapper接口文件

package cn.jnshu.students.mapper;

import java.util.List;

import cn.jnshu.pojo.Students;

public interface StudentsMapper {

public void addStudents(Students student) throws Exception;

public void deleteStudentsById(int id) throws Exception;

public Students getStudentsById(int id) throws Exception;

public void updateStudentsById(int id) throws Exception;

public List<Students> listStudents() throws Exception;

}

（4）pojo类（Students类）

package cn.jnshu.pojo;

public class Students {

private int id;

private String name;

private String qq;

private String school;

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public String getQq() {

return qq;

}

public void setQq(String qq) {

this.qq = qq;

}

public String getSchool() {

return school;

}

public void setSchool(String school) {

this.school = school;

}

}

（5）测试类

package cn.jnshu.students;

import java.io.IOException;

import java.io.InputStream;

import java.util.List;

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 org.junit.Test;

import cn.jnshu.pojo.Students;

public class TestMybatis {

// public static void main(String[] args) throws IOException {

// TODO Auto-generated method stub

// String resource = "mybatis-config.xml";

// InputStream inputStream = Resources.getResourceAsStream(resource);

// SqlSessionFactory sqlSessionFactory = new

// SqlSessionFactoryBuilder().build(inputStream);

// 根据id查询用户信息，得到一条记录结果

@Test

public void getStudentsById() throws IOException {

// mybatis配置文件

String resource = "mybatis-config.xml";

// 得到配置文件

InputStream inputStream = Resources.getResourceAsStream(resource);

// 创建会话工厂，传入mybatis的配置文件信息

SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);

// 通过工厂得到SqlSession

SqlSession sqlSession = sqlSessionFactory.openSession();

// 通过SqlSession操作数据

Students Students = sqlSession.selectOne("StudentsMapper.getStudentsById", 1);

System.out.println(Students);

// 释放资源

sqlSession.close();

}

// 根据用户名称模糊查询用户列表

@Test

public void listStudents() throws IOException {

// mybatis配置文件

String resource = "mybatis-config.xml";

// 得到配置文件

InputStream inputStream = Resources.getResourceAsStream(resource);

// 创建会话工厂，传入mybatis的配置文件信息

SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);

// 通过工厂得到SqlSession

SqlSession sqlSession = sqlSessionFactory.openSession();

// list中的Students和映射文件中resultType指定的类型一样

List<Students> list = sqlSession.selectOne("StudentsMapper.listStudents");

System.out.println(list);

sqlSession.close();

}

// 添加用户信息

@Test

public void addStudents() throws IOException {

// mybatis配置文件

String resource = "mybatis-config.xml";

// 得到配置文件

InputStream inputStream = Resources.getResourceAsStream(resource);

// 创建会话工厂，传入mybatis的配置文件信息

SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);

// 通过工厂得到SqlSession

SqlSession sqlSession = sqlSessionFactory.openSession();

// 插入用户对象

Students Students = new Students();

Students.setName("王小军");

Students.setQq("88888888");

Students.setSchool("复旦大学");

sqlSession.insert("StudentsMapper.addStudents", Students);

// 提交事务

sqlSession.commit();

// 获取用户信息主键

System.out.println(Students);

// 关闭会话

sqlSession.close();

}

// 根据id删除 用户信息

@Test

public void deleteStudentsById() throws IOException {

// mybatis配置文件

String resource = "mybatis-config.xml";

// 得到配置文件

InputStream inputStream = Resources.getResourceAsStream(resource);

// 创建会话工厂，传入mybatis的配置文件信息

SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);

// 通过工厂得到SqlSession

SqlSession sqlSession = sqlSessionFactory.openSession();

// 传入id删除 用户

sqlSession.delete("StudentsMapper.deleteStudentsById", 3);

// 提交事务

sqlSession.commit();

// 关闭会话

sqlSession.close();

}

// 更新用户信息

@Test

public void updateStudentsById() throws IOException {

// mybatis配置文件

String resource = "mybatis-config.xml";

// 得到配置文件

InputStream inputStream = Resources.getResourceAsStream(resource);

// 创建会话工厂，传入mybatis的配置文件信息

SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);

// 通过工厂得到SqlSession

SqlSession sqlSession = sqlSessionFactory.openSession();

// 更新用户信息

Students Students = new Students();

// 必须设置id

Students.setId(1);

Students.setName("李雷");

Students.setQq("33333333");

Students.setSchool("复旦大学");

sqlSession.update("StudentsMapper.updateStudentsById", Students);

// 提交事务

sqlSession.commit();

// 关闭会话

sqlSession.close();

}

}

2.明日计划

   1）学习junit测试

  2）编写测试用例

3.遇到的问题

 junit测试时，报错如下：

TestMybatis.getStudentsById

getStudentsById(cn.jnshu.students.TestMybatis)

org.apache.ibatis.exceptions.PersistenceException: 

### Error building SqlSession.

### The error may exist in cn/jnshu/students/mapper/StudentsMapper.xml

### Cause: org.apache.ibatis.builder.BuilderException: Error parsing SQL Mapper Configuration. Cause: java.lang.ClassNotFoundException: Cannot find class: cn.jnshu.students.mapper.StudentsMapper.java

at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30)

at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:80)

at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:64)

at cn.jnshu.students.TestMybatis.getStudentsById(TestMybatis.java:34)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.lang.reflect.Method.invoke(Unknown Source)

at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)

at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)

at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)

at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)

at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)

at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)

at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)

at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)

at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)

at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)

at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)

at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)

at org.junit.runners.ParentRunner.run(ParentRunner.java:363)

at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)

at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

Caused by: org.apache.ibatis.builder.BuilderException: Error parsing SQL Mapper Configuration. Cause: java.lang.ClassNotFoundException: Cannot find class: cn.jnshu.students.mapper.StudentsMapper.java

at org.apache.ibatis.builder.xml.XMLConfigBuilder.parseConfiguration(XMLConfigBuilder.java:120)

at org.apache.ibatis.builder.xml.XMLConfigBuilder.parse(XMLConfigBuilder.java:98)

at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:78)

... 25 more

Caused by: java.lang.ClassNotFoundException: Cannot find class: cn.jnshu.students.mapper.StudentsMapper.java

at org.apache.ibatis.io.ClassLoaderWrapper.classForName(ClassLoaderWrapper.java:200)

at org.apache.ibatis.io.ClassLoaderWrapper.classForName(ClassLoaderWrapper.java:89)

at org.apache.ibatis.io.Resources.classForName(Resources.java:261)

at org.apache.ibatis.builder.xml.XMLConfigBuilder.mapperElement(XMLConfigBuilder.java:376)

at org.apache.ibatis.builder.xml.XMLConfigBuilder.parseConfiguration(XMLConfigBuilder.java:118)

... 27 more

   按照师兄的指点，clean和install之后，还是有如上报错。

4.今日收获

1）了解SSM架构；

2）对Mybatis有了进一步了解