java - 更改Gradle Project的文件夹结构时，线程 “main” java.lang.ExceptionInInitializerError中的异常

Question

Exception in thread "main" java.lang.ExceptionInInitializerError
    at com.myBatis.Dao.VillageDAO.save(VillageDAO.java:14)
    at com.myBatis.service.RunMybatis.main(RunMybatis.java:17)
Caused by: org.apache.ibatis.exceptions.PersistenceException: 
### Error building SqlSession.
### The error may exist in SQL Mapper Configuration
### Cause: org.apache.ibatis.builder.BuilderException: Error parsing SQL Mapper Configuration. Cause: org.apache.ibatis.builder.BuilderException: Error registering typeAlias for 'village'. Cause: java.lang.ClassNotFoundException: Cannot find class: com.myBatis.mapper.Village
    at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:26)
    at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:82)
    at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:66)
    at com.myBatis.service.MyBatisUtil.<clinit>(MyBatisUtil.java:23)
    ... 2 more
Caused by: org.apache.ibatis.builder.BuilderException: Error parsing SQL Mapper Configuration. Cause: org.apache.ibatis.builder.BuilderException: Error registering typeAlias for 'village'. Cause: java.lang.ClassNotFoundException: Cannot find class: com.myBatis.mapper.Village
    at org.apache.ibatis.builder.xml.XMLConfigBuilder.parseConfiguration(XMLConfigBuilder.java:109)
    at org.apache.ibatis.builder.xml.XMLConfigBuilder.parse(XMLConfigBuilder.java:92)
    at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:80)
    ... 4 more
Caused by: org.apache.ibatis.builder.BuilderException: Error registering typeAlias for 'village'. Cause: java.lang.ClassNotFoundException: Cannot find class: com.myBatis.mapper.Village
    at org.apache.ibatis.builder.xml.XMLConfigBuilder.typeAliasesElement(XMLConfigBuilder.java:130)
    at org.apache.ibatis.builder.xml.XMLConfigBuilder.parseConfiguration(XMLConfigBuilder.java:99)
    ... 6 more
Caused by: java.lang.ClassNotFoundException: Cannot find class: com.myBatis.mapper.Village
    at org.apache.ibatis.io.ClassLoaderWrapper.classForName(ClassLoaderWrapper.java:190)
    at org.apache.ibatis.io.ClassLoaderWrapper.classForName(ClassLoaderWrapper.java:89)
    at org.apache.ibatis.io.Resources.classForName(Resources.java:256)
    at org.apache.ibatis.builder.xml.XMLConfigBuilder.typeAliasesElement(XMLConfigBuilder.java:123)
    ... 7 more

I tried to perform a simple CRUD operations in Gradle project using myBatis configuration.When i used all my java files at src/java/main with single package it is all good. but when i tried to split up the files with multiple packages inside the same src/main/java dir it throws the java.lang.ClassNotFoundException exception. help me out guys.

VillageMapper.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="com.myBatis.mapper.VillageMapper" >
    <resultMap id="villageResult" type="village">
        <id property="id" column="id" />
        <result property="name" column="name"/>
        <result property="district" column="district"/>
    </resultMap>
    <select id="selectVillage" resultType="village" parameterType="int" resultMap="villageResult">
        SELECT id, name, district from village WHERE id = #{id}
    </select>
    <insert id="insertVillage" parameterType="village"  keyProperty="id" useGeneratedKeys="true">
        INSERT into village(name,district) VALUES(#{name}, #{district})         
    </insert>
    <update id="updateVillage" parameterType="village">
        UPDATE village SET name=#{name}, district =#{district} WHERE id =#{id}          
    </update>
    <delete id="deleteVillage" parameterType="int">
        DELETE FROM village WHERE id =#{id}         
    </delete>
</mapper>

mybatis-config.xml

<?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>
     <typeAlias type="com.myBatis.mapper.Village" alias="village"/>
  </typeAliases>  
  <environments default="development">
    <environment id="development">
      <transactionManager type="JDBC"/>
      <dataSource type="POOLED">
        <property name="driver" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://192.168.11.122:3306/srikanth_k"/>
        <property name="username" value="srikanth_k"/>
        <property name="password" value="demo"/>
      </dataSource>
    </environment>
  </environments>
  <mappers>
    <mapper resource="com/myBatis/mapper/VillageMapper.xml" />
  </mappers>
</configuration> 

MyBatisUtil.java

package com.myBatis.service;

import java.io.IOException;
import java.io.InputStream;

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

public class MyBatisUtil {

    private static SqlSessionFactory sqlSessionFactory;

    static {

        String resource = "mybatis-config.xml";

        InputStream inputStream;

        try {

            inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);

        } catch (IOException e) {

            e.printStackTrace();
        }
    }

    public static SqlSessionFactory getSqlSessionFactory() {

        return sqlSessionFactory;
    }
}

build.gradle

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'war'
archivesBaseName = 'myBatis'
version = '1' 
repositories {
    mavenCentral()
}
dependencies {
    compile 'org.mybatis:mybatis:3.2.8'
    compile 'mysql:mysql-connector-java:5.1.34'
} 

我的项目目录多个软件包版本

myBatis
    -src/main/java
        -com.myBatis.api
            -Village.java
        -com.myBatis.Dao
            -VillageDao.java
        -com.myBatis.service
            -MyBatisUtil.java
            -RunMyBatis.java
    -src/main/resources
        -com.myBatis.mapper
            -VillageMapper.xml
        -mybatis-config.xml

我的项目目录单包版本

    myBatis
        -src/main/java
            -com.myBatis.api
                -Village.java
                -VillageDao.java
                -MyBatisUtil.java
                -RunMyBatis.java
        -src/main/resources
                -com.myBatis.mapper
                    -VillageMapper.xml
                -mybatis-config.xml

Answer 1

问题出在 mybatis-config.xml

<typeAlias type="com.myBatis.mapper.Village" alias="village"/>

代替

<typeAlias type="com.myBatis.api.Village" alias="village"/>

我在 VillageDAO.java 的所有CRUD方法中都引用了 Village.java ，相反，我应该将其映射到 VillageMapper.xml 。

VillageDAO.java

package com.myBatis.Dao;


import org.apache.ibatis.session.SqlSession;

import com.myBatis.api.Village;
import com.myBatis.service.MyBatisUtil;


public class VillageDAO {

    public void save(Village village) {

        SqlSession session  = MyBatisUtil.getSqlSessionFactory().openSession();
        session.insert("com.myBatis.mapper.VillageMapper.insertVillage", village);
        session.commit();
        session.close();
    }

    public void update(Village village) {

        SqlSession session  = MyBatisUtil.getSqlSessionFactory().openSession();
        session.update("com.myBatis.mapper.VillageMapper.updateVillage", village);
        session.commit();
        session.close();
    }

    public void delete(Integer id) {

        SqlSession session  = MyBatisUtil.getSqlSessionFactory().openSession();
        session.delete("com.myBatis.mapper.VillageMapper.deleteVillage", id);
        session.commit();
        session.close();
    }

    public Village getData(Integer id) {

        SqlSession session  = MyBatisUtil.getSqlSessionFactory().openSession();
        Village village     = session.selectOne("com.myBatis.mapper.VillageMapper.selectVillage", id);
        session.close();
        return village;
    }
}