When compiling the class Main.java, an error occurs:

Exception in thread "main" java.lang.ExceptionInInitializerError at com.sivalabs.mybatisdemo.service.BlogService.insertBlog(BlogService.java:13) at com.sivalabs.mybatisdemo.main.Main.main(Main.java:22) Caused by: org.apache.ibatis.exceptions.PersistenceException: ### Error building SqlSession. ### The error may exist in ./BlogMapper.xml ### The error occurred while processing mapper_resultMap[BlogResult] ### Cause: org.apache.ibatis.builder.BuilderException: Error parsing SQL Mapper Configuration. Cause: org.apache.ibatis.builder.BuilderException: Error creating document instance. Cause: org.xml.sax.SAXParseException; lineNumber: 2; columnNumber: 65; Document root element "mapper", must match DOCTYPE root "null". at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30) at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:54) at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:38) at com.sivalabs.mybatisdemo.service.MyBatisUtil.<clinit>(MyBatisUtil.java:22) ... 2 more

How to deal with this, please tell me?

Fragment of the project.

class Main:

 package com.sivalabs.mybatisdemo.main; import com.sivalabs.mybatisdemo.domain.Blog; import com.sivalabs.mybatisdemo.service.BlogService; import java.util.List; public class Main { public static void main(String[] args) { Blog blog = new Blog(); blog.setBlogId(1); blog.setBlogName("HELL0"); blog.setCreatedOn(null); BlogService blogService = new BlogService(); blogService.insertBlog(blog); List<Blog> blogs = blogService.getAllBlogs(); for (Blog bs : blogs) System.out.println(bs); } }

interface BlogMapper:

 package com.sivalabs.mybatisdemo.mappers; import java.util.List; import com.sivalabs.mybatisdemo.domain.Blog; public interface BlogMapper { public void insertBlog(Blog blog); public List<Blog> getAllBlogs(); }

class BlogService:

 package com.sivalabs.mybatisdemo.service; import com.sivalabs.mybatisdemo.domain.Blog; import java.util.List; import org.apache.ibatis.session.SqlSession; import com.sivalabs.mybatisdemo.mappers.BlogMapper; public class BlogService { public void insertBlog(Blog blog) { SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession(); try{ BlogMapper blogMapper = sqlSession.getMapper(BlogMapper.class); blogMapper.insertBlog(blog); sqlSession.commit(); } finally{ sqlSession.close(); } } public List<Blog> getAllBlogs() { SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession(); try{ BlogMapper blogMapper = sqlSession.getMapper(BlogMapper.class); return blogMapper.getAllBlogs(); }finally{ sqlSession.close(); } } }

class MyBatisUtil:

 package com.sivalabs.mybatisdemo.service; import java.io.IOException; import java.io.Reader; import org.apache.ibatis.io.Resources; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder; public class MyBatisUtil { private static SqlSessionFactory factory; private MyBatisUtil() { } static { Reader reader = null; try { reader = Resources.getResourceAsReader("mybatis-config.xml"); } catch (IOException e) { throw new RuntimeException(e.getMessage()); } factory = new SqlSessionFactoryBuilder().build(reader); } public static SqlSessionFactory getSqlSessionFactory() { return factory; } }

BlogMapper.xml:

 <?xml version="1.0" encoding="UTF-8"?> <mapper namespace="com.sivalabs.mybatisdemo.mappers.BlogMapper"> <resultMap type="Blog" id="BlogResult"> <id property="blogId" column="blog_id"/> <result property="blogName" column="BLOG_NAME"/> <result property="createdOn" column="CREATED_ON"/> </resultMap> <insert id="insertBlog" parameterType="Blog"> INSERT INTO blog (blog_id, BLOG_NAME, CREATED_ON) VALUES(#{blogId}, #{blogName}, #{createdOn}) </insert> <select id="getAllBlogs" resultMap="BlogResult"> SELECT b.blog_id, b.blog_name, b.created_on FROM blog b </select> </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.sivalabs.mybatisdemo.domain.User" alias="User"/> <typeAlias type="com.sivalabs.mybatisdemo.domain.Blog" alias="Blog"/> </typeAliases> <environments default="development"> <environment id="development"> <transactionManager type="JDBC"/> <dataSource type="POOLED"> <property name="driver" value="org.postgresql.Driver"/> <property name="url" value="jdbc.url=jdbc:postgresql://localhost:5432/mybatis"/> <property name="username" value="username"/> <property name="password" value="p@ssw0rd"/> </dataSource> </environment> </environments> <mappers> <mapper resource="./UserMapper.xml"/> <mapper resource="./BlogMapper.xml"/> </mappers> </configuration>

1 answer 1

You must specify the DOCTYPE for the MapMaper MapMaper:

 <?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.sivalabs.mybatisdemo.mappers.BlogMapper">

This is all described in the documentation.