數據庫

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目錄結構

映入jar包和junit單元測試

com.geyao.mybatis.mapper

AuthorMapper類
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package com.geyao.mybatis.mapper;import com.geyao.mybatis.pojo.Author; public interface AuthorMapper {Author selectAuthorById(Integer id); }

BlogMapper類

package com.geyao.mybatis.mapper;import com.geyao.mybatis.pojo.Blog;public interface BlogMapper {Blog selectBlogById(Integer id); }

AuthorMapper.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"> <!-- 為這個mapper指定一個唯一的namespace，namespace的值習慣上設置成包名+sql映射文件名，這樣就能夠保證namespace的值是唯一的 例如namespace="me.gacl.mapping.userMapper"就是me.gacl.mapping(包名)+userMapper(userMapper.xml文件去除后綴)--> <mapper namespace="com.geyao.mybatis.mapper.AuthorMapper"><resultMap type="Author" id="authorResultMap"><id column="id" property="id" jdbcType="INTEGER"></id></resultMap><select id="selectAuthorById" parameterType="int" resultMap="authorResultMap">select * from author where id=#{id}</select> </mapper>

BlogMapper.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.geyao.mybatis.mapper.BlogMapper"><resultMap type="Blog" id="blogResultMap"><id column="id" property="id" jdbcType="INTEGER"></id> <association property="author" column="author" javaType="Author"select="com.geyao.mybatis.mapper.AuthorMapper.selectAuthorById"></association></resultMap><select id="selectBlogById" parameterType="int" resultMap="blogResultMap">select * from Blog where id=#{id}</select> </mapper>

com.geyao.mybatis.pojo

Author類

package com.geyao.mybatis.pojo;public class Author {private Integer id;private String username;private String password;private String email;private String bio;private String favouriteSection;private String nickname;private String realname;public Author() {super();}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}public String getPassword() {return password;}public void setPassword(String password) {this.password = password;}public String getEmail() {return email;}public void setEmail(String email) {this.email = email;}public String getBio() {return bio;}public void setBio(String bio) {this.bio = bio;}public String getFavouriteSection() {return favouriteSection;}public void setFavouriteSection(String favouriteSection) {this.favouriteSection = favouriteSection;}public String getNickname() {return nickname;}public void setNickname(String nickname) {this.nickname = nickname;}public String getRealname() {return realname;}public void setRealname(String realname) {this.realname = realname;}public Author(Integer id, String username, String password, String email, String bio, String favouriteSection,String nickname, String realname) {super();this.id = id;this.username = username;this.password = password;this.email = email;this.bio = bio;this.favouriteSection = favouriteSection;this.nickname = nickname;this.realname = realname;}@Overridepublic String toString() {return "Author [id=" + id + ", username=" + username + ", password=" + password + ", email=" + email + ", bio="+ bio + ", favouriteSection=" + favouriteSection + ", nickname=" + nickname + ", realname=" + realname+ "]";}}

Blog類

package com.geyao.mybatis.pojo;import java.io.Serializable;public class Blog implements Serializable {private static final long serialVersionUID = 1L;private Integer id;private String title;private Author author;private String state;private boolean featured;private String style;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getTitle() {return title;}public void setTitle(String title) {this.title = title;}public Author getAuthor() {return author;}public void setAuthor(Author author) {this.author = author;}public String getState() {return state;}public void setState(String state) {this.state = state;}public boolean isFeatured() {return featured;}public void setFeatured(boolean featured) {this.featured = featured;}public String getStyle() {return style;}public void setStyle(String style) {this.style = style;}public static long getSerialversionuid() {return serialVersionUID;}@Overridepublic String toString() {return "Blog [id=" + id + ", title=" + title + ", author=" + author + ", state=" + state + ", featured="+ featured + ", style=" + style + "]";}}

com.geyao.mybatis.util

MybatisUtil類

package com.geyao.mybatis.util;import java.io.InputStream; 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 MyBatisUtil {private static SqlSessionFactory sqlSessionFactory =null;static {try {InputStream in = Resources.getResourceAsStream("mybatis-config.xml");sqlSessionFactory = new SqlSessionFactoryBuilder().build(in);} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}}private MyBatisUtil() {}public static SqlSession getSqlSession() {return sqlSessionFactory.openSession();} }

com.geyao.mybatis.mapper測試類

BlogMapperTest

package com.geyao.mybatis.mapper;import org.apache.ibatis.session.SqlSession; import org.junit.Test;import com.geyao.mybatis.pojo.Author; import com.geyao.mybatis.pojo.Blog; import com.geyao.mybatis.util.MyBatisUtil;public class BlogMapperTest {@Testpublic void testSelectBlog() {SqlSession session =MyBatisUtil.getSqlSession();BlogMapper blogMapper =session.getMapper(BlogMapper.class);Blog blog = blogMapper.selectBlogById(1);session.close();System.out.println(blog);}}

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> <settings><setting name="useGeneratedKeys" value="true"/> </settings> <typeAliases><typeAlias type="com.geyao.mybatis.pojo.Blog" alias="Blog"/><typeAlias type="com.geyao.mybatis.pojo.Author" alias="Author"/> </typeAliases><environments default="development"><environment id="development"><transactionManager type="JDBC" /><!-- 配置數據庫連接信息 --><dataSource type="POOLED"><property name="driver" value="com.mysql.cj.jdbc.Driver" /><property name="url" value="jdbc:mysql://localhost:3306/blog_gp1701?serverTimezone=GMT%2B8" /><property name="username" value="root" /><property name="password" value="123" /></dataSource></environment></environments><mappers><!-- 注冊userMapper.xml文件， userMapper.xml位于me.gacl.mapping這個包下，所以resource寫成me/gacl/mapping/userMapper.xml--><mapper resource="com/geyao/mybatis/mapper/BlogMapper.xml"/><mapper resource="com/geyao/mybatis/mapper/AuthorMapper.xml"/></mappers> </configuration>

log4j.properties

### \u914D\u7F6E\u6839 ### log4j.rootLogger = debug,console ,fileAppender,dailyRollingFile,ROLLING_FILE,MAIL,DATABASE### \u8BBE\u7F6E\u8F93\u51FAsql\u7684\u7EA7\u522B\uFF0C\u5176\u4E2Dlogger\u540E\u9762\u7684\u5185\u5BB9\u5168\u90E8\u4E3Ajar\u5305\u4E2D\u6240\u5305\u542B\u7684\u5305\u540D ### log4j.logger.org.apache=dubug log4j.logger.java.sql.Connection=dubug log4j.logger.java.sql.Statement=dubug log4j.logger.java.sql.PreparedStatement=dubug log4j.logger.java.sql.ResultSet=dubug### \u914D\u7F6E\u8F93\u51FA\u5230\u63A7\u5236\u53F0 ### log4j.appender.console = org.apache.log4j.ConsoleAppender log4j.appender.console.Target = System.out log4j.appender.console.layout = org.apache.log4j.PatternLayout log4j.appender.console.layout.ConversionPattern = %d{ABSOLUTE} %5p %c{1}:%L - %m%n

運行結果

總結

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