Classic cases of MyBatis and classic cases of MyBatis

Classic cases of MyBatis and classic cases of MyBatis

1. First, we first understand some jar packages of Mybatis.

--- And project framework

2. Next let's take a look at the configuration file (mybatis-config.xml) of mybatis)

 

<? Xml version = "1.0" encoding = "UTF-8"?> <! DOCTYPE configurationPUBLIC "-// mybatis.org//DTD Config 3.0 //" http://mybatis.org/dtd/mybatis-3-config.dtd "> <configuration> <! -- Alias --> <typeAliases> <package name = "cn. happy. entity "/> </typeAliases> <environments default =" development "> <environment id =" development "> <! -- Use jdbc transactions --> <transactionManager type = "JDBC"/> <! -- Use the built-in connection pool --> <dataSource type = "POOLED"> <property name = "driver" value = "oracle. jdbc. oracleDriver "/> <property name =" url "value =" jdbc: oracle: thin: @ localhost: 1521: orcl "/> <property name =" username "value =" happy "/> <property name =" password "value =" 1 "/> </dataSource> </environment> </environments> <mappers>
<! -- Connection configuration --> <mapper resource = "cn/happy/dao/StudentDAO. xml"/> </mappers> </configuration>

 

3. Small configuration on the dao layer (StudentDAO. xml)

 

<? Xml version = "1.0" encoding = "UTF-8"?> <! DOCTYPE mapperPUBLIC "-// mybatis.org//DTD Mapper 3.0 //" http://mybatis.org/dtd/mybatis-3-mapper.dtd "> <mapper namespace =" cn. happy. dao "> <! -- Add --> <insert id = "insertStudent"> insert into student (stuno, stuname, stuage, studate) values (ssm. nextval, # {stuname}, # {stuage}, # {studate}) <selectKey keyProperty = "stuno" resultType = "int"> select SSM. CURRVAL from dual </selectKey> </insert> <! -- Query all --> <select id = "findAll" resultType = "Student"> select * from student </select> <! -- Fuzzy query --> <select id = "findAllLike" resultType = "Student"> <! -- No matter why the parameter is available --> <! -- Select * from student where stuname like concat ('%', # {stuname}, '%') --> <! -- String --> <! -- Select * from student where stuname like '% $ {value} %' --> <! -- Object --> select * from student where stuname like '% $ {stuname} %' </select> <! -- Delete student --> <delete id = "delStudent"> delete from student where stuno =#{ id} <! -- # {Id} can be written as a placeholder --> </delete> </mapper>

 

 

4. entity layer entity class (Student)

 

package cn.happy.entity;import java.util.Date;public class Student {    private int stuno;    private String stuname;    private int stuage;    private Date studate;    public String toString() {        return "Student [stuno=" + stuno + ", stuname=" + stuname + ", stuage="                + stuage + ", studate=" + studate + "]";    }    public int getStuno() {        return stuno;    }    public void setStuno(int stuno) {        this.stuno = stuno;    }    public String getStuname() {        return stuname;    }    public void setStuname(String stuname) {        this.stuname = stuname;    }    public int getStuage() {        return stuage;    }    public void setStuage(int stuage) {        this.stuage = stuage;    }    public Date getStudate() {        return studate;    }    public void setStudate(Date studate) {        this.studate = studate;    }    }

 

 

5. dao layer (IStudentDAO)

 

Package cn. happy. dao; import java. io. IOException; import java. util. list; import cn. happy. entity. student; public interface IStudentDAO {/** add Student information */public int addStu (Student stu) throws IOException;/** query all */public List <Student> findAll () throws IOException;/** fuzzy query */public List <Student> findAlllike (Student stu) throws IOException; /** fuzzy query String */public List <Student> findAlllikebstuname (String stuname) throws IOException;/** Delete */public int delStudent (int id) throws IOException ;}

 

 

6. impl layer (IStudentDAOImpl) under dao Layer)

 

Package cn. happy. dao. impl; import java. io. IOException; import java. util. list; import org. apache. ibatis. session. sqlSession; import cn. happy. dao. IStudentDAO; import cn. happy. entity. student; import cn. happy. util. mybatisUtil; public class IStudentDAOImpl implements IStudentDAO {/** session member variable */SqlSession session;/** add * (non-Javadoc) * @ see cn. happy. dao. IStudentDAO # addStu (cn. happy. entity. student) */public int addStu (Student stu) throws IOException {// get session = MybatisUtil. getSession (); // Add insert int result = session. insert ("insertStudent", stu); // Add transaction session. commit (); // close the session. close (); return result;}/** query all * (non-Javadoc) * @ see cn. happy. dao. IStudentDAO # fandAll () */public List <Student> findAll () throws IOException {// get session = MybatisUtil. getSession (); List <Student> list = session. selectList ("findAll"); // closes the session. close (); return list;}/** fuzzy query * 1. the parameter is the object * (non-Javadoc) * @ see cn. happy. dao. IStudentDAO # findAll (cn. happy. entity. student) */public List <Student> findAlllike (Student stu) throws IOException {// get session = MybatisUtil. getSession (); List <Student> list = session. selectList ("findAllLike", stu); // close the session. close (); return list;}/** fuzzy query * 2. the parameter is a string * (non-Javadoc) * @ see cn. happy. dao. IStudentDAO # findAll (cn. happy. entity. student) */public List <Student> findAlllikebstuname (String stuname) throws IOException {// get session = MybatisUtil. getSession (); System. out. println ("222"); List <Student> list = session. selectList ("findAllLike", stuname); System. out. println ("333"); // closes the session. close (); return list;}/** Delete */public int delStudent (int id) throws IOException {// get session = MybatisUtil. getSession (); int result = session. delete ("delStudent", id); session. commit (); return result ;}}

 

 

7. util tool class (MybatisUtil)

 

Package cn. happy. util; import java. io. IOException; 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;/*** tool class * @ author Happy **/public class MybatisUtil {private static String config = "mybatis-config.xml"; static Reader reader; static {try {reader = Resources. getResourceAsReader (config);} catch (IOException e) {e. printStackTrace () ;}} private static SqlSessionFactory factory = new SqlSessionFactoryBuilder (). build (reader); // provides a method for obtaining the session public static SqlSession getSession () throws IOException {// 1.1 what is done by openSession SqlSession session = factory. openSession (); System. out. println ("3333"); return session ;}}

 

 

8. log information configuration file (log4j. properties)

 

### Direct log messages to stdout ### log4j. appender. stdout = org. apache. log4j. leleappenderlog4j. appender. stdout. target = System. outlog4j. appender. stdout. layout = org. apache. log4j. patternLayoutlog4j. appender. stdout. layout. conversionPattern = % d {ABSOLUTE} % 5 p % c {1}: % L-% m % n ### direct messages to file mylog. log ### log4j. appender. file = org. apache. log4j. fileAppenderlog4j. appender. file. file = c \: mylog. loglog4j. appender. file. layout = org. apache. log4j. patternLayoutlog4j. appender. file. layout. conversionPattern = % d {ABSOLUTE} % 5 p % c {1 }: % L-% m % n ### set log levels-for more verbose logging change 'info' to 'debug '###
// Record the information in the cn. happy. dao package log4j.logger.cn. happy. dao = trace, stdout

 

 

So much for now. If you want to know more, remember to pay more attention !!!!