第一步：编写一个工具类
package com.heerlin.utils;
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 java.io.IOException;
import java.io.InputStream;
public class MybatisUtils {
private static SqlSessionFactory sqlSessionFactory;
static
{
try {
String resource="mybatis-config.xml";
InputStream inputStream= Resources.getResourceAsStream(resource);
sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
} catch (IOException e) {
throw new RuntimeException(e);
}
}
public static SqlSession getSqlSession()
{
return sqlSessionFactory.openSession();
}
}
第二步：有了工具类我们需要一个配置文件，写在resource里：
package com.heerlin.utils;
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 java.io.IOException;
import java.io.InputStream;
public class MybatisUtils {
private static SqlSessionFactory sqlSessionFactory;
static
{
try {
String resource="mybatis-config.xml";
InputStream inputStream= Resources.getResourceAsStream(resource);
sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
} catch (IOException e) {
throw new RuntimeException(e);
}
}
public static SqlSession getSqlSession()
{
return sqlSessionFactory.openSession();
}
}
第三步：编写实体类
package com.heerlin.pojo;
public class User {
private int id;
private String name;
private String pwd;
public User() {
}
public User(int id, String name, String pwd) {
this.id = id;
this.name = name;
this.pwd = pwd;
}
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 getPwd() {
return pwd;
}
public void setPwd(String pwd) {
this.pwd = pwd;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", name='" + name + '\'' +
", pwd='" + pwd + '\'' +
'}';
}
}
第四步：写接口
第五步写：xml文件
最后写测试类：
package com.heerlin.dao;
import com.heerlin.pojo.User;
import com.heerlin.utils.MybatisUtils;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import java.util.List;
public class UserDaoTest {
@Test
public void test()
{
SqlSession sqlSession = MybatisUtils.getSqlSession();
//方法一
UserDao userDao = sqlSession.getMapper(UserDao.class);
List<User> userList = userDao.getUserList();
for(User user:userList)
{
System.out.println(user);
}
//关闭
sqlSession.close();
}
}
我们可能会遇到静态资源过滤问题：
D:\AAAW\myjdk17\bin\java.exe -ea -Didea.test.cyclic.buffer.size=1048576 "-javaagent:D:\Program Files\JetBrains\IntelliJ IDEA 2023.1.3\lib\idea_rt.jar=56344:D:\Program Files\JetBrains\IntelliJ IDEA 2023.1.3\bin" -Dfile.encoding=UTF-8 -classpath "D:\Program Files\JetBrains\IntelliJ IDEA 2023.1.3\lib\idea_rt.jar;D:\Program Files\JetBrains\IntelliJ IDEA 2023.1.3\plugins\junit\lib\junit5-rt.jar;D:\Program Files\JetBrains\IntelliJ IDEA 2023.1.3\plugins\junit\lib\junit-rt.jar;D:\javaproject\Myabtis-study\mybatis-01\target\test-classes;D:\javaproject\Myabtis-study\mybatis-01\target\classes;D:\AAAW\maven\apache-maven-3.6.1-bin\apache-maven-3.6.1\mvn_repo\mysql\mysql-connector-java\8.0.30\mysql-connector-java-8.0.30.jar;D:\AAAW\maven\apache-maven-3.6.1-bin\apache-maven-3.6.1\mvn_repo\com\google\protobuf\protobuf-java\3.19.4\protobuf-java-3.19.4.jar;D:\AAAW\maven\apache-maven-3.6.1-bin\apache-maven-3.6.1\mvn_repo\org\mybatis\mybatis\3.5.13\mybatis-3.5.13.jar;D:\AAAW\maven\apache-maven-3.6.1-bin\apache-maven-3.6.1\mvn_repo\junit\junit\4.12\junit-4.12.jar;D:\AAAW\maven\apache-maven-3.6.1-bin\apache-maven-3.6.1\mvn_repo\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar" com.intellij.rt.junit.JUnitStarter -ideVersion5 -junit4 com.heerlin.dao.UserDaoTest,test
java.lang.ExceptionInInitializerError
at com.heerlin.dao.UserDaoTest.test(UserDaoTest.java:14)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:568)
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$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69)
at com.intellij.rt.junit.IdeaTestRunner$Repeater$1.execute(IdeaTestRunner.java:38)
at com.intellij.rt.execution.junit.TestsRepeater.repeat(TestsRepeater.java:11)
at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:35)
at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:232)
at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:55)
Caused by: org.apache.ibatis.exceptions.PersistenceException:
### Error building SqlSession.
### The error may exist in com/heerlin/dao/UserMapper.xml
### Cause: org.apache.ibatis.builder.BuilderException: Error parsing SQL Mapper Configuration. Cause: java.io.IOException: Could not find resource com/heerlin/dao/UserMapper.xml
at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30)
at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:82)
at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:66)
at com.heerlin.utils.MybatisUtils.<clinit>(MybatisUtils.java:18)
... 25 more
Caused by: org.apache.ibatis.builder.BuilderException: Error parsing SQL Mapper Configuration. Cause: java.io.IOException: Could not find resource com/heerlin/dao/UserMapper.xml
at org.apache.ibatis.builder.xml.XMLConfigBuilder.parseConfiguration(XMLConfigBuilder.java:133)
at org.apache.ibatis.builder.xml.XMLConfigBuilder.parse(XMLConfigBuilder.java:110)
at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:80)
... 27 more
Caused by: java.io.IOException: Could not find resource com/heerlin/dao/UserMapper.xml
at org.apache.ibatis.io.Resources.getResourceAsStream(Resources.java:132)
at org.apache.ibatis.io.Resources.getResourceAsStream(Resources.java:113)
at org.apache.ibatis.builder.xml.XMLConfigBuilder.mapperElement(XMLConfigBuilder.java:395)
at org.apache.ibatis.builder.xml.XMLConfigBuilder.parseConfiguration(XMLConfigBuilder.java:131)
... 29 more
Process finished with exit code -1
静态资源过滤解决方法（在pom文件下加入）：
<build>
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>false</filtering>
</resource>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>false</filtering>
</resource>
</resources>
</build>
