mybatis 类中没有方法，配置文件错误？java.lang.NoSuchMethodException: com.imoc.pojo.User.<init>()

Question

log4j:WARN No appenders could be found for logger (org.apache.ibatis.logging.LogFactory).

log4j:WARN Please initialize the log4j system properly.

log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.

Exception in thread "main" org.apache.ibatis.exceptions.PersistenceException: 

### Error querying database.  Cause: org.apache.ibatis.reflection.ReflectionException: Error instantiating class com.imoc.pojo.User with invalid types () or values (). Cause: java.lang.NoSuchMethodException: com.imoc.pojo.User.<init>()

### The error may exist in com/imoc/mapping/userManpper.xml

### The error may involve com/imoc/mapping/userManpper.getUser-Inline

### The error occurred while setting parameters

### SQL: select * from users where id=?

### Cause: org.apache.ibatis.reflection.ReflectionException: Error instantiating class com.imoc.pojo.User with invalid types () or values (). Cause: java.lang.NoSuchMethodException: com.imoc.pojo.User.<init>()

at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:23)

at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:107)

at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:98)

at org.apache.ibatis.session.defaults.DefaultSqlSession.selectOne(DefaultSqlSession.java:62)

at com.imoc.test.Test.main(Test.java:24)

Caused by: org.apache.ibatis.reflection.ReflectionException: Error instantiating class com.imoc.pojo.User with invalid types () or values (). Cause: java.lang.NoSuchMethodException: com.imoc.pojo.User.<init>()

at org.apache.ibatis.reflection.factory.DefaultObjectFactory.instantiateClass(DefaultObjectFactory.java:83)

at org.apache.ibatis.reflection.factory.DefaultObjectFactory.create(DefaultObjectFactory.java:45)

at org.apache.ibatis.reflection.factory.DefaultObjectFactory.create(DefaultObjectFactory.java:38)

at org.apache.ibatis.executor.resultset.FastResultSetHandler.createResultObject(FastResultSetHandler.java:386)

at org.apache.ibatis.executor.resultset.FastResultSetHandler.createResultObject(FastResultSetHandler.java:365)

at org.apache.ibatis.executor.resultset.FastResultSetHandler.getRowValue(FastResultSetHandler.java:261)

at org.apache.ibatis.executor.resultset.FastResultSetHandler.handleRowValues(FastResultSetHandler.java:216)

at org.apache.ibatis.executor.resultset.FastResultSetHandler.handleResultSet(FastResultSetHandler.java:188)

at org.apache.ibatis.executor.resultset.FastResultSetHandler.handleResultSets(FastResultSetHandler.java:154)

at org.apache.ibatis.executor.statement.PreparedStatementHandler.query(PreparedStatementHandler.java:57)

at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:70)

at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:57)

at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:259)

at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:132)

at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:105)

at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:81)

at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:104)

... 3 more

Caused by: java.lang.NoSuchMethodException: com.imoc.pojo.User.<init>()

at java.lang.Class.getConstructor0(Class.java:2849)

at java.lang.Class.getDeclaredConstructor(Class.java:2053)

at org.apache.ibatis.reflection.factory.DefaultObjectFactory.instantiateClass(DefaultObjectFactory.java:57)

... 19 more

package com.imoc.pojo;

public class User {
	
	private int id;
    private String name;
    private int age;
    
	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 int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	
	
	public User(int id) {
		super();
		this.id = id;
	}
	public User(int id, String name, int age) {
		super();
		this.id = id;
		this.name = name;
		this.age = age;
	}
	@Override
	public String toString() {
		return "User [id=" + id + ", name=" + name + ", age=" + age + "]";
	}

}

<mapper namespace="com/imoc/mapping/userManpper">
  
    <select id="getUser" parameterType="int" 
        resultType="com.imoc.pojo.User">
         select * from users where id=#{id}
    </select>
</mapper>

<configuration>
	<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://localhost:3306/mybatis" />
                 <property name="username" value="root" />
                 <property name="password" value="" />
				
				</dataSource>
		</environment>
	</environments>
	<mappers>
		<mapper resource="com/imoc/mapping/userManpper.xml"/>
		
		</mappers>



</configuration>

	String resource = "config.xml";
InputStream is=Test.class.getClassLoader().getResourceAsStream(resource);
SqlSessionFactory sFactory=new SqlSessionFactoryBuilder().build(is);

SqlSession sqlSession=sFactory.openSession();

User user=sqlSession.selectOne("com/imoc/mapping/userManpper.getUser",1);

System.out.println(user);
sqlSession.close();

Answer 1

参数错了