最近在整一个mybatis的测试，其中一个类报空指针异常，代码及异常如下

[xuhao167]

package com.yihaomen.test;

import java.io.Reader;
import java.util.List;

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 com.yihaomen.mybatis.inter.IUserOperation;
import com.yihaomen.mybatis.model.User;
public class Test1{
	private static SqlSessionFactory sqlSessionFactory;
    private static Reader reader; 
public void getUserList(int id){
    SqlSession session = sqlSessionFactory.openSession();
    try {
        IUserOperation userOperation=session.getMapper(IUserOperation.class);          
        List<User> users = userOperation.selectUsers(id);
        for(User user:users){
            System.out.println(user.getId()+":"+user.getUserName()+":"+user.getUserAddress());
        }
        
    } finally {
        session.close();
    }
}
public static void main(String[] args) {
	int i=1;
    Test1 testUser=new Test1();
    testUser.getUserList(i);
}
}

Exception in thread "main" java.lang.NullPointerException
	at com.yihaomen.test.Test1.getUserList(Test1.java:17)
	at com.yihaomen.test.Test1.main(Test1.java:32)

[zhushanzhi]

sqlSessionFactory未初始化吧

[zhushanzhi]

或者是SessionFactory.openSession()

[zhushanzhi]

或者是SessionFactory.openSession()

[今天晴]

引用 6 楼 xuhao167 的回复:

[quote=引用 5 楼 TTWiFi 的回复:] sqlSessionFactory是空的

在getUserList()中增加了初始化，还是报空指针异常 sqlSessionFactory=new SqlSessionFactoryBuilder().build(reader);[/quote]你的reader也是空的

[尼古拉斯-全蛋]

sqlSessionFactory

[今天晴]

sqlSessionFactory是空的

[xuhao167]

引用 5 楼 TTWiFi 的回复:

sqlSessionFactory是空的

在getUserList()中增加了初始化，还是报空指针异常 sqlSessionFactory=new SqlSessionFactoryBuilder().build(reader);