MyBatis报错记录 Caused by: java.lang.NoClassDefFoundError: Could not initialize class ...

待我称王封你为后i 2022-03-28 06:28 541阅读 0赞

**在使用MyBatis+Servlet开发Web工程时，主要报错代码如下**

org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
        org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)
            	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:783)
            	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
            	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:789)
            	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1437)
            	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
            	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
            	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
            	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
            	at java.lang.Thread.run(Thread.java:745)
            Caused by: java.lang.NoClassDefFoundError: Could not initialize class cn.easybuy.utils.MyBatisUtil
            	at cn.easybuy.service.user.UserServiceImpl.getUser(UserServiceImpl.java:176)
            	at cn.easybuy.web.pre.LoginServlet.login(LoginServlet.java:53)
            	... 32 more

在经过检查配置文件和程序调试后，发现程序也可以正常走流程，但是总是报找不到MyBatisUtil工具类的错误，MyBatisUtil.java如下

package cn.smbms.utils;
    
    import java.io.IOException;
    import java.io.InputStream;
    
    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 factory;
    	
    	static{
    		try {
    			//1.获取mybatis-config.xml输入流
    			InputStream  is = Resources.getResourceAsStream("mybatis-config.xml");
    			//2.创建sqlSessionFactory对象 ，完成对配置文件的读取
    			factory=new SqlSessionFactoryBuilder().build(is);
    		} catch (IOException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    	}
    	
    	
    	/**
    	 * 创建sqlSession对象
    	 * @return
    	 */
    	public static SqlSession createSqlSession(){
    		
    		return factory.openSession(false);
    	}
    	
    	
    	/**
    	 * 关闭sqlSession
    	 * @param sqlSession
    	 */
    	public static void closeSqlSession(SqlSession sqlSession){
    		if(null!=sqlSession){
    			sqlSession.close();
    		}
    	}
    	
    }

**报错原因：**  
使用MyBatis+Servlet集成Web项目时，会有冲突，故换一种解析方式

**解决方案：**  
修改MyBatisUtil.java，换一种方式解析mybatis-config.xml核心配置文件,代码如下

package cn.easybuy.utils;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.net.URL;
    
    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 factory;
    	private static final long serialVersionUID = 1L;
    
    	static {
    		//mybatis-config.xml路径
    		String resource = "mybatis-config.xml";
    		URL o = Thread.currentThread().getContextClassLoader().getResource("");
    		//String path = o.getPath().replace("classes", "config");
    		InputStream is=null;
    		try {
    			is = new FileInputStream(new File(resource));
    			factory = new SqlSessionFactoryBuilder().build(is);
    
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    		
    	}
    
    	/**
    	 * 创建sqlSession对象
    	 * 
    	 * @return
    	 */
    	public static SqlSession createSqlSession() {
    
    		return factory.openSession(false);
    	}
    
    	/**
    	 * 关闭sqlSession会话
    	 * 
    	 * @param sqlSession
    	 */
    	public static void closeSqlSession(SqlSession sqlSession) {
    		try {
    			if (null != sqlSession) {
    				sqlSession.close();
    			}
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    
    	}
    
    }