1.根据xml创建sqlsession报错。
2.错误信息如下。

Exception in thread "main" org.apache.ibatis.exceptions.PersistenceException: 
Error building SqlSession.
Cause: org.apache.ibatis.builder.BuilderException: Error creating document instance.  Cause: org.xml.sax.SAXParseException; lineNumber: 13; columnNumber: 9; 文档根元素 "beans" 必须匹配 DOCTYPE 根 "null"。
    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.asiainfo.jf.common.commUtil.CommonParaUtil.getPara(CommonParaUtil.java:37)
    at com.asiainfo.jf.common.commUtil.CommonParaUtil.main(CommonParaUtil.java:130)
Caused by: org.apache.ibatis.builder.BuilderException: Error creating document instance.  Cause: org.xml.sax.SAXParseException; lineNumber: 13; columnNumber: 9; 文档根元素 "beans" 必须匹配 DOCTYPE 根 "null"。
    at org.apache.ibatis.parsing.XPathParser.createDocument(XPathParser.java:259)
    at org.apache.ibatis.parsing.XPathParser.(XPathParser.java:125)
    at org.apache.ibatis.builder.xml.XMLConfigBuilder.(XMLConfigBuilder.java:78)
    at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:79)
    ... 3 more
Caused by: org.xml.sax.SAXParseException; lineNumber: 13; columnNumber: 9; 文档根元素 "beans" 必须匹配 DOCTYPE 根 "null"。
    at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:198)
    at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.error(ErrorHandlerWrapper.java:134)
    at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:437)
    at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:368)
    at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:325)
    at com.sun.org.apache.xerces.internal.impl.dtd.XMLDTDValidator.rootElementSpecified(XMLDTDValidator.java:1599)
    at com.sun.org.apache.xerces.internal.impl.dtd.XMLDTDValidator.handleStartElement(XMLDTDValidator.java:1877)
    at com.sun.org.apache.xerces.internal.impl.dtd.XMLDTDValidator.startElement(XMLDTDValidator.java:742)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanStartElement(XMLDocumentFragmentScannerImpl.java:1363)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$ContentDriver.scanRootElementHook(XMLDocumentScannerImpl.java:1292)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:3138)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:880)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:606)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:510)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:848)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:777)
    at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
    at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:243)
    at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:347)
    at org.apache.ibatis.parsing.XPathParser.createDocument(XPathParser.java:257)
    ... 6 more

3.根据网上说的去掉xml中的注释，已经试过了，没有作用。
4.xml如下

       
          
     
    
    
        
            ${jdbc.driverClassName}
        
        
            ${jdbc.url}
        
        
            ${jdbc.username}
        
        
            ${jdbc.password}
        
    
   
    
        
        
        
    
    
        
        
    
    
    
        
    

    

    
        
            
            
            
            
            
            
            
            
            
            
            

            
            
            
            
            

            
        
    
    
        
        
    
    -->