求助：java.sql.SQLException: 类型长度大于最大值

各位高手请帮帮忙，在读取clob字段时出现以下问题：
java.sql.SQLException: 类型长度大于最大值
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:134)
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:179)
at oracle.jdbc.dbaccess.DBError.check_error(DBError.java:1160)
at oracle.jdbc.ttc7.MAREngine.unmarshalUCS2(MAREngine.java:1144)
at oracle.jdbc.ttc7.v8TTILobd.unmarshalClobUB2(v8TTILobd.java:527)
at oracle.jdbc.ttc7.v8TTILob.receiveReply(v8TTILob.java:971)
at oracle.jdbc.ttc7.v8TTIClob.read(v8TTIClob.java:153)
at oracle.jdbc.ttc7.TTC7Protocol.lobRead(TTC7Protocol.java:2540)
at oracle.sql.LobDBAccessImpl.getChars(LobDBAccessImpl.java:606)
at oracle.sql.CLOB.getChars(CLOB.java:428)
at DataImport.QuestionE.getCLOBContent(QuestionE.java:111)
at DataImport.QuestionE.build(QuestionE.java:75)
at DataImport.QuestionE.build(QuestionE.java:93)
at DataImport.QuestionE.main(QuestionE.java:45)
Exception in thread "main"