mybatis入门常见错误
1.Exception in thread "main" java.io.IOException: Could not find resource config2.xml
需要去Reader reader=Resources.getResourceAsReader("config2.xml");代碼處看下,是否和src下面的配置文件名稱(chēng)一樣,如果不一樣,澤會(huì)報(bào)沒(méi)有發(fā)現(xiàn)資源文件的錯(cuò)誤;
2.White spaces are required after keyword PUBLIC in DOCTYPE decl,原因是<!DOCTYPE configuration PUBLIC"-//mybatis.org//DTD Config 3.0//EN"
?? ?"http://mybatis.org/dtd/mybatis-3-config.dtd">,public后面應(yīng)該加空格;
3.Element type "enviroments" must be declared.或Element type "enviroment" must be declared.,Attribute "resourse" must be declared for element type "mapper".等type需要定義的錯(cuò)誤,則是標(biāo)簽出問(wèn)題了,需要檢查xml配置文件;
4.The content of element type "transactionManager" must match "(property)*".,錯(cuò)誤是<transactionManager type="JDBC"/>,標(biāo)簽用完就結(jié)束,不要包含property.
5.Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'Dept'.? Cause: java.lang.ClassNotFoundException: Cannot find class: Dept,,原因是<select id="selectOne" parameterType="int" resultType="Dept">,此處的返回類(lèi)型出問(wèn)題了!!!,需要返回bean包下的實(shí)體類(lèi)。
綜上所述,針對(duì)開(kāi)始學(xué)習(xí)配置文件的同學(xué)們來(lái)說(shuō),寫(xiě)的時(shí)候,要仔細(xì)再仔細(xì)!!!注意大小寫(xiě) 空格 單引號(hào) 全交 半角等等問(wèn)題!!!
6.### Error opening session.? Cause: java.lang.NullPointerException
### Cause: java.lang.NullPointerException,原因是配置環(huán)境問(wèn)題
<environments default="development">
?? ??? ??? ?<environment id="developmet">,id和default要一致;
?
總結(jié)
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