Summary of common problems in development

applicationContext.xml Configuration problem in

Q1：applicationContext.xml In file , You should use ref To receive “ Reference type ” or “ Complex type ” When the data is , The wrong is used value To receive “ Reference type ” or “ Complex type ” The data of , This resulted in the following error ：

A1: Solution ： From the picture ① and ② You can go to , The specific location of the problem , Namely applicationContext.xml In file , To configure TransactionManager when ,id=“‘transactionManager’” The location of , Actual configuration “javax.sql.DataSource” Complex references to types , But configuration “java.lang.String” String type value value , So will value It is amended as follows ref that will do .

Use mybatis Problems in Reverse Engineering

Q1: In the use of mybatis During reverse engineering of , All kinds of automatically generated files are prone to the problem of capitalization of the first letter of the package location , Cause subsequent calls , There is an error , The corresponding file cannot be found .

• Problem prone locations
  
  

A: Correct the path of the corresponding file , for example ：Indi.dsl.crud.dao.DepartmentMapper It is amended as follows indi.dsl.crud.dao.DepartmentMapper, The case of the first letter .

Use MAVEN There may be some problems in the process

Q1: adopt maven stay idea in , Use dependency to introduce jar When the package , Possible maven Don't complain , The enclosure successfully quoted , But when running the project , Not used successfully , For example, the following dependencies are introduced ：

<!--  introduce Json package , Support Json data format , Support ResponseBody -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.8.8</version>
        </dependency>

• relevant jar Successful introduction ,maven No report error
  

• Run time appears 500 problem

A1: Solution ： When such a problem occurs , You can consider whether the project is really successful JAR package , The specific location is as follows ：

- Introduce the following correlation jar After package , The program can run normally .

• Will succeed Json Information output