A: a common problem when running java web
错误1.This element neither has attached source nor attached Javadoc and hence no Javadoc
Cause of the problem: import lacks the required jar package
Solution: mouse on import Click the above question, there will jar package which directory the absence of import can be provided according to the path.
错误2.java.lang.NoSuchMethodException: org.apache.catalina.deploy.WebXml addServlet
Error reason: jar package conflicts
Solution: Remove the conflicting Jar package (I have here is a tomcat jar package conflicts, and to remove one, the problem is solved)
3. Run the Web project error error appears as shown in Figure
Cause: wrong address
Solution:
II: Custom Data Binding
In general, use basic data types and POJO type of the parameter data has been able to meet demand, but some special types of parameters can not be directly converted in the background, but there are special data types can not be direct data binding, it must first go through the data conversion, for example, the date data.
For special data types mentioned above, the developer would need to custom converter (Converter) or a format (the Formatter) for data binding.
1.spring Converter provides a framework for converting one type of object to another object type.
2. Custom Converter class needs to implement org.springframework.core.convert.converter.Converter interface.
3.Formatter same role Converter, but Formatter original type must be a String type, and Converter can be of any type.
4. Formatter custom converter org.springframework.format.Formatter class needs to implement the interface.
