May 3 class Notes-properties file, JUnit test, MVC seal layer, etc.

stringbuffer thread safety, low efficiency StringBuilder thread insecure, high efficiency determine if an array is null or emptyNULLEmpty Arrayint[] array=NULL; int[] array2=New int[]{}; Create several objects?String S=NewString ("Guan Yu"); Two objects created1.*read the Properties profile dbinfo.properties A. Reflected ClassLoader reads configuration file reflection: Maps the various components of a class to the corresponding class B . Tool class ResourceBundle ResourceBundle bundle= Resourcebundle.getbundle ("Cn/test/dbinfo");//incoming file name, no suffix requiredString age = bundle.getstring (' Age ');      System.out.println (age); 2the method return type for unit test JUnit JUNIT4 unit tests must be void to add annotations @Test import JUNIT4 assertions: Actual results Whether to match expected result Assert.assertequals (expected result, actual result)3. MVC Layered M----model (models layer) generally refers to JavaBean V----The view layer refers to the page at the Web stage, and in U1 generally refers to the console C----controller (Control layer) is to forward the user request to the model layer, after processing the results back to the interface layer presented in a middle-tier project sub-package M---bean Pojo Domain V----Store page C:dao data Operations Daoimpl service business logic Serviceimpl        Cn.bdqn.pojo Cn.bdqn.dao Cn.bdqn.dao.impl Cn.bdqn.service Cn.bdqn.service.impl Cn.bdqn.test

May 3 class Notes-properties file, JUnit test, MVC seal layer, etc.