creation

问题 I need to create 20 variables in Python. That variables are all needed, they should initially be empty strings and the empty strings will later be replaced with other strings. I cann not create the variables as needed when they are needed because I also have some if/else statements that need to check whether the variables are still empty or already equal to other strings. Instead of writing variable_a = '' variable_b = '' .... I thought at something like list = ['a', 'b'] for item in list:

问题 I have seen a post in this website regarding the dynamic POJO generation. I have the similar requirement now. I have some tables in the database. I want to have a POJO class for each table with fields and corresponding getters and setters. These classes are to be created dynamically. Once these classes are created I should use those setters and getters in other class to get and set the data and return the Java object. I have seen BCEL, CGLIB and some other open source tools for this, but

问题 I know this question was already asked here: Get File Creation Date Over HTTP BUT, I didn't get the answer needed. I don't want to get the "Last Modified" date. Instead I want the creation date. The following code gets me the last modified date from the headers. Dim request As System.Net.HttpWebRequest = DirectCast(WebRequest.Create("http://10.20.80.111/mobilepayment/myfile.crt"), System.Net.HttpWebRequest) Dim lastmodified As String Using response As WebResponse = request.GetResponse()

问题 My project uses spring and spring-dm for bean/service configuration. When I try to import an old project which also use spring for DI, bean will not be created. An example to make clear, I first define a url-alias in spring-appContext.xml <bean name="xxxx" class="XRegistry" init-method="init"> <property name="webRoot" value="/WebContent"></property> <property name="alias" value="/test"></property> <property name="cAliasPattern" value="/test/*.do" /> <property name="conConfigFile" value="ddd

问题 Consider the following code classes. public class A { public A() { callCreation(); } protected void callCreation() { System.out.println("A Created!!"); } } public class B extends A { protected void callCreation() { System.out.println("B Created!!"); } } public class C extends B { protected void callCreation() { System.out.println("C Created!!"); } public static void main(String[] args) { A a = new A(); A b = new B(); A c = new C(); } } The output of running the class C is given below. A

问题 PROBLEM: Static methods from a base class cannot be overriden, so I cannot compile this code (if I could, my design would be solved): public abstract class ParametersBase { public static abstract ParametersBase CreateDefault(); // THIS DOES NOT COMPILE! } public abstract class ParametersXml<T> where T : ParametersBase { public static T LoadOrDefault(string fname) { System.Threading.Thread.CurrentThread.CurrentCulture = System.Globalization.CultureInfo.InvariantCulture; T result; var

问题 Just I gone through, Under what conditions is a JSESSIONID created? Till now I am in a impression that, request.getSession() Gives me the current session( giving,not creating ) based upon the boolean passed to that method.Looks cool till here. Now I read that Session is created when your code calls request.getSession() or request.getSession(true) for the first time. So ,If I'm not calling request.getSession() in my any of servlets , And those servlets are made to serve some static html pages

问题 I have an access database created from 7 years ago. Unfortunately, tables didn't have time stamp column :( Is there any way to be able to know the creation date for each row in a specific table ? 回答1: Unless you have a time stamp you created yourself, there is no way to find this information. Is it possible that you have some old back-ups? That might help narrow it down. 来源： https://stackoverflow.com/questions/15613067/microsoft-access-how-can-i-get-creation-date-of-row

问题 In Pandas I have a series and a multi-index: s = pd.Series([1,2,3,4], index=['w', 'x', 'y', 'z']) idx = pd.MultiIndex.from_product([['a', 'b'], ['c', 'd']]) What is the best way for me to create a DataFrame that has idx as index, and s as value for each row, preserving the index in S as columns? df = w x y z a c 1 2 3 4 d 1 2 3 4 b c 1 2 3 4 d 1 2 3 4 回答1: Use the pd.DataFrame constructor followed by assign pd.DataFrame(index=idx).assign(**s) w x y z a c 1 2 3 4 d 1 2 3 4 b c 1 2 3 4 d 1 2 3

问题 I come from a c++ background and I find myself constantly doing this in java: SomeClass sc=new SomeClass(); if(null!=sc) { sc.doSomething(); } What I want to know is what will be in the variable sc if the constructor fails for some reason (like maybe not enough memory). I can' t find a straight answer, and I am worried that I am just wasting my time because maybe if the new operator fails would the program just crash anyway? 回答1: The Java Specification Language 3rd Edition covers your