java coding test for interview

{Publicvoid Eat (food){System.out.println ("Puppy gnawing" +food.getname ());}}/*** @authorleno* Food abstract class*/AbstractClass Food{protected String name;Public String GetName () {Returnname;}Publicvoid setName (String name) {THIS.name = name;}}/*** @authorleno* One food Category: Fish*/Class Fish extends Food{Public Fish (String name) {THIS.name = name;}}/*** @authorleno* One food Category: Bones*/Class Bone extends Food{Public Bone (String name) {THIS.name = name;}}/*** @authorleno* Breed

;CallableStatement st = null;Try {It's better not to do this, because the driver's name is written dead in the program.Class.forName ("Com.mysql.jdbc.Driver");In the actual project, datasource data is applied here, if the frameworkThis data source does not need our code to create, we only need to datasourceds=context.lookup ();conn = Ds.getconnection ();conn = Drivermanager.getconnection ("Jdbc:mysql:///test", "root", "root");st = Conn.preparecall ("{

). In the process of populating the handler, depending on your configuration, Spring will do some extra work for you: Httpmessageconveter: Converts the request message (such as Json, XML, and so on) to an object, converting the object to the specified response information. Data Transformation: Data conversion for a request message. such as string conversion to Integer, double, and so on. Data is initialized: Data is formatted for the request message. such as converting a string into a formatt

. Close session 8. Close Sesstionfactory Ø Why to use 1. The code for JDBC access to the database has been encapsulated, simplifying the cumbersome repetitive code of the data access layer. 2.Hibernate is a mainstream persistence framework based on JDBC and is an excellent ORM implementation. He simplifies the coding of the DAO layer to a large extent 3.hibernate uses a Java reflection mechanism rather

inherit it. Subclass overwrites the finalize () method to sort system resources or perform other cleanup tasks. The finalize () method is called before the Garbage Collector deletes an object. Second, can anonymous inner class (anonymous internal class) be extends (inherited) other classes, or implements (implemented) interface (Interface )? An anonymous internal class is an internal class without a name. It cannot be extends (inherited) other classes, but an internal class can be used as an in

directly supported, the most efficient, so, 2 times 8 and the most efficient method is 2 9, please design a 10 billion of the calculatorFirst of all to understand the question of the test point is what, first of all, we have to understand the underlying details of the computer principle, to know the bit operation principle of addition and subtraction, and know that the arithmetic operations in the computer will be out of bounds, the second is to have

is 443. The HTTP connection is simple and stateless; The HTTPS protocol is a network protocol built by the SSL+HTTP protocol for encrypted transmission and authentication, which is more secure than the HTTP protocol. HTTP uses port 80 by default, HTTPS uses 443 port by default How HTTPS ensures the security of data transmissionHTTPS is actually in the TCP layer and the HTTP layer between the SSL/TLS to secure the upper layer, the main use of symmetric encryption, asymmetric encrypt

programming, which is often more efficient in many cases with asynchronous approaches.49. Are the following two methods synchronized? (Invented by himself)Class Test{Synchronizedstatic VoidsayHello3 (){}Synchronizedvoid GetX () {}}50, multithreading there are several ways to achieve? How many ways to implement synchronization?There are two ways to implement multithreading, namely, inheriting the thread class and implementing the Runnable interface.Th

finalize () method to sort system resources or perform other cleanup tasks. The finalize () method is called before the Garbage Collector deletes an object. Second, can anonymous inner class (anonymous internal class) be extends (inherited) other classes, or implements (implemented) interface (Interface )? An anonymous internal class is an internal class without a name. It cannot be extends (inherited) other classes, but an internal class can be used as an interface and implemented by another i

This series of Java-related written interview knowledge, several other articles are as follows: Java written examination questions finishing Eighth wave The seventh wave of the Java written test face The sixth wave of the Java wri

)Analysis: When a class is loaded, from the parent class to the subclass, from top to bottom, execute the static code block, and then execute the main function , if there is a statement of the new object, The construction code block and constructor of the binding are executed. Note: static code blocks have and execute only once14. What is the result of the following code?public class a{public static void Main (string[] args) {String str;System.out.println ("" + str);}}Analysis: The above code w

, and future to implement threads with return resultsThe Executorservice, callable, and future three interfaces are actually executor frameworks. The thread that returns the result is a new feature introduced in the JDK1.5, and with this feature it is no longer necessary to get the return value. And it can be flawed if it is achieved.A task that can return a value must implement the callable interface. Similarly, a task without a return value must implement the Runnable interface.After performin

shared across multiple threads, and the heap is shared by all threads of the entire JVM.Stacks: Some of the basic types of variables defined in the function and the reference variables of the objects are allocated in the stack memory of the function, and when a variable is defined in a block of code, Java allocates the memory space for the variable in the stack, and when the scope of the variable is exceeded, Jav