Java

Solution: Use rs.getstring (); Be sure to add rs.next () before; Cause: The ResultSet object represents the result set executed by the SQL statement and maintains the cursor to its current data row. Each time the next () method is called, the cursor

The project needs to switch servers, switch from server2003 to server2008, weblogic11_64 for new environments, oracle11gAfter the project deployment is run, everything else is OK, and the following error is reported when querying a database field of

Sorting can be divided into two categories: inner and outer sort. During the sorting process, all records are stored in memory, called internal sorting, and if external memory is required during sorting, it becomes an outer sort.The following

From http://tutorials.jenkov.com/java-concurrency/synchronized.html by Jakob Jenkov Table of Contents The Java synchronized Keyword Synchronized Instance Methods Synchronized Static Methods Synchronized Blocks in

Reading English program Ape's ability, which is very important. The past few years have been learning English, a whim today, on the internet to find what Bowen brief translation.General level, limited capacity, crossing also ask you a lot of

Call someone else's program method, and someone else's method declares that there may be an abnormal invocation of the place must have two ways of processing (or ecplise will prompt syntax error): 1, also do the exception declaration, the exception

package nested_inner_class;public class StaticNestedTest3 {public static void main (string[] args) {//Peculiar inner class instantiation method Outer3 Outer3 = new Outer3 (); oute R3. Nested Nested = Outer3.new Nested ();//cannot be created using

Reprinted from Http://www.cnblogs.com/xiaoluo501395377/p/3383130.htmlProxy modeProxy mode is a common Java design pattern, his characteristic is that the proxy class and the delegate class have the same interface, the proxy class is mainly

Starting with the concept of generics in JDK1.5, generics are essentially a type that enables programmers to define security. In the absence of generics, Java also provides a reference to the object "arbitrary" operation, which is the object

A long time ago to do a thing, now take it out and put it in your own blog!I. Design OBJECTIVESWith the development of people's Internet, the way of communication between people is more convenient and diversified, the online chat tool has become an

Introduction: Title ImportJava.io.FileInputStream;/** * @authorCzchina **/ Public classTeststream { Public Static voidMain (string[] args) {//TODO auto-generated Method Stub//declaring a reference to an input streamFileInputStream FLS =NULL;

(i) Java static code block static method differencesIn general, if some code must be executed at the time of project startup, the use of static code blocks, the code is active, it needs to be initialized when the project is started, in the case of

Java constant pool is a long-lasting topic, but also the interviewer's favorite, the title of a variety of, side dishes have already heard of the constant pool, this time a good summary.TheoryIt's a little bit awkward. JVM Virtual Memory

Sorting has always been a headache for me, before the "data structure" soy sauce went, the whole semester down only reluctantly can write a bubble sort. Since the second half of the preparation of work, but also know the importance of sorting

break [flag];Directly ends the loop that falls to the flag layerno1:for (int i=0; ifor (int j=0; jsum = i*j;if (sum>500) {SYSTEM.OUT.PRINTLN (i+ "*" +j+ "=" +sum);Break NO1;}}}For example: When sum>500, exit the two-layer for loop;continue

Used in multi-threading, synchronous variables. thread to improve efficiency, a member variable (such as a) copy a copy (such as b), the thread of access to a actually access is B. Synchronization of A and B occurs only in certain actions. Thus

Webthe project often involvesAJAXRequest returnJSONand theJSONPData。 Jsondata is transmitted on both the server and browser side, essentially transmitting strings, but this string conforms to theJSONsyntax format. The browser is received in normal

1. java.lang.NullPointerException This exception is certainly often encountered, the abnormal explanation is "the program encountered a null pointer", simply called an uninitialized object or a nonexistent object, this error often appears in the

Reprint Please specify the Source:Jiq ' s technical BlogOne, Collection: storage of independent elementsThe interfaces in collection are optional, and their implementation classes do not necessarily implement all of their interfaces, in order to

Practical for beginners: several methods for transferring jsp data to action in struts2   First give the struts. xml code: {1}_{2}.jsp User_toLogin.jsp Method 1:   Import com. opensymphony.