Java

Take the tomcat environment as an example. Other WEB servers, such as jboss and weblogic, share the same principle.1. java. lang. OutOfMemoryError: PermGen spacePermGen space stands for Permanent Generation space, which is the Permanent storage area

Commons-logging-1.0.4.jar You do not need to import Struts2 after it is added. Log4j-1.2.15.jar Hibernate does not need to be imported after it is added.     Jar file: The red is the correct jar package. Operate the database jar Mysql-connector-java-

Usage of StringUtils in the Common-lang Package The operation object of the StringUtils method is java. lang. string-type objects are complementary to the String-type operation method provided by JDK, and are null safe (that is, if the input

[Java] import java. io. fileOutputStream; import java. io. IOException; import java. util. calendar; import java. util. date; import java. util. iterator; import org. apache. poi. hssf. usermodel. HSSFHeader; import org. apache. poi. hssf. usermodel.

The external android project is imported to ecplise. The compilation is normal and an error is returned. The logcat is as follows: 12-19 10:55:25. 915: E/AndroidRuntime (2929): fatal exception: main12-19 10:55:25. 915: E/AndroidRuntime (2929): java.

I believe that everyone is using hibernate (I am using 3.6 here, because I prefer spring, but the hibernate4.x series are a lot of duplicates with spring later, and spring also thinks that, hibernate4.x is a very well-developed framework. spring3.x

This article demonstrates how to use a Java Servlet, a JSP page, and a static Java class to construct an SQL gateway application. With this application, you can directly execute SQL commands in the browser. the browser will submit the SQL commands

The Blob field in Oracle is special. It has much better performance than the long field and can be used to save binary data such as sample slices.Writing Blob fields is very different from writing other types of fields. Because Blob itself has a

When I was learning j2ee, I used jdbc to connect to ms SQL server 2000. At the beginning, everything was normal, but then I encountered a headache, after we read data from the table and put it in the ResultSet, we must read the column values in the

Package com. adrop. util;Import java. SQL .*;Public class DBManager {// User NamePrivate String user = "";// PasswordPrivate String password = "";// HostPrivate String host = "";// Database NamePrivate String database = "";// Private DBManager dbm =

The performance of jdbc programs is mainly determined by two factors: one is the nature of the database itself, and the other is the use of jdbc application interfaces (APIS) that are relatively independent from the database. here we will talk about

The most commonly used SVN plug-in eclipse is subclipse, first to the subclipse Official Website: http://subclipse.tigris.org to download this plug-in. For example, click "Download and Install" to go To the Download page. Select the version to be

If you modify the List object when you use Iterator to iterate over the List object, a java. util. ConcurrentModificationException exception is reported. The following is an example: List list = ArrayList

Set in web. xml: DisplayChart org. jfree. chart. servlet. DisplayChart DisplayChart /DisplayChart Methods in java classes: Public String (String series [], double score [] [], String type [], String name ){Final int num =

In Web projects, various web frameworks are generally used together, such as spring + hibernate, spring + ibatis, so that other frameworks are integrated into spring, A little inconvenience, of course, spring has made this integration very easy. I

element --> Private String name; Public void sayHello (){ Helloservice. sayHello (); System. out. println (this. name ); } This. helloservice = helloservice; } This. name = name; } 2. constructor Injection --> Private

The event can be triggered by the user, or the code can be used to actively set the event occurrence. For example, setSelected ()Java. awt. event Listener Interface Event Type Adapter class ComponentListener    

A custom label is developed based on spring. The function test is normal and a compilation error is prompted in myeclipse: Multiple annotations found at this line:-Cvc-complex-type.2.4.c: The matching wildcard is strict, but no declaration can be

JavaMelody open-source system performance monitoring1. download the required jar package JavaMelody requires two jar packages: j2.16.jarand javamelody.jar. go to the official website to download javamelody-1.36.0.zip, which contains the two jar

After learning about session management in the same service, click to open the link. Today, let's take a look at the cross-service session management. I wrote the server last night, but only the client code is left, when I got off work, I had to