Java
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Why is the JavaMail connection timeout too long
In my application, I connect to the server to authenticate users This is the code: try { Properties prop = new…… -
Use prepared statements and variable bindings to use JDBC drivers in Java
I'm using it >JDBC template enables JDBC to connect to a MySQL Database > prepared statements to protect itself …… -
Java – Google App Engine 1.6 4 local slow?
Original problem Because I started from 1.6 3. Change the version To 1.6 I encountered serious performance problems wh…… -
Deserialization – for Java util. Gson deserializer for date
Does anyone have a deserializer job? Do I get the full JSON expression in the method "deserialize" instead of the elem…… -
Java – cannot instantiate type httpclient
I've taken it Jars is added to my library, and I can instantiate other classes in jars What gives? I tried to clean up…… -
Java – JNI, call boolean method
I get a Java method, get a string and return bool I call it JNI this way: jmethodID function2ID = env->getmethodID(…… -
java. lang.ClassNotFoundException：org. apache. commons. lang.exception. NestableRuntimeException
I tried to retrieve data from the database When I run the program, it displays the error Java lang.ClassNotFoundExcept…… -
Java – differences between JDBC
What is the main difference between spring JDBC and JDBC? Solution Let me look at a simple example of using JDBC: fina…… -
Java – simpledateformat parse (string STR) will not throw an exception when STR = 2011 / 12 / 12aaa?
Here is an example: public MyDate() throws ParseException { SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/d…… -
You can use Java util. Is logging configured to use compressed log files?
Can I configure Java util. Logging to compress the log file when it "scrolls" to a new log file? For example, an excer…… -
What is the difference between pointers and reference variables in Java?
My java book explains that to use objects, we can assign them to reference variables How is it different from a pointe…… -
Java – Eclipse JSP – no color, code completion and error detection
I tried to find a way to have color and code completion and error detection in JSP pages I have Eclipse Java EE IDE fo…… -
Java – how to use jruby9 1.2. Use GPG to encrypt files in 0?
I am using GPG to encrypt files and send them to my j Ruby project But I didn't find enough resources I've tried ruby …… -
Java – good practice for editing objects by reference?
Suppose I have a type called superstar Now I want to have a method to do some work and edit some properties of a super…… -
Java – how to package and run a simple dependency command line application using Maven?
I'm new Java and maven, so it may be simple If I follow Maven 2 Hello world's instructions: http://maven.apache.org/gu…… -
Objectmapper serialization in Jackson
I want to serialize different types of lists by using an object mapper, but I don't know how AccountingService accServ…… -
Java – how do I get a new stateful session bean in a servlet thread?
I'm experimenting with EJB3 I want to inject a stateful session bean into a servlet so that every user accessing the s…… -
Java: how to resolve lambda parameters of wildcard types?
Then we have a functional interface: public interface Consumer<T> { void accept(T t); } I can use it: .han…… -
Java – how to access managed beans and session beans from servlets
See the English answer > get JSF managed bean by name in any servlet related Class6 <p:dataTable value="#{myBean…… -
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Multithreading – why is the compareandswap instruction considered expensive?
Why is the compareandswap instruction considered expensive? I read a Book: "Memory impairment is expensive, like the e…… -
Java – how to easily submit neon using git in eclipse
I just upgraded from Mars to eclipse neon Previously, I could select submit from the team menu, and the dialog box wil…… -
Are there constants for language code in Java or Java libraries?
Do language codes in Java or Java libraries (such as "en" or "de") have constants? (or use string OK?) I know such thi…… -
Test whether the font is first-class in Java
I'm listing all the constant width fonts available on the user's machine I can get all fonts in swing in the following…… -
How to view the status of check boxes in the Java GUI?
I have about 200 check boxes in the Java GUI Now I want to list all the checkboxes that the user has checked I can do …… -
Memory – multithreaded heap management
In C / C + +, I can allocate memory in one thread and delete it in another thread However, as long as someone requests…… -
Java – automatically call superclass methods
Consider class class A{ public void init(){ //do this first; } public void atEnd()…… -
Java – distinguish between string args [] and string [] args
I've seen two different ways to declare a string array, but I don't show any difference Anyone can explain the differe…… -
Java – use interface classes as keys to get specific instance values?
I have the following test cases and can't retrieve values from the map: package tests; import java.util.HashMap; impo…… -
Java – use Apache POI to make columns read-only
I am using Apache POI to generate Excel files I need to make column 4 read-only, and the other 2 columns will be edite…… -
JavaFX: how to connect two nodes in a row?
I want to connect two nodes (from the center of the first to the center of the second) with a line Initial ideas: Supp…… -
Java Swing button color
See the English answer > how to set background color of a button in Java GUI? 7 Now my next stage is to add color t……