Java

Checked Exception: An exception that requires a forced catch.Unchecked Exception: This exception is unpredictable, that is, RuntimeException, is the runtime exception. Exception and ErrorException:1, can be controllable (checked) or uncontrollable

When many strings are connected, one might think that many strings are connected using StringBuilder or stringbuffer for processing, but I find that there is really no need to consider this when Jdk7, JDK7 will automatically handle the + Link string,

When sending a GET or POST request, the following exception is thrown:Java.lang.IllegalStateException:Cannot forward after response have been committedThe exception description response was delegated two times.Workaround:The method that inherits the

1. The difference between int and integerint is the basic data type, and integer is a reference data type.e.g:int num = 100; Not an ObjectInteger i = 100; is an objectNum. Properties and methods are not out of orderI. Point-out properties and

In the previous blog post, the use of the Member method interrupt () was introduced, and the last part of the article went on to describe the remaining two methods related to interrupts.2. Member method new Thread (). isinterrupted ()It is common to

Issues to be addressed in garbage collection Who needs to be recycled When is it recycled? How to Recycle Who needs to be recycledIf an object is never used again, it can be recycled, so the key is how to know that an object is

Java Thread Pool usage instructionsA Brief introductionThe use of threads is of paramount importance in Java, where the use of thread pools is very rudimentary in the JDK version of jdk1.4. The situation has changed a lot since the jdk1.5. Jdk1.5

Process process = Runtime.getruntime (). EXEC ("C:\\test.bat"); Executes a system command inputstream FIS = Process.getinputstream (); BufferedReader br = new BufferedReader (new InputStreamReader (FIS)); String line = null; StringBuffer

Previous steps for installing the Java Environment (teacher-given, including installing Tomcat) Step 1 install tomcat You must install the JDK before you install Tomcat. The full name of the JDK is Java development kit, a software development kit

Project Address: http://www.freeteam.cn/FREECMS Business Edition V2.1 update feature 1.web Page Information acquisition: Through simple configuration to crawl the target page information, support incremental acquisition, keyword replacement,

byte: Eight-bit binary integer -128--127, which can be used to save memory. short:16 bit binary integer -32768--32,767, also compared to save memory. int:32-bit binary integer -2,147,483,648--2,147,483,647, in general, integers are sufficient.long:6

Polymorphism (above) basically explains many polymorphic characteristics and problems. Continue below.1) Constructors and polymorphicThis question is actually written before, the constructor is actually a static method, but is implicitly declared,

One, file read and write1 Try {2FileInputStream FIS =NewFileInputStream (fileName);3InputStreamReader ISR =NewInputStreamReader (FIS, "UTF-8");4BufferedReader br =NewBufferedReader (ISR);5 String Line;6StringBuilder SB =NewStringBuilder ();7

Automatic Spring Assembly Strictly speaking, it can be divided into automatic detection and automatic assembly. Automatic Detection allows Spring to automatically detect and define beans. This means that you do not use You can also implement the

Design Pattern learning-DecoratorThe WhyDecorator mode is suitable for dynamically adding and deleting roles to objects. For example, in the QQ Show, we can select our own image and dynamically add clothes and decorations to make our image feel tall.

[Qt learning] multi-threaded Qthread operations I,QThread class overview The QThread class provides a platform-independent way for users to manage multithreading. # Include Inherited from QObject class II,QThread class details The QThread

POJ 1011 Sticks (Classic dfs) Language:DefaultSimplified ChineseSticks Time Limit:1000 MS Memory Limit:10000 K Total Submissions:120720 Accepted:27951

Use javaBean to encapsulate data JavaBean is a Java class and an important component that can be used for cross-platform development in java. Function of javaBean: encapsulate business logic and data. JSP action Tag: through the action tag, the

New Fibonacci Series Problem1: Description: Define a new Fibonacci sequence: F (0) = 7; F (1) = 11; F (n) = F (n-1) + F (n-2); (n> = 2) Input: Multiple groups are input. First, enter N (N Output: Determine whether F (n) can be divisible by 3. If

Java thread (2)-thread securityThe core of thread-safe code is to manage state access operations, especially shared and variable state access. When multiple threads access the same variable state without proper synchronization, an error occurs in