Java HashMap Example

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HashMap is collection which stores in the form of key-value pairs, where key is reference and value is actual data. HashMap always works on the principle of hashing to transform key-value pairs into the map. It uses hash table to store the map. It contains unique elements. We cannot use duplicate data for the keys […]

Java LinkedList Example

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LinkedList contains group of elements in the form of nodes. The linked lists are used to store array of data. It is a linear data structure in which each element is separate object. LinkedList contains set of nodes. Each node contains some of the data and link to the next node. When link of next […]

Create Custom Formatter for Logger Handler

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This example shows how to write a simple custom Formatter for the logging in Java. Java provides java.util.Formatter class for extending the format of the messages and that can be applied to the handlers. In our previous example, I have explained how to write the logging handlers. If you want to write the custom formatters, […]

java.util.Formatter Example

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java.util.Formatter class is used for formatting the values passed to the format() method. This class become part of Java since the Java 5 release. This feature is taken from the C language to format the string, numbers, date, etc. in the simplified manner. There is set of variables and expression defined for formatting the values. […]

Java Logging Handlers Example

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In our previous example I have explained how to write a simple logging configuration in your Java program. This example shows how to use the different log handlers for printing the log messages. Log handlers are the medium where the log messages has to be transfered for the future reference. In bigger applications, the handlers […]

Java Logging Example (java.util.logging.Logger)

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In our application, logging is one of the important mechanism to capture the messages thrown by the applications. One of the most popular logging framework is log4j which provides the logging in your applications. However, you can implement the logging without adding any third party implementations by the JDK’s built in logging APIs. java.util.logging package […]

Java Timer Example

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In Java, we have java.util.Timer class for scheduling the tasks at the frequent intervals. The steps for creating the simple job using the java.util.Timer class is: Create the task / job by extending the java.util.TimerTask. A task has to extend java.util.TimerTask and implement the run() method Create the Timer instance to manage the tasks. You […]

JQuery ID Selector Example

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JQuery Id selector selects elements with the given id attribute. It represents the tag with the given ID in the document object model. The id selector is a name preceded by a hash character (#). The id selector matches an element based on contents of the given id attribute which match exactly the value given […]

java.sql.SQLException: Can’t call commit when autocommit=true Exception

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When you work with JDBC application, by default the auto commit is set to true, after the transaction is completed all the transactions are committed to the database. When it is set as true, you can not explicitly call the commit method. If you call the connection.commit() method, then the below exception will be thrown.

State Design Pattern In Java

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This tutorial explains the state design pattern with a simple example program. State design pattern is very similar to the Strategy pattern, the only difference is that state design pattern maintains the state of the context where as strategy pattern passes the context and execute the specific strategy. The state design pattern is very useful […]