Tec Bar » Java https://www.tecbar.net Tue, 19 Dec 2017 20:49:54 +0000 en-US hourly 1 http://wordpress.org/?v=4.1 Java Date Format Pattern https://www.tecbar.net/java-date-format-pattern/ https://www.tecbar.net/java-date-format-pattern/#comments Wed, 12 Apr 2017 07:45:59 +0000 http://www.tecbar.net/?p=1195 Java SimpleDateFormat Date and time formats are specified by date and time pattern strings. Within format strings, unquoted letters from ‘A’ to ‘Z’ and from ‘a’ to ‘z’ are treated as format letters representing the components of a date or … Continue reading →

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]]> https://www.tecbar.net/java-date-format-pattern/feed/ 0 Difference between @Component, @Repository & @Service annotations in Spring https://www.tecbar.net/difference-between-component-repository-service-annotations-in-spring/ https://www.tecbar.net/difference-between-component-repository-service-annotations-in-spring/#comments Thu, 09 Jun 2016 18:39:22 +0000 http://www.tecbar.net/?p=1182 @Component – generic stereotype for any Spring-managed component (auto scan component) @Repository – stereotype for persistence layer (DAO component) @Service – stereotype for business layer (service component) @Controller – stereotype for presentation layer (spring-mvc)

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]]> https://www.tecbar.net/difference-between-component-repository-service-annotations-in-spring/feed/ 0 Get Current Date and Time in a Specific Timezone (Java) https://www.tecbar.net/get-current-date-and-time-in-a-specific-timezone-java/ https://www.tecbar.net/get-current-date-and-time-in-a-specific-timezone-java/#comments Fri, 29 Apr 2016 23:36:53 +0000 http://www.tecbar.net/?p=1165 [crayon-69df2516a0cce939319856/] Output: [crayon-69df2516a0cd9966916895/]

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]]> https://www.tecbar.net/get-current-date-and-time-in-a-specific-timezone-java/feed/ 0 Java HTTP client crashes on HTTPS connections https://www.tecbar.net/java-http-client-crashes-on-https-connections/ https://www.tecbar.net/java-http-client-crashes-on-https-connections/#comments Sun, 13 Dec 2015 07:10:25 +0000 http://www.tecbar.net/?p=1126 OS: CentOS 6.5 JAVA: 1.7.0_91 One use case in the project: due to the remote client server system upgrade, HTTPClient runs into such exception like javax.net.ssl.SSLException: java.security.ProviderException: java.security.KeyException: [crayon-69df2516a142b301260635/] After Java runtime was upgrade to Java 8, the exception is … Continue reading →

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]]> https://www.tecbar.net/java-http-client-crashes-on-https-connections/feed/ 3 Install Java 8 (JDK 8u66) on CentOS https://www.tecbar.net/install-java-8-jdk-8u66-on-centos/ https://www.tecbar.net/install-java-8-jdk-8u66-on-centos/#comments Tue, 27 Oct 2015 19:14:28 +0000 http://www.tecbar.net/?p=1111 Download latest 64 bit Java SE Development Kit 8 release [crayon-69df2516a1916524250775/] To download 32 bit Java 8 [crayon-69df2516a191e020232386/] Install Java [crayon-69df2516a1924965575832/] choose /opt/shared/jdk1.8.0_66/bin/java Setup Jar and Java c (optional) [crayon-69df2516a1929459582183/] Configuring Environment Variables (if necessary) it will auto load the … Continue reading →

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]]> https://www.tecbar.net/install-java-8-jdk-8u66-on-centos/feed/ 0 How HashSet implemented in Java https://www.tecbar.net/how-hashset-implemented-in-java/ https://www.tecbar.net/how-hashset-implemented-in-java/#comments Fri, 09 Oct 2015 00:14:59 +0000 http://www.tecbar.net/?p=1083 In Java, HashSet uses HashMap to finish: add, get, iterator etc. The HashMap also can help an element inside HashSet is unique. [crayon-69df2516a1d1e708563736/]

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]]> https://www.tecbar.net/how-hashset-implemented-in-java/feed/ 0 How HashMap works in Java https://www.tecbar.net/hashmap-implementation-in-java/ https://www.tecbar.net/hashmap-implementation-in-java/#comments Thu, 08 Oct 2015 19:33:51 +0000 http://www.tecbar.net/?p=1071 HashMap works on the principle of Hashing. There are several terms: key, hash code, hash function, bucket, entry in HashMap public int hashCode() hashCode returns an integer code, we can call this method as hash function A bucket is used … Continue reading →

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]]> https://www.tecbar.net/hashmap-implementation-in-java/feed/ 0 Queue example in Java https://www.tecbar.net/queue-example-in-java/ https://www.tecbar.net/queue-example-in-java/#comments Wed, 30 Sep 2015 00:07:10 +0000 http://www.tecbar.net/?p=985 Java provides us Queue interface, where we can keep and handle elements before processing. Except the methods that Collection provides, it also supports some basic operations in order to simulate the classic queue structure. Each of these operations exists in … Continue reading →

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]]> https://www.tecbar.net/queue-example-in-java/feed/ 0 Lock in Java https://www.tecbar.net/lock-in-java/ https://www.tecbar.net/lock-in-java/#comments Wed, 22 Jul 2015 19:20:22 +0000 http://www.tecbar.net/?p=839 In the previous post (Synchronized vs ReentrantLock in Java) ,  we have discussed the difference between synchronized and ReentrantLock. The keyword synchronized can be widely used in many multi-threaded environments. However, there are some drawbacks when using synchronized. The use of … Continue reading →

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]]> https://www.tecbar.net/lock-in-java/feed/ 0 Asynchronous method invocation in Spring Framework https://www.tecbar.net/asynchronous-method-invocation-in-spring-framework/ https://www.tecbar.net/asynchronous-method-invocation-in-spring-framework/#comments Tue, 26 May 2015 23:02:10 +0000 http://www.tecbar.net/?p=817 Since Spring 3.0, annotation support for both task scheduling and asynchronous method execution has been added. The post will give a demo of @Async annotation and its uses. @Service – annotate classes at service layer level. @Async – put @Async … Continue reading →

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