Java


PMD (Programming Mistake Detector)

PMD (Programming Mistake Detector) What is PMD? PMD aka Programming Mistake Detector is Java Source Code Analyzer. It is used to clean erroneous code in our java projects based on predefined set of rules. PMD supports the ability to write custom rules. Issues reported by PMD may not be true errors always, but rather inefficient code, i.e. the application could still function properly even if they were not corrected. PMD […]


Advanced Java Class Tutorial: A Guide to Class Reloading

In Java development, a typical workflow involves restarting the server with every class change, and no one complains about it. That is a fact about Java development. We have worked like that since our first day with Java. But is Java class reloading that difficult to achieve? And could that problem be both challenging and exciting to solve for skilled Java developers? In this Java class tutorial, I will try to address […]


Short Notes on Java Collections Framework

Java Collections Framework Notes: Collection Interface: The fundamental interface for collection classes in the Java library is the Collection interface.

The add method returns true if adding the element actually changes the collection, and false if the collection is unchanged. The iterator method returns an object that implements the Iterator interface. You can use the iterator object to visit the elements in the collection one by one. Iterator Interface: […]


Data Collection from HTTP Client into HBase 7

This post provides a proof of concept of data collection from HTTP client into HBase. In this post, we will setup a flume agent with HTTP Source, JDBC Channel and AsyncHBase Sink. Initially we concentrate on POC of HTTP client data collection into HBase and at the end of this post we will go deep into details of each component used for setup of this agent. Now lets create our […]


Java vs Hive 3

In this post we will discuss the differences between Java vs Hive with the help of word count example. We will examine the Word Count Algorithm first using the Java MapReduce API and then using Hive. The following Java implementation is included in the Apache Hadoop distribution.

For implementing the Word Count algorithm we need to write 63 lines of Java code and we need to compile it and build a Jar […]


Java Interface to HDFS File Read Write 1

Java Interface to HDFS File Read Write This post describes Java interface to HDFS File Read Write and it is a continuation for previous post, Java Interface for HDFS I/O.  Reading HDFS Files Through FileSystem API: In order to read any File in HDFS, We first need to get an instance of FileSystem underlying the cluster. Then we need to get an InputStream to read from the data of the file. We can use IOUtils class […]


Java Interface for HDFS File I/O 1

Java Interface for HDFS File I/O: This post describes Java Interface for Hadoop Distributed File System. It is recommended to go through this post after having basic knowledge on Java Basic Input and Output, Java Binary Input and Output and Java File Input and Output concepts. To explore more into Hadoop distributed file system through Java Interface, we must have knowledge on a few important main classes which provide I/O […]


Java File Input and Output

Java File Input and Output: A file is identified by its path through the file system, beginning from the root node. A symbolic link is a special file that serves as a reference to another file. when a symbolic link is deleted, or renamed then link itself is deleted, or renamed and not the target of the link. A Path object contains the file name and directory list used to […]


Java Basic Input and Output

JAVA Basic Input and Output Below are some basic and important notes on File input/output through Java Programming. In Java, I/O Streams are a powerful concept that simplifies I/O Operations. An I/O Stream represents an input source or output destination. Java programs uses an input stream to read data from a source, one item at a time. output stream is used to write data to a destination, one item at […]


Java Binary Input and Output

Java Binary Input and Output: Java provides two types of streams to address binary input and output operations. Data Streams: Data stream API supports binary input/output of Java Primitive data types (boolean, char, byte, short, int, long, float, and double) and String values.  Java provides two important interface for Data Streams – DataInput & DataOutput.  And the classes implementing these interfaces are – DataInputStream & DataOutputStream respectively. Data type   […]


Basic JAVA Programming Notes 1

This post describes basic JAVA Programming Notes. Comments: Java Comments can be specified in 3 styles: Mark each line with a // at the beginning of each comment line. /* and */ comment delimiters can be used tp block off a longer comment. Third kind of comment can be used to generate documentation automatically. This comment uses a /** to start and a */ to end. Data Types: In Java […]


Java Installation on Ubuntu 1

Below is the Installation Procedure for Oracle Java Installation on Ubuntu: Java Installation on Ubuntu: Download latest JDK version which is later than 1.6 from Oracle Site. In this installation, we used JDK 8 version. Download jdk-*-linux-x64.tar.gz zipped binary tarball for Linux 64 bit machine. Here ‘*’ refers to jdk version number for example 8 in our case. Copy the JDK binary zipped tarball and Extract the zipped tarball into your preferred directory […]


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I am a plsql developer. Intrested to move into bigdata.

Neetika Singh ITA

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