Java Map Iterator Example

18Mar2012 In: Core Java

Java Map Overview

Map is an important Java collection implementation defined in java.util package, it is designed to store with key and value  element pairs. In this how-to example, let’s go over how to iterate over a map in Java.

Way 1: Iterate over a Map using Java Map Iterator.

Maps do not provide an iterator method as Lists and Sets do, but it provides two APIs keySet() and values(), the two APIs return a set view of keys or values contained in this Map, the idea using keyset() or values() is to get keys or values in collection container form and then be able to iterate over it, the following is Java Map iterator example code: Read the rest of this entry »

Top1 Java Book Recommendation: Thinking in Java

Author: Bruce Eckel, Date of publication: February 2006, Reviewer: Meera Subbarao.
Download: http://www.mindviewinc.com/Books/downloads.html
Description: Thinking in Java is a comprehensive guide to the Java programming language, it gives insight of java and covers all aspects of core technologies including OO, Thread, Concurrency, IO, GUI/Swing and so on. It has been released five editions. The awards for Thinking in Java include Software Development Magazine Jolt Award for Best Book, Java Developer’s Journal Reader’s Choice Award for Best Book, Java Developer’s Journal Editor’s Choice Award for Best Book, Software Development Magazine Productivity Award. Thinking in Java has earned raves from programmers worldwide for its extraordinary clarity, careful organization, and small, direct programming examples. Read the rest of this entry »

Oracle’s WebLogic is a leading Java-based server software application that runs on a middle tier. Eclipse is an open-source community that develops open platforms and products. As they are both industry standard leading product, developers usually integrate the two toolkits together to develop the J2ee application, in order to significantly fix a server-side Java problem appeared trivia, we need to debug java code on weblogic server with eclipse via Java Debugger(jdb). In this how-to, we will guide you how to create a remote debugging connection between weblogic and eclipse. Read the rest of this entry »

Java HotSwap Overview

The terms of development is actually writing code, testing and fixing bugs with frequency, the most of common thing we want is that the modified java classes to be effective immediately without restarting the application. In this tutorial, we guide how Java classes can be reloaded without dynamic class loaders, and shows example step-by-step that reloads changes to JVM on-the-fly without downtime, we provide an ‘embedded’ software development solution that hotswap Java code. Read the rest of this entry »

The purpose of this tutorial is to write and test the first JDBC driver programs to connect PostgreSQL and manipulate the data stored in the PostgreSQL database.

Quick View PostgreSQL JDBC Driver.

PostgreSQL JDBC driver allows Java programs to connect to a PostgreSQL database using standard, database independent Java code. its current version is 9.1-901. It supports both JDBC3 and JDBC4 standard implementation(If you are using 1.6 or 1.7 JVM, Advice you use JDBC4 Postgresql Driver, Version 9.1-901). Read the rest of this entry »

The purpose of this tutorial is to write and test your first JDBC driver programs to connect mysql and manipulate the data stored in MySQL database.

Quick View JDBC MySQL Connector/J.

MySQL provides connectivity for client applications, which allows that the Java program has ability to connect, retrieve and modify data in MySQL through a JDBC driver, the latest official version of MySQL Connector/J is Type 4 pure Java JDBC driver. Read the rest of this entry »

How to Sort a List in Java

4Feb2012 In: Core Java

We usually have problem to sort the specified list into ascending order, according to the natural ordering of its elements. This article look though how to sort list/arrarylist in java. Assuming you have created a list, added the instantiation of string as the elements of the lists, please note all elements in the list must be able to implement the Comparable interface, and all elements in the list must be mutually comparable. Read the rest of this entry »

Oracle Error :: DRG-10758

Index owner does not have the privilege to use file or URL datastore Cause.

Error details:

When you tried to create an index, if the index owner does not have the privilege to use file or URL datastore, it will occur the following error stack:

IMP-00017: following statement failed with ORACLE error 29855:
"CREATE INDEX "FILES_CONTENT_IDX" ON "FILES" ("CONTENT_URL" )  INDEXTYPE IS "
""CTXSYS"."CONTEXT" PARAMETERS ('DATASTORE CTXSYS.FILES_CONTENT_PREF FILTER "
"CTXSYS.INSO_FILTER LEXER CTXSYS.ATTACHMENT_LEXER STORAGE CTXSYS.FILES_CONTE"
"NT_STORAGE ')"
IMP-00003: ORACLE error 29855 encountered
ORA-29855: error occurred in the execution of ODCIINDEXCREATE routine
ORA-20000: Oracle Text error:
DRG-10758: index owner does not have the privilege to use file or URL datastore

Read the rest of this entry »

DBA_TABLESPACES Introduction

The view Oracle DBA_TABLESPACES describes all tablespaces in the database. so if you select it, it returns the list of the tablespaces including system and user-defined in the database. it is unlike USER_TABLESPACES, which describes the tablespaces only accessible to the current user, the following table lists the columns and description for DBA_TABLESPACES. Read the rest of this entry »

The size of Tablespace is combination of  size of ALL individual datafiles, You can enlarge a database in four ways:

Add a datafile to a tablespace

You had ready created a tablespace, due to the restriction of size of  existing datafile is reached largest size you defined before or the drive where the file is existing does not have free space, to add a new datafile to an existing tablespace can be effective way to enlarge the size of tablespace. Simply follow the below command to increase 200M to workspace tablespace01. Notice file tablespace01_02.dbf will be created and allocated to 200M.

SQL>alter tablespace01 add datafile  ‘/us/oracle/ora/tablespace01_02.dbf’ size 200M; Read the rest of this entry »