java Archives - Page 19 of 23

Data truncation: Incorrect datetime value: ” for column 2

Nov

26

2014

While using Acitiviti API you might encounter this error which says something like this ### Error updating database. Cause: com.mysql.jdbc.MysqlDataTruncation: Data truncation: Incorrect datetime value: ” for column ‘DEPLOY_TIME_’ at row 1### The error may involve org.activiti.engine.impl.persistence.entity.DeploymentEntity.insertDeployment-Inline### The error occurred while setting parameters### Cause: com.mysql.jdbc.MysqlDataTruncation: Data truncation: Incorrect datetime value: ” for column ‘DEPLOY_TIME_’ at row ...

Add Two Integers without using Arithmetic Operators

Oct

18

2014

Recently came across an interesting question of adding two numbers without using any of the arithmetic operators and thought of giving it a try. The first thought of solving the question was using bit-manipulation operations. The idea was to add the numbers bit-by-bit taking any carry forward (without actually adding them and instead using bit-wise ...

To compare two folders (recursively) in Java 21

Jul

31

2014

Java package com.example; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; import java.security.MessageDigest; import java.util.Arrays; import java.util.HashMap; import java.util.Iterator; import java.util.Set; public class Compare { //This can be any folder locations which you want to compare File dir1 = new File("C:\\ComparisonFolder\\master"); File dir2 = new File("C:\\ComparisonFolder\\release"); public static void main(String ...args) { Compare compare = ...

Count Triangles in a Graph 1

Apr

20

2014

The following code implementation counts the number of triangles present in a graph G. For graph representation JUNG API is used but can be extended/ changed to use any other notation by simple means. Java import java.util.Collection; import java.util.HashSet; import java.util.Iterator; import edu.uci.ics.jung.graph.Graph; public class TriangleFinder { private Graph<Integer, String> g; /** * @return The ...

Dijkstra’s Algorithm : Finding all possible shortest paths between two vertices in a graph 4

Mar

26

2014

The following code implements the Dijkstra’s Shortest Path Algorithm and further extends is to get all possible shortest paths between two vertices. For graph representation we make use of JUNG API, its usage, however, is primarily in visualizing the graph and can be extended easily for any other representation as well. Random Graph Generator code ...

Code for Random Graph Generation G(n,p) 1

Mar

22

2014

Following is the Java code for generating a Random Graph G(n, p) where ‘n’ is the number of nodes/ vertices in the graph and ‘p’ is the probability that any edge will form or not. The code makes use of JUNG API for graph visualization and creation. More About JUNG… Java import java.awt.Dimension; import javax.swing.JFrame; ...

ConcurrentHashMap 1

Mar

10

2014

Javadoc says… “A hash table except supporting full concurrency of retrievals and adjustable expected concurrency for updates. This class obeys the same functional specification as Hashtable, and includes versions of methods corresponding to each method of Hashtable. However, even though all operations are thread-safe, retrieval operations do not entail locking, and there is not any ...

Matlab code to create k-connected Harary Graph 4

Oct

12

2013

The following is a MATLAB script to create a k-connected Harary Graph of n-nodes. Clearly the inputs required are n (no of nodes) and k (degree of each node). Also, while the code is a MATLAB script the basic technique to generate the adjacency matrix of the graph can be easily adopted to other languages ...

StringBuffer vs StringBuilder

Jul

10

2013

According to javadoc, StringBuilder is designed as a replacement for StringBuffer in single-threaded usage. Their key differences in simple term: StringBuffer is designed to be thread-safe and all public methods in StringBuffer are synchronized. StringBuilder does not handle thread-safety issue and none of its methods is synchronized. StringBuilder has better performance than StringBuffer under ...

executeQuery, executeUpdate and execute

Jun

3

2013

executeQuery public ResultSet executeQuery() throws SQLException Executes the SQL query in this PreparedStatement object and returns the ResultSet object generated by the query. Returns: a ResultSet object that contains the data produced by the query; never null Throws: SQLException – if a database access error occurs or the SQL statement does not return a ResultSet ...