How to read and write CSV file in Java
Two ways to do this, Using core JavaUsing OpenCSV Let's start with the core Java way. Using core Java Write content to the CSV file. public void writeContentToCSVFile() throws IOException…
How to parse XML using DOM in Java
This post will show you how to parse content from an XML file and convert it to Java Object. XML file <Books> <Book> <Id>1</Id> <Name>Java Programming</Name> <Author>Andrew Programming</Author> </Book> <Book>…
How to convert object to JSON and vice versa in Java
Maven dependencies <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-core</artifactId> <version>2.10.0</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.8.11.1</version> </dependency> Convert Object to Json Core Logic package jsondemo; import com.fasterxml.jackson.core.JsonGenerationException; import com.fasterxml.jackson.databind.JsonMappingException; import com.fasterxml.jackson.databind.ObjectMapper; import java.io.File; import java.io.IOException;…
Java Buffered Writer Demo
package FileDemo; import java.io.BufferedWriter; import java.io.File; import java.io.FileWriter; import java.io.IOException; public class BufferedWriterDemo { public static void main(String[] args) throws IOException { BufferedWriter bw = null; File file = new…
How to read/write from/to file in Java
Three ways to do this FileIutputStream and FileOutputStreamDataInputStream and DataOutputStreamBufferedInputStream and BufferedInputStream FileIutputStream and FileOutputStream package FileDemo; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; public class ReadAndWriteContentWithFile { public static void…
Log4j2 Example
Import Maven dependency <!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-core --> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-core</artifactId> <version>2.12.1</version> </dependency> <!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-api --> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-api</artifactId> <version>2.12.1</version> </dependency> Configuration File <?xml version="1.0" encoding="UTF-8"?> <Configuration status="INFO"> <Properties> <Property name="logPath">./</Property> <Property…
Java – HttpURLConnection Demo
HttpURLConnection package urlconnectiondemo; import java.net.HttpURLConnection; import java.net.URL; public class UrlConnectionDemo { public static void main(String[] args) { try { URL url = new URL("http://www.baidu.com"); HttpURLConnection huc = (HttpURLConnection) url.openConnection(); for…
Java-Properties file examples
The properties file is used to store the properties. Developers can read and write properties from or into it. This post will show: How to write into the write properties…
Java – How to display double in 2 decimal places
Three ways to do this: Decimal FormatString.formatBigDecimal Decimal Format import java.math.RoundingMode; import java.text.DecimalFormat; public class DecimalFormatDemo { private static DecimalFormat df = new DecimalFormat("#.###"); public static void main(String[] args) {…
Java – Convert String to int
Convert String to int You can use Integer.parseInt() to convert a String to int. //convert String to int String a = "123"; int a1 = Integer.parseInt(a); System.out.println(a1); Output 123 Convert…