Java Programming

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…

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…

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…

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) {…

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…

import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; public class CountDuplicatedItemInList { public static void main(String[] args) { List<String> list = new ArrayList<String>(); list.add("a"); list.add("a"); list.add("b"); list.add("b"); list.add("c"); list.add("c"); Map<String,…