This post explains how to create a zip file of a folder (also containing sub folders) with CRC32 checksum. The below code is similar to the previous post “Creating zip file of a folder” with minor change in main method. The main method code snippet from the previous post as shown below File folder =…… Continue reading Creating a zip file of a folder with CRC32 checksum
Category: Java
Combining Predicates
This post explains how we can combine two or more predicates using logical operations as mentioned below 1) and 2) or 3) negate Below is an example Person package Function; public class Person { private String ssn; private String fname; private String lname; private String description; private int age; public String getSsn() { return ssn;…… Continue reading Combining Predicates
Java Predicate
Java provides a new interface named Predicate which is a functional interface. A functional interface is an interface which will have exactly one abstract method in addition to one or more default methods. In the case of Predicate interface, the abstract method is test method whose signature is as shown below boolean test(T t) In…… Continue reading Java Predicate
Getting access to all printers configured in machine
This post explains how to programmatically get access to all printers configured in a machine. Java provides lookup facitlity through PrintServiceLookup class. This class has static methods through which we can get a reference to all the printers. We use the lookupPrintServices method in the PrintServiceLookup class. The api definition is as shown below public…… Continue reading Getting access to all printers configured in machine
Getting access to default printer
This post explains how to programmatically get access to a printer configured as default printer in a machine. Java provides PrintServiceLookup class, which provides static methods through which we can get a reference to the printer. Each printer installed in a machine is represented by an instance of PrintService interface. The PrintService interface provides methods…… Continue reading Getting access to default printer
PushBackReader Demo
This post explains PushBackReader class in java. This reader allows us to put the data read from the input stream back into the stream and reread it again. The below explains how to use it Main Class package IO; import java.io.PushbackReader; import java.io.StringReader; public class PushBackReaderDemo { public static void main(String[] args) throws Exception {…… Continue reading PushBackReader Demo
Creating dynamic proxy objects
This post explains how to create proxy objects using Java Proxy api. We need the below items to create a proxy. 1) proxy interfaces (list of interfaces the dynamic proxy class will implement). 2) dynamic proxy class is proxy class generated at runtime and implements the proxy interfaces. 3) proxy instance is an instance of…… Continue reading Creating dynamic proxy objects
Unzipping a zip file and checking for data integrity
This post explains how to unzip a zip file and check whether data were correctly extracted. package ZipDemo; import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.util.Enumeration; import java.util.zip.CRC32; import java.util.zip.CheckedInputStream; import java.util.zip.ZipEntry; import java.util.zip.ZipFile; public class ZipDemo6 { public static void main(String[] args) throws FileNotFoundException, IOException { String destination = “E:\\Projects\\JavaProjects\\JavaConcepts\\WorkFolder\\Folder1”;…… Continue reading Unzipping a zip file and checking for data integrity
Unzipping a zip file
This post explains how to unzip a zip file. package ZipDemo; import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.util.Enumeration; import java.util.zip.ZipEntry; import java.util.zip.ZipFile; public class ZipDemo3 { public static void main(String[] args) throws FileNotFoundException, IOException { String destination = “E:\\Projects\\JavaProjects\\JavaConcepts\\WorkFolder\\Folder1”; try (ZipFile zipFile = new ZipFile(“E:\\Projects\\JavaProjects\\JavaConcepts\\WorkFolder\\Folder1.zip”)){ File folder = new File(destination);…… Continue reading Unzipping a zip file
Creating a zip file of a folder
This post explains how to create a zip file of a folder (also containing sub folders) The below image shows the hierarchy of the folder package ZipDemo; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.nio.file.Path; import java.nio.file.Paths; import java.util.zip.ZipEntry; import java.util.zip.ZipOutputStream; public class ZipDemo2 { private File startingFolder; public ZipDemo2(File startingFolder)…… Continue reading Creating a zip file of a folder
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