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
Category: Java
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
Exploring a zip file
This post explains how to explore a zip file. Main Code package ZipDemo; import java.io.IOException; import java.util.Enumeration; import java.util.zip.ZipEntry; import java.util.zip.ZipFile; public class ZipDemo1 { public static void main(String[] args) { try (ZipFile zipFile = new ZipFile(“E:\\Projects\\JavaProjects\\JavaConcepts\\WorkFolder\\Folder1.zip”)){ Enumeration entries = zipFile.entries(); for (Enumeration e = entries; e.hasMoreElements();) { ZipEntry entry = e.nextElement(); System.out.println(entry.getName()); } }…… Continue reading Exploring a zip file
How to use SequenceInputStream
SequenceInputStream reads data from multiple inputstreams in an order. It starts with first inputstream and once it is done reading the first inputstream, it starts reading data from the next available inputstream. Two constructors are available for creating an instance of this stream. First one being SequenceInputStream(InputStream s1, InputStream s2) The above constructors limits us…… Continue reading How to use SequenceInputStream
LineNumberReader class setLineNumber method
As mentioned in Java API, LineNumberReader class keeps track of line number and return line number in addition to the data read. In this post I will mainly cover setLineNumber method in the class. The api document doesn’t clearly mention its purpose. The setLineNumber can be used for two purposes 1) Reset the line number…… Continue reading LineNumberReader class setLineNumber method
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