Maven is a powerful yet complex tool. When I started learning Maven, the first obstacle was, of course, its complexity. The second, was the lack of documentation that can get me off the ground quickly. This tutorial is an attempt to create a pragmatic guide that aims to get you familiar with Maven in the quickest way possible. The main theme is to get you on some hands on experience to start out and lead you through the creation of a simple Java EE project as quickly as possible. Instead of trying to give you a good read, I try to get you on the journey right away. The topics are roughly ordered by the logical sequence but you can jump around in any way...

The spring MVC annotation-driven declaration: <?xml version="1.0" encoding="UTF-8"?> <beans x... does the following magic : Among others, registers: RequestMappingHandlerMapping RequestMappingHandlerAdapter ExceptionHandlerExceptionResolver in support of processing requests with annotated controller methods using annotations such as @RequestMapping , @ExceptionHandler , etc. Enables Spring 3 style type conversion through a ConversionService instance in addition to the JavaBeans PropertyEditors used for Data Binding. Enables support for formatting Number fields using the @NumberFormat annotation through the ConversionService . Enables support for formatting Date, Calendar, Long, and Joda Time fields using the @DateTimeFormat annotation, if Joda Time 1.3 or higher is present on the classpath. Enables support for validating @Controller inputs with @Valid , if a JSR-303 Provider is present on the classpath. Enables HttpMessageConverter support for @RequestBody method parameters and...

For some reason I don't know writing to files in Android is very complicated and tedious. Here is some code for those who might need it. Apps should write in the SD in the directory /Android/data/package_name/files/ so that it is deleted with the app uninstall. package randomname; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.FileWriter; import java.io.IOException; import java.io.OutputStream; import java.io.OutputStreamWriter; import java.nio.ByteBuffer; import android.content.Context; import android.os.Environment; import android.util.Log; public class FileIOLibrary { String packageName; boolean mExternalStorageAvailable = false; boolean mExternalStorageWriteable = false; FileIOLibrary(String packageNamep) { this.packageName=packageNamep; } public boolean isExternalStorageAvailable() { updateExternalStorageState(); return mExternalStorageAvailable; } public boolean isExternalStorageWritable() { updateExternalStorageState(); return mExternalStorageWriteable; } /** * writes the current state of SD card to the corresponding variables */ void updateExternalStorageState() {...

This is an HTML image tag filter using Java regex. It takes a string, finds the img tags, replaces the src attribute with one provided by the filter, then adds a class name to the class attribute. import java.util.regex.*; import java.io.*; ... Test file: <div id="HTML snippet"> <img src="img/big/txt-m...

Read the whole contents of a file into a String. It's better to read the whole file as bytes and convert to String than to read the file line by line and concatenate the lines. String getFileContents(String fileName) throws... Using java.nio : import java.io.FileInputStream; import java...

To read a whole file at once into a byte array: File theFile = new File("test.bin"); byte[] byt... It is important that the total number of bytes read is used for the while condition. Changing the loop to the following may result in an infinite loop ! int m = 0, n = 0; while (n >= 0) { n = i...

The goal is to read a file like this: for (String line: textFileReader) { // do s... This is the code: import java.io.*; import java.util.Iterator; ...

Demo code for CSV parsing with SuperCSV parser . Java code: import java.io.*; import java.util.List; imp... Test with a simple CSV file: psmith01,CLASS2B,Peter Smith 1,YEAR2,1,N,ADVANCED,... The parser worked correctly: Line 1 has 11 values: |psmith01| |CLASS2B|... Test with a more complicated CSV file: "psmith01 abc", "CLASS2B " , " Peter... The parser messed up on all three lines: Line 1 has 5 values: |psmith01 abc| |CLASS... Using two lines input: "psmith01 abc", "CLASS2B " , " Peter... It generates an exception: Line 1 has 5 values: |psmith01 abc| |CLASS... Add a new line in item two: "One", "Two ", "Three" Result: Line 2 has 3 values: |One| |Two | |...

Java built-in X.509 certificate factory reads CertPath objects encoded in PkiPath or PKCS7 formats. The META-INF/<key_alias>.RSA file generated by Java jarsigner is in PKCS7 format. Example code: import java.util.*; import java.io.*; import... PKCS7 files can also be generated by openssl from certificate file(s): openssl crl2pkcs7 -nocrl -certfile Certs.pem -out ... Convert PKCS7 from DER to PEM: openssl pkcs7 -in certs.pk7 -inform DER -out certs... Sample PKCS7 file: -----BEGIN PKCS7----- MIIERwYJKoZIhvcNAQcCoIIEO...

Read certificate one at a time from BufferedInputStream : // import java.security.cert.*; public void rea... Read all certificates from a file as a collection: public void readCertificates(File f) throws Except...