Getting Started with Grails and MySQL database

Is is so much simple.

Create a file suppose named 'db-config.properties' in 'conf' folder with the following contents:
dataSource.driverClassName = com.mysql.jdbc.Driver
dataSource.username = root
dataSource.password =
dataSource.url = jdbc:mysql://localhost/license?useUnicode=yes&characterEncoding=UTF-8
dataSource.dbCreate = update
dataSource.logSql = true
dataSource.insertDummy = true
dataSource.dialect = org.hibernate.dialect.MySQL5InnoDBDialect

/* Your custom class to do some extra work if need */
dataSource.configClass = src.gorm.GormConfiguration;


Where root is your database username.
Where 'license' is your database name.

And make a entry in 'Config.groovy' file under 'conf' folder as following:
grails.config.locations = [ "classpath:db-config.properties" ]

And you need to must do one thing is to download a  java-mysql connector and put it inside lib folder of your project.
Sometimes you need to clean your project to adjust these changes.

You can use more config file like this as:

grails.config.locations =
[
    "classpath:db-config.properties",
    "classpath:some-config.properties" ,
    "file:${userHome}/.grails/${appName}-config.propertis"
]

Parse XML using java and store data in HashMap recursively

Download XmlParser.java class

Online Debug: http://ideone.com/eV2NDC

Follow the following link to build xml from hashmap/array list

package xmlparser;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

/**
 *
 * @author Pritom K Mondal
 * @published 12th September 2013 08:04 PM
 */
public class XmlParser {
    private String xmlString = "";
    private File xmlFile = null;
    private Document doc = null;

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        String xmlString = "YOUR XML STRING HERE IF YOU WANT PARSE DATA FROM STRING";
        File file = new File("xml1.xml");
        XmlParser xmlParser = new XmlParser(xmlString);
        xmlParser = new XmlParser(file);
        
        Map xmlMap = xmlParser.parseXML();
        print(xmlMap, 0);
    }
    
    public XmlParser(String xmlString) {
        this.xmlString = xmlString;
    }
    
    public XmlParser(File xmlFile) {
        this.xmlFile = xmlFile;
    }

    public Map parseXML() {
        try {
            DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
            DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();

            if (this.xmlFile != null) {
                doc = dBuilder.parse(this.xmlFile);
            }
            else {
                doc = dBuilder.parse( new ByteArrayInputStream(xmlString.getBytes()) );
            }

            doc.getDocumentElement().normalize();

            NodeList resultNode = doc.getChildNodes();

            HashMap result = new HashMap();
            XmlParser.MyNodeList tempNodeList = new XmlParser.MyNodeList();

            String emptyNodeName = null, emptyNodeValue = null;

            for(int index = 0; index < resultNode.getLength(); index ++) {
                Node tempNode = resultNode.item(index);
                if (tempNode.getNodeType() == Node.ELEMENT_NODE) {
                    tempNodeList.addNode(tempNode);
                }
                emptyNodeName = tempNode.getNodeName();
                emptyNodeValue = tempNode.getNodeValue();
            }

            if (tempNodeList.getLength() == 0 && emptyNodeName != null
                    && emptyNodeValue != null) {
                result.put(emptyNodeName, emptyNodeValue);
                return result;
            }

            this.parseXMLNode(tempNodeList, result);
            return result;
        } catch (Exception ex) {
            ex.printStackTrace();
            return null;
        }
    }

    private void parseXMLNode(NodeList nList, HashMap result) {
        for (int temp = 0; temp < nList.getLength(); temp++) {
            Node nNode = nList.item(temp);
            if (nNode.getNodeType() == Node.ELEMENT_NODE
                    && nNode.hasChildNodes()
                    && nNode.getFirstChild() != null
                    && (nNode.getFirstChild().getNextSibling() != null
                    || nNode.getFirstChild().hasChildNodes())) {
                NodeList childNodes = nNode.getChildNodes();
                XmlParser.MyNodeList tempNodeList = new XmlParser.MyNodeList();
                for(int index = 0; index < childNodes.getLength(); index ++) {
                    Node tempNode = childNodes.item(index);
                    if (tempNode.getNodeType() == Node.ELEMENT_NODE) {
                        tempNodeList.addNode(tempNode);
                    }
                }
                HashMap dataHashMap = new HashMap();
                if (result.containsKey(nNode.getNodeName()) && result.get(nNode.getNodeName()) instanceof List) {
                    List mapExisting = (List) result.get(nNode.getNodeName());
                    mapExisting.add(dataHashMap);
                } else if(result.containsKey(nNode.getNodeName())) {
                    List counterList = new ArrayList();
                    counterList.add(result.get(nNode.getNodeName()));
                    counterList.add(dataHashMap);
                    result.put(nNode.getNodeName(), counterList);
                } else {
                    result.put(nNode.getNodeName(), dataHashMap);
                }
                if (nNode.getAttributes().getLength() > 0) {
                    Map attributeMap = new HashMap();
                    for(int attributeCounter = 0;
                        attributeCounter < nNode.getAttributes().getLength();
                        attributeCounter++) {
                        attributeMap.put(
                                nNode.getAttributes().item(attributeCounter).getNodeName(),
                                nNode.getAttributes().item(attributeCounter).getNodeValue()
                        );
                    }
                    dataHashMap.put("<<attributes>>", attributeMap);
                }
                this.parseXMLNode(tempNodeList, dataHashMap);
            } else if (nNode.getNodeType() == Node.ELEMENT_NODE
                    && nNode.hasChildNodes() && nNode.getFirstChild() != null
                    && nNode.getFirstChild().getNextSibling() == null) {
                this.putValue(result, nNode);
            } else if(nNode.getNodeType() == Node.ELEMENT_NODE) {
                this.putValue(result, nNode);
            }
        }
    }

    private void putValue(HashMap result, Node nNode) {
        HashMap attributeMap = new HashMap();
        Object nodeValue = null;
        if(nNode.getFirstChild() != null) {
            nodeValue = nNode.getFirstChild().getNodeValue();
            if(nodeValue != null) {
                nodeValue = nodeValue.toString().trim();
            }
        }
        HashMap nodeMap = new HashMap();
        nodeMap.put("<<value>>", nodeValue);
        Object putNode = nodeValue;
        if (nNode.getAttributes().getLength() > 0) {
            for(int attributeCounter = 0;
                attributeCounter < nNode.getAttributes().getLength();
                attributeCounter++) {
                attributeMap.put(
                        nNode.getAttributes().item(attributeCounter).getNodeName(),
                        nNode.getAttributes().item(attributeCounter).getNodeValue()
                );
            }
            nodeMap.put("<<attributes>>", attributeMap);
            putNode = nodeMap;
        }
        if (result.containsKey(nNode.getNodeName()) && result.get(nNode.getNodeName()) instanceof List) {
            List mapExisting = (List) result.get(nNode.getNodeName());
            mapExisting.add(putNode);
        } else if(result.containsKey(nNode.getNodeName())) {
            List counterList = new ArrayList();
            counterList.add(result.get(nNode.getNodeName()));
            counterList.add(putNode);
            result.put(nNode.getNodeName(), counterList);
        } else {
            result.put(nNode.getNodeName(), putNode);
        }
    }

    class MyNodeList implements NodeList {
        List<Node> nodes = new ArrayList<Node>();
        int length = 0;
        public MyNodeList() {}

        public void addNode(Node node) {
            nodes.add(node);
            length++;
        }

        @Override
        public Node item(int index) {
            try {
                return nodes.get(index);
            } catch (Exception ex) {
                ex.printStackTrace();
            }
            return null;
        }

        @Override
        public int getLength() {
            return length;
        }
    }
    
    private static void print(Map map, Integer tab) {
        Iterator it = map.entrySet().iterator();
        while (it.hasNext()) {
            Map.Entry pairs = (Map.Entry) it.next();
            String key = pairs.getKey().toString();
            Object value = pairs.getValue();
            if (value instanceof Map) {
                System.out.println(getTab(tab) + key + " ==> [");
                print((Map) value, tab + 1);
                System.out.println(getTab(tab) + "]");
            }
            else if (value instanceof List) {
                System.out.println(getTab(tab) + key + " ==> [");
                print((List) value, tab + 1);
                System.out.println(getTab(tab) + "]");
            }
            else {
                System.out.println(getTab(tab) + key + " ==> " + value);
            }
        }
    }

    private static void print(List list, Integer tab) {
        for (Integer index = 0; index < list.size(); index++) {
            Object value = list.get(index);
            if (value instanceof Map) {
                System.out.println(getTab(tab) + index.toString() + ": {");
                print((Map) value, tab + 1);
                System.out.println(getTab(tab) + "}");
            }
            else if (value instanceof List) {
                print((List) value, tab + 1);
            }
            else {
                System.out.println(getTab(tab) + index.toString() + ": " + value);
            }
        }
    }

    public static String getTab(Integer tab) {
        String string = "";
        for (Integer index = 0; index < tab; index++) {
            string += "    ";
        }
        return string;
    }
}

Xml file as follows...

<?xml version="1.0"?>
<lib:library xmlns:lib="http://eric.van-der-vlist.com/ns/library" xmlns:hr="http://eric.van-der-vlist.com/ns/person">
    <lib:book id="b0836217462" available="true" checkingandfind='true'>
        <lib:isbn>0836217462</lib:isbn>
        <lib:title xml:lang="en">Being a Dog Is a Full-Time Job</lib:title>
        <hr:author id="CMS">
            <hr:name>Charles M Schulz</hr:name>
            <hr:born>1922-11-26</hr:born>
            <hr:dead>2000-02-12</hr:dead>
        </hr:author>
        <lib:character id="PP">
            <hr:name>Peppermint Patty</hr:name>
            <hr:born>1966-08-22</hr:born>
            <lib:qualification>bold, brash and tomboyish</lib:qualification>
        </lib:character>
        <lib:character id="Snoopy">
            <hr:name>Snoopy</hr:name>
            <hr:born>1950-10-04</hr:born>
            <lib:qualification>extroverted beagle</lib:qualification>
        </lib:character>
        <lib:character id="Schroeder">
            <hr:name>Schroeder</hr:name>
            <hr:born>1951-05-30</hr:born>
            <lib:qualification>brought classical music to the Peanuts strip</lib:qualification>
        </lib:character>
        <lib:character id="Lucy">
            <hr:name>Lucy</hr:name>
            <hr:born>1952-03-03</hr:born>
            <lib:qualification>bossy, crabby and selfish</lib:qualification>
        </lib:character>
    </lib:book>
    <Purchase>
        <PurchaseId>AAAAA</PurchaseId>
        <PurchaseType>ONLINE</PurchaseType>
    </Purchase>
    <Purchase>
        <PurchaseId>BBBBB</PurchaseId>
        <PurchaseType>OFFLINE</PurchaseType>
    </Purchase>
    <Purchase paid='True'>
        <Purchase>
            <Purchase2 nc='true'>List 1</Purchase2>
            <Purchase2>List 2</Purchase2>
        </Purchase>
    </Purchase>
</lib:library>

Output be as follows...

lib:library ==> [
    lib:book ==> [
        lib:isbn ==> 0836217462
        <<attributes>> ==> [
            id ==> b0836217462
            checkingandfind ==> true
            available ==> true
        ]
        lib:title ==> [
            <<attributes>> ==> [
                xml:lang ==> en
            ]
            <<value>> ==> Being a Dog Is a Full-Time Job
        ]
        lib:character ==> [
            0: {
                <<attributes>> ==> [
                    id ==> PP
                ]
                lib:qualification ==> bold, brash and tomboyish
                hr:name ==> Peppermint Patty
                hr:born ==> 1966-08-22
            }
            1: {
                <<attributes>> ==> [
                    id ==> Snoopy
                ]
                lib:qualification ==> extroverted beagle
                hr:name ==> Snoopy
                hr:born ==> 1950-10-04
            }
            2: {
                <<attributes>> ==> [
                    id ==> Schroeder
                ]
                lib:qualification ==> brought classical music to the Peanuts strip
                hr:name ==> Schroeder
                hr:born ==> 1951-05-30
            }
            3: {
                <<attributes>> ==> [
                    id ==> Lucy
                ]
                lib:qualification ==> bossy, crabby and selfish
                hr:name ==> Lucy
                hr:born ==> 1952-03-03
            }
        ]
        hr:author ==> [
            <<attributes>> ==> [
                id ==> CMS
            ]
            hr:dead ==> 2000-02-12
            hr:name ==> Charles M Schulz
            hr:born ==> 1922-11-26
        ]
    ]
    <<attributes>> ==> [
        xmlns:hr ==> http://eric.van-der-vlist.com/ns/person
        xmlns:lib ==> http://eric.van-der-vlist.com/ns/library
    ]
    Purchase ==> [
        0: {
            PurchaseId ==> AAAAA
            PurchaseType ==> ONLINE
        }
        1: {
            PurchaseId ==> BBBBB
            PurchaseType ==> OFFLINE
        }
        2: {
            <<attributes>> ==> [
                paid ==> True
            ]
            Purchase ==> [
                Purchase2 ==> [
                    0: {
                        <<attributes>> ==> [
                            nc ==> true
                        ]
                        <<value>> ==> List 1
                    }
                    1: List 2
                ]
            ]
        }
    ]
]

How to parse JSON in Java

JSON slurper which parses text or reader content into a data structure of lists and maps.

Example usage:

def slurper = new JsonSlurper()
def result = slurper.parseText('{"person":{"name":"Guillaume","age":33,"pets":["dog","cat"]}}')

println "Name: "+result.person.name;
println "Age: "+result.person.age;
println "Pet Size: "+result.person.pets.size();
println "Pet[0]: "+result.person.pets[0];
println "Pet[1]: "+result.person.pets[1];

Output:

Name: Guillaume
Age: 33
Pet Size: 2
Pet[0]: dog
Pet[1]: cat
 

http://groovy.codehaus.org/gapi/groovy/json/JsonSlurper.html

How to run a local plugin in Grails

grails.plugin.location.plugin_name = "C:\\pritom\\plugins\\grails_plugin"

Where plugin_name is the name of the plugin (not the name of the directory it's in). Make sure the path to the plugin is either an absolute path or the relative path to the plugin from the application.

I've found that this sometimes doesn't work if the plugin is listed in application.properties orBuildConfig.groovy, so if it is, remove it, then execute grails clean and restart the app.

HTTP RAW URL Address Encode in Java as application/x-www-form-urlencoded

package com.pritom.kumar;

import java.net.URLDecoder;
import java.net.URLEncoder;

public class RawUrlEncodeDecode {
    public static void main(String[] args) throws Exception{
        String toEncode = "a & b+c_d+e / é <p>Hello</p><?xml version='1.0'><name>Pritom K Mondal</name>";
        String encoded = URLEncoder.encode(toEncode, "UTF-8");
        System.out.println("Encoded: " + encoded);
        String decoded = URLDecoder.decode(encoded, "UTF-8");
        System.out.println("Decoded: " + decoded);
    }
}

Output

Encoded: a+%26+b%2Bc_d%2Be+%2F+%C3%A9+%3Cp%3EHello%3C%2Fp%3E%3C%3Fxml+version%3D%271.0%27%3E%3Cname%3EPritom+K+Mondal%3C%2Fname%3E

Decoded: a & b+c_d+e / é <p>Hello</p><?xml version='1.0'><name>Pritom K Mondal</name>

Convert A String (like testing123) To Binary In Java

The usual way is to use String#getBytes() to get the underlying bytes and then present those bytes in some other form (hex, binary whatever).

Note that getBytes() uses the default charset, so if you want the string converted to some specific character encoding, you should use getBytes(String encoding) instead, but many times (esp when dealing with ASCII) getBytes() is enough (and has the advantage of not throwing a checked exception).

For specific conversion to binary, here is an example:

  String s = "foo";
  byte[] bytes = s.getBytes();
  StringBuilder binary = new StringBuilder();
  for (byte b : bytes) {
     int val = b;
     for (int i = 0; i < 8; i++)
     {
        binary.append((val & 128) == 0 ? 0 : 1);
        val <<= 1;
     }
     binary.append(' ');
  }
  System.out.println("'" + s + "' to binary: " + binary);

Running this example will yield:

'foo' to binary: 01100110 01101111 01101111

http://stackoverflow.com/questions/917163/convert-a-string-like-testing123-to-binary-in-java

Redirect your site to https and www using htaccess

<ifmodule mod_rewrite.c>
   RewriteEngine on

   RewriteCond %{HTTPS} off
   RewriteCond %{HTTP_HOST} ^www\.(.+)$ [NC]
   RewriteRule ^(.*)$ https://%1/$1 [R=301,L]

   RewriteCond %{HTTPS} off
   RewriteCond %{HTTP_HOST} !^www\.(.+)$ [NC]
   RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]

   RewriteCond %{HTTPS} on
   RewriteCond %{HTTP_HOST} ^www\.(.+)$ [NC]
   RewriteRule ^(.*)$ https://%1/$1 [R=301,L]

   RewriteRule    ^$ app/webroot/    [L]
   RewriteRule    (.*) app/webroot/$1 [L]
</ifmodule>