Programming | edwin's journey

[Java] How to Map Properties from HashMap to Java Bean

By edwin / 7 March 2013 7 March 2013 / Java, Programming / basic, Java, Programming, util

On this example, im trying to do a simple mapping from java.util.Map to a simple Java Bean, using Apache Common BeanUtils.

First as usual, a simple java bean.

package com.edw.bean;

public class Student {
    public String name;
    public int age;

    public Student() {
    }

    // other setter and getter
}

And this is how i map simple values to Student bean.

package com.edw.main;

import com.edw.bean.Student;
import java.util.HashMap;
import java.util.Map;
import org.apache.commons.beanutils.BeanUtils;

public class Main {
    public static void main(String[] args) throws Exception {
        Student student = new Student();
        
        Map<String, Object> map = new HashMap<String, Object>();
        map.put("name", "edwin");
        map.put("age", 22);
        
        BeanUtils.populate(student, map);
        
        System.out.println(student.getName());
        System.out.println(student.getAge());
    }
}

This is the libraries that i used,

Actually, my plan is to create a dynamic bean to bean mapping configured via xml files. And this class is my starting point. (H)

[Java] Membuat Laporan Excel di Aplikasi Web Based

By edwin / 16 February 2013 16 February 2013 / Java, Programming / Java, Programming, report, util, web

Excel adalah salah satu format output yang disukai oleh enduser, selain dari pdf. Karena di excel pengguna bisa melakukan perhitungan-perhitungan, modifikasi ataupun kustomisasi yang lebih bebas dibandingkan dari pdf.

Di tutorial ini, akan dibahas bagaimana membuat export laporan aplikasi web-based ke format xls. Gw menggunakan library jxls (http://jxls.sourceforge.net/) karena lebih mudah dalam pembuatan format template excel jika dibandingkan dengan jasper. Konsepnya sebenarnya sederhana, sebuah servlet yang jika diinvoke dari method GET, akan meng-generate file excel dan mengirimkan ke pengguna langsung via browser.

Dimulai dengan membuat template excel yang akan kita isi dengan data (perhatikan baris ke-5), kemudian diletakkan dibawah folder WEB-INF.

Untuk sourcecodenya seperti biasa, sebuah java bean sederhana sebagai tempat untuk menampung data

package com.edw.bean;

public class Mahasiswa {

    private String nama;
    private String alamat;
    private int usia;

	// jangan lupa setter dan getter-nya    
}

Berikut adalah servlet yang digunakan untuk meng-generate laporan berformat xcel

package com.edw.servlet;

import com.edw.bean.Mahasiswa;
import java.io.FileInputStream;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Random;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import net.sf.jxls.transformer.XLSTransformer;
import org.apache.poi.ss.usermodel.Workbook;

public class ReportServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        // set output header
        ServletOutputStream os = response.getOutputStream();
        response.setContentType("application/vnd.ms-excel");
        response.setHeader("Content-Disposition", "attachment; filename=\"report." + new SimpleDateFormat("yyyyMMdd.hhmm").format(new Date()) + ".xls\"");

        // ambil file excelnya
        ServletContext context = getServletContext();
        String reportLocation = context.getRealPath("WEB-INF");

        // buat data
        List<Mahasiswa> mahasiswas = new ArrayList<Mahasiswa>();
        for (int i = 0; i < 10; i++) {
            Mahasiswa mahasiswa = new Mahasiswa();

            mahasiswa.setNama("Edwin " + new Random().nextInt());
            mahasiswa.setAlamat("Jakarta " + new Random().nextInt());
            mahasiswa.setUsia(new Random().nextInt());

            mahasiswas.add(mahasiswa);
        }

        // kirim ke excel
        Map beans = new HashMap();
        beans.put("x", mahasiswas);

        try {
            XLSTransformer transformer = new XLSTransformer();
            Workbook workbook = transformer.transformXLS(new FileInputStream(reportLocation + "/report.xls"), beans);
            workbook.write(os);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            os.flush();
        }
    }
}

Jangan lupa daftarkan servletnya di web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app  version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
          xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

    <display-name>Reporting Excel</display-name>

    <session-config>
        <session-timeout>
            30
        </session-timeout>
    </session-config>  
    
    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>
	
    <servlet>
        <servlet-name>reportServlet</servlet-name>
        <servlet-class>com.edw.servlet.ReportServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>reportServlet</servlet-name>
        <url-pattern>/reportServlet</url-pattern>
    </servlet-mapping>	  

</web-app>

Kemudian file jsp yang akan dijadikan sebagai halaman landing page

<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
    </head>
    <body>
        <h1>Download</h1>
        <a href="reportServlet">here</a>        
    </body>
</html>

Jika dijalankan, akan menghasilkan aplikasi web seperti ini,

Ini adalah isi file excel hasil download ketika dibuka

Berikut adalah konfigurasi dan library yang gw gunakan di Netbeans gw,

Ga terlalu sulit kan bikin laporan pakek JXLS 😉

[Java] Algoritma Bilangan Romawi

By edwin / 13 February 2013 15 February 2013 / Java, Programming / basic, Java, Programming, util, utility

Berawal dari ngobrol iseng-iseng dengan temen gw ( Kamplenk SKom ) sepulang dari ngopi bareng, beliau kebetulan nanya soal algoritma bilangan romawi untuk digunakan sebagai nomer surat. Kebetulan karena waktu gw agak kosong, iseng-iseng bikin kayak ginian ( setelah dibantu om google juga sih :p ).

package com.edw.main;

public class RomanNumber {
    
    private static final char[] ROMAWI = {'M', 'D', 'C', 'L', 'X', 'V', 'I'};
    private static final int MAX = 1000; 
    private static final int[][] DIGITS = {
        {}, {0}, {0, 0}, {0, 0, 0}, {0, 1}, {1},
        {1, 0}, {1, 0, 0}, {1, 0, 0, 0}, {0, 2}}; 
        // konstanta digit modulus 10, 
        // array ke 4(0,1) maksudnya IV, array ke 9(0,2) --> IX

    public static String int2roman(int number) {
        if (number <= 0) {
            return "N";
        }
        StringBuilder sb = new StringBuilder();
        for (int i = 0, m = MAX; m > 0; m /= 10, i += 2) {
            int[] d = DIGITS[(number / m) % 10];
            for (int n : d) {
                sb.append(ROMAWI[i - n]);
            }
        }
        return sb.toString();
    }
    
    public static void main(String[] args) {
        System.out.println(int2roman(1990));
        System.out.println(int2roman(2012));
        System.out.println(int2roman(231));
    }
}

Oi plenk, udah jadi nih wkkwkwk….

A Simple Blowfish Encryption / Decryption using Java

By edwin / 8 February 2013 8 February 2013 / Java, Programming / encryption, Java, Programming, util, utility

This is a simple encryption using Blowfish Algorithm that i use to encrypt several properties on my application. On this example im using username appended with password as salt to encrypt password variables.

package com.edw.main;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

public class BlowfishTest {

    public static void main(String[] args) throws Exception {
        encrypt("edwin","password");
        decrypt("6VsVtA/nhHKUZuWWmod/BQ==");
    }

    private static void encrypt(String username, String password) throws Exception {
        byte[] keyData = (username+password).getBytes();
        SecretKeySpec secretKeySpec = new SecretKeySpec(keyData, "Blowfish");
        Cipher cipher = Cipher.getInstance("Blowfish");
        cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec);
        byte[] hasil = cipher.doFinal(password.getBytes());
        System.out.println(new BASE64Encoder().encode(hasil));
    }
    
    private static void decrypt(String string) throws Exception {
        byte[] keyData = ("edwin"+"password").getBytes();
        SecretKeySpec secretKeySpec = new SecretKeySpec(keyData, "Blowfish");
        Cipher cipher = Cipher.getInstance("Blowfish");
        cipher.init(Cipher.DECRYPT_MODE, secretKeySpec);
        byte[] hasil = cipher.doFinal(new BASE64Decoder().decodeBuffer(string));
        System.out.println(new String(hasil));
    }
}

[Java] How to Convert .csv to Shapefile shape format (.shp)?

By edwin / 18 January 2013 18 January 2013 / Java, Programming / gis, Java, Programming, spatial, utility, web

On my previous project, i had a request to provide a csv to shp converter feature. After googling for a while, i found a simple java code snippet, i modified some of its part so i could integrate it on my GIS project and hope it will be more flexible.

This is part of inflasi3.csv file that will be converted into shp

KOTA,LAT,LON,JULIL2009,AGUS2009,9-Sep,OKT2009,9-Nov,DES2009,10-Jan,10-Feb,10-Mar,10-Apr,MEI2010,JUNI2010
BANDA ACEH,5.546181947,95.32366186,0.8,1.45,1.82,-1.3,0.45,-0.23,-0.3,-0.04,0.7,-0.47,0.63,0.63
TARAKAN,3.276090324,117.6193848,0.99,0.97,1.53,-0.74,0.64,1.76,0.24,0.2,0.08,0.09,-0.19,1.44
MANADO,1.493103951,124.8409503,0.46,0.65,-0.36,0.83,1.27,0.38,-1.35,1.25,1.29,-1.32,-0.64,-0.12

And this is my java class,

package com.baculsoft.main;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;

import org.geotools.data.DataStoreFactorySpi;
import org.geotools.data.DataUtilities;
import org.geotools.data.DefaultTransaction;
import org.geotools.data.FeatureStore;
import org.geotools.data.Transaction;
import org.geotools.data.shapefile.ShapefileDataStore;
import org.geotools.data.shapefile.ShapefileDataStoreFactory;
import org.geotools.feature.FeatureCollection;
import org.geotools.feature.FeatureCollections;
import org.geotools.feature.simple.SimpleFeatureBuilder;
import org.geotools.geometry.jts.JTSFactoryFinder;
import org.geotools.referencing.crs.DefaultGeographicCRS;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;

import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.GeometryFactory;

public class Csv2Shape {

    public static void main(String[] args) throws Exception {
        File file = new File("inflasi3.csv");

        FeatureCollection<SimpleFeatureType, SimpleFeature> collection = FeatureCollections.newCollection();
        BufferedReader reader = new BufferedReader(new FileReader(file));
        SimpleFeatureType TYPE = null;
        try {
            String line = reader.readLine();
            
            StringBuilder stringBuilder = new StringBuilder();
            stringBuilder.append("location:Point,");

            String[] headers = line.split("\\,"); 
            for (String header : headers) {
                stringBuilder.append("").append(header).append(":String,");
            }

            TYPE = DataUtilities.createType("Location", stringBuilder.substring(0, stringBuilder.toString().length() - 1));
            GeometryFactory factory = JTSFactoryFinder.getGeometryFactory(null);

            for (line = reader.readLine(); line != null; line = reader.readLine()) {
                String split[] = line.split("\\,");

                String name = split[0]; 
                double latitude = Double.parseDouble(split[1]);
                double longitude = Double.parseDouble(split[2]);

                Object[] o = new Object[split.length+1];
                for (int i = 2; i < o.length; i++) {
                    o[i] = split[i-1];
                }

                o[0] = factory.createPoint(new Coordinate(longitude, latitude));
                o[1] = name;

                SimpleFeature feature = SimpleFeatureBuilder.build(TYPE, o, null);
                collection.add(feature);
            }
        } finally {
            reader.close();
        }
        File newFile = new File("inflasi4.shp");

        DataStoreFactorySpi factory = new ShapefileDataStoreFactory();

        Map<String, Serializable> create = new HashMap<String, Serializable>();
        create.put("url", newFile.toURI().toURL());
        create.put("create spatial index", Boolean.TRUE);

        ShapefileDataStore newDataStore = (ShapefileDataStore) factory.createNewDataStore(create);
        newDataStore.createSchema(TYPE);
        newDataStore.forceSchemaCRS(DefaultGeographicCRS.WGS84);

        Transaction transaction = new DefaultTransaction("create");

        String typeName = newDataStore.getTypeNames()[0];
        FeatureStore<SimpleFeatureType, SimpleFeature> featureStore;
        featureStore = (FeatureStore<SimpleFeatureType, SimpleFeature>) newDataStore.getFeatureSource(typeName);

        featureStore.setTransaction(transaction);
        try {
            featureStore.addFeatures(collection);
            transaction.commit();
        } catch (Exception ex) {
            ex.printStackTrace();
            transaction.rollback();
        } finally {
            transaction.close();
        }
    }
}

And this is my pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.edw</groupId>
    <artifactId>CSV2SHP</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>CSV2SHP</name>
    <url>http://maven.apache.org</url>
    
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <!-- use the latest snapshot -->
        <geotools.version>8.4</geotools.version>
    </properties>
  
    <repositories>
        <repository>
            <id>maven2-repository.dev.java.net</id>
            <name>Java.net repository</name>
            <url>http://download.java.net/maven/2</url>
        </repository>
        <repository>
            <id>osgeo</id>
            <name>Open Source Geospatial Foundation Repository</name>
            <url>http://download.osgeo.org/webdav/geotools/</url>
        </repository>
    </repositories>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.geotools</groupId>
            <artifactId>gt-shapefile</artifactId>
            <version>${geotools.version}</version>
        </dependency>
        <dependency>
            <groupId>org.geotools</groupId>
            <artifactId>gt-swing</artifactId>
            <version>${geotools.version}</version>
        </dependency>
    </dependencies>
</project>

This is the screenshot of my viewer (geoexplorer) after i uploaded inflasi4.shp, which is the result of converting inflasi3.csv

Hope it helps other, have fun (H)