Programming Posts

How to Convert from a Point to a KML files and Generate a Circle with Radius on Each Point

Yesterday I got a challenging assignment to generate a telco network coverage map. But the only data i got is BTS (Base Transceiver Station) location, which is only latitude, longitude and coverage radius given on excel file. I need to convert those excel sheet data into a google map page, and displayed it to subscribers accordingly.

The biggest problem that i had is the number of data is quite big, i need to map more than 20k BTS location and need displayed it fast and without lagging. So a simple google maps script wont work because google maps have a limitation for this.

So i need to create a workaround, and after researching for quite some times i pick KML and Google FusionTable. KML data format for creating radius, and Google FusionTable for displaying it.

This is my PHP code for converting latitude, longitude and radius into KML code.

<?
$lats = array('4.53191944444444','5.34593888888889');
$longs = array('97.93600000000001','95.99299999999999');
$meter = 2000; 
 
$kml = '<?xml version="1.0" encoding="UTF-8"?><kml xmlns="http://www.opengis.net/kml/2.2" xmlns:atom="http://www.w3.org/2005/Atom"><Document>        
            <Style id="style0">
                    <LineStyle>
                      <color>ff000000</color>
                      <width>1</width>
                    </LineStyle>
                    <PolyStyle>
                      <color>7FAAAAAA</color>
                      <fill>1</fill>
                      <outline>1</outline>
                    </PolyStyle>               
            </Style>';

for($i = 0; $i < count($lats); $i++) {

    $lat = $lats[$i];
    $long = $longs[$i];

    // Get circle coordinates
    $coordinatesList = getCirclecoordinates($lat, $long, $meter);

    // Output
    $kml  .= '<Placemark><name>Circle '.$i.'</name><styleUrl>#style0</styleUrl><Polygon><outerBoundaryIs><LinearRing><coordinates>'.$coordinatesList.'</coordinates></LinearRing></outerBoundaryIs></Polygon></Placemark>';
}


$kml .= '</Document></kml>';
 
function getCirclecoordinates($lat, $long, $meter) {
  // convert coordinates to radians
  $lat1 = deg2rad($lat);
  $long1 = deg2rad($long);
  $d_rad = $meter/6378137;
 
  $coordinatesList = "";
  // loop through the array and write path linestrings
  for($i=0; $i<=360; $i+=3) {
    $radial = deg2rad($i);
    $lat_rad = asin(sin($lat1)*cos($d_rad) + cos($lat1)*sin($d_rad)*cos($radial));
    $dlon_rad = atan2(sin($radial)*sin($d_rad)*cos($lat1), cos($d_rad)-sin($lat1)*sin($lat_rad));
    $lon_rad = fmod(($long1+$dlon_rad + M_PI), 2*M_PI) - M_PI;
    $coordinatesList .= rad2deg($lon_rad).",".rad2deg($lat_rad).",0 ";
  }
  return $coordinatesList;
}

$fp = fopen('e:\lele.kml', 'w');
fwrite($fp, $kml);
fclose($fp);
?>

After KML is done, i just need to upload it to Google FusionTable and display it on my web page.
kmlcircle

Google+

Error java.sql.SQLException: Numeric Overflow when Connect to Oracle using Hibernate

Got weird error today, here is the complere stacktrace

2018-01-31 12:14:56 WARN  SqlException: - SQL Error: 17026, SQLState: 99999
2018-01-31 12:14:56 ERROR SqlException: - Numeric Overflow

Caused by: java.sql.SQLException: Numeric Overflow
	at oracle.jdbc.driver.NumberCommonAccessor.throwOverflow(NumberCommonAccessor.java:4136)
	at oracle.jdbc.driver.NumberCommonAccessor.getInt(NumberCommonAccessor.java:103)
	at oracle.jdbc.driver.GeneratedStatement.getInt(GeneratedStatement.java:197)
	at oracle.jdbc.driver.GeneratedScrollableResultSet.getInt(GeneratedScrollableResultSet.java:244)
	at oracle.jdbc.driver.GeneratedResultSet.getInt(GeneratedResultSet.java:554)
	at org.apache.tomcat.dbcp.dbcp.DelegatingResultSet.getInt(DelegatingResultSet.java:275)
	at org.apache.tomcat.dbcp.dbcp.DelegatingResultSet.getInt(DelegatingResultSet.java:275)
	at org.hibernate.type.descriptor.sql.IntegerTypeDescriptor$2.doExtract(IntegerTypeDescriptor.java:66)
	at org.hibernate.type.descriptor.sql.BasicExtractor.extract(BasicExtractor.java:64)
	at org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:265)
	at org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:261)
	at org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:251)
	at org.hibernate.type.AbstractStandardBasicType.hydrate(AbstractStandardBasicType.java:336)
	at org.hibernate.persister.entity.AbstractEntityPersister.hydrate(AbstractEntityPersister.java:2924)
	at org.hibernate.loader.Loader.loadFromResultSet(Loader.java:1695)
	at org.hibernate.loader.Loader.instanceNotYetLoaded(Loader.java:1627)
	at org.hibernate.loader.Loader.getRow(Loader.java:1509)
	at org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:719)
	at org.hibernate.loader.Loader.processResultSet(Loader.java:949)
	at org.hibernate.loader.Loader.doQuery(Loader.java:917)
	at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:348)
	at org.hibernate.loader.Loader.doList(Loader.java:2550)
	... 75 more	

And here is my java class,

public class Class {
   private Integer value;

   // other setter and getter
}

How to solve the issue is actually quite simple, it’s all happen because im having a data on database which is bigger than Integer’s max value. Updating my bean from Integer to BigDecimal solve the problem,

public class Class {
   private BigDecimal value;

   // other setter and getter
}
Google+

Error “Can not write a field name, expecting a value;” while Writing JSON on Spring MVC

The error started since i upgraded my jackson library, somehow it never happen before. This is my full stacktrace

com.fasterxml.jackson.core.JsonGenerationException: Can not write a field name, expecting a value
	com.fasterxml.jackson.core.JsonGenerator._reportError(JsonGenerator.java:1649)
	com.fasterxml.jackson.core.json.UTF8JsonGenerator.writeFieldName(UTF8JsonGenerator.java:186)
	com.edw.test.jackson.TestSerializer.serialize(TestSerializer.java:27)
	com.edw.test.jackson.TestSerializer.serialize(TestSerializer.java:19)
	com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:130)
	com.fasterxml.jackson.databind.ObjectWriter$Prefetch.serialize(ObjectWriter.java:1387)
	com.fasterxml.jackson.databind.ObjectWriter.writeValue(ObjectWriter.java:889)
	org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.writeInternal(AbstractJackson2HttpMessageConverter.java:292)
	org.springframework.http.converter.AbstractGenericHttpMessageConverter.write(AbstractGenericHttpMessageConverter.java:106)
	org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:231)
	org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:174)
	org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:81)
	org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:113)
	org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
	org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
	org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
	org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
	org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
	org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
	org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
	org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)

Looks like this error happen on my custom json serializer,

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:p="http://www.springframework.org/schema/p"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd">
    
    <mvc:annotation-driven>
        <mvc:message-converters register-defaults="false">
            <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter" p:objectMapper-ref="testObjectMapper"/>
        </mvc:message-converters>
    </mvc:annotation-driven>
    
    <context:component-scan base-package="com.edw.test.jackson"/>
</beans>

And this is the content of my objectMapper java class,

package com.edw.test.jackson;

import com.edw.test.jackson.bean.Test;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.databind.module.SimpleModule;
import org.springframework.stereotype.Component;

@Component
public class TestObjectMapper extends ObjectMapper {
    public TestObjectMapper() {
        super();
        
        SimpleModule module = new SimpleModule();
        module.addSerializer(Test.class, new TestSerializer());
        registerModule(module);
        configure(SerializationFeature.INDENT_OUTPUT, false);
    }
}

And as you can see, the main culprit is on class TestSerializer

package com.edw.test.jackson;

import com.edw.test.jackson.bean.Test;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
import java.io.IOException;

public class TestSerializer extends JsonSerializer<Test> {

    @Override
    public void serialize(Test t, JsonGenerator jgen, SerializerProvider sp) throws IOException, JsonProcessingException {
        jgen.writeStartObject();
        jgen.writeRaw("{");
        jgen.writeFieldName("test01");
        jgen.writeRaw(t.getTest01());
        jgen.writeFieldName("test02");
        jgen.writeRaw(t.getTest02());
        jgen.writeRaw("}");
        jgen.writeEndObject();
    }
}

replacing writeFieldName method with writeRaw method solve my problem.

package com.edw.test.jackson;

import com.edw.test.jackson.bean.Test;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
import java.io.IOException;

public class TestSerializer extends JsonSerializer<Test> {
    @Override
    public void serialize(Test t, JsonGenerator jgen, SerializerProvider sp) throws IOException, JsonProcessingException {
        jgen.writeStartObject();
        jgen.writeRaw("test01");
        jgen.writeRaw(t.getTest01());
        jgen.writeRaw("test02");
        jgen.writeRaw(t.getTest02());
        jgen.writeEndObject();
    }
}

Hope it helps :)

Google+

[Java] Cara Cache Data Hasil Query dengan SpringMVC

Pada tulisan kali ini, saya coba membuat suatu metode caching untuk menyimpan data-data master kedalam memory, sehingga tidak perlu query ke database lagi. Hal ini cocok digunakan untuk menyimpan data-data master yang sangat jarang berubah, seperti kode provinsi ataupun kode cabang.

Okay, di tutorial ini saya menggunakan Spring MVC 4, Hibernate dan ehCache sebagai cache provider. Berikut adalah pom.xml yang digunakan,

<?xml version="1.0" encoding="UTF-8"?>
<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>mavenproject5</artifactId>
    <version>1</version>
    <packaging>war</packaging>

    <name>mavenproject5</name>

    <properties>
        <endorsed.dir>${project.build.directory}/endorsed</endorsed.dir>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
    
    <dependencies>
        <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-web-api</artifactId>
            <version>6.0</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>
        
        
        <!-- Spring 4 dependencies -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>4.1.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>4.1.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>4.1.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>4.1.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>4.1.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>cglib</groupId>
            <artifactId>cglib</artifactId>
            <version>2.2</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>4.1.2.RELEASE</version>
         </dependency>
         
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.6</version>
        </dependency>
        
        
        <dependency>
            <groupId>commons-dbcp</groupId>
            <artifactId>commons-dbcp</artifactId>
            <version>1.2.2</version>
        </dependency>
        
        <!--ehcache-->
        <dependency>
            <groupId>net.sf.ehcache</groupId>
            <artifactId>ehcache</artifactId>
            <version>2.7.0</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.5</version>
        </dependency>
        
        <!--hibernate-->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>4.3.8.Final</version>
        </dependency>
        
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                    <compilerArguments>
                        <endorseddirs>${endorsed.dir}</endorseddirs>
                    </compilerArguments>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>2.3</version>
                <configuration>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-dependency-plugin</artifactId>
                <version>2.6</version>
                <executions>
                    <execution>
                        <phase>validate</phase>
                        <goals>
                            <goal>copy</goal>
                        </goals>
                        <configuration>
                            <outputDirectory>${endorsed.dir}</outputDirectory>
                            <silent>true</silent>
                            <artifactItems>
                                <artifactItem>
                                    <groupId>javax</groupId>
                                    <artifactId>javaee-endorsed-api</artifactId>
                                    <version>7.0</version>
                                    <type>jar</type>
                                </artifactItem>
                            </artifactItems>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

</project>

Kemudian konfigurasi standard yang digunakan di SpringMVC, applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:cache="http://www.springframework.org/schema/cache"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
        http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.0.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
        http://www.springframework.org/schema/cache http://www.springframework.org/schema/cache/spring-cache.xsd">

    <context:annotation-config/>
    
    <tx:annotation-driven/>
    
    <cache:annotation-driven />
    
    <context:component-scan base-package="com.edw.mavenproject5.service"/>
    
     <!-- datasource  -->
    <bean id="ds" class="org.apache.tomcat.jdbc.pool.DataSource" destroy-method="close"
          p:driverClassName="com.mysql.jdbc.Driver" p:url="jdbc:mysql://localhost/test"
          p:username="root" p:password=""
          p:initialSize="10"
          p:maxActive="50"
          p:maxIdle="10"
          p:minIdle="3"
          p:maxWait="30000"
          p:removeAbandoned="true"
          p:removeAbandonedTimeout="30"
          p:validationQuery="SELECT 1" />
    
    <bean id="sessionFactory"
        class="org.springframework.orm.hibernate4.LocalSessionFactoryBean"
        p:dataSource-ref="ds" p:configLocations="classpath:hibernate.cfg.xml" depends-on="ds">
        <property name="hibernateProperties">
            <value>
                hibernate.dialect=org.hibernate.dialect.MySQLDialect
                hibernate.query.substitutions=true
                hibernate.show_sql=true
                hibernate.enable_lazy_load_no_trans=true
            </value>
        </property>
    </bean> 
    
    <bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory" />
    </bean>
    
    <bean id="cacheManager" 
          class="org.springframework.cache.ehcache.EhCacheCacheManager" 
          p:cache-manager-ref="ehcache"/>
    <bean id="ehcache" class="org.springframework.cache.ehcache.EhCacheManagerFactoryBean"
          p:config-location="classpath:ehcache.xml"/>
    
</beans>

dan dispatcher-servlet.xml,

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:p="http://www.springframework.org/schema/p"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">


    <context:component-scan base-package="com.edw.mavenproject5.controller" />
	
    <mvc:annotation-driven />
    <mvc:default-servlet-handler />

    <bean id="viewResolver"
          class="org.springframework.web.servlet.view.InternalResourceViewResolver"
          p:prefix="/WEB-INF/jsp/"
          p:suffix=".jsp" />
</beans>

yang kemudian dipanggil dari web.xml,

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" 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_3_0.xsd">
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/applicationContext.xml</param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <servlet>
        <servlet-name>dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>2</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>dispatcher</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
</web-app>

Nah, ada satu konfigurasi xml yang penting dalam membuat cache. Yaitu ehcache.xml, disana disimpan nama cache serta lama waktu hidupnya

<?xml version="1.0" encoding="UTF-8"?>
<!--
    caching configuration
-->
<ehcache>
    
    <defaultCache
        maxElementsInMemory="5000"
        eternal="true"
        overflowToDisk="false"
        memoryStoreEvictionPolicy="LRU"
    />
    
    <!--2menit-->
    <cache name="duaMenit"
           maxElementsInMemory="10000"
           timeToLiveSeconds="120"
           memoryStoreEvictionPolicy="LRU" 
    />
    
    <!--1menit-->
    <cache name="satuMenit"
           maxElementsInMemory="10000"
           timeToLiveSeconds="60"
           memoryStoreEvictionPolicy="LRU" 
    />
</ehcache>

Nah sekarang kita buat class java-nya, dimulai dari service layer. Perhatikan annotation Cacheable, konfigurasi tersebut adalah konfigurasi yang menandakan lokasi method yang kita cache.

package com.edw.mavenproject5.service;

import com.edw.mavenproject5.bean.Dosen;
import java.util.List;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

@Service
@Transactional
public class DosenService {

    @Autowired
    private SessionFactory sessionFactory;
    
    @Cacheable(key = "#root.methodName", value = "duaMenit")
    public List<Dosen> getDosens() {
        return sessionFactory.getCurrentSession().createCriteria(Dosen.class).list();
    }
    
    @Cacheable(key = "#root.methodName + #idDosen", value = "satuMenit")
    public Dosen getDosen(String idDosen) {
        return (Dosen) sessionFactory.getCurrentSession().get(Dosen.class, idDosen);
    }
    
}

Yang kemudian dipanggil dari controller,

package com.edw.mavenproject5.controller;

import com.edw.mavenproject5.service.DosenService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
public class IndexController {
    
    @Autowired
    private DosenService dosenService;
    
    @RequestMapping(value = "/", method = RequestMethod.GET)
    public String index(ModelMap modelMap){
        modelMap.put("dosens", dosenService.getDosens());
        return "index";
    }
    
    @RequestMapping(value = "/get", method = RequestMethod.GET)
    public String get(ModelMap modelMap, String id){
        modelMap.put("dosen", dosenService.getDosen(id));
        return "index";
    }
}

Dan berikut adalah ui yang digunakan untuk menampilkan hasil query didatabase,

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
    </head>
    <body>
        <h1>Hello World!</h1>
        
        <c:if test="${not empty dosens}">
        <table class="table table-hover table-striped">
            <thead>
                <tr>
                    <th>ID Dosen</th>
                    <th>Nama Dosen</th>
                </tr>
            </thead>
            <tbody>
            <c:forEach items="${dosens}" var="dosen">
                <tr>
                    <td>${dosen.iddosen}</td>
                    <td>${dosen.namadosen}</td>
                </tr>
            </c:forEach>
            </tbody>
        </table>
        </c:if>
        
        <c:if test="${not empty dosen}">
            <h1>Hello Dosen ${dosen.namadosen}!</h1>
        </c:if>
    </body>
</html>

Hasil akhirnya adalah sebagai berikut, data dengan kode 02 dan 321 sudah diubah secara langsung didatabase, namun walaupun browser di-refresh berulang kali, tetap menampilkan data yang lama, yaitu “Dodol” dan “Testing 123 123”.
capture1

Untuk sourcecode lengkapnya bisa diunduh di github, https://github.com/edwinkun/CachingWithSpringMVC. (*)

Google+

Using Sitemesh and Got Error 330 (net::ERR_CONTENT_DECODING_FAILED) on Google Chrome

Basically i never had this error before, it become so challenging because it happen after i adding sitemesh library on my maven project. My first guess is, somehow Sitemesh have a conflicting configuration with other libraries. But i never found any reference nor article to support my theory. Even after i heavily removed several library, the error still happens.

Suddenly i have an enlightenment, after i remove my ehcache gzip compression filter. It turns out that in order to work i need to put sitemesh filter location after ehcache gzip filter.

Here is my final web.xml looks like,

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" 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_3_0.xsd">
    
    <!-- gzip -->
    <filter>
        <filter-name>CompressionFilter</filter-name>
        <filter-class>net.sf.ehcache.constructs.web.filter.GzipFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>CompressionFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    
    <!-- sitemesh -->
    <filter>
        <filter-name>sitemesh</filter-name>
        <filter-class>com.opensymphony.sitemesh.webapp.SiteMeshFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>sitemesh</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    
</web-app>
Google+