And Todays’s Quote Would Be..

Life begins at the end of your comfort zone.

Neale Donald Walsch

Fixing MySql’s Error, “Cant create test file /folder/data/servername.lower-test” on RedHat OS

Had a very weird error starting my MySql after im moving MySql’s data folder from /var/lib/mysql to /folder/data on my RHEL 7 Server,

2017-03-23 11:50:52 2119 [Warning] Can't create test file /folder/data/servername.lower-test
2017-03-23 11:50:52 2119 [Warning] Can't create test file /folder/data/servername.lower-test
2017-03-23 11:50:52 2119 [ERROR] /usr/sbin/mysqld: Can't create/write to file 
    '/folder/data/servername.lower-test' (Errcode: 13 - Permission denied)

very very weird because im already change the ownership of my /folder data to mysql user, and still not working. I even chmod it to 777 for testing purpose, yet still no positive result. After a while i found out that my SELinux is blocking it, here is the command to unblock it.

[root@servername ~]# setenforce 0
[root@servername ~]# getenforce
Permissive

but the commands above only configure your SELinux until reboot. If you want to make it permanent, you could use this command,

[root@servername ~]# vi /etc/selinux/config 
# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
SELINUX=permissive
# SELINUXTYPE= can take one of these two values:
#     targeted - Targeted processes are protected,
#     mls - Multi Level Security protection.
SELINUXTYPE=targeted  

Hope it helps others, cheers

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How to Find Root Cause of Error 400 on SpringMVC using Log4J

Error 400 is basically telling us that our request is syntactically incorrect. But it will need a while to found out which parameter is incorrect, especially when you are submitting a lot of parameters.

But do not worry, on SpringMVC we can always log which parameters causing error 400 using Log4J. Adding these values on your log4j.properties will display the error location.

log4j.logger.org.springframework.web=debug

And we can see the root cause on our log file,

2017-02-28 22:33:07,241 [DefaultHandlerExceptionResolver] DEBUG org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver:133 - Resolving exception from handler [public java.util.Map xxx.yyy.controller.ZZZController.saveZZZ(xxx.yyy.bean.DDDD,org.springframework.web.multipart.MultipartFile,org.springframework.web.multipart.MultipartFile,javax.servlet.http.HttpSession)]: org.springframework.validation.BindException: org.springframework.validation.BeanPropertyBindingResult: 1 errors
Field error in object 'DDDD' on field 'rupiah': rejected value [100.000.000,000000]; codes [typeMismatch.DDDD.rupiah,typeMismatch.rupiah,typeMismatch.java.math.BigDecimal,typeMismatch]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [DDDD.rupiah,rupiah]; arguments []; default message [rupiah]]; default message [Failed to convert property value of type 1 to required type 1 for property 'rupiah'; nested exception is java.lang.NumberFormatException]

As you can see, it happens because i expect a BigDecimal on my bean, but i send a String instead.

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[nginx] Replacing HTTP 302 Location URL from HTTP to HTTPS

Had this weird problem today, i can login to my web if i access it directly, but unable to do it if my website is on an iframe of another web. I found out that it happen because im using SSL on both of my website (on the iframe) and the iframe parent’s website.

It actually happen because when im successfully login on my iframed-website, it will gives http 302 (Moved Temporarily) to my dashboard page. But somehow the 302 location is not an HTTPS page, it will gives a regular HTTP pages instead. Which is not a problem when im accessing my web directly, but will gives problem when accessed using an iframe website.

The solution is quite simple, using nginx “proxy_redirect” will change my 302 page from HTTP into HTTPS.

proxy_redirect http:// https://;

Hope it helps :)

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[Java] org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (ORA-00923: FROM keyword not found where expected

Had this weird error, when connecting to Oracle Database

### The error occurred while executing a query
### Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; 
nested exception is org.apache.commons.dbcp.SQLNestedException: 
Cannot create PoolableConnectionFactory (ORA-00923: FROM keyword not found where expected
)

Somehow it never happens on my MySql Configuration. Here is my configuration,

<bean id="dataSourceOracle" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"
          p:driverClassName="oracle.jdbc.driver.OracleDriver" p:url="${db.url.oracle}"
          p:username="${db.username.oracle}" p:password="${db.password.oracle}"
          p:initialSize="2"
          p:maxActive="30"
          p:maxIdle="10"
          p:minIdle="3"
          p:maxWait="30000"
          p:removeAbandoned="true"
          p:removeAbandonedTimeout="30"
          p:validationQuery="SELECT 1" />

After investigating for a while, i found out that it happens because i use MySql’s specific validationQuery, “SELECT 1″. Changing it into “SELECT 1 FROM DUAL” make the error go away. :-P

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[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. (*)

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