web | edwin's journey

How to Create A HTTP Request with Proxy Using Apache HTTP Client

By edwin / 16 February 2016 16 February 2016 / Java, Programming / basic, Java, Programming, util, utility, web

In this tutorial, im trying to simuate a http GET request using apache http client, the version im using is 4.5.1

<!-- http client -->
<dependency>
	<groupId>org.apache.httpcomponents</groupId>
	<artifactId>httpclient</artifactId>
	<version>4.5.1</version>
</dependency>
<dependency>
	<groupId>org.apache.httpcomponents</groupId>
	<artifactId>httpmime</artifactId>
	<version>4.5.1</version>
</dependency>

Usually, my application connects well without proxy. But on production environment, I need to put a proxy configuration. So this is my method for making a proxy request connection.

public String process(String lat, String lon) {
	try {
		HttpClient httpclient = HttpClientBuilder.create().build();
		HttpGet httpGet = new HttpGet("<INPUT YOUR URL HERE>");
		
		HttpHost proxy = new HttpHost("127.0.0.1", 3128, "http");
		RequestConfig config = RequestConfig.custom()
				.setProxy(proxy)
				.build();
		httpGet.setConfig(config);
		
		HttpResponse response = httpclient.execute(httpGet);
		HttpEntity resEntity = response.getEntity();

		String responseText = EntityUtils.toString(resEntity);		
		return responseText;
	} catch (IOException e) {
		logger.error(e, e);
	} catch (Exception e) {
		logger.error(e, e);
	}
	return null;
}

[Java] How to Create a HTTP Get Request

By edwin / 5 November 2015 5 November 2015 / Java, Programming / Java, Programming, web

Basically i use this class to mimic a json request to a different domain, to prevent CORS error. So this is my code, oh and i use Spring Framework, which explain the Service annotation .

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import org.springframework.stereotype.Service;

@Service
public class JsonService {

    public String get() {
        try {
            return getHTML("myurl");
        } catch (Exception e) {
            return "";
        }
    }
    
   private String getHTML(String urlToRead) throws Exception {
      StringBuilder result = new StringBuilder();
      URL url = new URL(urlToRead);
      HttpURLConnection conn = (HttpURLConnection) url.openConnection();
      conn.setRequestMethod("GET");
      BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
      String line;
      while ((line = rd.readLine()) != null) {
         result.append(line);
      }
      rd.close();
      return result.toString();
   }
}

Hope it can help others, cheers (B)

[Weird Javascript Error] Leading Zero on Integer Variable Become Octal on Old Browser

By edwin / 23 December 2014 23 December 2014 / Javascript, Programming / basic, Programming, util, utility, web

Ive met a very weird error, that somehow never occurs to me on my browser. I found this error only happen on old mozilla browsers, and only happen on javascript’s parseInt method. Here is a simple example,

alert(parseInt("09")-1);

When im running it on my browser (Mozilla version 34), this is what happen,

But when running on old browsers (Mozilla version 3.6), this is what happen,

I finally found out that that on old browsers, leading zeros are treated as octal values instead of plain integers. So this is my workaround,

alert(parseInt("09".replace(/^[0]+/g,""))-1);

I removed the leading zero before parsing it into int.

Hope it can help others 🙂

Belajar Spring Security Sederhana

By edwin / 24 November 2014 24 November 2014 / Java, Programming / Java, Programming, spring, web

Beberapa hari yang lalu, gw ditanya oleh salah seorang temen gw, Ariestania Winda. Dia nanya, gimana caranya bikin validasi login sederhana dengan Spring Security. Oke, berikut adalah tutorial yang gw kasih ke dia. Semoga bisa bermanfaat untuk yang lain.

Semua dimulai dengan konfigurasi maven sederhana, berikut pom.xml yang gw punya,

<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>SpringSecurityExample</artifactId>
    <version>1.0</version>
    <packaging>war</packaging>

    <name>SpringSecurityExample</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>
            <scope>runtime</scope>
        </dependency>
        
        <!-- Spring 3 dependencies -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>4.1.1.RELEASE</version>
        </dependency> 
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>4.1.1.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>4.1.1.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>4.1.1.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>4.1.1.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>cglib</groupId>
            <artifactId>cglib</artifactId>
            <version>2.2</version>
        </dependency>
        
        <!-- Spring Security -->
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-web</artifactId>
            <version>3.2.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-config</artifactId>
            <version>3.2.5.RELEASE</version>
        </dependency>
        
        <!-- slf4j -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.5.6</version>
        </dependency>
        
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.3.2</version>
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                    <compilerArguments>
                        <endorseddirs>${endorsed.dir}</endorseddirs>
                    </compilerArguments>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>2.1.1</version>
                <configuration>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-dependency-plugin</artifactId>
                <version>2.1</version>
                <executions>
                    <execution>
                        <phase>validate</phase>
                        <goals>
                            <goal>copy</goal>
                        </goals>
                        <configuration>
                            <outputDirectory>${endorsed.dir}</outputDirectory>
                            <silent>true</silent>
                            <artifactItems>
                                <artifactItem>
                                    <groupId>javax</groupId>
                                    <artifactId>javaee-endorsed-api</artifactId>
                                    <version>6.0</version>
                                    <type>jar</type>
                                </artifactItem>
                            </artifactItems>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

Kemudian register konfigurasi spring di 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, /WEB-INF/applicationSecurity.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>
    
    <!-- Spring Security -->
    <filter>
        <filter-name>springSecurityFilterChain</filter-name>
        <filter-class>org.springframework.web.filter.DelegatingFilterProxy
        </filter-class>
    </filter>
 
    <filter-mapping>
        <filter-name>springSecurityFilterChain</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    
    <session-config>
        <session-timeout>
            30
        </session-timeout>
    </session-config>
</web-app>

Dan 3 xml milik Spring, ApplicationContext.xml, dispatcher-servlet.xml dan applicationSecurity.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:aop="http://www.springframework.org/schema/aop"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:jee="http://www.springframework.org/schema/jee"
       xmlns:tx="http://www.springframework.org/schema/tx"
       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">

    <context:annotation-config/>
    
    <context:component-scan base-package="com.edw.springsecurityexample.controller"/>
</beans>

<?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">


    <!-- the mvc resources tag does the magic -->
    <mvc:resources mapping="/css/**" location="/css/" />
    <mvc:resources mapping="/js/**" location="/js/" />
    <mvc:resources mapping="/img/**" location="/img/" />
    
    <context:component-scan base-package="com.edw.springsecurityexample.controller" />
	
    <mvc:annotation-driven />

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

<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/security"
             xmlns:beans="http://www.springframework.org/schema/beans" 
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://www.springframework.org/schema/beans
	http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
	http://www.springframework.org/schema/security
	http://www.springframework.org/schema/security/spring-security-3.2.xsd">
    
    <http auto-config="true" use-expressions="true">
        <intercept-url pattern="/admin/**" access="hasRole('ROLE_USER')" />
        <intercept-url pattern="/" 	access="isAnonymous()"/>
        <form-login login-page="/" 
                    authentication-failure-url="/?error=1" 
                    default-target-url="/admin/index" always-use-default-target="true"/>
        <logout logout-url="/logout" logout-success-url="/" />
    </http>
 
    <authentication-manager>
        <authentication-provider>
            <user-service>
                <user name="edw" password="123456" authorities="ROLE_USER" />
            </user-service>
        </authentication-provider>
    </authentication-manager>
    
    
</beans:beans>

Lalu gw bikin satu java class sebagai controller,

package com.edw.springsecurityexample.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
public class IndexController {
    @RequestMapping(value = "/", method = RequestMethod.GET)
    public String index() {
        return "index";
    }
    
    @RequestMapping(value = "/admin/index", method = RequestMethod.GET)
    public String adminIndex() {
        return "adminIndex";
    }
}

Kemudian satu jsp sederhana sebagai halaman login,

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

<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
    </head>
    <body>
        <h1>Hello Spring MVC!</h1>
        <h2>Tolong Login Dulu </h2>
        
        <c:if test="${not empty param.error}">
                <div style="color: red;">
                    Username atau Password Salah
                </div>
        </c:if>
        
        <form action="j_spring_security_check" method="POST">
            <table>
                <tr>
                    <td>
                        username
                    </td>
                    <td>
                        <input name="j_username" type="text" />
                    </td>
                </tr>
                <tr>
                    <td>
                        password
                    </td>
                    <td>
                        <input name="j_password" type="password" />
                    </td>
                </tr>
                <tr>
                    <td colspan="2">
                        <input name="submit" type="submit" />
                    </td>
                </tr>
            </table>
        </form>
    </body>
</html>

Dan halaman admin sederhana, yang hanya bisa diakses apabila sudah login yang isinya link logout.

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
    </head><a href="http://edwin.baculsoft.com/wp-content/uploads/2014/11/springsecurity-login-gagal.png"><img src="http://edwin.baculsoft.com/wp-content/uploads/2014/11/springsecurity-login-gagal.png" alt="springsecurity login gagal" width="458" height="287" class="aligncenter size-full wp-image-1535" /></a>
    <body>
        <h1>Selamat, anda sudah login -- admin page</h1>
        <br />
        <a href="${pageContext.request.contextPath}/logout">logout</a>
    </body>
</html>

Berikut adalah tampilan struktur netbeans project

Tampilan halaman login, dan tampilan jika login gagal,

Jika login dengan username edw dan password 123456, maka akan tampil halaman seperti berikut,

Source lengkapnya, bisa diakses di github saya, di url ini.

Logging HTTP Request Parameters using HTTP Servlet

By edwin / 6 April 2014 13 June 2014 / Java, Programming / Java, servlet, util, utility, web

This is a servlet filter that i use if i want to log what parameters fired by my REST client, basically it’s just a simple http servlet filter.

package com.edw;

import java.io.IOException;
import java.util.Enumeration;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import org.apache.log4j.Logger;

public class LoggingFilter implements Filter {

    private Logger logger = Logger.getLogger(this.getClass());
    
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        
        try {
            HttpServletRequest req = (HttpServletRequest) request;
            
            String uri = req.getRequestURI();
            logger.debug("Requested Resource::"+uri);
            
            Enumeration<String> enumeration = req.getParameterNames();
            
            while(enumeration.hasMoreElements()) {
                String parametername = enumeration.nextElement();
                logger.debug(parametername + " : " +req.getParameter(parametername));
            }
        } catch (Exception e) {
            logger.error(e,e);
        }
        
        chain.doFilter(request, response);
    }

    @Override
    public void destroy() {
    }
}

Add your servlet filer to your web.xml and listen for a specific url request, on this example i listen for requests to /services/ url.

<?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">    
    <session-config>
        <session-timeout>
            30
        </session-timeout>
    </session-config>
    
    <filter>
	<filter-name>LogFilter</filter-name>
	<filter-class>
		com.edw.LoggingFilter
	</filter-class>
    </filter>
    <filter-mapping>
            <filter-name>LogFilter</filter-name>
            <url-pattern>/services/*</url-pattern>
    </filter-mapping>    
</web-app>