This example shows you how to use Maven to exclude the logback.xml file from the final Jar file. Note Please, DO NOT include the logback.xml into the final Jar file, it will cause multiple logback.xml files in the classpath, if someone is using your Jar, you may override other’s logging configurations accidentally. pom.xml <project> <build> […]
In this article, we will show you how to block referrer spam in one of our Nginx web server. 1. Find the Patterns Check the Nginx access.log file, and identify the “referrer spam” patterns. $ sudo tail -f /var/log/nginx/access.log Some patterns : 200 http://???.ru/engine/redirect.php?url=http://mywebsite.com/site/blogspot.com.au 200 http://???.com/tp/out.php?link=alternatevideo&url=http%3A//mywebsite.com/site/readyliftproshop.com 200 http://???.edu/online/redirect.asp?url=http://mywebsite/site/wheretoshophongkong.com We are going to block following patterns […]
This tutorial shows you how to configure Nginx as a reverse proxy to redirect the traffics from port 80 to Apache Tomcat on port 8080. Here is the environment in my Linode server : Debian 7.5 Nginx 1.2.1 Tomcat 7.0.28 P.S Both Nginx and Tomcat are installed via apt-get install. 1. Tomcat Configuration Edit server.xml, […]
Normally, we are using the following ways to generate a random number in Java. 1. ThreadLocalRandom (JDK 1.7) //Generate number between 0-9 int index = ThreadLocalRandom.current().nextInt(10); 2. Random() //Generate number between 0-9 Random random = new Random(); int index = random.nextInt(10); 3. Math.random() //Generate number between 0-9 int index = (int)(Math.random()*10); Note 1. For single […]
In Nginx, you can block certain user agents (normally it is crawler) like this : /etc/nginx/sites-enabled/default server { listen 80; server_name mysite.com; root /etc/tomcat7/webapps/mysite; if ($http_user_agent ~* (ahrefs|wget|crawler|majestic) ) { return 403; } location / { <!– xxx –> } } In above example, for “user agent” that contains one of this pattern : ahrefs|wget|crawler|majestic, […]
Recently, many referer spam hit on my server, below is the command I used to find and count the IP Address from a Nginx access log file. $ sudo awk ‘{print $1}’ /var/log/nginx/access.log | sort | uniq -c | sort -nr Full example. $ sudo awk ‘{print $1}’ /var/log/nginx/access.log | sort | uniq -c | […]
This example shows you how to use jsoup to send a search query to Google. Document doc = Jsoup .connect("https://www.google.com/search?q=mario"); .userAgent("Mozilla/5.0") .timeout(5000).get(); Unusual traffic from your computer network Don’t use this example to spam Google, you will get above message from Google, read this Google answer. 1. jsoup example Example to send a “mario” search […]
In Java, we can use getResourceAsStream or getResource to read a file or multiple files from a resources folder or root of the classpath. The getResourceAsStream method returns an InputStream. // the stream holding the file content InputStream is = getClass().getClassLoader().getResourceAsStream("file.txt"); // for static access, uses the class name directly InputStream is = JavaClassName.class.getClassLoader().getResourceAsStream("file.txt"); The […]
By default, Tomcat’s manager webapp is able to access via yourapp:8080/manager. It is a good practice to change the default /manager to something else, to avoid potential brute force attack. Environment Tomcat 7 (apt-get install) Debian 7.5 1. Solution This article show you how to change / rename the default manager webapp path from “/manager” […]
The current environment is using Tomcat 7 + JDK 6. How to configure Tomcat to use JDK 7? Environment Tomcat 7 (apt-get install) Debian 7.5 JDK 6 and JDK 7 P.S Tomcat 7 is installed via apt-get Note You may interest at this tutorial – Apache Tomcat 8 + JDK 8 on Debian 1. Solution […]
In this article, we will show you how to find out which JRE / JDK or JAVA_HOME is used by the Tomcat container. Environment : Debian 7.5 Tomcat 7, installed via apt-get JDK 6 and JDK 7 Note To understand how Tomcat pick up which JDK to run, refer to the Tomcat startup script – […]
Apache log4j, a classic logging tool in Java. Here are a series of Log4j 1.2 tutorials.
In Eclipse IDE, If a project contains errors, a small “red-x” icon will be displayed in the files that are causing the error. This useful feature is supported in Java related perspectives only, for example, “Package Explorer”. 1. Problem Personally, I prefer to use the “Project Explorer” perspective (pure folder structure), but the “red-x” icon […]
This article shows you 2 ways to export a MongoDB “aggregation” result into another new collection. 1. $out Example This $out operator is New in version 2.6. 1.1 Review a simple grouping example, it writes the result to a new variable “result”. > var result = db.hc_hosting.aggregate( { $group : { _id : "$hosting", total […]
Dual boot Windows and Ubuntu, but Ubuntu is unable to access the Windows partition /dev/sdb3, shows the following error message : Error mounting /dev/sdb3 … status 14: The disk contains an unclean file system (0, 0). Metadata kept in Windows cache, refused to mount. Failed to mount ‘/dev/sdb3’: Operation not permitted The NTFS partition is […]
On Linux, gzip is unable to compress a folder, it used to compress a single file only. To compress a folder, you should use tar + gzip, which is tar -z. Note $ tar –help -z, -j, -J, –lzma Compress archive with gzip/bzip2/xz/lzma For example, tar -zcvf outputFileName folderToCompress 1. Tar + Gzip a folder […]
A collection with NumberLong type data as follows : > db.hc_whois.findOne(); { "_id" : NumberLong(3000001), "startIpInLong" : NumberLong(1543503872), "endIpInLong" : NumberLong(1544552447), "name" : "ap-net-1", //… } Export it with mongoexport : server1 $ mongoexport -d mydb -c hc_whois -o whois.json whois.json { "_id" : { "$numberLong" : "3000001" }, "startIpInLong" : { "$numberLong" : "1543503872" […]
Deployed a “war” file on Tomcat, and hits following error messages : Jul 17, 2014 7:59:55 PM org.apache.catalina.loader.WebappClassLoader validateJarFile INFO: validateJarFile(D:\apache-tomcat-7.0.53\webapps\hc\WEB-INF\lib\servlet-api-2.5.jar) – jar not loaded. See Servlet Spec 3.0, section 10.7.2. Offending class: javax/servlet/Servlet.class Tools used : JDK1.7 Maven 3 Tomcat 7 1. Reason The Tomcat’s container comes with own version of servlet-api.jar, and the […]
In this tutorial, we will show you how to integrate the log4j framework with the JSF 2.x web application. JSF is using java.util.logging, you need extra works to redirect the logging from JSF’s java.util.logging to log4j, with a serious penalty of performance, make sure use this trick only during local development or debugging environment. Review […]
In this tutorial, we will show you how to use the classic log4j 1.2.x to log a debug or error message in a Java application. 1. Project Directory Review the final project structure, a standard Maven style Java project. 2. Get Log4j Declares the following dependencies : pom.xml <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.17</version> </dependency> For non-Maven […]
Normally, you use Secure copy or SCP to download a file from another server via SSH connection. For example, scp username@remotehost:remoteFileToDownload localFolderNameToSaveTheFile 1. SCP Examples 1.1 Download File From Server Example to download a log file (hc.audit.log) from server (198.58.x.x), into your current local folder. scp [email protected]:/var/log/tomcat7/hc.audit.log . 1.2 Upload File To Server Example to […]
Deployed a Debian 7.5 on Linode server, the default is using OpenJDK 1.6. How to upgrade to OpenJDK 1.7? $ java -version java version "1.6.0_31" OpenJDK Runtime Environment (IcedTea6 1.13.3) (6b31-1.13.3-1~deb7u1) OpenJDK 64-Bit Server VM (build 23.25-b01, mixed mode) Tracing the java, it’s using the Debian’s alternative settings : $ ls -lsa /usr/bin/ | grep […]
Here’s an XML version of log4j properties file, just for sharing. 1. Output to Console Redirect the logging to console. log4j.xml <?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE log4j:configuration SYSTEM "log4j.dtd"> <log4j:configuration debug="true" xmlns:log4j=’http://jakarta.apache.org/log4j/’> <appender name="console" class="org.apache.log4j.ConsoleAppender"> <layout class="org.apache.log4j.PatternLayout"> <param name="ConversionPattern" value="%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L – %m%n" /> </layout> </appender> <root> <level value="DEBUG" /> <appender-ref ref="console" /> […]
In this tutorial, previous Spring Security + Hibernate4 XML example will be reused, and convert it to a annotation-based example. Technologies used : Spring 3.2.8.RELEASE Spring Security 3.2.3.RELEASE Hibernate 4.2.11.Final MySQL Server 5.6 Tomcat 7 (Servlet 3.x container) Quick Note : Create a session factory with LocalSessionFactoryBuilder Inject session factory into a UserDao Integrate UserDao […]
In this tutorial, we will show you how to integrate Hibernate 4 in Spring Security, XML configuration example. Note For annotation version, please read this Spring Security + Hibernate Annotation Example. Technologies used : Spring 3.2.8.RELEASE Spring Security 3.2.3.RELEASE Hibernate 4.2.11.Final MySQL Server 5.6 JDK 1.6 Maven 3 Eclipse 4.3 Quick Notes Create a session […]
Spring 3.2.x + Hibernate 4.3.x integration, hits JtaPlatform ClassNotFoundException, search the project classpath, find out that JtaPlatform is at different package? hibernate-core.4.3.5.Final.jar org.hibernate.engine.transaction.jta.platform.spi.JtaPlatform Error message shows org.hibernate.service.jta.platform.spi.JtaPlatform Caused by: java.lang.NoClassDefFoundError: org/hibernate/service/jta/platform/spi/JtaPlatform at org.springframework.orm.hibernate4.SpringSessionContext.<init>(SpringSessionContext.java:56) ~[spring-orm-3.2.8.RELEASE.jar:3.2.8.RELEASE] … 40 common frames omitted Caused by: java.lang.ClassNotFoundException: org.hibernate.service.jta.platform.spi.JtaPlatform //… pom.xml <!– Hibernate ORM –> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-core</artifactId> <version>4.3.5.Final</version> </dependency> <!– […]
In Spring Security, database authentication with bcrypt password hashing. import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder; import org.springframework.security.crypto.password.PasswordEncoder; //… String password = “123456”; PasswordEncoder passwordEncoder = new BCryptPasswordEncoder(); String hashedPassword = passwordEncoder.encode(password); spring-security.xml <authentication-manager> <authentication-provider> <password-encoder hash="bcrypt" /> //… </authentication-provider> </authentication-manager> CREATE TABLE users ( username VARCHAR(45) NOT NULL , password VARCHAR(45) NOT NULL , enabled TINYINT NOT NULL DEFAULT […]
In this tutorial, we will show you how to implement “Remember Me” login feature in Spring Security, which means, the system will remember the user and perform automatic login even after the user’s session is expired. Technologies and tools used : Spring 3.2.8.RELEASE Spring Security 3.2.3.RELEASE Spring JDBC 3.2.3.RELEASE Eclipse 4.2 JDK 1.6 Maven 3 […]
Problem After upgrading from Windows 8 Enterprise to Windows 8.1, Google Chrome displays pink color screen like this : Windows Environment Chrome 34.0.1847.137 m Windows 8.1 NVIDIA 331.58 Chrome GPU : NVIDIA 9.18.13.3158 To get the Chrome GPU, type chrome://gpu in the browser URL, refer to the driver version. Driver vendor NVIDIA Driver version 9.18.13.3523 […]
Spring + Hibernate4 integration, and transaction are managed by Spring AOP, example : spring-hibernate.xml <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" 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/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd"> <bean id="txManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager"> <property name="sessionFactory" ref="sessionFactory"></property> </bean> <tx:advice id="txAdvice" transaction-manager="txManager"> <tx:attributes> <tx:method name="get*" read-only="true" /> <tx:method name="*" /> </tx:attributes> </tx:advice> <aop:config> <aop:pointcut id="userDaoPointCut" expression="execution(* com.mkyong.users.service.*Dao.*(..))" /> <aop:advisor advice-ref="txAdvice" pointcut-ref="userDaoPointCut" /> […]
This Spring Security example shows you how to check if a user is login from a “remember me” cookie. private boolean isRememberMeAuthenticated() { Authentication authentication = SecurityContextHolder.getContext().getAuthentication(); if (authentication == null) { return false; } return RememberMeAuthenticationToken.class.isAssignableFrom(authentication.getClass()); } @RequestMapping(value = "/admin/update**", method = RequestMethod.GET) public ModelAndView updatePage() { ModelAndView model = new ModelAndView(); if (isRememberMeAuthenticated()) […]
Integrates Spring 3 and Hibernate 4, the system shows the following message while performing database operation : org.hibernate.HibernateException: No Session found for current thread The sessionFactory is injected like this : spring-hibernate4.xml <beans xmlns="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-3.0.xsd"> <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"> <property name="driverClassName" value="com.mysql.jdbc.Driver" /> <property name="url" value="jdbc:mysql://localhost:3306/test" /> <property name="username" value="root" /> <property name="password" […]
In this tutorial, we will show you how to limit login attempts in Spring Security, which means, if a user try to login with an invalid password more than 3 times, the system will lock the user and make it unable to login anymore. Technologies and tools used : Spring 3.2.8.RELEASE Spring Security 3.2.3.RELEASE Spring […]
A Simple DAO class extends JdbcDaoSupport, but, unable to inject or @autowired a “dataSource”, the method setDataSource is final, can’t override. UserDetailsDaoImpl.java package com.mkyong.users.dao; import javax.sql.DataSource; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.jdbc.core.support.JdbcDaoSupport; import org.springframework.stereotype.Repository; @Repository public class UserDetailsDaoImpl extends JdbcDaoSupport implements UserDetailsDao { //Error, cannot override the final method from JdbcDaoSupport @Autowired public void setDataSource(DataSource dataSource) { […]
In MySQL workbench, issue a simple delete all commands delete FROM users; But it shows me following error message : Error Code: 1175. You are using safe update mode and you tried to update a table without a WHERE that uses a KEY column To disable safe mode, toggle the option in Preferences -> SQL […]
Upgrading Spring version and noticed that queryForInt() is deprecated, what should be replaced by? private boolean isUserExists(String username) { String sql = "SELECT count(*) FROM USERS WHERE username = ?"; boolean result = false; //The method queryForInt(String, Object…) from the type JdbcTemplate is deprecated int count = getJdbcTemplate().queryForInt(sql, new Object[] { username }); if (count […]
In this example, we will show you how to read an XML file and print out its values, via Python xml.dom.minidom. 1. XML File A simple XML file, later parse it with Python minidom. staff.xml <?xml version="1.0"?> <company> <name>Mkyong Enterprise</name> <staff id="1001"> <nickname>mkyong</nickname> <salary>100,000</salary> </staff> <staff id="1002"> <nickname>yflow</nickname> <salary>200,000</salary> </staff> <staff id="1003"> <nickname>alex</nickname> <salary>20,000</salary> </staff> […]
In this tutorial, we will convert previous Spring Security custom login form (XML) project to a pure annotation-based project. Technologies used : Spring 3.2.8.RELEASE Spring Security 3.2.3.RELEASE Eclipse 4.2 JDK 1.6 Maven 3 Tomcat 7 (Servlet 3.x) Note In this example, last Spring Security hello world annotation example will be reused, enhance it to support […]
Reviewing a legacy project, and found this Spring JDBC code snippets : public User getUser(String username) { String sql = "SELECT * FROM USER WHERE username = ?"; return getJdbcTemplate().queryForObject( sql, new Object[] { username }, new RowMapper<UserAttempts>() { public UserAttempts mapRow(ResultSet rs, int rowNum) throws SQLException { User user = new User(); user.setId(rs.getInt("id")); user.setUsername(rs.getString("username")); […]
