Cannot run Spring application: BeanDefinitionParsingException

When you try to run Spring based application you can see the exception

org.springframework.beans.factory.parsing.BeanDefinitionParsingException: Unable to locate Spring NamespaceHandler for XML schema namespace

The problem may be caused by not having all neccessary Spring jars or by jar conflicts.

First of all check that you have all jars you need. Here is the list of possible jars with explanations for Spring 3.0.5 (the original of this list of dependencies is Spring Blog):

<!-- Shared version number properties -->
<properties>
    <org.springframework.version>3.0.5.RELEASE</org.springframework.version>
</properties>
 
<!--
    Core utilities used by other modules.
    Define this if you use Spring Utility APIs (org.springframework.core.*/org.springframework.util.*)
-->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-core</artifactId>
  <version>${org.springframework.version}</version>
</dependency>
 
<!--
    Expression Language (depends on spring-core)
    Define this if you use Spring Expression APIs (org.springframework.expression.*)
-->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-expression</artifactId>
  <version>${org.springframework.version}</version>
</dependency>
 
<!--
    Bean Factory and JavaBeans utilities (depends on spring-core)
    Define this if you use Spring Bean APIs (org.springframework.beans.*)
-->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-beans</artifactId>
  <version>${org.springframework.version}</version>
</dependency>
 
<!--
    Aspect Oriented Programming (AOP) Framework (depends on spring-core, spring-beans)
    Define this if you use Spring AOP APIs (org.springframework.aop.*)
-->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-aop</artifactId>
  <version>${org.springframework.version}</version>
</dependency>
 
<!--
    Application Context (depends on spring-core, spring-expression, spring-aop, spring-beans)
    This is the central artifact for Spring's Dependency Injection Container and is generally always defined
-->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-context</artifactId>
  <version>${org.springframework.version}</version>
</dependency>
 
<!--
    Various Application Context utilities, including EhCache, JavaMail, Quartz, and Freemarker integration
    Define this if you need any of these integrations
-->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-context-support</artifactId>
  <version>${org.springframework.version}</version>
</dependency>
 
<!--
    Transaction Management Abstraction (depends on spring-core, spring-beans, spring-aop, spring-context)
    Define this if you use Spring Transactions or DAO Exception Hierarchy
    (org.springframework.transaction.*/org.springframework.dao.*)
-->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-tx</artifactId>
  <version>${org.springframework.version}</version>
</dependency>
 
<!--
    JDBC Data Access Library (depends on spring-core, spring-beans, spring-context, spring-tx)
    Define this if you use Spring's JdbcTemplate API (org.springframework.jdbc.*)
-->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-jdbc</artifactId>
  <version>${org.springframework.version}</version>
</dependency>
 
<!--
    Object-to-Relation-Mapping (ORM) integration with Hibernate, JPA, and iBatis.
    (depends on spring-core, spring-beans, spring-context, spring-tx)
    Define this if you need ORM (org.springframework.orm.*)
-->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-orm</artifactId>
  <version>${org.springframework.version}</version>
</dependency>
 
<!--
    Object-to-XML Mapping (OXM) abstraction and integration with JAXB, JiBX, Castor, XStream, and XML Beans.
    (depends on spring-core, spring-beans, spring-context)
    Define this if you need OXM (org.springframework.oxm.*)
-->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-oxm</artifactId>
  <version>${org.springframework.version}</version>
</dependency>
 
<!--
    Web application development utilities applicable to both Servlet and Portlet Environments
    (depends on spring-core, spring-beans, spring-context)
    Define this if you use Spring MVC, or wish to use Struts, JSF, or another web framework with Spring (org.springframework.web.*)
-->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-web</artifactId>
  <version>${org.springframework.version}</version>
</dependency>
 
<!--
    Spring MVC for Servlet Environments (depends on spring-core, spring-beans, spring-context, spring-web)
    Define this if you use Spring MVC with a Servlet Container such as Apache Tomcat (org.springframework.web.servlet.*)
-->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-webmvc</artifactId>
  <version>${org.springframework.version}</version>
</dependency>
 
<!--
    Spring MVC for Portlet Environments (depends on spring-core, spring-beans, spring-context, spring-web)
    Define this if you use Spring MVC with a Portlet Container (org.springframework.web.portlet.*)
-->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-webmvc-portlet</artifactId>
  <version>${org.springframework.version}</version>
</dependency>
 
<!--
    Support for testing Spring applications with tools such as JUnit and TestNG
    This artifact is generally always defined with a 'test' scope for the integration testing framework and unit testing stubs
-->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-test</artifactId>
  <version>${org.springframework.version}</version>
  <scope>test</scope>
</dependency>

If this does not help then try Maven Shade plugin to solve the most probable conflicts:

<plugin>
 <groupId>org.apache.maven.plugins</groupId>
 <artifactId>maven-shade-plugin</artifactId>
 <version>1.4</version>
 <executions>
  <execution>
   <phase>package</phase>
   <goals>
    <goal>shade</goal>
   </goals>
   <configuration>
    <transformers>
     <transformer
      implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
      <resource>META-INF/spring.handlers</resource>
     </transformer>
     <transformer
      implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
      <resource>META-INF/spring.schemas</resource>
     </transformer>
    </transformers>
   </configuration>
  </execution>
 </executions>
</plugin>

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Work with annotations in Spring Framework

Annotations are a very useful feature in Java programming language and if you use Spring Framework than it can be also very easy to create annotation processor.

I expect you to be familiar with basics of annotations (read here). In this tutorial we'll create annotation for SLF4J. Here is the annotation code:

package uay.log;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Log {

}

Now let's create annotation processor using Spring Framework capabilities:

package uay.log;

import java.lang.reflect.Field;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.stereotype.Component;
import org.springframework.util.ReflectionUtils;
import org.springframework.util.ReflectionUtils.FieldCallback;

@Component
public class LogProcessor implements BeanPostProcessor {
 public Object postProcessAfterInitialization(Object bean, String beanName)
            throws BeansException {
        return bean;
    }

    public Object postProcessBeforeInitialization(final Object bean, String beanName)
            throws BeansException {
        ReflectionUtils.doWithFields(bean.getClass(), new FieldCallback() {
            public void doWith(Field field) throws IllegalArgumentException, IllegalAccessException {
                if (field.getAnnotation(Log.class) != null) {
                    Logger log = LoggerFactory.getLogger(bean.getClass());
                    field.setAccessible(true);
                    field.set(bean, log);
                    field.setAccessible(false);
                }
            }
        });
        return bean;
    }
}

And it's that easy. Now we can use this annotation in our code:

@Log
Logger log;

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Quickstart with SLF4J

In this tutorial we will configure SLF4J logging with log4j implementation.

SLF4J is a facade of abstractions for various logging frameworks(log4j, java.util.logging, commons logging, logback). It is really easy to swap between logging frameworks when you use SLF4J. Here is what you have to add to your Maven pom.xml to use SLF4J with log4j implementaion:

<properties>
 <slf4j.version>1.6.6</slf4j.version>
</properties>
<dependencies>    
 <!-- Logging -->
 <dependency>
  <groupId>log4j</groupId>
  <artifactId>log4j</artifactId>
  <version>1.2.17</version>
 </dependency>
 <dependency>
  <groupId>org.slf4j</groupId>
  <artifactId>slf4j-api</artifactId>
  <version>${slf4j.version}</version>
 </dependency>
 <dependency>
  <groupId>org.slf4j</groupId>
  <artifactId>slf4j-log4j12</artifactId>
  <version>${slf4j.version}</version>
 </dependency>
</dependencies>

Run

mvn install

Now we need to configure log4j as usual. There are two ways to do it: via xml or via properties file. Let's use properties file. We need to create log4j.properties in the classpath. Here is the code of the file:

# Root logger option
log4j.rootLogger=INFO, file, stdout
 
# Direct log messages to a log file
log4j.appender.file=org.apache.log4j.DailyRollingFileAppender
log4j.appender.file.DatePattern = '.'yyyy-MM-dd
log4j.appender.file.Append = true
log4j.appender.file.File=logs/main.log
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n
 
# Direct log messages to stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{dd-MM-yy HH:mm:ss,SSS} %5p [%c{1}:%M:%L] - %m%n

According to this configuration we defined the lowest log priority to INFO and set the output to Console and to the logs/main.log file(logs/main.log file will be rolled by days automatically).

Now we can test how the logging works:

package uay.test;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class App 
{
    private static Logger log = LoggerFactory.getLogger(App.class);
    public static void main( String[] args )
    {
     log.info("test");
    }
}

If we run the code the Console output would be:

01-12-12 23:12:24,840  INFO [App:main:11] - test

The file output would be:

23:12:24,840  INFO App:11 - test

Thus, we have configured the code to use log4j via SLF4J. As a further improvement of code you should think about using annotations to make the code look like this:

@Log
private Logger log;

This tutorial will definitely help you with it. Later I will show how to implement this annotation even easier using Spring Framework.

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Simple analysis and improvement of MySQL schema

Here is some basic analysis and advises on improvement of MySQL database performance. From time to time you should check you MySQL schema status, I use the following request for it:

SELECT                                                                                                                                                                                                                                                                         
    table_name AS table_name,                                                                                                                                                                                                                                                  
    engine,                                                                                                                                                                                                                                                                    
    ROUND(data_length/1024/1024,2) AS total_data_size_mb,                                                                                                                                                                                                                      
    ROUND(index_length/1024/1024,2) AS total_index_size_mb,                                                                                                                                                                                                                    
    ROUND((data_length+index_length)/1024/1024,2) AS total_size_mb,                                                                                                                                                                                                            
    ROUND(data_free/1024/1024,2) AS total_free_size_mb,                                                                                                                                                                                                                        
    ROUND(data_free/(data_length/100)) AS defragment_percent,                                                                                                                                                                                                                  
    table_rows                                                                                                                                                                                                                                                                 
FROM                                                                                                                                                                                                                                                                           
    information_schema.tables                                                                                                                                                                                                                                                  
WHERE                                                                                                                                                                                                                                                                          
    table_schema=DATABASE();

Field defragment_percent value should be 0, but it may be even higher than 100(e.g. you loaded 3MB of data to the table and then deleted 2MB, the table will still be 3MB with real data of 1MB). The most prone to fragmentation are VARCHAR fields so pay attention to the tables where you use VARCHAR a lot. To optimize tables you can use MySQL command:

OPTIMIZE [NO_WRITE_TO_BINLOG | LOCAL] TABLE mi_tabla1 [, mi_tabla2] ...;

To optimize the whole schema you can use:

mysqlcheck -o <databasename>

Field total_index_size_mb should be less than total total_data_size_mb. If it is not so then review your indexes.

Also I'd recommend to use MySQLTuner. MySQLTuner is a script written in Perl that allows you to review a MySQL installation quickly and make adjustments to increase performance and stability. To get it you can use:

wget http://mysqltuner.com/mysqltuner.pl

Then run it with

perl mysqltuner.pl

This tool will provide you with analysis of your MySQL server and some advises on how to improve its performance.

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Execute scripts in multiple databases

Have you ever needed to execute the same script on several databases? I have met such need and developed a simple algorithm for it. This algorithm I'd like to share.

At first I tried to develop it using only JDBC but unfortunately it has the really big limitation: it cannot execute at once several calls, which is pretty common for SQL scripts. So I decided to run scripts merely from a command line.

Here is the code:

package uay.loader;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileFilter;
import java.io.FileReader;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.log4j.Logger;

public class BulkScriptLoader {

    private static final String   DB_PREFIX     = "ua";
    private static final String[] DB_SKIP = { "ua_1", "ua_2" };
    private static final String   FOLDER_NAME   = "scripts";
    private static final String   FILE_EXT      = ".sql";
    private static final String   URL           = HOST + ":" + PORT;
    private static final String   USER_NAME     = "xxx";
    private static final String   PASSWORD      = "xxx";

    private final static Logger   LOGGER        = Logger.getLogger(BulkScriptLoader.class);

    public static void main(String[] args) {
        Connection connection;
        try {
            connection = DriverManager.getConnection(URL, USER_NAME, PASSWORD);
        } catch (SQLException e1) {
            LOGGER.error(e1);
            throw new RuntimeException(e1);
        }

        List<String> dbNames = getDbNames(connection);
        File[] scriptFiles = getScriptFiles();
        for (File file : scriptFiles) {
            LOGGER.info("Work with " + file.getName());
            BufferedReader bf;
            StringBuilder statement = new StringBuilder();
            try {
                bf = new BufferedReader(new FileReader(file));
                String line = "";
                while ((line = bf.readLine()) != null) {
                    statement.append(line).append("\n");
                }
            } catch (IOException e) {
                LOGGER.error(e, e);
            }
            if (statement.toString().length() > 0) {
                execute(connection, dbNames, statement.toString(), URL, USER_NAME, PASSWORD);
            }
        }
    }

    public static File[] getScriptFiles() {
        File folder = new File(FOLDER_NAME);
        if (folder.exists() && folder.isDirectory()) {
            return folder.listFiles(new FileFilter() {
                @Override
                public boolean accept(File pathname) {
                    return pathname.getName().toLowerCase().endsWith(FILE_EXT.toLowerCase());
                }
            });
        }
        return null;
    }

    public static void execute(Connection connection, List<String> dbNames,
            String generalStatement, String url, String userName, String password) {
        for (String dbName : dbNames) {
            String cmdCommand = String.format("mysql -u %s -p%s -h %s -P %s -D %s",userName, password, 
              parseHost(url), parsePort(url), dbName);
            LOGGER.info(cmdCommand);
            try {
                Process process = Runtime.getRuntime().exec(cmdCommand);
                Writer w = new OutputStreamWriter(process.getOutputStream());
                // System.out.println(statement);
                w.write(generalStatement);
                w.flush();
                w.close();
            } catch (IOException e) {
                LOGGER.error(e, e);
            }
        }
    }

    public static String parseHost(String url) {
        return url.substring(0, (url.indexOf(":") > 0 ? url.indexOf(":"): url.length()))

    }

    public static String parsePort(String url) {
        Pattern p = Pattern.compile("(\\d\\d\\d\\d)");
        Matcher m = p.matcher(url);
        if (m.find()) {
            return m.group(0);
        }
        return "3306";
    }

    public static List<String> getDbNames(Connection connection) {
        List<String> dbNames = new ArrayList<String>();
        try {
            PreparedStatement preparedStatement = connection.
               prepareStatement("select schema_name from information_schema.schemata");
            if (preparedStatement.execute()) {
                ResultSet rs = preparedStatement.getResultSet();
                while (rs.next()) {
                    String dbName = rs.getString(1);
                    if (dbName.startsWith(DB_PREFIX) && !Arrays.asList(DB_SKIP).contains(dbName)) {
                        dbNames.add(dbName);
                    }
                }
            }
        } catch (SQLException e) {
            LOGGER.error(e, e);
        }
        return dbNames;
    }
}

As you can see it's really simple. All scripts that I'd like to execute I place in 'scripts' folder with '.sql' extension. I configure database connection, prefix of databases that I want to update and specify the list of databases that I want to skip with this update.

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