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Spring

April 13, 2020

Spring 4+ with Ehcache 3.x

This post describes an example of using Ehcache with a Spring MVC application deployed on Tomcat (not using Spring boot). It is a legacy app that needs to be upgraded.

The dependencies are:

<dependency>
    <groupId>javax.cache</groupId>
    <artifactId>cache-api</artifactId>
    <version>1.1.1</version>
</dependency>
<dependency>
    <groupId>org.ehcache</groupId>
    <artifactId>ehcache</artifactId>
    <version>3.8.1</version>
</dependency>

Application context must be updated in this way:

<!-- ***** CACHE CONFIGURATION v.3 ***** -->
<cache:annotation-driven cache-manager="ehCacheManager" />
<bean id="ehCacheManager" class="org.springframework.cache.jcache.JCacheCacheManager">
  <property name="cacheManager">
    	<bean class="org.springframework.cache.jcache.JCacheManagerFactoryBean" 
        p:cacheManagerUri="classpath:ehcache.xml" />
  </property>
</bean>

The method must be annotated with @Cacheable so that Spring will handle the caching. As a result of this annotation, Spring will create a proxy of the NumberService to intercept calls to the square method and call Ehcache.

This is how to annotate the method (a service or a Dao implementation) providing the cache alias and the key for the cache:

@Cacheable(value = "retrieveUserIdOfMYGroup", key = "#userId")
public ArrayList<Integer> retrieveUserIdOfMYGroup(int userId) {
    [...]
}

Now, ehcache.xml config that is completely different than the previous version of ehcache (this is a simple config):

<?xml version="1.0" encoding="UTF-8"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://www.ehcache.org/v3"
    xmlns:jsr107="http://www.ehcache.org/v3/jsr107"
    xsi:schemaLocation="
            http://www.ehcache.org/v3 http://www.ehcache.org/schema/ehcache-core-3.0.xsd
            http://www.ehcache.org/v3/jsr107 http://www.ehcache.org/schema/ehcache-107-ext-3.0.xsd">
	
	<cache-template name="myDefaults">
	<listeners>
            <listener>
                <class>com.afm.web.configuration.CacheLogger</class>
                <event-firing-mode>ASYNCHRONOUS</event-firing-mode>
                <event-ordering-mode>UNORDERED</event-ordering-mode>
                <events-to-fire-on>CREATED</events-to-fire-on>
                <events-to-fire-on>EXPIRED</events-to-fire-on>
                <events-to-fire-on>EVICTED</events-to-fire-on>
            </listener>
        </listeners>        
	</cache-template>
	
	<!-- @Cacheable(value = "retrieveUserIdOfMYGroup", key = "#userId") -->
	<cache alias="retrieveUserIdOfMYGroup" uses-template="myDefaults">
		<heap unit="entries">200</heap>
	</cache>
            
</config>

Cache listeners allow implementers to register callback methods that will be executed when a cache event occurs and print on the log appender. This is how class CacheLogger is implemented:

public class CacheLogger implements CacheEventListener<Object, Object> {

  protected final Log LOG = LogFactory.getLog(getClass());
	
	@Override
	public void onEvent(CacheEvent<? extends Object, ? extends Object> cacheEvent) {
		LOG.info("Key: " + cacheEvent.getKey()  
      + " | EventType: " + cacheEvent.getType() 
      + " | Old value: " + cacheEvent.getOldValue() 
      + " | New value: " + cacheEvent.getNewValue());		
	}

}
March 23, 2018

How to use Spring DataSource bean as data source for Log4j 2 JDBC appender

I would like to log log4j2 messages into a relational database using the datasource defined on application context and initialized using spring using log4j 2.10.

One possibility is to add a JDBC appender inside log4j2 xml configuration but, Log4j is initialized before Spring so, dataSource won’t be available at runtime so the only solution is to add an appender programmatically. Of course, it is possible to use a log4j2 jdbc appender but, this approach allow to have the possibility to use spring.properties file to override the spring application context with proper environment settings in according to my profile.

This is the datasource defined on application context xml:

<!--  ############ SQLSERVER DATABASE SECTION ############ -->
<bean id="dataSourceMSSqlServer" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="com.microsoft.sqlserver.jdbc.SQLServerDriver" />
    <property name="url" value="jdbc:sqlserver://${sqlserver.hostname};databaseName=${sqlserver.database};" />
    <property name="username" value="${sqlserver.user}" />
    <property name="password" value="${sqlserver.pass}" />
</bean>

this allow me to configure different database for every environment.
This is the table on which I want to log the entries:

[Id] [INT] IDENTITY(1,1) NOT NULL,
[CreatedTimeStamp] [datetimeoffset](7) NOT NULL,
[Level] [INT] NOT NULL,
[SOURCE] [nvarchar](MAX) NULL,
[Message] [nvarchar](MAX) NULL,
[Content] [nvarchar](MAX) NULL,
[ProductName] [nvarchar](MAX) NULL,
[Version] [nvarchar](MAX) NULL,
[LogType] [INT] NOT NULL DEFAULT ((0)),
[AuditEventType] [INT] NULL,
[UserId] [nvarchar](128) NULL,

The plan is to create a spring bean, inject the DataSource bean, and add JDBC Appender configuration dynamically in @PostConstruct method.

package com.afm.web.utility;
 
import java.sql.Connection;
import java.sql.SQLException;
 
import javax.annotation.PostConstruct;
import javax.sql.DataSource;
 
import org.apache.logging.log4j.Level;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.core.Appender;
import org.apache.logging.log4j.core.LoggerContext;
import org.apache.logging.log4j.core.appender.db.ColumnMapping;
import org.apache.logging.log4j.core.appender.db.jdbc.ColumnConfig;
import org.apache.logging.log4j.core.appender.db.jdbc.ConnectionSource;
import org.apache.logging.log4j.core.appender.db.jdbc.JdbcAppender;
import org.apache.logging.log4j.core.config.AppenderRef;
import org.apache.logging.log4j.core.config.Configuration;
import org.apache.logging.log4j.core.config.LoggerConfig;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
 
@Component
public class JDBCLog {
 
    @Autowired
    private DataSource dataSourceMSSqlServer;
 
    // Inner class
    class Connect implements ConnectionSource {
 
	private DataSource dsource;
 
	public Connect(DataSource dsource) {
	    this.dsource = dsource;
	}
 
	@Override
	public Connection getConnection() throws SQLException {
	    return this.dsource.getConnection();
	}
 
    }
 
    public JDBCLog() {}
 
    @PostConstruct
    private void init(){
 
	System.out.println("####### JDBCLog init() ########");      
	final LoggerContext ctx = (LoggerContext) LogManager.getContext(false); 
	final Configuration config = ctx.getConfiguration();
 
	// Here I define the columns I want to log. 
	ColumnConfig[] columnConfigs = new ColumnConfig[] {
	    ColumnConfig.newBuilder()
                .setName("CreatedTimeStamp")
                .setPattern(null)
                .setLiteral(null)
                .setEventTimestamp(true)
                .setUnicode(false)
                .setClob(false).build(),
	    ColumnConfig.newBuilder()
                .setName("Source")
                .setPattern("%K{className}")
                .setLiteral(null)
                .setEventTimestamp(false)
                .setUnicode(false)
                .setClob(false).build(),
	    ColumnConfig.newBuilder()
                .setName("Level")
                .setPattern("%level")
                .setLiteral(null)
                .setEventTimestamp(false)
                .setUnicode(false)
                .setClob(false).build(),
	    ColumnConfig.newBuilder()
                .setName("Message")
                .setPattern("%K{message}")
                .setLiteral(null)
                .setEventTimestamp(false)
                .setUnicode(false)
                .setClob(false).build(),
	    ColumnConfig.newBuilder()
                .setName("Content")
                .setPattern("%K{exception}")
                .setLiteral(null)
                .setEventTimestamp(false)
                .setUnicode(false)
                .setClob(false).build(),
	    ColumnConfig.newBuilder()
                .setName("ProductName")
                .setPattern(null)
                .setLiteral("'DHC'")
                .setEventTimestamp(false)
                .setUnicode(false)
                .setClob(false).build(),
	    ColumnConfig.newBuilder()
                .setName("Version")
                .setPattern(null)
                .setLiteral("'1.0'")
                .setEventTimestamp(false)
                .setUnicode(false)
                .setClob(false).build(),
	    ColumnConfig.newBuilder()
                .setName("AuditEventType")
                .setPattern("%K{eventId}")
                .setLiteral(null)
                .setEventTimestamp(false)
                .setUnicode(false)
                .setClob(false).build(),
	    ColumnConfig.newBuilder()
                .setName("UserId"
                .setPattern("%K{userId}")
                .setLiteral(null)
                .setEventTimestamp(false)
                .setUnicode(false)
                .setClob(false).build(),
	    ColumnConfig.newBuilder()
                .setName("LogType")
                .setPattern("%K{logType}")
                .setLiteral(null)
                .setEventTimestamp(false)
                .setUnicode(false)
                .setClob(false).build()
        };
 
	Appender jdbcAppender = JdbcAppender.newBuilder()
		.setBufferSize(0)
                .setColumnConfigs(columnConfigs)
                .setColumnMappings(new ColumnMapping[]{})
                .setConnectionSource(new Connect(dataSourceMSSqlServer))
                .setTableName("dhc.LogItems")
                .withName("databaseAppender")
                .withIgnoreExceptions(true)
                .withFilter(null)
                .build();
 
	jdbcAppender.start();
	config.addAppender(jdbcAppender);
 
	// Create an Appender reference.
	// @param ref The name of the Appender.
	// @param level The Level to filter against.
	// @param filter The filter(s) to use.
	// @return The name of the Appender.
	AppenderRef ref= AppenderRef.createAppenderRef("JDBC_Appender", null, null);
        AppenderRef[] refs = new AppenderRef[] {ref};
 
        /*
         * Factory method to create a LoggerConfig.
         *
         * @param additivity true if additive, false otherwise.
         * @param level The Level to be associated with the Logger.
         * @param loggerName The name of the Logger.
         * @param includeLocation whether location should be passed downstream
         * @param refs An array of Appender names.
         * @param properties Properties to pass to the Logger.
         * @param config The Configuration.
         * @param filter A Filter.
         * @return A new LoggerConfig.
         * @since 2.6
         */
        LoggerConfig loggerConfig = LoggerConfig.createLogger(
                false, Level.DEBUG, "JDBC_Logger", null, refs, null, config, null);        
        loggerConfig.addAppender(jdbcAppender, null, null);
 
        config.addLogger("JDBC_Logger", loggerConfig);       
        ctx.updateLoggers();  
 
        System.out.println("####### JDBCLog init() - DONE ########");  
 
    }
 
    public DataSource getDataSource() {
	return dataSourceMSSqlServer;
    }
 
    public void setDataSource(DataSource dataSourceMSSqlServer) {
	this.dataSourceMSSqlServer = dataSourceMSSqlServer;
    }	  
 
}

At this point, is possible to call the logger from the code in this way:

Logger jdbcLogger = LogManager.getContext(false).getLogger("JDBC_Logger"); 
jdbcLogger.info(new StringMapMessage()
    .with("eventId", AuditEventType.Logger_General.toString())
    .with("exception", "")
    .with("userId", "TESTUSER")
    .with("message", "TEST!!")
    .with("className", 
        this.getClass().getPackage().toString().replaceAll("package ", "") 
        + "." + this.getClass().getSimpleName() 
        + "." + new Object() {}.getClass().getEnclosingMethod().getName())
);

If you are using Log4j in a Servlet 2.5 web application, or if you have disabled auto-initialization with the isLog4jAutoInitializationDisabled context parameter, you must configure the Log4jServletContextListener and Log4jServletFilter in the deployment descriptor or programmatically. The filter should match all requests of any type. The listener should be the very first listener defined in your application, and the filter should be the very first filter defined and mapped in your application. This is easily accomplished using the following web.xml code:

<listener>
    <listener-class>
        org.apache.logging.log4j.web.Log4jServletContextListener
    </listener-class>
</listener>
 
<filter>
    <filter-name>log4jServletFilter</filter-name>
    <filter-class>
        org.apache.logging.log4j.web.Log4jServletFilter
    </filter-class>
</filter>
<filter-mapping>
    <filter-name>log4jServletFilter</filter-name>
    <url-pattern>/*</url-pattern>
    <dispatcher>REQUEST</dispatcher>
    <dispatcher>FORWARD</dispatcher>
    <dispatcher>INCLUDE</dispatcher>
    <dispatcher>ERROR</dispatcher>
    <!-- 
        Servlet 3.0 w/ disabled auto-initialization only; 
        not supported in 2.5 
    -->
    <dispatcher>ASYNC</dispatcher>
</filter-mapping>

This dependency must be added to pom.xml:

<dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-web</artifactId>
    <version>2.10.0</version>
</dependency>

Of course, if you are not already included, add it to the component-scan into Spring application-context:

<context:component-scan base-package="com.afm.web.utility" />

PS: if you like it please, click on the banner :)

December 8, 2015

MappingJacksonHttpMessageConverter not found

I was trying to run a java batch that call an application context without success (it’s a java app that calls a Camel spring context). This is what I get during the startup:

ERROR ApplicationProperties @ addApplicationProperty [28] org.springframework.beans.factory.BeanDefinitionStoreException: Unexpected exception parsing XML document from file [/MessageRouting/src/test/resources/META-INF/spring/LOCALHOST-db-context.xml]; nested exception is java.lang.NoClassDefFoundError: org/springframework/http/converter/json/MappingJacksonHttpMessageConverter
Fatal error! java.lang.RuntimeException: Error loading ClassPathXmlApplicationContext file - src/test/resources/META-INF/spring/LOCALHOST-db-context.xml

I’m using spring 4.2.3 (updated yesterday, probably the reason for which it doesn’t work. It was 4.0.9). I know that MappingJacksonHttpMessageConverter has been replaced by MappingJackson2HttpMessageConverter but, how can I tell to spring to use the new version???

I followed some suggestion and I added this to my pom.xml:

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.6.3</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.6.3</version>
</dependency>   
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-annotations</artifactId>
    <version>2.6.3</version>
</dependency>

But this didn’t fix so, I finally resolved the issue adding this dependency to my pom.xml:

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>${org.springframework-version}</version>
</dependency>