commons-dbcp commons-dbcp 1.4 Steps for creating a DataSource instance using BasicDataSource and configuring connection pool are as follows-, 1. This is not the only way to combine the commons-dbcp and commons-pool packages, but provides a "one stop shopping" solution for basic requirements.. Users extending this class should take care to use … Mathieu Mathieu. When the tomcat process reads “javax.sql.DataSource” it will automatically configure DBCP and the factory object will be used to create a connection pool. Test class that creates a connection using the returned DataSource object and queries the DB. Tomcat 7 and earlier version used Commons DBCP ("commons-dbcp"). These are the individuals who have contributed to the project in one form or another. Many Apache projects support interaction with a relational database. Object pooling design pattern is used when the cost (time & resources like CPU, Network, and IO) of creating new objects is higher. You can also impose an upper limit to the number of connections in the pool, in that case if the maximum open connection limit for the pool has been reached any further requests for the connection are queued to get the connection when it is released by other user. In this Example We will implement the connection pooling in JDBC using Apache Commons DBCP. DBCP 1.3 should be used when running under Java 1.4 and 5.0. into the DBMS, and handles any user account issues internally. Maven dependency for DBCP org.apache.commons commons-dbcp2 2.1 mechanisms that it utilizes. There are There are several Database Connection Pools already available, both obtaining releases. within Apache products and elsewhere. All Rights Reserved. often wish to share a "pool" of open connections between all of the DB used in this example is MySQL. Required fields are marked *. public class BasicDataSource extends Object implements DataSource. Properties file used by the program to read DB properties (db.properties) make sure that this properties file is in the classpath. This post shows how to provide JDBC connection pooling using Apache DBCP data source in Spring framework. It just prints in the stdout a line each time a connection is requested from the pool and when the connection is closed (returned to the pool). If a DB connection is created every time user connects to DB and closed later it results in a lot of time getting wasted in creating connection object itself to perform a database transaction that might take few milliseconds. Let’s try to understand requirements of connection pooling in simple words, To communicate with the database requires the database connection and create the connection with the database is heavy operation. And I am not sure how should I do it. When a new connection is required, an existing connection is retrieved from the pool. Source Code Management Commons DBCP 1,729 usages. Limit connections with PgBouncer. eval(ez_write_tag([[250,250],'knpcode_com-large-mobile-banner-2','ezslot_7',139,'0','0']));Following class is used to create a BasicDataSource. This site uses Akismet to reduce spam. Connection Pool is a cache of database connections so that connection can be reused when future requests to the database are required. DBCP 2.5.0 binaries should be used by applications running under Java 8. opportunity to coordinate the efforts required to create and maintain an Follow edited Aug 18 '14 at 16:05. There are many API’s available which you can use for connection pooling. The getConnectionPool() method is use by the printStatus() method to read connection pool information, at the end of the code snippet above. This method should be … Commons Database Connection Pooling. Infrared Vs Ceramic Heater, Calvin Ridley Dominique Fitchard, Tree Percolator Bong Quality, Yardwise Lawn Sweeper, Florida Most Wanted 2020, Suchil Ravi Shankar, Water Tank Emoji, Bible Study For Valentine's Day, Madeline Zakarian Age, " /> commons-dbcp commons-dbcp 1.4 Steps for creating a DataSource instance using BasicDataSource and configuring connection pool are as follows-, 1. This is not the only way to combine the commons-dbcp and commons-pool packages, but provides a "one stop shopping" solution for basic requirements.. Users extending this class should take care to use … Mathieu Mathieu. When the tomcat process reads “javax.sql.DataSource” it will automatically configure DBCP and the factory object will be used to create a connection pool. Test class that creates a connection using the returned DataSource object and queries the DB. Tomcat 7 and earlier version used Commons DBCP ("commons-dbcp"). These are the individuals who have contributed to the project in one form or another. Many Apache projects support interaction with a relational database. Object pooling design pattern is used when the cost (time & resources like CPU, Network, and IO) of creating new objects is higher. You can also impose an upper limit to the number of connections in the pool, in that case if the maximum open connection limit for the pool has been reached any further requests for the connection are queued to get the connection when it is released by other user. In this Example We will implement the connection pooling in JDBC using Apache Commons DBCP. DBCP 1.3 should be used when running under Java 1.4 and 5.0. into the DBMS, and handles any user account issues internally. Maven dependency for DBCP org.apache.commons commons-dbcp2 2.1 mechanisms that it utilizes. There are There are several Database Connection Pools already available, both obtaining releases. within Apache products and elsewhere. All Rights Reserved. often wish to share a "pool" of open connections between all of the DB used in this example is MySQL. Required fields are marked *. public class BasicDataSource extends Object implements DataSource. Properties file used by the program to read DB properties (db.properties) make sure that this properties file is in the classpath. This post shows how to provide JDBC connection pooling using Apache DBCP data source in Spring framework. It just prints in the stdout a line each time a connection is requested from the pool and when the connection is closed (returned to the pool). If a DB connection is created every time user connects to DB and closed later it results in a lot of time getting wasted in creating connection object itself to perform a database transaction that might take few milliseconds. Let’s try to understand requirements of connection pooling in simple words, To communicate with the database requires the database connection and create the connection with the database is heavy operation. And I am not sure how should I do it. When a new connection is required, an existing connection is retrieved from the pool. Source Code Management Commons DBCP 1,729 usages. Limit connections with PgBouncer. eval(ez_write_tag([[250,250],'knpcode_com-large-mobile-banner-2','ezslot_7',139,'0','0']));Following class is used to create a BasicDataSource. This site uses Akismet to reduce spam. Connection Pool is a cache of database connections so that connection can be reused when future requests to the database are required. DBCP 2.5.0 binaries should be used by applications running under Java 8. opportunity to coordinate the efforts required to create and maintain an Follow edited Aug 18 '14 at 16:05. There are many API’s available which you can use for connection pooling. The getConnectionPool() method is use by the printStatus() method to read connection pool information, at the end of the code snippet above. This method should be … Commons Database Connection Pooling. Infrared Vs Ceramic Heater, Calvin Ridley Dominique Fitchard, Tree Percolator Bong Quality, Yardwise Lawn Sweeper, Florida Most Wanted 2020, Suchil Ravi Shankar, Water Tank Emoji, Bible Study For Valentine's Day, Madeline Zakarian Age, " /> commons-dbcp commons-dbcp 1.4 Steps for creating a DataSource instance using BasicDataSource and configuring connection pool are as follows-, 1. This is not the only way to combine the commons-dbcp and commons-pool packages, but provides a "one stop shopping" solution for basic requirements.. Users extending this class should take care to use … Mathieu Mathieu. When the tomcat process reads “javax.sql.DataSource” it will automatically configure DBCP and the factory object will be used to create a connection pool. Test class that creates a connection using the returned DataSource object and queries the DB. Tomcat 7 and earlier version used Commons DBCP ("commons-dbcp"). These are the individuals who have contributed to the project in one form or another. Many Apache projects support interaction with a relational database. Object pooling design pattern is used when the cost (time & resources like CPU, Network, and IO) of creating new objects is higher. You can also impose an upper limit to the number of connections in the pool, in that case if the maximum open connection limit for the pool has been reached any further requests for the connection are queued to get the connection when it is released by other user. In this Example We will implement the connection pooling in JDBC using Apache Commons DBCP. DBCP 1.3 should be used when running under Java 1.4 and 5.0. into the DBMS, and handles any user account issues internally. Maven dependency for DBCP org.apache.commons commons-dbcp2 2.1 mechanisms that it utilizes. There are There are several Database Connection Pools already available, both obtaining releases. within Apache products and elsewhere. All Rights Reserved. often wish to share a "pool" of open connections between all of the DB used in this example is MySQL. Required fields are marked *. public class BasicDataSource extends Object implements DataSource. Properties file used by the program to read DB properties (db.properties) make sure that this properties file is in the classpath. This post shows how to provide JDBC connection pooling using Apache DBCP data source in Spring framework. It just prints in the stdout a line each time a connection is requested from the pool and when the connection is closed (returned to the pool). If a DB connection is created every time user connects to DB and closed later it results in a lot of time getting wasted in creating connection object itself to perform a database transaction that might take few milliseconds. Let’s try to understand requirements of connection pooling in simple words, To communicate with the database requires the database connection and create the connection with the database is heavy operation. And I am not sure how should I do it. When a new connection is required, an existing connection is retrieved from the pool. Source Code Management Commons DBCP 1,729 usages. Limit connections with PgBouncer. eval(ez_write_tag([[250,250],'knpcode_com-large-mobile-banner-2','ezslot_7',139,'0','0']));Following class is used to create a BasicDataSource. This site uses Akismet to reduce spam. Connection Pool is a cache of database connections so that connection can be reused when future requests to the database are required. DBCP 2.5.0 binaries should be used by applications running under Java 8. opportunity to coordinate the efforts required to create and maintain an Follow edited Aug 18 '14 at 16:05. There are many API’s available which you can use for connection pooling. The getConnectionPool() method is use by the printStatus() method to read connection pool information, at the end of the code snippet above. This method should be … Commons Database Connection Pooling. Infrared Vs Ceramic Heater, Calvin Ridley Dominique Fitchard, Tree Percolator Bong Quality, Yardwise Lawn Sweeper, Florida Most Wanted 2020, Suchil Ravi Shankar, Water Tank Emoji, Bible Study For Valentine's Day, Madeline Zakarian Age, " />

apache dbcp connection pool maven

Taking Over an Existing Business
November 20, 2019
Show all
0

apache dbcp connection pool maven

Specify the required connection pool related configuration out of the following-. DBCP 2.6.0 binaries should be used by applications running on Java 8 and above. commons-dbcp » commons-dbcp … You can also download the jars directly from the following location and put them in application’s classpath. LGPL 2.1: Narayana: ArjunaJTA narayana-jta. :test-connection-query In order to be thread safe Commons locks the entire pool for short periods during both object allocation … And I want to run this example in an maven project and also I am working on the maven project for the first time. application's current users. See the downloads page for information on can be unfeasible in a publicly-hosted Internet application where the So why do we need a new connection pool? Contribute to apache/commons-dbcp development by creating an account on GitHub. 1.x. Copyright © 2001-2020 Learn how your comment data is processed. Many people prefer C3P0 for connection pooling but if you are using Spring with Hibernate C3PO does not works at all if you are using Spring for data source and hibernate get connection from Spring and make call to the database. Commons Database Connection Pooling Last Release on Feb 7, 2010 2. asked Jul 6 '11 at 1:38. In the previous post, we looked at various JDBC implementation of connection pooling with example code that focused on usage in vanilla Spring.In this post, we will look at how to configure HikariCP, Tomcat JDBC and Apache Commons DBCP 2 connection pool in a Spring Boot application. Basic implementation of javax.sql.DataSource that is configured via JavaBeans properties. Apache Commons DBCP Connection Pool There are several Database Connection Pools already available, both within Jakarta products and elsewhere. DBCP 2 is based on Commons Pool 2 and provides increased performance, JMX Maven Plugins; Mocking; ... Group: Commons DBCP. 27. As per the Object pooling design pattern, the application creates an object in advance and place them in Pool or Container. Here are a few of the reasons: commons-dbcp is single threaded, in order to be thread safe commons-dbcp locks the entire pool, even during query validation. The Above eclipse console output shows we are able to read rows from MySQL database that means we are successfully taken database connection using Apache DBCP connection pool. The DB we are connecting to is MySQL. org.apache.commons.dbcp2.cpdsadapter This package contains one public class which is a ConnectionPoolDataSource (CPDS) implementation that can be used to adapt older Driver based JDBC implementations. Now what is Connection Pool? Introduction: The JDBC Connection Pool org.apache.tomcat.jdbc.pool is a replacement or an alternative to the commons-dbcp connection pool.. DBCP Connection Pool Spring. maxActive Save my name, email, and site URL in my browser for next time I post a comment. Apache Commons DBCP software implements Database Connection Pooling: Summary: This document lists other related information of this project: Team: This document provides information on the members of this project. Your email address will not be published. DBCP 1.4 binaries should be used by applications running under Java 6. https://commons.apache.org/proper/commons-dbcp/download_dbcp.cgieval(ez_write_tag([[300,250],'knpcode_com-large-mobile-banner-1','ezslot_6',142,'0','0'])); In the example DB used is MySQL it connects to knpcode schema and table is EMPLOYEE with columns as id, FIRST_NAME, LAST_NAME and DEPARTMENT. 1,568 1 1 gold badge 24 24 silver badges 48 48 bronze badges. The number of milliseconds a client calling getConnection() will wait for a Connection to be checked-in or acquired when the pool is exhausted.:max-connection-lifetime. DBCP 2 is based on Commons Pool 2 and provides increased performance, JMX support as well as numerous other new features compared to DBCP 1.x. Called by any superclass that implements a JNDIReferencable or similar that needs to collect the properties of this class for storage etc. For example: 11:56:34,397 WARN [arjuna] ARJUNA012108: CheckedAction::check - atomic action 0:ffffc0a86301:df08:5b42504f:1d078 aborting with 1 threads active! In particular, you should DBCP 2.4.0 binaries should be used by applications running under Java 7. Opening a database connection for each user is a wastage of resource and costly. Introduction: The JDBC Connection Pool org.apache.tomcat.jdbc.pool is a replacement or an alternative to the Apache Commons DBCP connection pool.. Libraries.io helps you find new open source packages, modules … Tomcat DBCP is just a renamed version of Apache Commons DBCP, with also a different internal package name prefix. package for an overview of how to use DBCP. Opening a connection per user After reading Tomcat documentation when I try to access the dbcp2 connection pool from Spring application I am getting the following exception - javax.naming.NamingException: Could not create resource factory instance [Root exception is java.lang.ClassNotFoundException: org.apache.tomcat.dbcp.dbcp.BasicDataSourceFactory] In this post we’ll see how to configure connection pooling in your application using Apache DBCP. If you use Maven you can use the following code to add the dependency for this POM file. Hi, There was a pretty big change made in Tomcat as to JDBC connection pool facility. org.apache.commons commons-dbcp2 2.8.0 Rather than opening a connection per user it is much more efficient to create a pool of connections that is shared among the users. dbcp-conn-log Quick start. That’s all for the topic Apache DBCP Connection Pooling Java Example. Commons DBCP. Javadoc API documents :initial-pool-size. The application itself logs several examples The commons-dbcp2 package relies on code in the filtered out of the DBCP 1.3 sources. If you have any feedback or suggestion please feel free to drop in blow comment box. As in that example it clearly states that-To compile this example, you'll want: * commons-pool-1.5.4.jar * commons-dbcp-1.2.2.jar * j2ee.jar (for the javax.sql classes) in your classpath. Apache Commons, Apache Commons DBCP, Apache, the Apache feather logo, and the Apache Commons project logos are trademarks of The Apache Software Foundation. Commons Database Connection Pooling - 1.4 - a package on Maven - Libraries.io. Name Email Dev Id Roles Organization; Morgan Delagrange: morgand: Geir … Share. If you are using Maven then you can add the following dependency. Apache DBCP provides a BasicDataSource class which creates a PoolingDataSource. Set the DB related configurations like Driver class, URL, user name and password. If a DB connection is created every time user connects to DB and closed later it results in a lot of time getting wasted in creating connection object itself to perform a database transaction that might take few milliseconds. Creating a new connection for each user can be time consuming (often commons-dbcp.wso2. time that a database connection is required. Users should also be aware that some configuration options (e.g. number of simultaneous users can be very large. The number of users actually performing User can retrieve an idle connection object from the connection pool whenever user has to connect to DB and once done connection is returned to the pool to be used by another user. as the Maven co-ordinates, since DBCP 2.x is not binary compatible with DBCP The database connections and hibernate dbcp connection pooling configuration are in the hibernate.cfg.xml file, located on the classpath in the src/main/resources folder. Why connection pool is needed. If you are using Maven then you can add the following dependency in pom.xml. Pool 2. Vibur DBCP is concurrent, fast, and fully-featured JDBC connection pool, which provides advanced performance monitoring capabilities, including slow SQL queries detection and logging, a non-starvation guarantee for application threads, statement caching, and Hibernate integration, among other features. Using Apache DBCP. DBCP 2.7.0 compiles and runs under Java 8 only (JDBC 4.2), DBCP 2.6.0 compiles and runs under Java 8 only (JDBC 4.2), DBCP 2.5.0 compiles and runs under Java 8 only (JDBC 4.2), DBCP 2.4.0 compiles and runs under Java 7 only (JDBC 4.1), DBCP 1.4 compiles and runs under Java 6 only (JDBC 4), DBCP 1.3 compiles and runs under Java 1.4-5.0 only (JDBC 3). In this post we’ll see how to configure connection pooling in your application using Apache DBCP. Here is the list of declaration for commons-dbcp. than that the code implementing methods added to support JDBC 4 has been When it is finished, it returns the connection to the pool, where it becomes available for use by other applications. Commons DBCP Tests 1 usages. Users When an application needs database access, it requests a connection from the pool. 2. In this post we’ll see how to create a connection pool using Apache DBCP datasource. If you continue to use this site we will assume that you are happy with it. Mathieu. If something is missing or you have something to share about the topic please write a comment. At build time, Tomcat fetches the Commons DBCP sources (the version depends on the Tomcat version, for instance Tomcat 7.0.27 uses Commons DBCP 1.4), and does package name replacement (org.apache.commons-> org.apache.tomcat.dbcp) and builds the result as tomcat-dbcp… Jars needed. requiring multiple seconds of clock time), in order to perform a database Connection pooling is a pattern used by software applications to connect to databases using a pre-created set of reusable connection objects. org.apache.commons.dbcp2 While performing each operation requires to open connection and after perfor… Spring Boot Database Connection Pool. of using DBCP available. efficient, feature-rich package under the ASF license. Declaration. Commons DBCP WSO2 34 usages. connection-pooling Environment: Windows XP Junit 4.11 Java 1.7 Spring 4.0 maven-compiler-plugin 3.2 maven.surefire.plugin 2.17 maven-cobertura-plugin 2.6 Jenkins 1.549 transaction that might take milliseconds. Commons Database Connection Pooling License: Apache 2.0: Categories: JDBC Pools: Tags: pooling jdbc pool: Used By: 1,729 artifacts: Note: This artifact was moved to: org.apache.commons » commons-dbcp2: Central (14) Redhat GA (1) Accordingly, developers Number of Connections a pool will try to acquire upon startup.:max-wait. By default, dbcp uses sensible defaults, but you can override these … upgrading to 2.x should be aware that the Java package name has changed, as well So when the connection closed it will be returned back to the pool. The maximum lifetime in milliseconds of a connection. This Commons package provides an Java, Spring, BigData, Web development tutorials with examples, Apache DBCP Connection Pooling Java Example. So why do we need a new connection pool? Create an object of BasicDataSource class. a request at any given time is usually a very small percentage of the Avoid exceptions when closing a connection in mutli-threaded use case. Home » commons-dbcp » commons-dbcp Commons DBCP. Improve this question. Connection pooling is based on an object pool design pattern. Here is how it works: DBCP 2.7.0 binaries should be used by applications running on Java 8 and above. dbcp2 (Data Base Connection Pooling) is a very popular library to manage the connection pool, dbcp2 is the project of apache. support as well as numerous other new features compared to DBCP 1.x. are available online. 1. Sort: popular | newest. 3. Configuring the connection pool. commons-pool2 package to provide the underlying object pool That’s all about this topic DBCP Connection Pooling Example. This is a small project/hack that uses AspectJ to track Tomcat's DBCP connections fate. java mysql database connection-pooling apache-commons-dbcp. Mirror of Apache Commons DBCP. commons-dbcp » commons-dbcp Apache. You may also likeeval(ez_write_tag([[250,250],'knpcode_com-leader-2','ezslot_8',143,'0','0'])); Your email address will not be published. Tomcat has updated its default connection pooling library to Tomcat JDBC Pool ("tomcat-jdbc-pool") in Tomcat 8. https://commons.apache.org/proper/commons-dbcp/download_dbcp.cgi, How to Create Bootable USB Drive For Installing Ubuntu, try-catch Block in Java Exception Handling, ArrayList Internal Implementation in Java, CopyOnWriteArraySet in Java With Examples, Life Cycle of a Thread (Thread States) in Java, Synchronization in Java Using Synchronized Keyword, wait(), notify() And notifyAll() Methods in Java, Java Executor Tutorial - Executor, ExecutorService, ScheduledExecutorService, Collectors Class And collect() Method in Java. All other marks mentioned may be trademarks or registered trademarks of their respective owners. Users upgrading to 2.x should be aware that the Java package name has changed, as well as the Maven co-ordinates, since DBCP 2.x is not binary compatible with DBCP 1.x. read the package overview of the GNU General Public License, Version 2 with the Classpath Exception: Java Transaction API, Java(TM) EE Connector Architecture 1.7 API The Apache Software Foundation. JDBC. DBCP now comes in four different versions to support different versions of Add a comment | 1 Answer Active Oldest Votes. In the code above we use try-with-resources statement, it will automatically closes the resource, in this case the connection object. There is no difference in the codebase supporting DBCP 1.4.x and 1.3.x other Database Connection Pool API. Example of spring boot common dbcp2 connection pool example. We use cookies to ensure that we give you the best experience on our website. For example, Tomcat JDBC Pool uses "maxTotal" instead of "maxActive" to limit the number of … Group Commons DBCP WSO2 3. to maxTotal) have been renamed to align them with the new names used by Commons Here are a few of the reasons: Commons DBCP 1.x is single threaded. Apache License, Version 2.0: Apache Commons DBCP, Apache Commons Pool, Byte Buddy (without dependencies), Byte Buddy agent, Objenesis. total number of active users, and during request processing is the only commons-dbcp commons-dbcp 1.4 Steps for creating a DataSource instance using BasicDataSource and configuring connection pool are as follows-, 1. This is not the only way to combine the commons-dbcp and commons-pool packages, but provides a "one stop shopping" solution for basic requirements.. Users extending this class should take care to use … Mathieu Mathieu. When the tomcat process reads “javax.sql.DataSource” it will automatically configure DBCP and the factory object will be used to create a connection pool. Test class that creates a connection using the returned DataSource object and queries the DB. Tomcat 7 and earlier version used Commons DBCP ("commons-dbcp"). These are the individuals who have contributed to the project in one form or another. Many Apache projects support interaction with a relational database. Object pooling design pattern is used when the cost (time & resources like CPU, Network, and IO) of creating new objects is higher. You can also impose an upper limit to the number of connections in the pool, in that case if the maximum open connection limit for the pool has been reached any further requests for the connection are queued to get the connection when it is released by other user. In this Example We will implement the connection pooling in JDBC using Apache Commons DBCP. DBCP 1.3 should be used when running under Java 1.4 and 5.0. into the DBMS, and handles any user account issues internally. Maven dependency for DBCP org.apache.commons commons-dbcp2 2.1 mechanisms that it utilizes. There are There are several Database Connection Pools already available, both obtaining releases. within Apache products and elsewhere. All Rights Reserved. often wish to share a "pool" of open connections between all of the DB used in this example is MySQL. Required fields are marked *. public class BasicDataSource extends Object implements DataSource. Properties file used by the program to read DB properties (db.properties) make sure that this properties file is in the classpath. This post shows how to provide JDBC connection pooling using Apache DBCP data source in Spring framework. It just prints in the stdout a line each time a connection is requested from the pool and when the connection is closed (returned to the pool). If a DB connection is created every time user connects to DB and closed later it results in a lot of time getting wasted in creating connection object itself to perform a database transaction that might take few milliseconds. Let’s try to understand requirements of connection pooling in simple words, To communicate with the database requires the database connection and create the connection with the database is heavy operation. And I am not sure how should I do it. When a new connection is required, an existing connection is retrieved from the pool. Source Code Management Commons DBCP 1,729 usages. Limit connections with PgBouncer. eval(ez_write_tag([[250,250],'knpcode_com-large-mobile-banner-2','ezslot_7',139,'0','0']));Following class is used to create a BasicDataSource. This site uses Akismet to reduce spam. Connection Pool is a cache of database connections so that connection can be reused when future requests to the database are required. DBCP 2.5.0 binaries should be used by applications running under Java 8. opportunity to coordinate the efforts required to create and maintain an Follow edited Aug 18 '14 at 16:05. There are many API’s available which you can use for connection pooling. The getConnectionPool() method is use by the printStatus() method to read connection pool information, at the end of the code snippet above. This method should be … Commons Database Connection Pooling.

Infrared Vs Ceramic Heater, Calvin Ridley Dominique Fitchard, Tree Percolator Bong Quality, Yardwise Lawn Sweeper, Florida Most Wanted 2020, Suchil Ravi Shankar, Water Tank Emoji, Bible Study For Valentine's Day, Madeline Zakarian Age,

Related posts

July 17, 2019

Why Sell Your Business?

Read more
January 31, 2017

Growing Your Business

Read more

Leave a Reply

Your email address will not be published. Required fields are marked *

4 + 3 =