Configuration problem: Unable to locate Spring NamespaceHandler for XML schema namespace [http://www.springframework.org/schema/p]

I'm beginner in SPRING , I have got this error Configuration problem: Unable to locate Spring NamespaceHandler for XML schema namespace

my spring-app-context.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:http="http://www.springframework.org/schema/c"

       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd">

    <bean id="provider" class="com.alex.sp.HelloWorldMessageProvider"/>

    <bean id="renderer" class="com.alex.sp.StandardOutMessageRenderer"
          p:messageProvider-ref="provider"/>

StandardOutMessageRenderer.java

package com.alex.sp;

import com.alex.sp.Interface.MessageProvider;
import com.alex.sp.Interface.MessageRenderer;

public class StandardOutMessageRenderer implements MessageRenderer {

    private MessageProvider messageProvider;

    public StandardOutMessageRenderer(){
        System.out.println(" --> StandardOutMessageRenderer: constructor called");
    }

    @Override
    public void render() {
        if (messageProvider == null) {
            throw new RuntimeException(
                    "You must set the property messageProvider of class:"
                            + StandardOutMessageRenderer.class.getName());
        }
        System.out.println(messageProvider.getMessage());
    }

    @Override
    public void setMessageProvider(MessageProvider provider) {
        System.out.println(" --> StandardOutMessageRenderer: setting the provider");
        this.messageProvider = provider;
    }

    @Override
    public MessageProvider getMessageProvider() {
        return this.messageProvider;
    }
}

my main class

import com.alex.sp.HelloWorldConfiguration;
import com.alex.sp.Interface.MessageRenderer;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class HelloSpringDI {

    public static  void main(String... args){
        ApplicationContext ctx = new
                ClassPathXmlApplicationContext("spring-app-context.xml");
         //       AnnotationConfigApplicationContext(HelloWorldConfiguration.class);

        MessageRenderer renderer = ctx.getBean("renderer", MessageRenderer.class );
        renderer.render();
    }
}

my pom.xml file

<?xml version="1.0" encoding="UTF-8"?>
<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>gl2</groupId>
    <artifactId>gl2</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.version>1.8</maven.compiler.version>
        <classpathentry path="src/main/resources" kind="src" />
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>5.2.2.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.2.2.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>5.2.2.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>5.2.2.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jcl</artifactId>
            <version>5.2.2.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-expression</artifactId>
            <version>5.2.2.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>5.2.2.RELEASE</version>
        </dependency>

    </dependencies>


    <build>
        <pluginManagement>
            <plugins>

                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.6.1</version>
                    <configuration>
                        <source>${maven.compiler.version}</source>
                        <target>${maven.compiler.version}</target>
                    </configuration>
                </plugin>

                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-shade-plugin</artifactId>
                    <version>3.2.1</version>
                    <executions>
                        <execution>
                            <phase>package</phase>
                            <goals><goal>shade</goal></goals>
                            <configuration>
                                <transformers>
                                    <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                        <mainClass>HelloSpringDI</mainClass>
                                    </transformer>
                                    <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                                        <resource>spring-app-context.xml</resource>
                                    </transformer>

                                </transformers>
                            </configuration>
                        </execution>
                    </executions>
                </plugin>

 <!--               <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-assembly-plugin</artifactId>
                    <version>3.2.0</version>
                    <configuration>
                        <archive>
                            <manifest>
                                <mainClass>HelloSpringDI</mainClass>
                            </manifest>
                        </archive>
                        <descriptorRefs>
                            <descriptorRef>jar-with-dependencies</descriptorRef>
                        </descriptorRefs>
                    </configuration>
                    <executions>
                        <execution>
                            <id>make-assembly</id>
                            <phase>package</phase>
                            <goals>
                                <goal>single</goal>
                            </goals>
                        </execution>
                    </executions>
                </plugin>
-->
            </plugins>
        </pluginManagement>

        <plugins> <!-- did NOT work without this  -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
            </plugin>
        </plugins>



    </build>


</project>

example work in intelliJ IDEA but when I make jar and run mvn clean package java -jar ./target/gl2-1.0-SNAPSHOT.jar I have got exception:

Exception in thread "main" org.springframework.beans.factory.parsing.BeanDefinitionParsingException: Configuration problem: Unable to locate Spring NamespaceHandler for XML schema namespace [http://www.springframework.org/schema/p]
Offending resource: class path resource [spring-app-context.xml]

        at org.springframework.beans.factory.parsing.FailFastProblemReporter.error(FailFastProblemReporter.java:72)
        at org.springframework.beans.factory.parsing.ReaderContext.error(ReaderContext.java:119)
        at org.springframework.beans.factory.parsing.ReaderContext.error(ReaderContext.java:111)
        at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.error(BeanDefinitionParserDelegate.java:274)
        at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.decorateIfRequired(BeanDefinitionParserDelegate.java:1456)
        at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.decorateBeanDefinitionIfRequired(BeanDefinitionParserDelegate.java:1420)
        at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.decorateBeanDefinitionIfRequired(BeanDefinitionParserDelegate.java:1401)
        at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.processBeanDefinition(DefaultBeanDefinitionDocumentReader.java:308)
        at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.parseDefaultElement(DefaultBeanDefinitionDocumentReader.java:197)
        at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.parseBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:176)
        at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.doRegisterBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:149)
        at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.registerBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:96)
        at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.registerBeanDefinitions(XmlBeanDefinitionReader.java:514)
        at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:394)
        at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:337)
        at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:305)
        at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:188)
        at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:224)
        at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:195)
        at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:257)
        at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:128)
        at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:94)
        at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:133)
        at org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:637)
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:522)
        at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:144)
        at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:85)
        at HelloSpringDI.main(HelloSpringDI.java:12)

Solution

There are no schema p exists for springframework. If you look at https://www.springframework.org/schema/ you see all avaliable schemas. If I understand your code right, then you want just set instance of HelloWorldMessageProvider class into object of StandardOutMessageRenderer class. Then you dont need to define additional spring schema. Then you can use setter injection like <bean id="renderer" class="com.alex.sp.StandardOutMessageRenderer"> <property name="provider" ref="provider"/> </bean>

Look https://www.springbyexample.org/examples/intro-to-ioc-basic-setter-injection.html for explanation.