Maven project is not run on server in Spring tool suite

<project xmlns="http://ift.tt/IH78KX" xmlns:xsi="http://ift.tt/ra1lAU" xsi:schemaLocation="http://ift.tt/IH78KX http://ift.tt/VE5zRx">
  <modelVersion>4.0.0</modelVersion>
  <groupId>org.springframework.samples.service.service</groupId>
  <artifactId>OnlineExam</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>war</packaging>
  
    <properties>

                <!-- Generic properties -->
                <java.version>1.8</java.version>
                <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
                <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
                
                <!-- Web -->
                <jsp.version>2.2</jsp.version>
                <jstl.version>1.2</jstl.version>
                <servlet.version>2.5</servlet.version>
                

                <!-- Spring -->
                <spring-framework.version>4.2.0.RELEASE</spring-framework.version>

                <!-- Hibernate / JPA -->
                <hibernate.version>4.2.1.Final</hibernate.version>

                <!-- Logging -->
                <logback.version>1.0.13</logback.version>
                <slf4j.version>1.7.5</slf4j.version>

                <!-- Test -->
                <junit.version>4.11</junit.version>

        </properties>
        
        <dependencies>
        
                <!-- Spring MVC -->
                <dependency>
                        <groupId>org.springframework</groupId>
                        <artifactId>spring-webmvc</artifactId>
                        <version>${spring-framework.version}</version>
                </dependency>
                
                <!-- Other Web dependencies -->
                <dependency>
                        <groupId>javax.servlet</groupId>
                        <artifactId>jstl</artifactId>
                        <version>${jstl.version}</version>
                </dependency>
                <dependency>
                        <groupId>javax.servlet</groupId>
                        <artifactId>servlet-api</artifactId>
                        <version>${servlet.version}</version>
                        <scope>provided</scope>
                </dependency>
                <dependency>
                        <groupId>javax.servlet.jsp</groupId>
                        <artifactId>jsp-api</artifactId>
                        <version>${jsp.version}</version>
                        <scope>provided</scope>
                </dependency>
        
                <!-- Spring and Transactions -->
                <dependency>
                        <groupId>org.springframework</groupId>
                        <artifactId>spring-tx</artifactId>
                        <version>${spring-framework.version}</version>
                </dependency>

                <!-- Logging with SLF4J & LogBack -->
                <dependency>
                        <groupId>org.slf4j</groupId>
                        <artifactId>slf4j-api</artifactId>
                        <version>${slf4j.version}</version>
                        <scope>compile</scope>
                </dependency>
                <dependency>
                        <groupId>ch.qos.logback</groupId>
                        <artifactId>logback-classic</artifactId>
                        <version>${logback.version}</version>
                        <scope>runtime</scope>
                </dependency>

                <!-- Hibernate -->
                <dependency>
                        <groupId>org.hibernate</groupId>
                        <artifactId>hibernate-entitymanager</artifactId>
                        <version>${hibernate.version}</version>
                </dependency>

                
                <!-- Test Artifacts -->
                <dependency>
                        <groupId>org.springframework</groupId>
                        <artifactId>spring-test</artifactId>
                        <version>${spring-framework.version}</version>
                        <scope>test</scope>
                </dependency>
                <dependency>
                        <groupId>junit</groupId>
                        <artifactId>junit</artifactId>
                        <version>${junit.version}</version>
                        <scope>test</scope>
                </dependency>

        </dependencies>   
</project>

hi friends i try to make smiple web maven project in Spring tool suite but every time when i try to run the project on server there is no option come to run on server.. then i change the java version 1.5 to 1.8 but again its not working..

then i go to the project facet and select the Dynamic web module 3.0 then it show run on server but it also show error in pom.xml file that it dont have web.xml file..

but file is there .i waste my lot of time but still no solution