Issue with ojdbc jar in Maven

I've developed a project in Java 8 and I've installed the ojdbc jar in maven when I developed the project using java 8. Now I'm converting the project into java 7. While doing so, I'm facing issue with ojdbc.jar dependency in pom.xml. Its showing:

Missing artifact com.oracle:ojdbc7:jar:12.1.0

at oracle dependency tag. When I try to run the mvn install for ojdbc jar, that also throws an error.

[ERROR] Failed to execute goal on project SlotBookingAvailability: Could not resolve dependencies for project org.logicInfo.oms:SlotBookingAvailability:war:0.0. 1-SNAPSHOT: Failure to find com.oracle:ojdbc7:jar:12.1.0 in https://repo.maven.a pache.org/maven2 was cached in the local repository, resolution will not be reat tempted until the update interval of central has elapsed or updates are forced.

pom.xml

<?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>org.logicInfo.oms</groupId>
<artifactId>SlotBookingAvailability</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>

<name>SlotBookingAvailability</name>
<description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>


<properties>
    <start-class>org.logicInfo.oms.SlotBookingAvailability.SlotBookingAvailabilityApplication</start-class>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <java.version>1.7</java.version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>com.oracle</groupId>
        <artifactId>ojdbc7</artifactId>
        <version>12.1.0</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.json/json -->
    <dependency>
        <groupId>org.json</groupId>
        <artifactId>json</artifactId>
        <version>20180813</version>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>

</project>

Can someone help me out of this?