Problem when using JasperReports in a .jar

I'm making an application that uses JasperReports, I run the program from my computer and it generates the report well but when I make the .jar and try it from another computer it does not show me anything. My code is as follows

public class Reportes {

    private final String hospi = "/Imagenes/Hospital.jpg";
    private final String secre = "/Imagenes/Secretaria.jpg";
    String path = "/Reporte/newReport.jrxml";

    public void ReporteCelulares(int id) throws SQLException, JRException{
        Connection a;
        a = ConexionSql.getConnection();
        Map parametros  = new HashMap();
        parametros.put("idCompra",id);
        parametros.put("Hospital",this.getClass().getResourceAsStream(hospi));
        parametros.put("Secretaria",this.getClass().getResourceAsStream(secre));

        JasperReport jasper = (JasperReport) JRLoader.loadObject(getClass().getResource(path));

        JasperPrint print = JasperFillManager.fillReport(jasper, parametros, a);
        JasperViewer ver = new JasperViewer(print,false);
        ver.setTitle("Solicitud de compra");
        ver.setVisible(true);
    }
}

also in a video mention that I must modify the build.xml file because it can not find the libraries because they are out and said that I should enter these lines:

<target name="-post-jar">
    <property name="store.jar.name" value="REMA"/>

    <property name="store.dir" value="dist"/>
    <property name="store.jar" value="${store.dir}/${store.jar.name}.jar"/>

    <echo message="Packaging ${application.title} into a single JAR at ${store.jar}"/>

    <jar destfile="${store.dir}/temp_final.jar" filesetmanifest="skip">
        <zipgroupfileset dir="dist" includes="*.jar"/>
        <zipgroupfileset dir="dist/lib" includes="*.jar"/>

        <manifest>
            <attribute name="Main-Class" value="${main.class}"/>
        </manifest>
    </jar>

    <zip destfile="${store.jar}">
        <zipfileset src="${store.dir}/temp_final.jar"
        excludes="META-INF/*.SF, META-INF/*.DSA, META-INF/*.RSA"/>
    </zip>
    <delete file="${store.dir}/temp_final.jar"/>
    <delete dir="${store.dir}/lib"/>
    <delete file="${store.dir}/README.TXT"/>
    </target>

but it does not come out that way either.