ClassLoaderHelper.java

package com.ldbc.driver.util;

import com.ldbc.driver.Db;
import com.ldbc.driver.DbException;
import com.ldbc.driver.OperationException;
import com.ldbc.driver.OperationHandler;
import com.ldbc.driver.Workload;
import com.ldbc.driver.WorkloadException;

import static java.lang.String.format;

public class ClassLoaderHelper
{
    /**
     * DB
     */
    public static Db loadDb( String dbClassName ) throws DbException
    {
        try
        {
            return loadDb( loadClass( dbClassName, Db.class ) );
        }
        catch ( ClassLoadingException e )
        {
            throw new DbException( format( "Error creating DB [%s]", dbClassName ), e );
        }
    }

    public static Db loadDb( Class<? extends Db> dbClass ) throws DbException
    {
        try
        {
            return dbClass.getConstructor().newInstance();
        }
        catch ( Exception e )
        {
            throw new DbException( format( "Error creating DB [%s]", dbClass.getName() ), e );
        }
    }

    /**
     * Workload
     */
    public static Workload loadWorkload( String workloadClassName ) throws WorkloadException
    {
        try
        {
            return loadWorkload( loadClass( workloadClassName, Workload.class ) );
        }
        catch ( ClassLoadingException e )
        {
            throw new WorkloadException( format( "Error creating Workload [%s]", workloadClassName ), e );
        }
    }

    public static Workload loadWorkload( Class<? extends Workload> workloadClass ) throws WorkloadException
    {
        try
        {
            return workloadClass.getConstructor().newInstance();
        }
        catch ( Exception e )
        {
            throw new WorkloadException( format( "Error creating Workload [%s]", workloadClass.getName() ), e );
        }
    }

    public static OperationHandler loadOperationHandler( Class<? extends OperationHandler> operationHandlerClass )
            throws OperationException
    {
        try
        {
            OperationHandler operationHandler = operationHandlerClass.getConstructor().newInstance();
            return operationHandler;
        }
        catch ( Exception e )
        {
            throw new OperationException(
                    format( "Error creating OperationHandler [%s]", operationHandlerClass.getName() ),
                    e );
        }
    }

    /**
     * Helper Methods
     */
    public static <C> Class<? extends C> loadClass( String className, Class<C> baseClass ) throws ClassLoadingException
    {
        try
        {
            ClassLoader classLoader = ClassLoaderHelper.class.getClassLoader();
            Class<?> loadedClass = classLoader.loadClass( className );
            // Class<?> loadedClass = Class.forName(className,false,classLoader)
            return (Class<? extends C>) loadedClass;
        }
        catch ( ClassNotFoundException e )
        {
            throw new ClassLoadingException( format( "Error loading class [%s]", className ), e );
        }
    }

    public static Class<?> loadClass( String className ) throws ClassLoadingException
    {
        try
        {
            ClassLoader classLoader = ClassLoaderHelper.class.getClassLoader();
            Class<?> loadedClass = classLoader.loadClass( className );
            return loadedClass;
        }
        catch ( ClassNotFoundException e )
        {
            throw new ClassLoadingException( format( "Error loading class [%s]", className ), e );
        }
    }
}