hackdapp

public interface ChannelRepository extends JpaRepository<Channel, Long>{

    @Query(value = "select new com.reyun.lizard.service.model.KeyValue(str(a.channel),a.surl) from Campaign a where a.channel in (?1)")
    List<KeyValue> findSurl(List<Long> channels);
    
}

hackdapp

public class SingletonOne
{
    private static SingletonOne singletonOne = null;

    private SingletonOne()
    {
    }

    public static SingletonOne getInstance()
    {

hackdapp

public class SingletonTwo
{
    private static SingletonTwo singletonTwo;

    private SingletonTwo()
    {
    }

    public static synchronized SingletonTwo getSingletonTwo()
    {

hackdapp

/**
 * description:
 * 在多线程环境下，有可能在实例未完成的情况下进行调用出现错误
 * @author nolan
 * @date 09/08/2017
 */
public class SingletonThreee
{
    private static SingletonThreee singletonThreee;

hackdapp

public class SingleFour
{
    private static class SingleHolder {
        private static SingleFour instance = new SingleFour();
    }

    public static SingleFour getInstance(){
        return SingleHolder.instance;
    }
}

hackdapp

public class SingletonFive
{
    private static SingletonFive singletonFive;

    private SingletonFive()
    {
    }

    public static SingletonFive getInstance()
    {

hackdapp

/**
 * description:
 * 在多线程环境下，有可能在实例未完成的情况下进行调用出现错误
 * @author nolan
 * @date 09/08/2017
 */
public class SingletonThree
{
    private static SingletonThree singletonThree;

hackdapp

public class SingletonThree
{
    private static volatile SingletonThree singletonThree;

    private SingletonThree()
    {
    }

    public static SingletonThree getInstace()
    {

hackdapp

public interface Logger
{
    void log(String message);
}

hackdapp

public class XMLLogger
        implements Logger
{
    public void log(String message)
    {
    }
}