java – 连接到AEM 6.0 JCR：前提条件失败

我一直在使用这个tutorial开始.

这是我非常简单的代码示例：

import java.io.FileNotFoundException;
import java.io.FileReader;

import javax.jcr.Repository;
import javax.jcr.Session;
import javax.jcr.SimpleCredentials;

import org.apache.jackrabbit.commons.JcrUtils;

import com.opencsv.CSVReader;


public class Main { 

    public static void main(String[] args) throws FileNotFoundException {
        Repository repository;
        FileReader fileReader;
        CSVReader csvReader;

        try {
            System.out.println("connecting to repository");
            repository = JcrUtils.getRepository("http://localhost:4502/crx/server");

            Session session = repository.login( new SimpleCredentials("admin","admin".toCharArray())); // throws javax.jcr.lock.LockException: Precondition Failed

        }
        catch(Exception e) {
            System.out.println(e);
        }
    }

}

任何指导将不胜感激.