連接到本地主機上運行的cassandra實例

Question

有人可以幫助和回答我，爲什麼我無法連接並在netbeans中出現錯誤。我得到以下錯誤消息：。

Exception in thread "main" java.lang.NoClassDefFoundError: org/slf4j/LoggerFactory at com.datastax.driver.core.Cluster.(Cluster.java:63) at testcassandra.TestCassandra.main(TestCassandra.java:30) Caused by: java.lang.ClassNotFoundException: org.slf4j.LoggerFactory at java.net.URLClassLoader$1.run(URLClassLoader.java:366) at java.net.URLClassLoader$1.run(URLClassLoader.java:355) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:354) at java.lang.ClassLoader.loadClass(ClassLoader.java:423) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308) at java.lang.ClassLoader.loadClass(ClassLoader.java:356) ... 2 more

（與Datstax DevCenter我可以連接）在簇

錯誤= Cluster.builder（）addContactPoint（ 「本地主機」）withPort（9042）.build（ ）;

import com.datastax.driver.core.Cluster; 
import com.datastax.driver.core.ResultSet; 
import com.datastax.driver.core.Row; 
import com.datastax.driver.core.Session; 

public class TestCassandra { 

/** 
* @param args the command line arguments 
*/ 
public static void main(String[] args) { 
    // TODO code application logic here 
    Cluster cluster; 
    Session session; 
    // Connect to the cluster and keyspace "demo" 
    cluster = Cluster.builder().addContactPoint("localhost").withPort(9042).build(); 
    session = cluster.connect("demo"); 
    // Insert one record into the users table 
    session.execute("INSERT INTO users (lastname, age, city, email, firstname) VALUES ('Jones', 35, 'Austin', 'bob@example.com', 'Bob')"); 
    // Use select to get the user we just entered 
    ResultSet results = session.execute("SELECT * FROM users WHERE lastname='Jones'"); 
    for (Row row : results) { 
     System.out.format("%s %d\n", row.getString("firstname"), row.getInt("age")); 
    } 
    cluster.close(); 
} 

}

Answer 1

看來，你可能缺少合適的包裝中。您可以下載JAR文件here該網站也有關於如何實施的完整文檔。

如果安裝後仍然存在問題，請確認您沒有使用SLF4J和Log4j 2，因爲它們會導致事件在它們之間無休止地路由。

還請確保您有正確的import語句

例子：

import org.slf4j.Logger; 
import org.slf4j.LoggerFactory; 

OR

import org.apache.logging.log4j.LogManager; 
import org.apache.logging.log4j.Logger;