Question

我的Jar文件

  cassandra-driver-core-2.1.0.jar

我对com/datastax/driver/core/Cluster

的Javap命令

  javap -classpath cassandra-driver-core-2.1.0.jar com/datastax/driver/core/Cluster

显示

 public class com.datastax.driver.core.Cluster implements java.io.Closeable {
 final com.datastax.driver.core.Cluster$Manager manager;
 protected com.datastax.driver.core.Cluster(java.lang.String, java.util.List<java.net.InetSocketAddress>, com.datastax.driver.core.Configuration);
 protected com.datastax.driver.core.Cluster(com.datastax.driver.core.Cluster$Initializer);
 public com.datastax.driver.core.Cluster init();
 public static com.datastax.driver.core.Cluster buildFrom(com.datastax.driver.core.Cluster$Initializer);
 public static com.datastax.driver.core.Cluster$Builder builder();
 ...............

我的Java文件是

 import com.datastax.driver.core.Cluster;
 import com.datastax.driver.core.Host;
 import com.datastax.driver.core.Metadata;

 public class SimpleClient {
    private Cluster cluster;

    public void connect(String node) {
       System.out.println("I am in");
       cluster = Cluster.builder().addContactPoint(node).build(); 
       //ERROR
 }

 public void close() {
   cluster.close();
 }

 public static void main(String[] args) {
  SimpleClient client = new SimpleClient();
   System.out.println("Obj Created");
  client.connect("127.0.0.1");
 // client.close();
  }
 }

我的编译命令是

   javac -classpath cassandra-driver-core-2.1.0.jar SimpleClient.java

我的跑步命令

   tried1:   java  -classpath cassandra-driver-core-2.1.0.jar SimpleClient

说

  Could not find or load main class SimpleClient

但是课堂已经存在。

  Tried2:  java  -classpath SimpleClient

它说

  Obj Created
  I am in
  Exception in thread "main" java.lang.NoClassDefFoundError: com/datastax/driver/core/Cluster
    at SimpleClient.connect(SimpleClient.java:12)
    at SimpleClient.main(SimpleClient.java:29)
   Caused by: java.lang.ClassNotFoundException: com.datastax.driver.core.Cluster

请让我知道解决方案。

Answer 1

你必须使用

java  -classpath ./;cassandra-driver-core-2.1.0.jar SimpleClient

在Windows机器上

或

java  -classpath ./:cassandra-driver-core-2.1.0.jar SimpleClient

在linux机器上。

这会将实际目录添加到类路径中。

NoClassDefFoundError但是存在类

1 个答案: