Question

我正在尝试通过Java与我的Cassandra实例建立一个简单的连接。我为cqlsh创建了一个'demo'键空间，并在java程序中创建了一个表。代码如下：

使用的罐子：

slf4j.api-1.6.1

卡桑德拉-全2.1.2

public class CassandraConnection {

    public static void main(String[] args){

        String ipAddress="127.0.0.1";
        String keySpace="demo";

        Cluster cluster;

        Session session;

        cluster=Cluster.builder().addContactPoint(ipAddress).build();

        session=cluster.connect(keySpace);

        System.out.println("====================Before insert");

        String cqlInsertStmt="insert into users (lastname,age,city,email,firstname) values"
        +"('Gopalan',32,'Paramakkudi','murugan@gmail.com','Murugan') ";

        session.execute(cqlInsertStmt);

        String cqlSelectStmt="select * from users";
        ResultSet resultSet=session.execute(cqlSelectStmt);

        System.out.println("=================After insert");

        for(Row row: resultSet){

            System.out.format("%s %s %d %s %s \n", row.getString("firstname"),row.getString("lastname"),row.getInt("age"),row.getString("city"),row.getString("email"));
        }

        System.out.println("=================After update");

    }
}

我收到以下错误：

Failed to instantiate SLF4J LoggerFactory
Reported exception:
java.lang.NoClassDefFoundError: ch/qos/logback/core/joran/spi/JoranException
    at org.slf4j.LoggerFactory.bind(LoggerFactory.java:150)
    at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:124)
    at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:412)
    at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:357)
    at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:383)
    at com.datastax.driver.core.Cluster.<clinit>(Cluster.java:60)
    at CassandraConnection.main(CassandraConnection.java:21)
Caused by: java.lang.ClassNotFoundException: ch.qos.logback.core.joran.spi.JoranException
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    ... 7 more
Exception in thread "main" java.lang.NoClassDefFoundError: ch/qos/logback/core/joran/spi/JoranException
    at org.slf4j.LoggerFactory.bind(LoggerFactory.java:150)
    at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:124)
    at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:412)
    at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:357)
    at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:383)
    at com.datastax.driver.core.Cluster.<clinit>(Cluster.java:60)
    at CassandraConnection.main(CassandraConnection.java:21)
Caused by: java.lang.ClassNotFoundException: ch.qos.logback.core.joran.spi.JoranException
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    ... 7 more

Answer 1

您必须确保 logback JAR在您的类路径中。

首先查看here;除此之外;真正的外卖：运行时告诉你它找不到某个类;它会为您提供该类的完整名称。或者你看here来阅读Cassandra关于logback的内容。

你接受了那个输入;然后你转向你最喜欢的搜索引擎，以便了解正在发生的事情。

Answer 2

此问题的根本原因是CLASSPATH中无法使用所需的jar。请添加以下依赖项 - 它们将解决您的问题。

<dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.2.3</version>
        </dependency>
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.2.3</version>
            <exclusions>
                <exclusion>
                    <groupId>org.slf4j</groupId>
                    <artifactId>slf4j-log4j12</artifactId>

                </exclusion>
            </exclusions>
        </dependency>

        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-core</artifactId>
            <version>1.2.3</version>
        </dependency>

连接Cassandra DB时java.lang.NoClassDefFoundError：ch / qos / logback / core / joran / spi / JoranException

2 个答案: