驱动下载
https://github.com/datastax/java-driver/
java代码示例
http://blog.csdn.net/guotong1988/article/details/9145697
语法细节
http://zhaoyanblog.com/archives/180.html
运行时报错
Exception in thread "main" java.lang.NoClassDefFoundError: io/netty/util/Timer报错
Exception in thread "main" com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: /xx.93.xx.xx:9042 (com.datastax.driver.core.ConnectionException: [/xx.93.xx.xx:9042] Unexpected error during transport initialization (com.datastax.driver.core.TransportException: [/xx.93.xx.xx:9042] Connection has been closed)))一种解释为驱动不兼容但是用的是3.1版本的jar包：
百度上这错误很少，谷歌有一堆。
问题：java jdbc连接Cassandra集群数据库
Exception in thread "main" com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: /192.168.1.2:9042 (com.datastax.driver.core.ConnectionException: [/192.168.1.2:9042] Unexpected error during transport initialization (com.datastax.driver.core.TransportException: [/192.168.1.2:9042] Connection has been closed)))这个问题困扰了很久！
windows下telnet 到数据库IP的9042端口是通的。
放在linux主机上本地改IP为192.168.1.2运行也是报这个同样的错误！
联通云控制台里面已经放行了7000-9999的端口！
到底是什么问题。Cassandra配置文件有问题吗？
linux主机上直接bin/cqlsh 192.168.1.5 打开的控制台能正常查询
cqlsh> SELECT cluster_name, listen_address FROM system.local;
cluster_name | listen_address
--------------+----------------
Test Cluster | 192.168.1.5想不通是什么问题
代码里用户名和密码也正确
public static void main(String[] args)
{
QueryOptions options = new QueryOptions();
options.setConsistencyLevel(ConsistencyLevel.QUORUM);
//Connection has been closed
Cluster cluster = Cluster.builder()
.addContactPoint("192.168.1.2")
.withCredentials("cassandra", "pwdcassandra123")
.withQueryOptions(options)
// .withPort(9042) // 默认的端口号 [/xx.xx.xx.xx:9042] Connection has been closed)))
// .withPort(9160) Cannot connect
.build();
Session session = cluster.connect();
session.execute("CREATE KEYSPACE kp WITH replication = {‘class‘: ‘SimpleStrategy‘, ‘replication_factor‘: 1};");
// 针对keyspace的session，后面表名前面不用加keyspace
Session kpSession = cluster.connect("kp");
kpSession.execute("CREATE TABLE tbl(a INT, b INT, c INT, PRIMARY KEY(a));");
RegularStatement insert = QueryBuilder.insertInto("kp", "tbl").values(new String[] {"a", "b", "c"}, new Object[] {1, 2, 3});
kpSession.execute(insert);
RegularStatement insert2 = QueryBuilder.insertInto("kp", "tbl").values(new String[] {"a", "b", "c"}, new Object[] {3, 2, 1});
kpSession.execute(insert2);
RegularStatement delete = QueryBuilder.delete().from("kp", "tbl").where(QueryBuilder.eq("a", 1));
kpSession.execute(delete);
RegularStatement update = QueryBuilder.update("kp", "tbl").with(QueryBuilder.set("b", 6)).where(QueryBuilder.eq("a", 3));
kpSession.execute(update);
RegularStatement select = QueryBuilder.select().from("kp", "tbl").where(QueryBuilder.eq("a", 3));
ResultSet rs = kpSession.execute(select);
Iterator<Row> iterator = rs.iterator();
while (iterator.hasNext())
{
Row row = iterator.next();
System.out.println("a=" + row.getInt("a"));
System.out.println("b=" + row.getInt("b"));
System.out.println("c=" + row.getInt("c"));
}
kpSession.close();
session.close();
cluster.close();
}真是没辙了啊！
有遇到过类似问题的童鞋么？
2016年9月18日17:45:16
我觉得这是历史性的一刻
刚刚改了程序后报错信息
[[email protected] tmp]# java -jar 5mavencass.jar
---打开连接
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
--连接成功----
获取执行方法
Connected to cluster: Test Cluster
Datatacenter: datacenter1; Host: /192.168.1.2; Rack: rack1
Datatacenter: datacenter1; Host: /192.168.1.4; Rack: rack1
Datatacenter: datacenter1; Host: /192.168.1.5; Rack: rack1
Exception in thread "main" com.datastax.driver.core.exceptions.InvalidQueryException: Keyspace pimin_net does not exist
at com.datastax.driver.core.exceptions.InvalidQueryException.copy(InvalidQueryException.java:50)
at com.datastax.driver.core.DriverThrowables.propagateCause(DriverThrowables.java:37)
at com.datastax.driver.core.AbstractSession.prepare(AbstractSession.java:100)
at net.pimin.cassandra.TestJava.insertData(TestJava.java:77)
at net.pimin.cassandra.TestJava.main(TestJava.java:194)
Caused by: com.datastax.driver.core.exceptions.InvalidQueryException: Keyspace pimin_net does not exist
at com.datastax.driver.core.Responses$Error.asException(Responses.java:136)
at com.datastax.driver.core.SessionManager$4.apply(SessionManager.java:224)
at com.datastax.driver.core.SessionManager$4.apply(SessionManager.java:200)
at com.google.common.util.concurrent.Futures$ChainingListenableFuture.run(Futures.java:861)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)源码：
package net.pimin.cassandra;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.util.HashSet;
import java.util.Set;
import java.util.UUID;
import com.datastax.driver.core.BoundStatement;
import com.datastax.driver.core.Cluster;
import com.datastax.driver.core.Host;
import com.datastax.driver.core.Metadata;
import com.datastax.driver.core.PreparedStatement;
import com.datastax.driver.core.ResultSet;
import com.datastax.driver.core.Row;
import com.datastax.driver.core.Session;
/**
* 测试Cassandra 2.0.10
*
* @author pimin.net
*
*/
public class TestJava {
private Cluster cluster;
private Session session;
public Cluster getCluster() {
return cluster;
}
public void setCluster(Cluster cluster) {
this.cluster = cluster;
}
public Session getSession() {
return session;
}
public void setSession(Session session) {
this.session = session;
}
/**
* 连接节点
*
* @param node
*/
public void connect(String node) {
System.out.println("---打开连接");
try{
cluster = Cluster.builder().addContactPoint(node).build();
}catch(Exception e){
System.out.println(e.getMessage());
}
System.out.println("--连接成功----");
Metadata metadata = cluster.getMetadata();
System.out.println("获取执行方法");
System.out.printf("Connected to cluster: %s\n",
metadata.getClusterName());
for (Host host : metadata.getAllHosts()) {
System.out.printf("Datatacenter: %s; Host: %s; Rack: %s\n",
host.getDatacenter(), host.getAddress(), host.getRack());
}
this.session = cluster.connect("mycas");
}
public void insertData() {
PreparedStatement insertStatement = getSession().prepare(
"INSERT INTO pimin_net.users "
+ "(id, first_name, last_name, age, emails,avatar) "
+ "VALUES (?, ?, ?, ?, ?, ?);");
BoundStatement boundStatement = new BoundStatement(insertStatement);
Set<String> emails = new HashSet<String>();
emails.add("[email protected]");
emails.add("[email protected]");
java.nio.ByteBuffer avatar = null;
try {
avatar = toByteBuffer("f:\\user.png");
avatar.flip();
System.out.println("头像大小：" + avatar.capacity());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
getSession()
.execute(
boundStatement.bind(
UUID.fromString("756716f7-2e54-4715-9f00-91dcbea6cf50"),
"pi", "min", 10, emails, avatar));
}
public void loadData() {
ResultSet resultSet = getSession().execute(
"SELECT first_name,last_name,age,avatar FROM pimin_net.users;");
System.out
.println(String
.format("%-30s\t%-20s\t%-20s\n%s", "first_name",
"last_name", "age",
"-------------------------------+-----------------------+--------------------"));
for (Row row : resultSet) {
System.out.println(String.format("%-30s\t%-20s\t%-20s",
row.getString("first_name"), row.getString("last_name"),
row.getInt("age")));
ByteBuffer byteBuffer = row.getBytes("avatar");
System.out.println("头像大小："
+ (byteBuffer.limit() - byteBuffer.position()));
FileOutputStream fileOutputStream = null;
try {
fileOutputStream = new FileOutputStream("f:\\2.png");
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
fileOutputStream.write(byteBuffer.array(),
byteBuffer.position(),
byteBuffer.limit() - byteBuffer.position());
fileOutputStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
System.out.println();
}
public void close() {
cluster.close();
}
/**
* 读取文件
*
* @param filename
* @return
* @throws IOException
*/
public static ByteBuffer toByteBuffer(String filename) throws IOException {
File f = new File(filename);
if (!f.exists()) {
throw new FileNotFoundException(filename);
}
FileChannel channel = null;
FileInputStream fs = null;
try {
fs = new FileInputStream(f);
channel = fs.getChannel();
ByteBuffer byteBuffer = ByteBuffer.allocate((int) channel.size());
while ((channel.read(byteBuffer)) > 0) {
// do nothing
// System.out.println("reading");
}
return byteBuffer;
} catch (IOException e) {
e.printStackTrace();
throw e;
} finally {
try {
channel.close();
} catch (IOException e) {
e.printStackTrace();
}
try {
fs.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
public static void main(String[] args) {
TestJava client = new TestJava();
client.connect("192.168.1.5");
client.insertData();
client.loadData();
client.session.close();
client.close();
}
}
改动的地方：
pom.xml文件
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>net.pimin</groupId>
<artifactId>cassandra.test</artifactId>
<version>0.0.1-SNAPSHOT</version>
<dependencies>
<!-- <dependency>
<groupId>com.datastax.cassandra</groupId>
<artifactId>cassandra-driver-core</artifactId>
<version>2.1.0</version>
</dependency> -->
<!-- https://mvnrepository.com/artifact/com.datastax.cassandra/cassandra-driver-core -->
<dependency>
<groupId>com.datastax.cassandra</groupId>
<artifactId>cassandra-driver-core</artifactId>
<version>3.1.0</version>
</dependency>
</dependencies>
</project>驱动改为3.1.0了
翻墙谷歌查询到这篇
最后一句：
Fixed it by going to driver 3.0.0.
折腾了不止一天终于有点眉目了！不容易！贵在坚持！
改进了程序
/*
* Copyright (C) 2012-2015 DataStax Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package net.pimin.cassandra;
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 CreateAndPopulateKeyspace {
static String[] CONTACT_POINTS = {"192.168.1.5"};
static int PORT = 9042;
public static void main(String[] args) {
CreateAndPopulateKeyspace client = new CreateAndPopulateKeyspace();
try {
client.connect(CONTACT_POINTS, PORT);
client.createSchema();
client.loadData();
client.querySchema();
} finally {
client.close();
}
}
private Cluster cluster;
private Session session;
/**
* Initiates a connection to the cluster
* specified by the given contact point.
*
* @param contactPoints the contact points to use.
* @param port the port to use.
*/
public void connect(String[] contactPoints, int port) {
cluster = Cluster.builder()
.addContactPoints(contactPoints).withPort(port)
.build();
System.out.printf("Connected to cluster: %s%n", cluster.getMetadata().getClusterName());
session = cluster.connect();
}
/**
* Creates the schema (keyspace) and tables
* for this example.
*/
public void createSchema() {
session.execute("CREATE KEYSPACE IF NOT EXISTS simplex WITH replication " +
"= {‘class‘:‘SimpleStrategy‘, ‘replication_factor‘:1};");
System.out.println("创建了命名空间 simplex");
session.execute(
"CREATE TABLE IF NOT EXISTS simplex.songs (" +
"id uuid PRIMARY KEY," +
"title text," +
"album text," +
"artist text," +
"tags set<text>," +
"data blob" +
");");
session.execute(
"CREATE TABLE IF NOT EXISTS simplex.playlists (" +
"id uuid," +
"title text," +
"album text, " +
"artist text," +
"song_id uuid," +
"PRIMARY KEY (id, title, album, artist)" +
");");
System.out.println("---创建了3个---表");
}
/**
* Inserts data into the tables.
*/
public void loadData() {
session.execute(
"INSERT INTO simplex.songs (id, title, album, artist, tags) " +
"VALUES (" +
"756716f7-2e54-4715-9f00-91dcbea6cf50," +
"‘La Petite Tonkinoise‘," +
"‘Bye Bye Blackbird‘," +
"‘Joséphine Baker‘," +
"{‘jazz‘, ‘2013‘})" +
";");
session.execute(
"INSERT INTO simplex.playlists (id, song_id, title, album, artist) " +
"VALUES (" +
"2cc9ccb7-6221-4ccb-8387-f22b6a1b354d," +
"756716f7-2e54-4715-9f00-91dcbea6cf50," +
"‘La Petite Tonkinoise‘," +
"‘Bye Bye Blackbird‘," +
"‘Joséphine Baker‘" +
");");
System.out.println("插入了一顿数据---");
}
/**
* Queries and displays data.
*/
public void querySchema() {
System.out.println("查询一下");
ResultSet results = session.execute(
"SELECT * FROM simplex.playlists " +
"WHERE id = 2cc9ccb7-6221-4ccb-8387-f22b6a1b354d;");
System.out.printf("%-30s\t%-20s\t%-20s%n", "title", "album", "artist");
System.out.println("-------------------------------+-----------------------+--------------------");
for (Row row : results) {
System.out.printf("%-30s\t%-20s\t%-20s%n",
row.getString("title"),
row.getString("album"),
row.getString("artist"));
}
}
/**
* Closes the session and the cluster.
*/
public void close() {
session.close();
cluster.close();
}
}
创建了表再查询
报错
[[email protected] tmp]# java -jar beautiful.jar
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
Connected to cluster: Test Cluster
创建了命名空间 simplex
---创建了3个---表
Exception in thread "main" com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: /192.168.1.5:9042 (com.datastax.driver.core.exceptions.UnavailableException: Not enough replicas available for query at consistency LOCAL_ONE (1 required but only 0 alive)))
at com.datastax.driver.core.exceptions.NoHostAvailableException.copy(NoHostAvailableException.java:84)
at com.datastax.driver.core.exceptions.NoHostAvailableException.copy(NoHostAvailableException.java:37)
at com.datastax.driver.core.DriverThrowables.propagateCause(DriverThrowables.java:37)
at com.datastax.driver.core.DefaultResultSetFuture.getUninterruptibly(DefaultResultSetFuture.java:245)
at com.datastax.driver.core.AbstractSession.execute(AbstractSession.java:64)
at com.datastax.driver.core.AbstractSession.execute(AbstractSession.java:39)
at net.pimin.cassandra.CreateAndPopulateKeyspace.loadData(CreateAndPopulateKeyspace.java:103)
at net.pimin.cassandra.CreateAndPopulateKeyspace.main(CreateAndPopulateKeyspace.java:37)
Caused by: com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: /192.168.1.5:9042 (com.datastax.driver.core.exceptions.UnavailableException: Not enough replicas available for query at consistency LOCAL_ONE (1 required but only 0 alive)))
at com.datastax.driver.core.RequestHandler.reportNoMoreHosts(RequestHandler.java:208)
at com.datastax.driver.core.RequestHandler.access$1000(RequestHandler.java:43)
at com.datastax.driver.core.RequestHandler$SpeculativeExecution.sendRequest(RequestHandler.java:274)
at com.datastax.driver.core.RequestHandler$SpeculativeExecution$1.run(RequestHandler.java:429)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745没有足够的副本可以在一致性local_one查询
把其他几个节点都启动
OK了
心情是激动的！
附录：
时间： 2024-10-13 00:14:11