小编Man*_*rek的帖子

我这样做是为了连接cassandra.But我的代码返回错误..这是我的代码

public class CassandraConnection {

public static void main(String[] args) {
    String serverIp = "166.78.10.41";
    String keyspace = "gamma";
    CassandraConnection connection;

    Cluster cluster = Cluster.builder()
            .addContactPoints(serverIp)
            .build();

    Session session = cluster.connect(keyspace);


    String cqlStatement = "SELECT * FROM TestCF";
    for (Row row : session.execute(cqlStatement)) {
        System.out.println(row.toString());
    }

}
}

这是错误日志..

无法在项目CassandraConnection上执行目标:无法解析项目com.mycompany的依赖项:CassandraConnection:jar:1.0-SNAPSHOT:无法解析以下工件:org.specs2:scalaz-effect_2.11.0-SNAPSHOT:jar:7.0. 1-SNAPSHOT,org.scalaz:scalaz-effect_2.9.3:jar:7.1.0-SNAPSHOT:找不到工件org.specs2:scalaz-effect_2.11.0-SNAPSHOT:jar:7.0.1-SNAPSHOT - > [Help 1 ]

要查看错误的完整堆栈跟踪,请使用-e开关重新运行Maven.使用-X开关重新运行Maven以启用完整的调试日志记录.

有关错误和可能的解决方案的更多信息,请阅读以下文章:[帮助1] http://cwiki.apache.org/confluence/display/MAVEN/DependencyResolutionException

我是Cassandra的新手我想在Cassandra做一个CRUD操作.我可以从java类连接Cassandra.但现在当我做CRUD它不工作.这是我的代码..

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

public class AnotherClient {

private Session session;

private Cluster cluster;

public void connect(String node) {
    cluster = Cluster.builder().addContactPoint(node).build();
    Metadata metadata = cluster.getMetadata();
    System.out.println("Cassandra connection established");
    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());
        session = cluster.connect();

    }
}

public void createSchema() {
    session.execute("CREATE KEYSPACE simplex WITH replication "
            + "= {'class':'SimpleStrategy', 'replication_factor':3};");

    session.execute("CREATE TABLE simplex.songs (" …

I am new to opencv and I am trying to print the pixels.

import numpy as np
import cv2
img = cv2.imread('freelancer.jpg',cv2.IMREAD_COLOR)
px  = img[55,55]
print(px)

I am getting

Traceback (most recent call last):
  File "C:/Users/Jeet Chatterjee/image processing/basic_image_op.py", line 6, in <module>
 px  = img[55,55]
TypeError: 'NoneType' object is not subscriptable

我正在尝试使用 lambda 启动和停止 EC2 Windows 实例，我正在使用 Node.js 8.10 编写启动和停止脚本。当我测试脚本时，脚本已成功执行，但 EC2 实例不受影响。我给出下面的实例详细信息和脚本

const AWS = require('aws-sdk');

exports.handler = async (event) => {

const ec2 = new AWS.EC2({ region: event.instanceRegion });
 ec2.stopInstances({ InstanceIds: [event.instanceId] }).promise()
    .then(() => callback(null, `Successfully stopped ${event.instanceId}`))
    .catch(err => callback(err));
};

脚本执行成功

以下是实例详细信息

这是停止脚本，但这无法停止实例，请帮助我，我是 aws 新手。提前致谢

我正在尝试使用无服务器框架部署 lambda 函数，部署成功但我无法看到 lambda 函数的 api 网关，并且部署后没有创建端点，我在下面发布代码

无服务器.yml

# Welcome to Serverless!
#
# This file is the main config file for your service.
# It's very minimal at this point and uses default values.
# You can always add more config options for more control.
# We've included some commented out config examples here.
# Just uncomment any of them to get that config option.
#
# For full config options, check the docs:
#    docs.serverless.com
#
# Happy …

我正在尝试调用一个 lambda 函数，它将一些消息推送到 s3 存储桶中。但是每次我调用 lambda 函数时，我都会收到以下错误

 ClientError: An error occurred (AccessDenied) when calling the PutObject operation: Access Denied

下面是我的 lambda 代码

import json
import boto3

def lambda_handler(event, context):
s3 = boto3.client("s3")
#data = json.loads(event["Records"][0]["body"])
data = event["Records"][0]["body"]

s3.put_object(Bucket="sqsmybucket",Key="data.json", Body=json.dumps(data))
#print(event) 
return {
    'statusCode': 200,
    'body': json.dumps('Hello from Lambda!')     
}

我使用的用户帐户也具有访问 S3 的角色

我已经检查了 s3 存储桶权限，并且所有公共访问权限都已为其打开

但是我在 cloudwatch 日志中反复收到以下错误消息

2020-06-05T23:48:20.920+05:30

[ERROR] ClientError: An error occurred (AccessDenied) when calling the PutObject operation: Access Denied
Traceback (most recent call last):
 File "/var/task/lambda_function.py", …

我正在使用HH:mm格式在 java 中打印小时和分钟。它会给格式的时间 05:12，00:04。但我的要求是获得个位数的小时数：

05:12 => 5:12
00:04 => 0:04  
10:18 => 10:18

下面我有我正在运行以生成日期的代码，

import java.time.LocalTime;
import java.time.format.DateTimeFormatter;

public class TestDateUtil {

    public static void main(String ar[]) {
        LocalTime time = LocalTime.now();
        String t = time.format(DateTimeFormatter.ofPattern("HH:mm"));
        System.out.println(t);  

    }
} 

我知道我可以使用字符串操作在 : 的基础上进行时间分割，然后改变它，但这也需要更多的条件检查变化，我不想这样做。有什么办法吗？