小编Are*_*efe的帖子

我在一个小Django应用程序上工作,并得到一个错误告诉我,super(type, obj): obj must be an instance or subtype of type.我views.py在介绍这个函数后从文件中得到它get_object_or_404.下面views.py提供的文件,

from django.shortcuts import render, get_object_or_404    
from django.http import HttpResponse, HttpResponseRedirect     
from django.views import View     
from .models import URL


# function based view 
def redirect_view(request, shortcode=None, *args, **kwargs):
    obj = get_object_or_404(URL, shortcode=shortcode)
    return HttpResponse("Hello World, the shortcode is {shortcode}".format(shortcode = obj.url))


# class based view 
class ShortenerView(View):

    def get(self, request, shortcode=None,  *args, **kwargs):
        obj = get_object_or_404(URL, shortcode=shortcode)
        return HttpResponse("Hello World …

我创建了一个Spring boot项目,目前Spring initializer只有初始代码.

示例代码

@SpringBootApplication
public class EcommerceApplication {

    public static void main(String[] args) {
        SpringApplication.run(EcommerceApplication.class, args);
    }
}


@Controller
@RequestMapping(value = "/")
public class HomeController {

    @GetMapping
    public String index() {
        return "index";
    }
}

我希望它index.html从templates文件夹返回页面.相反,我被重定向到该http://localhost:8080/login地址并要求输入用户名/密码.在application.properties文件中,我尝试使用配置,

server.port=8080
spring.application.name=Bootstrap Spring Boot
spring.thymeleaf.cache=false
spring.thymeleaf.enabled=true 
spring.thymeleaf.prefix=classpath:/templates/
spring.thymeleaf.suffix=.html
spring.datasource.driver-class-name=org.h2.Driver
spring.datasource.url=jdbc:h2:mem:bootapp;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE
spring.datasource.username=testuser
spring.datasource.password=testpassword
server.error.path=/error
server.error.whitelabel.enabled=false 

我尝试使用用户名testuser和密码登录testpassword.这没有用.

我pom.xml在项目中使用以下内容,

<?xml version="1.0" encoding="UTF-8"?>
<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> …

我没什么经验,MySQL Workbench需要一些帮助来找出问题.我从.MWBGUI中的文件加载了一个新的EER图,并试图将其转换为SQLwith Forward engineer.最初,我连接到了localhost,当我按下时Forward engineer...,没有任何反应.该图如下,我在Mac OS Sierra操作系统中工作.

我在这里缺少什么？一些建议将有助于更专业的用户.

我用的是MySQL Workbench 6.3版本,

我试图解决下面提供的Codility中的问题,

写一个函数:

class Solution { public int solution(int[] A); }

在给定N个整数的数组A的情况下,返回A中不存在的最小正整数(大于0).

例如,给定A = [1,3,6,4,1,2],函数应返回5.

Given A = [1, 2, 3], the function should return 4.

Given A = [?1, ?3], the function should return 1.

假使,假设:

N是[1..100,000]范围内的整数; 数组A的每个元素都是[-1,000,000..1,000,000]范围内的整数.复杂:

预期的最坏情况时间复杂度是O(N); 预期的最坏情况空间复杂度是O(N)(不计算输入参数所需的存储空间).

我写下面的解决方案,性能很低,但是,我看不到这个bug.

public static int solution(int[] A) {

        Set<Integer> set = new TreeSet<>();

        for (int a : A) {
            set.add(a);
        }

        int N = set.size();

        int[] C = new int[N];

        int index = 0;

        for (int a : set) {
            C[index++] …

我尝试设置为在Mac OS中使用来运行Hadoop brew。下面提供了所采取的步骤，

1. hadoop使用命令安装$brew install hadoop

2. 在文件夹内，usr/local/Cellar/hadoop/3.1.0/libexec/etc/hadoop并在文件中添加命令hadoop-env.sh，

   export HADOOP_OPTS="$HADOOP_OPTS -Djava.net.preferIPv4Stack=true -Djava.security.krb5.realm= -Djava.security.krb5.kdc=" export JAVA_HOME="/Library/Java/JavaVirtualMachines/jdk1.8.0_151.jdk/Contents/Home"

最后，该文件如下所示：

#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in …

我想按照文档中的规定使用docker启动Confluence控制中心：

https://docs.confluence.io/platform/current/quickstart/ce-docker-quickstart.html

这是docker-compose.yaml他们提供的文件；

---
version: '2'
services:
  zookeeper:
    image: confluentinc/cp-zookeeper:5.5.0
    hostname: zookeeper
    container_name: zookeeper
    ports:
      - "2181:2181"
    environment:
      ZOOKEEPER_CLIENT_PORT: 2181
      ZOOKEEPER_TICK_TIME: 2000

  broker:
    image: confluentinc/cp-server:5.5.0
    hostname: broker
    container_name: broker
    depends_on:
      - zookeeper
    ports:
      - "9092:9092"
    environment:
      KAFKA_BROKER_ID: 1
      KAFKA_ZOOKEEPER_CONNECT: 'zookeeper:2181'
      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: PLAINTEXT:PLAINTEXT,PLAINTEXT_HOST:PLAINTEXT
      KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://broker:29092,PLAINTEXT_HOST://localhost:9092
      KAFKA_METRIC_REPORTERS: io.confluent.metrics.reporter.ConfluentMetricsReporter
      KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
      KAFKA_GROUP_INITIAL_REBALANCE_DELAY_MS: 0
      KAFKA_CONFLUENT_LICENSE_TOPIC_REPLICATION_FACTOR: 1
      KAFKA_TRANSACTION_STATE_LOG_MIN_ISR: 1
      KAFKA_TRANSACTION_STATE_LOG_REPLICATION_FACTOR: 1
      CONFLUENT_METRICS_REPORTER_BOOTSTRAP_SERVERS: broker:29092
      CONFLUENT_METRICS_REPORTER_ZOOKEEPER_CONNECT: zookeeper:2181
      CONFLUENT_METRICS_REPORTER_TOPIC_REPLICAS: 1
      CONFLUENT_METRICS_ENABLE: 'true'
      CONFLUENT_SUPPORT_CUSTOMER_ID: 'anonymous'

  schema-registry:
    image: confluentinc/cp-schema-registry:5.5.0
    hostname: schema-registry
    container_name: schema-registry
    depends_on:
      - zookeeper
      - broker …

我有一个运行Tomcat 8服务器的Java/Maven/JSP.项目结构如下,

我在pom.xml下面提供了这个文件,

<?xml version="1.0" encoding="UTF-8"?>
<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>com.puut.wallet</groupId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>
    <artifactId>WalletApp</artifactId>
    <name>simple-bitcoin-wallet</name>

    <parent>
        <groupId>org.bitcoinj</groupId>
        <artifactId>bitcoinj-parent</artifactId>
        <version>RELEASE</version>
    </parent>

    <build>
        <resources>
            <resource>
                <directory>src/main/resources</directory>
                <filtering>true</filtering>
            </resource>
            <resource>
                <directory>src/main/java</directory>
            </resource>
        </resources>
    </build>

    <dependencies>
        <dependency>
            <groupId>org.bitcoinj</groupId>
            <artifactId>bitcoinj-core</artifactId>
            <version>${project.parent.version}</version>
        </dependency>
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>18.0</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.20</version>
        </dependency>
        <dependency>
            <groupId>net.glxn</groupId>
            <artifactId>qrgen</artifactId>
            <version>1.3</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>
</project>

当我运行该项目时,我收到以下错误,

Error:Maven Resources Compiler: Maven project configuration required for module 'WalletApp' isn't available. Compilation of Maven …

我使用Spring MVC RESTful应用程序并ConstraintViolationException坚持下去。下面提供的错误消息，

Exception in thread " STARTING" javax.validation.ConstraintViolationException: Validation failed for classes [mobi.puut.entities.WalletInfo] during persist time for groups [javax.validation.groups.Default, ]
List of constraint violations:[
    ConstraintViolationImpl{interpolatedMessage='may not be null', propertyPath=id, rootBeanClass=class mobi.puut.entities.WalletInfo, messageTemplate='{javax.validation.constraints.NotNull.message}'}
    ConstraintViolationImpl{interpolatedMessage='may not be null', propertyPath=currency, rootBeanClass=class mobi.puut.entities.WalletInfo, messageTemplate='{javax.validation.constraints.NotNull.message}'}
]
    at org.hibernate.cfg.beanvalidation.BeanValidationEventListener.validate(BeanValidationEventListener.java:140)
    at org.hibernate.cfg.beanvalidation.BeanValidationEventListener.onPreInsert(BeanValidationEventListener.java:80)
    at org.hibernate.action.internal.EntityIdentityInsertAction.preInsert(EntityIdentityInsertAction.java:197)
    at org.hibernate.action.internal.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:75)
    at org.hibernate.engine.spi.ActionQueue.execute(ActionQueue.java:626)
    at org.hibernate.engine.spi.ActionQueue.addResolvedEntityInsertAction(ActionQueue.java:280)
    at org.hibernate.engine.spi.ActionQueue.addInsertAction(ActionQueue.java:261)
    at org.hibernate.engine.spi.ActionQueue.addAction(ActionQueue.java:306)
    at org.hibernate.event.internal.AbstractSaveEventListener.addInsertAction(AbstractSaveEventListener.java:318)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:275)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:182)
    at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:113)
    at org.hibernate.event.internal.DefaultPersistEventListener.entityIsTransient(DefaultPersistEventListener.java:189)
    at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:132)
    at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:58)
    at org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:780)
    at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:765) …

我在使用Java/Spring/ Apache Cxf网络应用程序，突然间，我做了一些显然很幼稚的更改，却收到了错误消息，

25-Aug-2017 11:48:43.036 INFO [RMI TCP Connection(2)-127.0.0.1] org.apache.jasper.servlet.TldScanner.scanJars At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
log4j:WARN No appenders could be found for logger (org.apache.cxf.common.logging.LogUtils).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more …

我在 macOS M1 机器上安装了适用于 Apple Silicon 的 Goland 和 go SDK。在终端我得到 -

$ go version
go version go1.18.3 darwin/amd64

当我尝试调试 go 应用程序时，出现以下错误 -

Debugging programs compiled with go version go1.18.3 darwin/amd64 are not supported. Use go SDK for darwin/arm64.

如何在 MacOS 中安装 go darwin/arm64 SDK？