小编Ng *_*rma的帖子

该类的Oracle Tutorial页面Instant显示了此示例代码:

Instant oneHourLater = Instant.now().plusHours(1);

当我尝试编译此代码时,编译器抛出错误:

• 错误

InstantPrint.java:6: error: cannot find symbol
        Instant oneHourLater = Instant.now().plusHours(1);
                                            ^
  symbol:   method plusHours(int)
  location: class Instant

但是这个Java文档提到了plusHours()方法,但我检查了这个Instant类,它不包含plusHours()方法.

此后,为什么plusHours()在这个例子中提到这个方法呢？

我知道,这是重复的问题,但问题是新的,请不要标记重复的问题.这个程序在Window 10中运行它运行正常并创建一个数据库,但是当在Debian 9中运行相同的程序时它会抛出异常.之后,我在谷歌上检查了这个问题.有人说,创建一个所有用户类状态的setter和getter方法.我创建了一个setter和getter方法,但抛出了同样的异常.

用户类

@Entity
public class User {

    @Id
    private Long id;
    private String firstName;
    private String lastName;
    private String professional;
    private int age;

    public User() {}

    public User(Long id, String firstName, String lastName, String professional, int age) {
        this.id = id;
        this.firstName = firstName;
        this.lastName = lastName;
        this.professional = professional;
        this.age = age;
    }

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getFirstName() {
        return firstName;
    }

    public …

更新到1.19.1后，我不断收到此错误。 磁盘上的内容是较新的。单击比较以将您的版本与磁盘上的版本进行比较。

我正在为断路器编写一个小程序，运行该应用程序时会抛出异常。
springboot 版本 2.5.4，Hystrix 版本使用2.2.6
BeanCreationException：创建类路径资源 [org/springframework/cloud/autoconfigure/ConfigurationPropertiesRebinderAutoConfiguration.class] 中定义的名为“configurationPropertiesBeans”的 bean 时出错：合并 bean 定义的后处理失败；嵌套异常是 java.lang.IllegalStateException：无法从 ClassLoader [jdk.internal.loader.ClassLoaders$AppClassLoader@659e0bfd] 内省类 [org.springframework.cloud.context.properties.ConfigurationPropertiesBeans]

Pom.xml

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.5.4</version>
    <relativePath /> <!-- lookup parent from repository -->
</parent>
<groupId>com.ramgovindhare</groupId>
<artifactId>cricuitbreakerhystrix</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>CricuitBreakerHystrix</name>
<description>firstMicroserviceProject</description>
<properties>
    <java.version>11</java.version>
</properties>
<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.springframework.cloud/spring-cloud-starter-netflix-hystrix -->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
        <version>2.2.8.RELEASE</version> <--- **See this**
    </dependency>
    
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
        <optional>true</optional>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build> …

我创建了一个简单的 Spring REST 服务（POST、PUT）。但是当我从邮递员调用此服务时，值存储在null中。

学生Pojo班

import java.io.Serializable;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

import org.springframework.hateoas.ResourceSupport;

@SuppressWarnings("serial")
@Entity
@Table(schema="fishpool")
public class Student extends ResourceSupport implements Serializable {

@Id @GeneratedValue(strategy=GenerationType.AUTO)
private Long sId;
private String name;
private String email;

public Student() {

}

public Student(Long sId, String name, String email) {
    this.sId = sId;
    this.name = name;
    this.email = email;
}

public Long getsId() {
    return sId;
}

public void setsId(Long sId) {
    this.sId …

请任何人解释一下为什么允许导入模块描述符文件？
模块描述符文件中的语句的用途是什么import。

import java.util.*;

module superman {
}

我的应用程序正在运行,但是什么时候,我遇到应用程 我曾多次尝试过同样的事情.我检查了数据库连接,一切都很好.这些是我的日志

例外

Caused by: java.lang.IllegalArgumentException: URL must start with 'jdbc'
at org.springframework.util.Assert.isTrue(Assert.java:116) ~[spring-core-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.boot.jdbc.DatabaseDriver.fromJdbcUrl(DatabaseDriver.java:268) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.autoconfigure.jdbc.DataSourceProperties.determineDriverClassName(DataSourceProperties.java:230) ~[spring-boot-autoconfigure-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.autoconfigure.jdbc.DataSourceProperties.initializeDataSourceBuilder(DataSourceProperties.java:176) ~[spring-boot-autoconfigure-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.autoconfigure.jdbc.DataSourceConfiguration.createDataSource(DataSourceConfiguration.java:43) ~[spring-boot-autoconfigure-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.autoconfigure.jdbc.DataSourceConfiguration$Hikari.dataSource(DataSourceConfiguration.java:81) ~[spring-boot-autoconfigure-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_161]
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_161]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_161]
at java.lang.reflect.Method.invoke(Unknown Source) ~[na:1.8.0_161]
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
... 40 common frames omitted

application.properties

#======================
# DATA SOURCE
#=====================

spring.datasource.url="jdbc:mysql://localhost:3306/customerdb?useSSL=false"
spring.datasource.username=root
spring.datasource.password=root
#spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.dbcp2.test-while-idle=true
spring.datasource.dbcp2.validation-query= SELECT 1


#============================
# JPA/Hibernate
#===========================
spring.jpa.show-sql=true
spring.jpa.hibernate.ddl-auto=create-drop
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5Dialect
spring.jpa.hibernate.naming.physical-strategy=org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy

#===================================================================
# Spring Security / …

可能一切正常，但我收到错误。基本上我在应用程序属性文件中添加视图解析器属性，然后运行这个项目并打开浏览器，浏览器显示此错误Whitelabel Error Page 404 file not found。我不明白帮助我并建议如何解决这个问题，我是 Spring Boot 的新手。在这打击我的项目细节的 .

错误

 2018-04-07 12:11:51.661 DEBUG 3740 --- [nio-8080-exec-1] o.s.w.s.v.ContentNegotiatingViewResolver : Returning [org.springframework.web.servlet.view.InternalResourceView: name 'home'; URL [/WEB-INF/jsp/home.jsp]] based on requested media type 'text/html'
2018-04-07 12:11:51.661 DEBUG 3740 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Rendering view [org.springframework.web.servlet.view.InternalResourceView: name 'home'; URL [/WEB-INF/jsp/home.jsp]] in DispatcherServlet with name 'dispatcherServlet'
2018-04-07 12:11:51.661 TRACE 3740 --- [nio-8080-exec-1] o.s.w.servlet.view.InternalResourceView  : Rendering view with name 'home' with model {} and static attributes {}
2018-04-07 12:11:51.684 DEBUG 3740 --- [nio-8080-exec-1] …

当我运行第一段时，它非常好并生成一个输出。但是在第二种情况下，当我运行此段 2 时，它会生成

DateTimeException : Unable to extract ZoneId from temporal.

第 1 部分：

LocalDate ld = LocalDate.now();
System.out.println(DateTimeFormatter.ofLocalizedDate(FormatStyle.FULL).format(ld));

第 2 部分：

LocalDateTime ldt = LocalDateTime.now();
DateTimeFormatter dtf = DateTimeFormatter.ofLocalizedDateTime(FormatStyle.FULL);
System.out.println(dtf.format(ldt));

当编译安全帽项目时，当它显示Nothing to Compile时。

{
  "name": "HardhAtToken",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "@nomiclabs/hardhat-ethers": "^2.0.6",
    "@nomiclabs/hardhat-waffle": "^2.0.3",
    "chai": "^4.3.6",
    "ethereum-waffle": "^3.4.4",
    "ethers": "^5.6.6",
    "hardhat": "^2.9.6-dev.1"
  },
  "dependencies": {
    "glob": "^7.2.0"
  }
}

问题：如何获取位置https://github.com/TEK-Leads/Config-Properties.git中的数据

当我尝试运行此应用程序时，它不显示任何结果，它只显示默认的传递结果（请参阅MessageController）。或显示此类消息的 ConfigClient 端日志。

无法找到 PropertySource：“http://localhost:8888/application/default”的 GET 请求发生 I/O 错误：连接被拒绝；嵌套异常是 java.net.ConnectException: 连接被拒绝

当将配置服务器端application.yml文件更改为bootstrap.yml时，抛出下面的异常时。

If you are using the git profile, you need to set a Git URI in your configuration.  If you have set spring.cloud.config.server.bootstrap=true, you need to use a composite configuration.

配置服务器部分

Pom.xml

    <properties>
    <java.version>11</java.version>
    <spring-cloud.version>2020.0.3</spring-cloud.version>
</properties>
<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-config-server</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>
<dependencyManagement> …

我尝试显示数组数据，但在 React 网页上不显示数据。任何人都指导我哪里有错误并纠正我。请参阅评论行//

/* eslint-disable */

import React, { Component } from 'react';

import axios from 'axios';


class RestaurantList extends Component<{}, any> {

    constructor(props: any) {
        super(props);
        this.state = { restoLists: null };
    }

    componentDidMount() {

        axios.get("http://localhost:3030/restauranst")
            .then((response) => {
                this.setState({ restoLists: response.data })
                console.log(response);
            })
            .catch((error) => console.error(error));
    }

    render() {
        console.log(this.state.restoLists);
        return (
            <div>
                <h1>RestaurantList</h1>
                {
                    this.state.restoLists ?
                        <div>
                            <ul>
                                {
                                    this.state.restoLists.map((itme: any) => {
                                        console.log(itme.name); // work this line
                                        <li>
                                            {itme.name} {/**Does not work this line …