java - 数据库连接mysql和Spring框架-6ren

java - 数据库连接mysql和Spring框架

转载作者：行者123 更新时间：2023-11-30 22:04:56

我想获取数据库名称为:myschema，表:user(有 3 列 -> id、用户名、密码)的数据。但是加载失败。

我的项目结构:

Project Structure Picture

Controller :

package com.project.pr.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.bind.annotation.RestController;

import com.project.pr.entity.User;
import com.project.pr.service.ProjectService;

@RestController
public class ProjectController {

    @Autowired
    private ProjectService projectService; 

    @GetMapping(name="user")
    @ResponseStatus(HttpStatus.OK)
    public List<User> getUser(){
        return projectService.getUser();
    }

}

服务:

package com.project.pr.service;

import java.util.List;

import javax.transaction.Transactional;

import org.hibernate.SessionFactory;
import org.hibernate.transform.Transformers;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

import com.project.pr.entity.User;

@Repository
public class ProjectService {

    @Autowired
    private SessionFactory sessionFactory;

    @Transactional
    public List<User> getUser() {
        String sql = "SELECT * FROM USER";
        List result = this.sessionFactory.getCurrentSession().createSQLQuery(sql).setResultTransformer(Transformers.ALIAS_TO_ENTITY_MAP).list();
        return result;
    }

}

实体:

package com.project.pr.entity;

import java.io.Serializable;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="USER")
public class User implements Serializable {

    @Id
    @Column(name="id")
    private String id;  

    @Column(name="username")
    private String username;

    @Column(name="password")
    private String password;

    public String getId() {
        return id;
    }

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

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

}

BeansLocations.xml:

<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-2.5.xsd">

    <!-- Database Configuration -->
    <import resource="../database/DataSource.xml"/>
    <import resource="../database/Hibernate.xml"/>

    <!-- Auto scan the components -->
    <context:component-scan
        base-package="com.project.pr." />

</beans>

数据源.xml:

<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">

<bean
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="location">
        <value>properties/database.properties</value>
    </property>
</bean>

<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource" destroy-method="close">
    <property name="driverClassName" value="${jdbc.driverClassName}" />
    <property name="url" value="${jdbc.url}" />
    <property name="username" value="${jdbc.username}" />
    <property name="password" value="${jdbc.password}" />
</bean>

</beans>

hibernate .xml:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">

<!-- Hibernate session factory -->
<bean id="sessionFactory"
class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">

    <property name="dataSource">
      <ref bean="dataSource"/>
    </property>

    <property name="hibernateProperties">
       <props>
         <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
         <prop key="hibernate.show_sql">true</prop>
       </props>
    </property>

    <property name="annotatedClasses">
    <list>
        <value>com.project.pr.entity.User</value>
    </list>
    </property>

    </bean>
</beans>

pom.xml:

<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/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.project</groupId>
  <artifactId>PROJECT</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>PROJECT Maven Webapp</name>
  <url>http://maven.apache.org</url>
      <properties>
        <java-version>1.8</java-version>
        <org.springframework-version>4.3.0.RELEASE</org.springframework-version>
        <jackson.version>2.7.5</jackson.version>
        <jaxb-api.version>2.2.11</jaxb-api.version>
        <hibernate.version>4.3.11.Final</hibernate.version>
        <slf4j.version>1.7.21</slf4j.version>       
      </properties>    

      <repositories>
        <repository>
          <id>JBoss repository</id>
          <url>http://repository.jboss.com/maven2/</url>
        </repository>
      </repositories>   

  <dependencies>

        <dependency>
          <groupId>junit</groupId>
          <artifactId>junit</artifactId>
          <version>3.8.1</version>
          <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${org.springframework-version}</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>  

        <!-- Dependency untuk mysql --> 

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.9</version>
        </dependency>   

        <!-- Hibernate framework -->
        <dependency>
            <groupId>hibernate</groupId>
            <artifactId>hibernate3</artifactId>
            <version>3.2.3.GA</version>
        </dependency>

        <!-- Hibernate annotation -->
        <dependency>
            <groupId>hibernate-annotations</groupId>
            <artifactId>hibernate-annotations</artifactId>
            <version>3.3.0.GA</version>
        </dependency>

        <dependency>
            <groupId>hibernate-commons-annotations</groupId>
            <artifactId>hibernate-commons-annotations</artifactId>
            <version>3.0.0.GA</version>
        </dependency>

        <!-- Hibernate library dependecy start -->
        <dependency>
            <groupId>dom4j</groupId>
            <artifactId>dom4j</artifactId>
            <version>1.6.1</version>
        </dependency>

        <dependency>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging</artifactId>
            <version>1.1.1</version>
        </dependency>

        <dependency>
            <groupId>commons-collections</groupId>
            <artifactId>commons-collections</artifactId>
            <version>3.2.1</version>
        </dependency>

        <dependency>
            <groupId>antlr</groupId>
            <artifactId>antlr</artifactId>
            <version>2.7.7</version>
        </dependency>
        <!-- Hibernate library dependecy end -->        

        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>${hibernate.version}</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-validator</artifactId>
            <version>5.2.4.Final</version>
        </dependency>       

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-simple</artifactId>
            <version>${slf4j.version}</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>${slf4j.version}</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>jul-to-slf4j</artifactId>
            <version>${slf4j.version}</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>${slf4j.version}</version>
        </dependency>       

  </dependencies>
  <build>
    <finalName>PROJECT</finalName>
        <pluginManagement>
            <plugins>
                <plugin>
                    <groupId>org.apache.tomcat.maven</groupId>
                    <artifactId>tomcat7-maven-plugin</artifactId>
                    <version>2.2</version>
                    <configuration>
                        <path>/PROJECT</path>
                    </configuration>
                </plugin>
            </plugins>
        </pluginManagement>    
  </build>
</project>
<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/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.project</groupId>
  <artifactId>PROJECT</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>PROJECT Maven Webapp</name>
  <url>http://maven.apache.org</url>
      <properties>
        <java-version>1.8</java-version>
        <org.springframework-version>4.3.0.RELEASE</org.springframework-version>
        <jackson.version>2.7.5</jackson.version>
        <jaxb-api.version>2.2.11</jaxb-api.version>
        <hibernate.version>4.3.11.Final</hibernate.version>
        <slf4j.version>1.7.21</slf4j.version>       
      </properties>    

      <repositories>
        <repository>
          <id>JBoss repository</id>
          <url>http://repository.jboss.com/maven2/</url>
        </repository>
      </repositories>   

  <dependencies>

        <dependency>
          <groupId>junit</groupId>
          <artifactId>junit</artifactId>
          <version>3.8.1</version>
          <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${org.springframework-version}</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>  

        <!-- Dependency untuk mysql --> 

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.9</version>
        </dependency>   

        <!-- Hibernate framework -->
        <dependency>
            <groupId>hibernate</groupId>
            <artifactId>hibernate3</artifactId>
            <version>3.2.3.GA</version>
        </dependency>

        <!-- Hibernate annotation -->
        <dependency>
            <groupId>hibernate-annotations</groupId>
            <artifactId>hibernate-annotations</artifactId>
            <version>3.3.0.GA</version>
        </dependency>

        <dependency>
            <groupId>hibernate-commons-annotations</groupId>
            <artifactId>hibernate-commons-annotations</artifactId>
            <version>3.0.0.GA</version>
        </dependency>

        <!-- Hibernate library dependecy start -->
        <dependency>
            <groupId>dom4j</groupId>
            <artifactId>dom4j</artifactId>
            <version>1.6.1</version>
        </dependency>

        <dependency>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging</artifactId>
            <version>1.1.1</version>
        </dependency>

        <dependency>
            <groupId>commons-collections</groupId>
            <artifactId>commons-collections</artifactId>
            <version>3.2.1</version>
        </dependency>

        <dependency>
            <groupId>antlr</groupId>
            <artifactId>antlr</artifactId>
            <version>2.7.7</version>
        </dependency>
        <!-- Hibernate library dependecy end -->        

        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>${hibernate.version}</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-validator</artifactId>
            <version>5.2.4.Final</version>
        </dependency>       

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-simple</artifactId>
            <version>${slf4j.version}</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>${slf4j.version}</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>jul-to-slf4j</artifactId>
            <version>${slf4j.version}</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>${slf4j.version}</version>
        </dependency>       

  </dependencies>
  <build>
    <finalName>PROJECT</finalName>
        <pluginManagement>
            <plugins>
                <plugin>
                    <groupId>org.apache.tomcat.maven</groupId>
                    <artifactId>tomcat7-maven-plugin</artifactId>
                    <version>2.2</version>
                    <configuration>
                        <path>/PROJECT</path>
                    </configuration>
                </plugin>
            </plugins>
        </pluginManagement>    
  </build>
</project>

数据库.属性:

jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/myschema
jdbc.username=root
jdbc.password=

错误日志:

Feb 09, 2017 1:00:59 AM org.apache.catalina.core.StandardContext listenerStart
SEVERE: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'projectController': Unsatisfied dependency expressed through field 'projectService': Error creating bean with name 'projectService': Unsatisfied dependency expressed through field 'sessionFactory': No qualifying bean of type [org.hibernate.SessionFactory] found for dependency [org.hibernate.SessionFactory]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.hibernate.SessionFactory] found for dependency [org.hibernate.SessionFactory]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'projectService': Unsatisfied dependency expressed through field 'sessionFactory': No qualifying bean of type [org.hibernate.SessionFactory] found for dependency [org.hibernate.SessionFactory]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.hibernate.SessionFactory] found for dependency [org.hibernate.SessionFactory]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:573)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:350)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1214)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:775)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:861)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:541)
    at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:444)
    at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:326)
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:107)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4937)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5434)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'projectService': Unsatisfied dependency expressed through field 'sessionFactory': No qualifying bean of type [org.hibernate.SessionFactory] found for dependency [org.hibernate.SessionFactory]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.hibernate.SessionFactory] found for dependency [org.hibernate.SessionFactory]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:573)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:350)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1214)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:187)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1208)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1048)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1018)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:570)
    ... 24 more
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.hibernate.SessionFactory] found for dependency [org.hibernate.SessionFactory]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1398)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1051)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1018)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:570)
    ... 38 more

Feb 09, 2017 1:00:59 AM org.apache.catalina.core.StandardContext startInternal
SEVERE: Error listenerStart
Feb 09, 2017 1:00:59 AM org.apache.catalina.core.StandardContext startInternal
SEVERE: Context [/PROJECT] startup failed due to previous errors
Feb 09, 2017 1:00:59 AM org.apache.catalina.core.ApplicationContext log
INFO: Closing Spring root WebApplicationContext
Feb 09, 2017 1:00:59 AM org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc
SEVERE: The web application [/PROJECT] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
Feb 09, 2017 1:00:59 AM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-bio-8080"]

我想从用户表中获取数据 json 但失败了。我按照这个指令配置:https://www.mkyong.com/spring/maven-spring-hibernate-annotation-mysql-example/

如何解决这个问题？

谢谢。鲍比

最佳答案

我认为您需要创建一个 Factory 类来创建您的 SessionFactory 对象。如本 answer 中所述.

关于java - 数据库连接mysql和Spring框架，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/42120504/

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我不知道为什么每次有人访问我网站上的页面时，都会打开一个与数据库的新连接。最终我到达了大约 300 并收到错误并且页面不再加载。我认为它应该工作的方式是，我将 maxIdle 设置为 30，这意味着
python - 使用 Python 3 连接/连接 txt 文件中的行
希望清理 NMEA GPS 中的 .txt 文件。我当前的代码如下。 deletes = ['$GPGGA', '$GPGSA', '$GPGSV', '$PSRF156', ] searchquer
c# - 通过 C#.Net 创建/连接 VPN 连接
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c++ - 将字符串 vector 连接(连接)到字符缓冲区，零字节作为分隔符/终止符
有没有更好的方法将字符串 vector 转换为字符 vector ，字符串之间的终止符为零。因此，如果我有一个包含以下字符串的 vector "test","my","string"，那么我想接收一
android - 在 Android Instrumented 测试中模拟无 Internet 连接/慢速 Internet 连接
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Mysql 数据库无法使用 "loclhost"连接，但可以使用 "127.0.0.1"Centos 7 (Cloudlinux) 连接
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ruby-on-rails - 无法打开到本地主机的 TCP 连接:9200(连接被拒绝 - 连接(2)用于 "localhost"端口 9200)(Faraday::ConnectionFailed)
我收到错误:Puma 发现此错误:无法打开到本地主机的 TCP 连接:9200(连接被拒绝 - 连接(2)用于“本地主机”端口 9200)(Faraday::ConnectionFailed)在我的
ruby-on-rails - ActionView::Template::Error(无法打开到本地主机的 TCP 连接:9292(连接被拒绝 - 连接(2)用于 "localhost"端口 9292))
请给我一些解决以下错误的方法。这是一个聊天应用....代码和错误如下:: conversations_controller.rb def create if Conversation.bet
Excel 连接
我想将两个单元格中的数据连接到一个单元格中。我还想只组合那些具有相同 ID 的单元格。任务 ID 名称 4355.2 参与者 4355.2 领袖 4462.1 在线 4462.1 快速 4597.1
TSQL 连接
我经常需要连接 TSQL 中的字段... 使用“+”运算符时 TSQL 强制您处理的两个问题是 Data Type Precedence和 NULL 值。使用数据类型优先级，问题是转换错误。 1)
Facebook 连接
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连接/打印字符串文字
我在连接或打印字符串时遇到了一个奇怪的问题。我有一个 char * ，可以将其设置为字符串文字的几个值之一。 char *myStrLiteral = NULL; ... if(blah) myS
Xquery 连接
对于以下数据 - let $x := "Yahooooo !!!! Select one number - " let $y := 1 2 3 4 5 6 7 我想得到
Perl 连接
我正在看 UDEMY for perl 的培训视频，但是视频不清晰，看起来有错误。培训展示了如何使用以下示例连接 2 个字符串: #!usr/bin/perl print $str = "Hi";

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java - 数据库连接mysql和Spring框架