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该问题已被官方收录

连接池连不上数据库

0

1

数据库

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

class="cursor-pointer"> 源码

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;

import javax.sql.DataSource;

import org.apache.commons.dbcp2.BasicDataSourceFactory;

/**
* DBCP配置类
* @author SUN
*/
public class KCYDBCPUtil {

private static Properties properties = new Properties();
   private static DataSource dataSource;
   //加载DBCP配置文件
   static{
try{
            InputStream fis = new FileInputStream("config/dbcp.properties");
           properties.load(fis);
       }catch(IOException e){
System.out.println("出错啦啦啦啦啦");
           e.printStackTrace();
       }

try{
dataSource = BasicDataSourceFactory.createDataSource(properties);
       }catch(Exception e){
e.printStackTrace();
       }
}

//从连接池中获取一个连接
   public static Connection getConnection(){
Connection connection = null;
       try {
connection = dataSource.getConnection();
           connection.setAutoCommit(false);
       } catch (SQLException e) {
e.printStackTrace();
       }
return connection;
   }

public static void main(String[] args) {
getConnection();
   }
}

该问题已被官方收录

多个tomcat异常

0

1

Nginx

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

class="cursor-pointer"> 源码

<?xml version="1.0" encoding="UTF-8"?>
<!--
  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 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.
-->
<!-- Note:  A "Server" is not itself a "Container", so you may not
     define subcomponents such as "Valves" at this level.
     Documentation at /docs/config/server.html
 -->
<Server port="8005" shutdown="SHUTDOWN">
  <Listener className="org.apache.catalina.startup.VersionLoggerListener" />
  <!-- Security listener. Documentation at /docs/config/listeners.html
  <Listener className="org.apache.catalina.security.SecurityListener" />
  -->
  <!--APR library loader. Documentation at /docs/apr.html -->
  <Listener className="org.apache.catalina.core.AprLifecycleListener" SSLEngine="on" />
  <!-- Prevent memory leaks due to use of particular java/javax APIs-->
  <Listener className="org.apache.catalina.core.JreMemoryLeakPreventionListener" />
  <Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener" />
  <Listener className="org.apache.catalina.core.ThreadLocalLeakPreventionListener" />

  <!-- Global JNDI resources
       Documentation at /docs/jndi-resources-howto.html
  -->
  <GlobalNamingResources>
    <!-- Editable user database that can also be used by
         UserDatabaseRealm to authenticate users
    -->
    <Resource name="UserDatabase" auth="Container"
              type="org.apache.catalina.UserDatabase"
              description="User database that can be updated and saved"
              factory="org.apache.catalina.users.MemoryUserDatabaseFactory"
              pathname="conf/tomcat-users.xml" />
  </GlobalNamingResources>

  <!-- A "Service" is a collection of one or more "Connectors" that share
       a single "Container" Note:  A "Service" is not itself a "Container",
       so you may not define subcomponents such as "Valves" at this level.
       Documentation at /docs/config/service.html
   -->
  <Service name="Catalina">

    <!--The connectors can use a shared executor, you can define one or more named thread pools-->
    <!--
    <Executor name="tomcatThreadPool" namePrefix="catalina-exec-"
        maxThreads="150" minSpareThreads="4"/>
    -->


    <!-- A "Connector" represents an endpoint by which requests are received
         and responses are returned. Documentation at :
         Java HTTP Connector: /docs/config/http.html
         Java AJP  Connector: /docs/config/ajp.html
         APR (HTTP/AJP) Connector: /docs/apr.html
         Define a non-SSL/TLS HTTP/1.1 Connector on port 8080
    -->
    <Connector port="8080" protocol="HTTP/1.1"
               connectionTimeout="20000"
               redirectPort="8443" />
    <!-- A "Connector" using the shared thread pool-->
    <!--
    <Connector executor="tomcatThreadPool"
               port="8080" protocol="HTTP/1.1"
               connectionTimeout="20000"
               redirectPort="8443" />
    -->
    <!-- Define a SSL/TLS HTTP/1.1 Connector on port 8443
         This connector uses the NIO implementation. The default
         SSLImplementation will depend on the presence of the APR/native
         library and the useOpenSSL attribute of the
         AprLifecycleListener.
         Either JSSE or OpenSSL style configuration may be used regardless of
         the SSLImplementation selected. JSSE style configuration is used below.
    -->
    <!--
    <Connector port="8443" protocol="org.apache.coyote.http11.Http11NioProtocol"
               maxThreads="150" SSLEnabled="true">
        <SSLHostConfig>
            <Certificate certificateKeystoreFile="conf/localhost-rsa.jks"
                         type="RSA" />
        </SSLHostConfig>
    </Connector>
    -->
    <!-- Define a SSL/TLS HTTP/1.1 Connector on port 8443 with HTTP/2
         This connector uses the APR/native implementation which always uses
         OpenSSL for TLS.
         Either JSSE or OpenSSL style configuration may be used. OpenSSL style
         configuration is used below.
    -->
    <!--
    <Connector port="8443" protocol="org.apache.coyote.http11.Http11AprProtocol"
               maxThreads="150" SSLEnabled="true" >
        <UpgradeProtocol className="org.apache.coyote.http2.Http2Protocol" />
        <SSLHostConfig>
            <Certificate certificateKeyFile="conf/localhost-rsa-key.pem"
                         certificateFile="conf/localhost-rsa-cert.pem"
                         certificateChainFile="conf/localhost-rsa-chain.pem"
                         type="RSA" />
        </SSLHostConfig>
    </Connector>
    -->

    <!-- Define an AJP 1.3 Connector on port 8009 -->
    <Connector port="8009" protocol="AJP/1.3" redirectPort="8443" />


    <!-- An Engine represents the entry point (within Catalina) that processes
         every request.  The Engine implementation for Tomcat stand alone
         analyzes the HTTP headers included with the request, and passes them
         on to the appropriate Host (virtual host).
         Documentation at /docs/config/engine.html -->

    <!-- You should set jvmRoute to support load-balancing via AJP ie :
    <Engine name="Catalina" defaultHost="localhost" jvmRoute="jvm1">
    -->
    <Engine name="Catalina" defaultHost="localhost">

      <!--For clustering, please take a look at documentation at:
          /docs/cluster-howto.html  (simple how to)
          /docs/config/cluster.html (reference documentation) -->
      <!--
      <Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"/>
      -->

      <!-- Use the LockOutRealm to prevent attempts to guess user passwords
           via a brute-force attack -->
      <Realm className="org.apache.catalina.realm.LockOutRealm">
        <!-- This Realm uses the UserDatabase configured in the global JNDI
             resources under the key "UserDatabase".  Any edits
             that are performed against this UserDatabase are immediately
             available for use by the Realm.  -->
        <Realm className="org.apache.catalina.realm.UserDatabaseRealm"
               resourceName="UserDatabase"/>
      </Realm>

      <Host name="localhost"  appBase="webapps"
            unpackWARs="true" autoDeploy="true">

        <!-- SingleSignOn valve, share authentication between web applications
             Documentation at: /docs/config/valve.html -->
        <!--
        <Valve className="org.apache.catalina.authenticator.SingleSignOn" />
        -->
<Context path="" docBase="/java/webapp/test" debug="0" privileged="true"></Context>

        <!-- Access log processes all example.
             Documentation at: /docs/config/valve.html
             Note: The pattern used is equivalent to using pattern="common" -->
        <Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs"
               prefix="localhost_access_log" suffix=".txt"
               pattern="%h %l %u %t "%r" %s %b" />

      </Host>
    </Engine>
  </Service>
</Server>

2018/11/17 07:15:17 [error] 24325#0: *249 connect() failed (111: Connection refused) while connecting to upstream, client: 183.13.190.48, server: localhost, request: "GET / HTTP/1.1", upstream: "http://193.112.131.157:8080/", host: "193.112.131.157", referrer: "http://193.112.131.157/position"
2018/11/17 07:18:22 [error] 24325#0: *282 connect() failed (111: Connection refused) while connecting to upstream, client: 183.13.190.48, server: localhost, request: "GET / HTTP/1.1", upstream: "http://193.112.131.157:8081/", host: "193.112.131.157", referrer: "http://193.112.131.157/position"
2018/11/17 07:19:56 [error] 24325#0: *300 connect() failed (111: Connection refused) while connecting to upstream, client: 183.13.190.48, server: localhost, request: "GET / HTTP/1.1", upstream: "http://193.112.131.157:8081/", host: "193.112.131.157", referrer: "http://193.112.131.157/position"
2018/11/17 07:19:56 [error] 24325#0: *300 connect() failed (111: Connection refused) while connecting to upstream, client: 183.13.190.48, server: localhost, request: "GET / HTTP/1.1", upstream: "http://193.112.131.157:8080/", host: "193.112.131.157", referrer: "http://193.112.131.157/position"
2018/11/17 07:19:57 [error] 24325#0: *300 no live upstreams while connecting to upstream, client: 183.13.190.48, server: localhost, request: "GET / HTTP/1.1", upstream: "http://hello/", host: "193.112.131.157", referrer: "http://193.112.131.157/position"
2018/11/17 07:19:57 [error] 24325#0: *300 no live upstreams while connecting to upstream, client: 183.13.190.48, server: localhost, request: "GET / HTTP/1.1", upstream: "http://hello/", host: "193.112.131.157", referrer: "http://193.112.131.157/position"
2018/11/17 07:19:58 [error] 24325#0: *300 no live upstreams while connecting to upstream, client: 183.13.190.48, server: localhost, request: "GET / HTTP/1.1", upstream: "http://hello/", host: "193.112.131.157", referrer: "http://193.112.131.157/position"
2018/11/17 07:19:59 [error] 24325#0: *300 no live upstreams while connecting to upstream, client: 183.13.190.48, server: localhost, request: "GET / HTTP/1.1", upstream: "http://hello/", host: "193.112.131.157", referrer: "http://193.112.131.157/position"
2018/11/17 07:19:59 [error] 24325#0: *300 no live upstreams while connecting to upstream, client: 183.13.190.48, server: localhost, request: "GET / HTTP/1.1", upstream: "http://hello/", host: "193.112.131.157", referrer: "http://193.112.131.157/position"
2018/11/17 07:20:00 [error] 24325#0: *300 no live upstreams while connecting to upstream, client: 183.13.190.48, server: localhost, request: "GET / HTTP/1.1", upstream: "http://hello/", host: "193.112.131.157", referrer: "http://193.112.131.157/position"
2018/11/17 07:20:01 [error] 24325#0: *300 no live upstreams while connecting to upstream, client: 183.13.190.48, server: localhost, request: "GET / HTTP/1.1", upstream: "http://hello/", host: "193.112.131.157", referrer: "http://193.112.131.157/position"
2018/11/17 07:20:01 [error] 24325#0: *300 no live upstreams while connecting to upstream, client: 183.13.190.48, server: localhost, request: "GET / HTTP/1.1", upstream: "http://hello/", host: "193.112.131.157", referrer: "http://193.112.131.157/position"
2018/11/17 07:20:02 [error] 24325#0: *300 no live upstreams while connecting to upstream, client: 183.13.190.48, server: localhost, request: "GET / HTTP/1.1", upstream: "http://hello/", host: "193.112.131.157", referrer: "http://193.112.131.157/position"
2018/11/17 07:27:38 [notice] 12226#0: signal process started
2018/11/17 07:29:25 [notice] 14710#0: signal process started
2018/11/17 07:30:38 [error] 14711#0: *409 connect() failed (111: Connection refused) while connecting to upstream, client: 183.13.190.48, server: localhost, request: "GET /views/imges/789678978.png HTTP/1.1", upstream: "http://193.112.131.157:8080/views/imges/789678978.png", host: "193.112.131.157", referrer: "http://193.112.131.157/views/Untitled-3.css"
2018/11/17 07:31:08 [error] 14711#0: *409 connect() failed (111: Connection refused) while connecting to upstream, client: 183.13.190.48, server: localhost, request: "GET / HTTP/1.1", upstream: "http://193.112.131.157:8081/", host: "193.112.131.157", referrer: "http://193.112.131.157/position"
2018/11/17 07:31:08 [error] 14711#0: *409 connect() failed (111: Connection refused) while connecting to upstream, client: 183.13.190.48, server: localhost, request: "GET / HTTP/1.1", upstream: "http://193.112.131.157:8080/", host: "193.112.131.157", referrer: "http://193.112.131.157/position"
2018/11/17 07:31:09 [error] 14711#0: *409 no live upstreams while connecting to upstream, client: 183.13.190.48, server: localhost, request: "GET / HTTP/1.1", upstream: "http://hello/", host: "193.112.131.157", referrer: "http://193.112.131.157/position"
2018/11/17 07:31:09 [error] 14711#0: *409 no live upstreams while connecting to upstream, client: 183.13.190.48, server: localhost, request: "GET / HTTP/1.1", upstream: "http://hello/", host: "193.112.131.157", referrer: "http://193.112.131.157/position"

该问题已被官方收录

关于前台传来的VO对象，和我们给前台发送的对象，有没有什么最佳实践

0

1

接口文档

class="cursor-pointer"> 详细描述

该问题已被官方收录

springcloud加载不到配置中心的文件

0

1

mybatis

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

该问题已被官方收录

rest风格post方法页面报错不支持get方法

0

1

rest

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

该问题已被官方收录

用./shutdown.sh关闭rmi服务器的tomcat,然后启动客户端的错误

0

1

springRMI

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

java.rmi.ConnectException: Connection refused to host:127.0.0.1; nested exception is:
        java.net.ConnectException: Connection refused: connect
        at sun.rmi.transport.tcp.TCPEndpoint.newSocket(Unknown Source)
        at sun.rmi.transport.tcp.TCPChannel.createConnection(Unknown Source)
        at sun.rmi.transport.tcp.TCPChannel.newConnection(Unknown Source)
        at sun.rmi.server.UnicastRef.invoke(Unknown Source)
        at java.rmi.server.RemoteObjectInvocationHandler.invokeRemoteMethod
        (Unknown Source)
        at java.rmi.server.RemoteObjectInvocationHandler.invoke(Unknown Source)
        at $Proxy0.call(Unknown Source)
        at RMI.Client.callRMI(Client.java:39)
        at RMI.Client.main(Client.java:53)
        Caused by: java.net.ConnectException: Connection refused: connect
        at java.net.PlainSocketImpl.socketConnect(Native Method)
        at java.net.PlainSocketImpl.doConnect(Unknown Source)
        at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
        at java.net.PlainSocketImpl.connect(Unknown Source)
        at java.net.SocksSocketImpl.connect(Unknown Source)
        at java.net.Socket.connect(Unknown Source)
        at java.net.Socket.connect(Unknown Source)
        at java.net.Socket.<init>(Unknown Source)
        at java.net.Socket.<init>(Unknown Source)
        at sun.rmi.transport.proxy.RMIDirectSocketFactory.createSocket
        (Unknown Source)
        at sun.rmi.transport.proxy.RMIMasterSocketFactory.createSocket
        (Unknown Source)
        ... 9 more

该问题已被官方收录

mybatis在连接数据库中运行项目时找不到项目文件。

0

1

spring

class="cursor-pointer"> 详细描述

log4j:WARN No appenders could be found for logger (org.apache.ibatis.logging.LogFactory).

log4j:WARN Please initialize the log4j system properly.

log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.

Exception in thread "main" org.apache.ibatis.exceptions.PersistenceException:

### Error building SqlSession.

### The error may exist in SQL Mapper Configuration

### Cause: org.apache.ibatis.builder.BuilderException: Error parsing SQL Mapper Configuration. Cause: java.io.IOException: Could not find resource jdbc.properties

at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30)

at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:80)

at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:64)

at Test.main(Test.java:18)

Caused by: org.apache.ibatis.builder.BuilderException: Error parsing SQL Mapper Configuration. Cause: java.io.IOException: Could not find resource jdbc.properties

at org.apache.ibatis.builder.xml.XMLConfigBuilder.parseConfiguration(XMLConfigBuilder.java:121)

at org.apache.ibatis.builder.xml.XMLConfigBuilder.parse(XMLConfigBuilder.java:99)

at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:78)

... 2 more

Caused by: java.io.IOException: Could not find resource jdbc.properties

at org.apache.ibatis.io.Resources.getResourceAsStream(Resources.java:114)

at org.apache.ibatis.io.Resources.getResourceAsStream(Resources.java:100)

at org.apache.ibatis.io.Resources.getResourceAsProperties(Resources.java:128)

at org.apache.ibatis.builder.xml.XMLConfigBuilder.propertiesElement(XMLConfigBuilder.java:225)

at org.apache.ibatis.builder.xml.XMLConfigBuilder.parseConfiguration(XMLConfigBuilder.java:106)

... 4 more

Process finished with exit code 1

class="cursor-pointer"> 错误截图

该问题已被官方收录

FileInputStream读取文件显示不存在

0

1

JDBC

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

该问题已被官方收录

jdbc连接数据库的驱动版本和jdk的版本，以及mysql的版本有什么关联？

0

1

maven

class="cursor-pointer"> 详细描述

该问题已被官方收录

启动Spring Boot时，，抛出异常信息如下：

0

1

springboot

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 源码

import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Configuration;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.boot.SpringApplication;
@Controller
@SpringBootApplication
@Configuration
public class HelloApplication {
    @RequestMapping("hello")
    @ResponseBody
    public String hello() {
        return "hello world！";
    }
    public static void main(String[] args) {
        SpringApplication.run(HelloApplication.class, args);
    }
}