我在本地主机上创建了我的第一个 restapi。
这是我的代码:
package RestClient;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
@Path("/RestClient")
public class Restwebclient {
@GET
@Produces(MediaType.TEXT_XML)
public String sayXMLHello() {
return "<?xml version=\"1.0\"?>" + "<hello> Hello Its my first Rest API" + "</hello>";
}
}
Web.xml文件
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1">
<display-name>Webservice</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>JAVA WS</servlet-name>
<servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
<init-param>
<param-name>jersey.config.server.provider.packages</param-name>
<param-value>RestClient</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>JAVA WS</servlet-name>
<url-pattern>*</url-pattern>
</servlet-mapping>
</web-app>
Tomcat 服务器端口:
Tomcat admin port: 8005
HTTP/1.1: 8080
AJP/1.3: 8009
当我运行这个时，我得到这样的错误
Several ports (8005, 8080, 8009) required by Tomcat v8.5 Server at localhost are already in use. The server may already be running in another process, or a system process may be using the port. To start this server you will need to stop the other process or change the port number(s).
然后我创建了新端口，
Tomcat admin port: 8002
HTTP/1.1: 8001
AJP/1.3: 8003
出现这样的错误:
Server Tomcat v8.5 Server at localhost failed to start.
用 Google 搜索，然后发现我在 eclipse 中提到的任何端口都应该存在于 httpd 配置文件中。但这不存在于 Apache 安装文件夹中。
我发现了更多信息，有一个名为 server.xml 的文件，我们可以在其中更改端口。但是无论如何我都无法保存更改后的文件。
谁能告诉我发生了什么事？
日志信息:localhost_access_log.2017-09-09.log
0:0:0:0:0:0:0:1 - - [09/Sep/2017:18:52:48 +0530] "GET / HTTP/1.1" 200 11452
0:0:0:0:0:0:0:1 - - [09/Sep/2017:18:52:48 +0530] "GET /tomcat.png HTTP/1.1" 200 5103
0:0:0:0:0:0:0:1 - - [09/Sep/2017:18:52:48 +0530] "GET /tomcat.css HTTP/1.1" 200 5931
0:0:0:0:0:0:0:1 - - [09/Sep/2017:18:52:48 +0530] "GET /bg-nav.png HTTP/1.1" 200 1401
0:0:0:0:0:0:0:1 - - [09/Sep/2017:18:52:48 +0530] "GET /bg-middle.png HTTP/1.1" 200 1918
0:0:0:0:0:0:0:1 - - [09/Sep/2017:18:52:48 +0530] "GET /bg-upper.png HTTP/1.1" 200 3103
0:0:0:0:0:0:0:1 - - [09/Sep/2017:18:52:48 +0530] "GET /asf-logo-wide.svg HTTP/1.1" 200 26726
0:0:0:0:0:0:0:1 - - [09/Sep/2017:18:52:48 +0530] "GET /bg-button.png HTTP/1.1" 200 713
0:0:0:0:0:0:0:1 - - [09/Sep/2017:18:52:48 +0530] "GET /favicon.ico HTTP/1.1" 200 21630
0:0:0:0:0:0:0:1 - - [09/Sep/2017:18:58:15 +0530] "GET / HTTP/1.1" 200 11452
0:0:0:0:0:0:0:1 - - [09/Sep/2017:18:58:17 +0530] "GET /manager/status HTTP/1.1" 401 2536
0:0:0:0:0:0:0:1 - - [09/Sep/2017:18:58:24 +0530] "GET /manager/status HTTP/1.1" 401 2536
0:0:0:0:0:0:0:1 - - [09/Sep/2017:18:58:25 +0530] "GET /manager/status HTTP/1.1" 401 2536
0:0:0:0:0:0:0:1 - - [09/Sep/2017:19:47:46 +0530] "GET / HTTP/1.1" 200 11452
0:0:0:0:0:0:0:1 - - [09/Sep/2017:19:48:17 +0530] "GET / HTTP/1.1" 200 11452
0:0:0:0:0:0:0:1 - - [09/Sep/2017:20:01:45 +0530] "GET / HTTP/1.1" 200 11452
0:0:0:0:0:0:0:1 - - [09/Sep/2017:20:01:46 +0530] "GET / HTTP/1.1" 200 11452
0:0:0:0:0:0:0:1 - - [09/Sep/2017:20:03:03 +0530] "GET / HTTP/1.1" 200 11452
0:0:0:0:0:0:0:1 - - [09/Sep/2017:20:03:25 +0530] "GET /manager/status HTTP/1.1" 401 2536
0:0:0:0:0:0:0:1 - - [09/Sep/2017:21:32:26 +0530] "GET / HTTP/1.1" 200 11452
0:0:0:0:0:0:0:1 - - [09/Sep/2017:21:42:20 +0530] "GET / HTTP/1.1" 200 11452
0:0:0:0:0:0:0:1 - - [09/Sep/2017:21:42:23 +0530] "GET /manager/status HTTP/1.1" 401 2536
0:0:0:0:0:0:0:1 - - [09/Sep/2017:21:47:00 +0530] "GET / HTTP/1.1" 200 11452
0:0:0:0:0:0:0:1 - - [09/Sep/2017:21:47:01 +0530] "GET / HTTP/1.1" 200 11452
0:0:0:0:0:0:0:1 - - [09/Sep/2017:21:47:01 +0530] "GET / HTTP/1.1" 200 11452
0:0:0:0:0:0:0:1 - - [09/Sep/2017:21:47:01 +0530] "GET / HTTP/1.1" 200 11452
0:0:0:0:0:0:0:1 - - [09/Sep/2017:21:47:02 +0530] "GET / HTTP/1.1" 200 11452
0:0:0:0:0:0:0:1 - - [09/Sep/2017:21:47:02 +0530] "GET / HTTP/1.1" 200 11452
0:0:0:0:0:0:0:1 - - [09/Sep/2017:21:47:02 +0530] "GET / HTTP/1.1" 200 11452
0:0:0:0:0:0:0:1 - - [09/Sep/2017:21:47:02 +0530] "GET / HTTP/1.1" 200 11452
0:0:0:0:0:0:0:1 - - [09/Sep/2017:21:47:03 +0530] "GET / HTTP/1.1" 200 11452
catalina.2.017-09-09.log
09-Sep-2017 14:13:05.928 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Server version: Apache Tomcat/8.5.20
09-Sep-2017 14:13:05.930 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Server built: Aug 2 2017 21:35:49 UTC
09-Sep-2017 14:13:05.930 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Server number: 8.5.20.0
09-Sep-2017 14:13:05.930 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log OS Name: Windows 7
09-Sep-2017 14:13:05.930 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log OS Version: 6.1
09-Sep-2017 14:13:05.931 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Architecture: amd64
09-Sep-2017 14:13:05.931 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Java Home: C:\Program Files\Java\jre1.8.0_73
09-Sep-2017 14:13:05.931 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log JVM Version: 1.8.0_73-b02
09-Sep-2017 14:13:05.931 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log JVM Vendor: Oracle Corporation
09-Sep-2017 14:13:05.931 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log CATALINA_BASE: C:\Program Files\Apache Software Foundation\Tomcat 8.5
09-Sep-2017 14:13:05.931 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log CATALINA_HOME: C:\Program Files\Apache Software Foundation\Tomcat 8.5
09-Sep-2017 14:13:05.931 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcatalina.home=C:\Program Files\Apache Software Foundation\Tomcat 8.5
09-Sep-2017 14:13:05.931 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcatalina.base=C:\Program Files\Apache Software Foundation\Tomcat 8.5
09-Sep-2017 14:13:05.931 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.io.tmpdir=C:\Program Files\Apache Software Foundation\Tomcat 8.5\temp
09-Sep-2017 14:13:05.932 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager
09-Sep-2017 14:13:05.932 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.util.logging.config.file=C:\Program Files\Apache Software Foundation\Tomcat 8.5\conf\logging.properties
09-Sep-2017 14:13:05.932 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: exit
09-Sep-2017 14:13:05.932 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Xms128m
09-Sep-2017 14:13:05.933 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Xmx256m
09-Sep-2017 14:13:05.933 INFO [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [C:\Program Files\Apache Software Foundation\Tomcat 8.5\bin;C:\Windows\Sun\Java\bin;C:\Windows\system32;C:\Windows;C:\ProgramData\Oracle\Java\javapath;C:\Program Files (x86)\Intel\iCLS Client\;C:\Program Files\Intel\iCLS Client\;C:\Informatica\9.0.1\clients\tools\datadirect;C:\Informatica\9.0.1\clients\DeveloperClient\bin;C:\Informatica\9.0.1\tools\datadirect;C:\app\product\11.2.0\dbhome_1\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files (x86)\Intel\OpenCL SDK\2.0\bin\x86;C:\Program Files (x86)\Intel\OpenCL SDK\2.0\bin\x64;C:\Program Files\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files\Intel\WiFi\bin\;C:\Program Files\Common Files\Intel\WirelessCommon\;C:\Program Files\Java\jdk1.8.0_60\bin;C:\Program Files\mysql\bin;C:\Program Files\Java\jdk1.8.0_73\;C:\Python27;C:\Program Files (x86)\Skype\Phone\;;.]
09-Sep-2017 14:13:06.488 INFO [main] org.apache.coyote.AbstractProtocol.init Initializing ProtocolHandler ["http-nio-8080"]
09-Sep-2017 14:13:06.786 INFO [main] org.apache.tomcat.util.net.NioSelectorPool.getSharedSelector Using a shared selector for servlet write/read
09-Sep-2017 14:13:06.788 INFO [main] org.apache.coyote.AbstractProtocol.init Initializing ProtocolHandler ["ajp-nio-8009"]
09-Sep-2017 14:13:06.790 INFO [main] org.apache.tomcat.util.net.NioSelectorPool.getSharedSelector Using a shared selector for servlet write/read
09-Sep-2017 14:13:06.791 INFO [main] org.apache.catalina.startup.Catalina.load Initialization processed in 1623 ms
09-Sep-2017 14:13:06.873 INFO [main] org.apache.catalina.core.StandardService.startInternal Starting service [Catalina]
09-Sep-2017 14:13:06.874 INFO [main] org.apache.catalina.core.StandardEngine.startInternal Starting Servlet Engine: Apache Tomcat/8.5.20
09-Sep-2017 14:13:06.928 INFO [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Deploying web application directory [C:\Program Files\Apache Software Foundation\Tomcat 8.5\webapps\docs]
09-Sep-2017 14:13:07.545 WARNING [localhost-startStop-1] org.apache.catalina.util.SessionIdGeneratorBase.createSecureRandom Creation of SecureRandom instance for session ID generation using [SHA1PRNG] took [106] milliseconds.
09-Sep-2017 14:13:07.574 INFO [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Deployment of web application directory [C:\Program Files\Apache Software Foundation\Tomcat 8.5\webapps\docs] has finished in [646] ms
09-Sep-2017 14:13:07.575 INFO [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Deploying web application directory [C:\Program Files\Apache Software Foundation\Tomcat 8.5\webapps\manager]
09-Sep-2017 14:13:07.648 INFO [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Deployment of web application directory [C:\Program Files\Apache Software Foundation\Tomcat 8.5\webapps\manager] has finished in [73] ms
09-Sep-2017 14:13:07.648 INFO [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Deploying web application directory [C:\Program Files\Apache Software Foundation\Tomcat 8.5\webapps\ROOT]
09-Sep-2017 14:13:07.674 INFO [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Deployment of web application directory [C:\Program Files\Apache Software Foundation\Tomcat 8.5\webapps\ROOT] has finished in [26] ms
09-Sep-2017 14:13:07.678 INFO [main] org.apache.coyote.AbstractProtocol.start Starting ProtocolHandler ["http-nio-8080"]
09-Sep-2017 14:13:07.688 INFO [main] org.apache.coyote.AbstractProtocol.start Starting ProtocolHandler ["ajp-nio-8009"]
09-Sep-2017 14:13:07.691 INFO [main] org.apache.catalina.startup.Catalina.start Server startup in 900 ms
09-Sep-2017 20:11:14.438 INFO [Thread-6] org.apache.coyote.AbstractProtocol.pause Pausing ProtocolHandler ["http-nio-8080"]
09-Sep-2017 20:11:14.620 INFO [Thread-6] org.apache.coyote.AbstractProtocol.pause Pausing ProtocolHandler ["ajp-nio-8009"]
09-Sep-2017 20:11:14.797 INFO [Thread-6] org.apache.catalina.core.StandardService.stopInternal Stopping service [Catalina]
09-Sep-2017 20:11:14.869 INFO [Thread-6] org.apache.coyote.AbstractProtocol.stop Stopping ProtocolHandler ["http-nio-8080"]
09-Sep-2017 20:11:14.883 INFO [Thread-6] org.apache.coyote.AbstractProtocol.stop Stopping ProtocolHandler ["ajp-nio-8009"]
09-Sep-2017 21:32:21.436 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Server version: Apache Tomcat/8.5.20
09-Sep-2017 21:32:21.440 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Server built: Aug 2 2017 21:35:49 UTC
09-Sep-2017 21:32:21.440 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Server number: 8.5.20.0
09-Sep-2017 21:32:21.440 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log OS Name: Windows 7
09-Sep-2017 21:32:21.440 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log OS Version: 6.1
09-Sep-2017 21:32:21.440 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Architecture: amd64
09-Sep-2017 21:32:21.441 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Java Home: C:\Program Files\Java\jre1.8.0_73
09-Sep-2017 21:32:21.441 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log JVM Version: 1.8.0_73-b02
09-Sep-2017 21:32:21.441 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log JVM Vendor: Oracle Corporation
09-Sep-2017 21:32:21.441 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log CATALINA_BASE: C:\Program Files\Apache Software Foundation\Tomcat 8.5
09-Sep-2017 21:32:21.441 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log CATALINA_HOME: C:\Program Files\Apache Software Foundation\Tomcat 8.5
09-Sep-2017 21:32:21.441 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcatalina.home=C:\Program Files\Apache Software Foundation\Tomcat 8.5
09-Sep-2017 21:32:21.441 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcatalina.base=C:\Program Files\Apache Software Foundation\Tomcat 8.5
09-Sep-2017 21:32:21.442 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.io.tmpdir=C:\Program Files\Apache Software Foundation\Tomcat 8.5\temp
09-Sep-2017 21:32:21.442 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager
09-Sep-2017 21:32:21.442 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.util.logging.config.file=C:\Program Files\Apache Software Foundation\Tomcat 8.5\conf\logging.properties
09-Sep-2017 21:32:21.442 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: exit
09-Sep-2017 21:32:21.442 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Xms128m
09-Sep-2017 21:32:21.442 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Xmx256m
09-Sep-2017 21:32:21.443 INFO [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [C:\Program Files\Apache Software Foundation\Tomcat 8.5\bin;C:\Windows\Sun\Java\bin;C:\Windows\system32;C:\Windows;C:\ProgramData\Oracle\Java\javapath;C:\Program Files (x86)\Intel\iCLS Client\;C:\Program Files\Intel\iCLS Client\;C:\Informatica\9.0.1\clients\tools\datadirect;C:\Informatica\9.0.1\clients\DeveloperClient\bin;C:\Informatica\9.0.1\tools\datadirect;C:\app\product\11.2.0\dbhome_1\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files (x86)\Intel\OpenCL SDK\2.0\bin\x86;C:\Program Files (x86)\Intel\OpenCL SDK\2.0\bin\x64;C:\Program Files\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files\Intel\WiFi\bin\;C:\Program Files\Common Files\Intel\WirelessCommon\;C:\Program Files\Java\jdk1.8.0_60\bin;C:\Program Files\mysql\bin;C:\Program Files\Java\jdk1.8.0_73\;C:\Python27;C:\Program Files (x86)\Skype\Phone\;C:\Program Files\Apache Software Foundation\Tomcat 8.5\bin\bin;.]
09-Sep-2017 21:32:21.592 INFO [main] org.apache.coyote.AbstractProtocol.init Initializing ProtocolHandler ["http-nio-8080"]
09-Sep-2017 21:32:21.674 INFO [main] org.apache.tomcat.util.net.NioSelectorPool.getSharedSelector Using a shared selector for servlet write/read
09-Sep-2017 21:32:21.676 INFO [main] org.apache.coyote.AbstractProtocol.init Initializing ProtocolHandler ["ajp-nio-8009"]
09-Sep-2017 21:32:21.678 INFO [main] org.apache.tomcat.util.net.NioSelectorPool.getSharedSelector Using a shared selector for servlet write/read
09-Sep-2017 21:32:21.679 INFO [main] org.apache.catalina.startup.Catalina.load Initialization processed in 686 ms
09-Sep-2017 21:32:21.703 INFO [main] org.apache.catalina.core.StandardService.startInternal Starting service [Catalina]
09-Sep-2017 21:32:21.704 INFO [main] org.apache.catalina.core.StandardEngine.startInternal Starting Servlet Engine: Apache Tomcat/8.5.20
09-Sep-2017 21:32:21.713 INFO [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Deploying web application directory [C:\Program Files\Apache Software Foundation\Tomcat 8.5\webapps\docs]
09-Sep-2017 21:32:22.148 INFO [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Deployment of web application directory [C:\Program Files\Apache Software Foundation\Tomcat 8.5\webapps\docs] has finished in [435] ms
09-Sep-2017 21:32:22.149 INFO [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Deploying web application directory [C:\Program Files\Apache Software Foundation\Tomcat 8.5\webapps\manager]
09-Sep-2017 21:32:22.217 INFO [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Deployment of web application directory [C:\Program Files\Apache Software Foundation\Tomcat 8.5\webapps\manager] has finished in [68] ms
09-Sep-2017 21:32:22.218 INFO [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Deploying web application directory [C:\Program Files\Apache Software Foundation\Tomcat 8.5\webapps\ROOT]
09-Sep-2017 21:32:22.242 INFO [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Deployment of web application directory [C:\Program Files\Apache Software Foundation\Tomcat 8.5\webapps\ROOT] has finished in [24] ms
09-Sep-2017 21:32:22.246 INFO [main] org.apache.coyote.AbstractProtocol.start Starting ProtocolHandler ["http-nio-8080"]
09-Sep-2017 21:32:22.259 INFO [main] org.apache.coyote.AbstractProtocol.start Starting ProtocolHandler ["ajp-nio-8009"]
09-Sep-2017 21:32:22.262 INFO [main] org.apache.catalina.startup.Catalina.start Server startup in 583 ms
最佳答案
改吧，我以前也是这样，改成8006 8088 8008然后保存，就ok了! 在xml文件或双击服务都可以改就可以了!
关于java - 无法在本地主机上运行 rest api Web 服务，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/46132906/