线程“main”中的异常 java.lang.NoClassDefFoundError: org/apache/http/ConnectionReuseStrategy:
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Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/http/ConnectionReuseStrategy:
提问by Toni.W
I am trying to run as Java Application in a maven project with Eclipse and I am getting the following run time error.The error is shown below.
我试图在 Eclipse 的 maven 项目中作为 Java 应用程序运行，但出现以下运行时错误。错误如下所示。
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/http/ConnectionReuseStrategy at com.wang.testMaven.App.main(App.java:16) Caused by: java.lang.ClassNotFoundException: org.apache.http.ConnectionReuseStrategy at java.net.URLClassLoader.findClass(URLClassLoader.java:381) at java.lang.ClassLoader.loadClass(ClassLoader.java:424) at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
线程“main”中的异常 java.lang.NoClassDefFoundError: org/apache/http/ConnectionReuseStrategy at com.wang.testMaven.App.main(App.java:16) 由：java.lang.ClassNotFoundException: org.apache.http .ConnectionReuseStrategy at java.net.URLClassLoader.findClass(URLClassLoader.java:381) at java.lang.ClassLoader.loadClass(ClassLoader.java:424) at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
and my code is shown below
我的代码如下所示
public class App
{
public static void main( String[] args )
{
System.out.println( "Hello World!" );
HttpClient httpClient = HttpClientBuilder.create().build();
System.out.println( "Hello World!" );
}
}
My pom.xml is shown below
我的 pom.xml 如下所示
<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.wang</groupId>
<artifactId>testMaven</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>testMaven</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpcore</artifactId>
<version>4.1-alpha1</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.2</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpmime</artifactId>
<version>4.5.2</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpcore</artifactId>
<version>4.1</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient-cache</artifactId>
<version>4.5.2</version>
</dependency>
</dependencies>
</project>
any idea..thanks
任何想法..谢谢
采纳答案by asg
I realised that there are couple of dependencies with the same groupId and artifactId.
我意识到有几个依赖项具有相同的 groupId 和 artifactId。
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpcore</artifactId>
<version>4.1-alpha1</version>
</dependency>
And
和
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpcore</artifactId>
<version>4.1</version>
</dependency>
Actually you should have only one dependency with the same groupId and artifactId.
实际上，您应该只有一个具有相同 groupId 和 artifactId 的依赖项。
So firstly I removed httpcore:4.1-alpha1 dependency and executed the test class. I got the exception as
所以首先我删除了 httpcore:4.1-alpha1 依赖项并执行了测试类。我得到了例外
java.lang.NoClassDefFoundError: org/apache/http/config/Lookup
at com.test.so.Test1.test(Test1.java:12)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
Then I used httpcore:4.1-alpha1 instead of httpcore-4.1, I got the same exception.
然后我使用 httpcore:4.1-alpha1 而不是 httpcore-4.1，我得到了同样的异常。
And hence when I updated the httpcore version to 4.3.3 based on SO link, I got the exception as -
因此，当我根据SO 链接将 httpcore 版本更新为 4.3.3 时，我得到了异常 -
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/http/ssl/SSLContexts
at org.apache.http.impl.client.HttpClientBuilder.build(HttpClientBuilder.java:966)
at com.amitg.so.App.main(App.java:11)
Finally updating the httpcore version to 4.4, it worked perfectly fine. So it should work for all httpcore version jars above 4.4. (I tested for 4.4.4 and it also worked fine.). Version available are mentioned here. Please find the working code over here.
最后将 httpcore 版本更新到 4.4，它工作得很好。所以它应该适用于 4.4 以上的所有 httpcore 版本的 jar。（我测试了 4.4.4，它也运行良好。）。这里提到了可用的版本。请在这里找到工作代码。
