Question

我正在尝试创建一个Jar文件来连接我在Node.js中编写的休息服务。我按照本指南这样做了。

https://www.mkyong.com/webservices/jax-rs/restful-java-client-with-apache-httpclient/

使用Maven编译后，会出现此错误：

 Error: A JNI error has occurred, please check your installation and try again
    Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/http/client/methods/HttpUriRequest
        at java.lang.Class.getDeclaredMethods0(Native Method)
        at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
        at java.lang.Class.privateGetMethodRecursive(Class.java:3048)
        at java.lang.Class.getMethod0(Class.java:3018)
        at java.lang.Class.getMethod(Class.java:1784)
        at sun.launcher.LauncherHelper.validateMainClass(LauncherHelper.java:544)
        at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:526)
    Caused by: java.lang.ClassNotFoundException: org.apache.http.client.methods.HttpUriRequest
        at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)

App.java

package com.vogella.build.maven.java;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.MalformedURLException;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.DefaultHttpClient;

public class App {

    public static void main(String[] args) {

      try {

        DefaultHttpClient httpClient = new DefaultHttpClient();
        HttpPost postRequest = new HttpPost(
            "http://localhost:3001/getTestData");

        HttpResponse response = httpClient.execute(postRequest);

        if (response.getStatusLine().getStatusCode() != 201) {
            throw new RuntimeException("Failed : HTTP error code : "
                + response.getStatusLine().getStatusCode());
        }

        BufferedReader br = new BufferedReader(
                        new InputStreamReader((response.getEntity().getContent())));

        String output;
        System.out.println("Output from Server .... \n");
        while ((output = br.readLine()) != null) {
            System.out.println(output);
        }

        httpClient.getConnectionManager().shutdown();

      } catch (MalformedURLException e) {

        e.printStackTrace();

      } catch (IOException e) {

        e.printStackTrace();

      }

    }

}

的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.vogella.build.maven.java</groupId>
  <artifactId>com.vogella.build.maven.java</artifactId>
  <packaging>jar</packaging>
  <version>1.0-SNAPSHOT</version>

  <name>com.vogella.build.maven.java</name>
  <url>http://maven.apache.org</url>

  <dependencies>
    <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>4.1.1</version>
    </dependency>
  </dependencies>
</project>

有人知道这有什么问题吗？

Answer 1

您的应用程序依赖于httpclient-4.1.1.jar，您需要通过在类路径中使用jar来运行您的应用程序。在构建应用程序时，Maven将jar下载到本地存储库中。

您可以找到很多关于如何指定classpath similar example

的示例

Running a java program at the command line, what am I doing wrong?

找不到HttpUriRequest的类

1 个答案: