HTTPClient Example - Exception in thread "main" java.lang.NoSuchFieldError: INSTANCE

Question

I am using HttpClient components from Apache for the following simple program and I see the below exception:

Exception in thread "main" java.lang.NoSuchFieldError: INSTANCE
    at org.apache.http.impl.io.DefaultHttpRequestWriterFactory.(DefaultHttpRequestWriterFactory.java:52)
    at org.apache.http.impl.io.DefaultHttpRequestWriterFactory.(DefaultHttpRequestWriterFactory.java:56)
    at org.apache.http.impl.io.DefaultHttpRequestWriterFactory.(DefaultHttpRequestWriterFactory.java:46)
    at org.apache.http.impl.conn.ManagedHttpClientConnectionFactory.(ManagedHttpClientConnectionFactory.java:72)
    at org.apache.http.impl.conn.ManagedHttpClientConnectionFactory.(ManagedHttpClientConnectionFactory.java:84)
    at org.apache.http.impl.conn.ManagedHttpClientConnectionFactory.(ManagedHttpClientConnectionFactory.java:59)
    at org.apache.http.impl.conn.PoolingHttpClientConnectionManager$InternalConnectionFactory.(PoolingHttpClientConnectionManager.java:487)
    at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.(PoolingHttpClientConnectionManager.java:147)
    at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.(PoolingHttpClientConnectionManager.java:136)
    at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.(PoolingHttpClientConnectionManager.java:112)
    at org.apache.http.impl.client.HttpClientBuilder.build(HttpClientBuilder.java:726)
    at com.starwood.rms.controller.property.HttpExample.main(HttpExample.java:14)

public class HttpExample {

    public static void main(String[] args) {
        HttpClient client = HttpClientBuilder.create().build();
        HttpGet request = new HttpGet("https://www.google.com/?q=java");

        try {
            HttpResponse response = client.execute(request);
            System.out.println(response.getStatusLine());

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

I am using

• Httpclient-4.3.3.jar
• Httpcore-4.3.2.jar

Any ideas?

Answer 1

This code works...without any error.. check the packages if you are using similar import .

package com.jai.http;

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.HttpClientBuilder;

public class HttpExample {

    /**
     * @param args
     */
    public static void main(String[] args) {
        HttpClient client = HttpClientBuilder.create().build();
        HttpGet request = new HttpGet("https://www.google.com/?q=java");
        try {
            HttpResponse response = client.execute(request);
            System.out.println(response.getStatusLine());

        } catch (Exception e) {
            e.printStackTrace();

        }

    }
}