HTTPClient 示例 - 线程“main”中的异常 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

I had this problem with Hadoop. It used an old version of httpclient-4.2.5.jar and httpcore-4.2.5.jar in their shared lib.

I solved this by shading parts via the maven-shade-plugin

<relocations>
    <relocation>
        <pattern>org.apache.http</pattern>
        <shadedPattern>shaded.org.apache.http</shadedPattern>
    </relocation>
</relocations>

Answer 2

Looking at the source code of DefaultHttpRequestWriterFactory

package org.apache.http.impl.io;

import org.apache.http.HttpRequest;
import org.apache.http.annotation.Immutable;
import org.apache.http.io.HttpMessageWriter;
import org.apache.http.io.HttpMessageWriterFactory;
import org.apache.http.io.SessionOutputBuffer;
import org.apache.http.message.BasicLineFormatter;
import org.apache.http.message.LineFormatter;

@Immutable

public class  [More ...] DefaultHttpRequestWriterFactory implements HttpMessageWriterFactory<HttpRequest> {

    public static final DefaultHttpRequestWriterFactory INSTANCE = new DefaultHttpRequestWriterFactory();

    private final LineFormatter lineFormatter;

    public  [More ...] DefaultHttpRequestWriterFactory(final LineFormatter lineFormatter) {
        super();
        this.lineFormatter = lineFormatter != null ? lineFormatter : BasicLineFormatter.INSTANCE;
    }

    public  [More ...] DefaultHttpRequestWriterFactory() {
        this(null);
    }

    public HttpMessageWriter<HttpRequest>  [More ...] create(final SessionOutputBuffer buffer) {
        return new DefaultHttpRequestWriter(buffer, lineFormatter);
    }

}

Are you sure you are using HttpCore 4.3.2? DefaultHttpRequestWriterFactory try to resolve

BasicLineFormatter.INSTANCE

field but can not find it.

Check your classpath for libraries which could contains another BasicLineFormatter class, maybe you have a HttpCore from an old version in conflict with the 4.3.2 version.

Answer 3

Caused by: java.lang.NoSuchFieldError: INSTANCE

one of the solution of java.lang.NoSuchFieldError: INSTANCE : This happens if we have two diff version of same class in our classpath…. […], So we first find that class(one version of class) , click that class, select "build path", then we click "remove from build path" . by 333ccc333

Answer 4

I had this problem. It looks like there is a problem while initializing HttpClient with HttpClientBuilder.create().build(). If you want more immediate solution just use new DefaultHttpClient() to initialize HttpClient.

HttpClient client = new DefaultHttpClient();

Answer 5

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();

        }

    }
}

Answer 6

对于那些使用 Webpshere 的人，请确保您的类加载策略设置为“Parent Last”，否则它将无法工作，因为 WAS 使用的是它自己的 commons http 版本，这可能会发生冲突。

Answer 7

I had this problem too, i realized it was when we upgraded to java 1.8, i just downgraded to 1.7 and works as expected. Not sure why the version became an issue.

Answer 8

I also was frustrated by this and Eclipse until I realized that similar to Pat B's Webpshere tip, it does cause issues for Eclipse if you have the dependencies in the wrong order.

Properties -> Java Build Path -> Order and Export

Play a bit around here with the order of core and client.

Answer 9

I have this error too, in my class path
I have httpclient-4.4.1.jar , and httpcore-4.4.1.jar
However, for some reason,
the classloader loaded the class org.apache.http.message.BasicLineFormatter from httpcore-4.0.jar in a unexpected location and caused this error
you can use below code to check which jar it is using

try{
Class cls=Class.forName('org.apache.http.message.BasicLineFormatter');
  println cls.getProtectionDomain().getCodeSource().getLocation();
}catch (Error ex){
  println ex
}

Hope this help~