user2526311 user2526311 - 1 year ago 220
Java Question

The type List is not generic; it cannot be parameterized with arguments [HTTPClient]

import java.awt.List;
import java.awt.image.BufferedImage;
import java.util.ArrayList;

import javax.imageio.ImageIO;

import org.apache.commons.codec.binary.Base64;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.omg.DynamicAny.NameValuePair;

public class Upload {

public static void main (String[] args) {

System.out.println(Imgur("C:\\Users\\username\\Desktop\\image.jpg", "clientID"));

public static String Imgur (String imageDir, String clientID) {
//create needed strings
String address = "";

//Create HTTPClient and post
HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost(address);

//create base64 image
BufferedImage image = null;
File file = new File(imageDir);

try {
//read image
image =;
ByteArrayOutputStream byteArray = new ByteArrayOutputStream();
ImageIO.write(image, "png", byteArray);
byte[] byteImage = byteArray.toByteArray();
String dataImage = new Base64().encodeAsString(byteImage);

//add header
post.addHeader("Authorization", "Client-ID" + clientID);
//add image
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1);
nameValuePairs.add(new BasicNameValuePair("image", dataImage));
post.setEntity(new UrlEncodedFormEntity(nameValuePairs));

HttpResponse response = client.execute(post);

//read response
BufferedReader rd = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
String all = null;

//loop through response
while (rd.readLine() != null) {
all = all + " : " + rd.readLine();

return all;

catch (Exception e){
return "error: " + e.toString();

So I have that code and I got it from uploading to Imgur v3 using Java https errors and I get an error on line 50 for "List" telling me

The type List is not generic; it cannot be parameterized with arguments

What can I do to solve this?

I'm using and want to upload an image to imgur using their v3 API.

EDIT: After changing the import I now get these errors.

That solves that but give me two more errors.

nameValuePairs.add(new BasicNameValuePair("image", dataImage));

The method add(NameValuePair) in the type List is not applicable for the arguments (BasicNameValuePair)


post.setEntity(new UrlEncodedFormEntity(nameValuePairs));

The constructor UrlEncodedFormEntity(List) is undefined

Answer Source

Your import has a subtle error:

import java.awt.List;

It should be:

import java.util.List;

The problem is that both awt and Java's util package provide a class called List. The former is a display element, the latter is a generic type used with collections. Furthermore, java.util.ArrayList extends java.util.List, not java.awt.List so if it wasn't for the generics, it would have still been a problem.

Edit: (to address further questions given by OP) As an answer to your comment, it seems that there is anther subtle import issue.

import org.omg.DynamicAny.NameValuePair;

should be

import org.apache.http.NameValuePair

nameValuePairs now uses the correct generic type parameter, the generic argument for new UrlEncodedFormEntity, which is List<? extends NameValuePair>, becomes valid, since your NameValuePair is now the same as their NameValuePair. Before, org.omg.DynamicAny.NameValuePair did not extend org.apache.http.NameValuePair and the shortened type name NameValuePair evaluated to org.omg... in your file, but org.apache... in their code.

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