未定义类型对象错误的方法

Question

我一直在研究这个问题，但我似乎无法纠正错误。我只是android开发中的新手。 我在getStatusCode()和getReasonPhrase()上均出现“方法未为类型对象定义”错误。 任何帮助，将不胜感激。

package com.javapapers.java.io;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpRequestBase;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.params.BasicHttpParams;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;

public class HttpUtil {

    public String getHttpResponse(HttpRequestBase request) {
        String result = null;
        try {

            DefaultHttpClient httpClient = new DefaultHttpClient(new BasicHttpParams());
            HttpResponse httpResponse = httpClient.execute(request);
            int statusCode = httpResponse.getStatusLine().getStatusCode();
            String reason = httpResponse.getStatusLine().getReasonPhrase();
            StringBuilder sb = new StringBuilder();
            if (statusCode == 200) {
                HttpEntity entity = httpResponse.getEntity();
                InputStream inputStream = entity.getContent();
                BufferedReader bReader = new BufferedReader(
                        new InputStreamReader(inputStream, "UTF-8"), 8);
                String line = null;
                while ((line = bReader.readLine()) != null) {
                    sb.append(line);
                }
            } else {
                sb.append(reason);
            }
            result = sb.toString();
        } catch (UnsupportedEncodingException ex) {
        } catch (ClientProtocolException ex1) {
        } catch (IOException ex2) {
        }
        return result;
    }
}

然后有人告诉我，我不应该使用Apache HTTP客户端，而应该使用HttpURLConnection，所以我更改了代码，我想知道这样做是否有效，结果是否相同

public class HttpUtil {
    public static void main(String[] args) throws Exception {

        if (args.length != 2) {
            System.err.println("Usage:  java Reverse "
                + "https://twitter.com/aaroadwatch"
                + " string_to_reverse");
            System.exit(1);
        }

        String stringToReverse = URLEncoder.encode(args[1], "UTF-8");

        URL url = new URL(args[0]);
        URLConnection connection = url.openConnection();
        connection.setDoOutput(true);

        OutputStreamWriter out = new OutputStreamWriter(
                                         connection.getOutputStream());
        out.write("string=" + stringToReverse);
        out.close();

        BufferedReader in = new BufferedReader(
                                    new InputStreamReader(
                                    connection.getInputStream()));
        String decodedString;
        while ((decodedString = in.readLine()) != null) {
            System.out.println(decodedString);
        }
        in.close();
    }
}

甚至像这样的东西

  URL url = new URL("https://twitter.com/aaroadwatch");
   HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
   try {
     InputStream in = new BufferedInputStream(urlConnection.getInputStream());
     readStream(in);
    finally {
     urlConnection.disconnect();
   }
 }

我的Twitter API类我在getHttpResponse和getHttpResponse包com.javapapers.social.twitter上有错误；

import android.util.Base64;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import com.javapapers.java.io.HttpUtil;

import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.ArrayList;

public class TwitterAPI {

    private String twitterApiKey;
    private String twitterAPISecret;
    final static String TWITTER_TOKEN_URL = "https://api.twitter.com/oauth2/token";
    final static String TWITTER_STREAM_URL = "https://api.twitter.com/1.1/statuses/user_timeline.json?screen_name=";

    public TwitterAPI(String twitterAPIKey, String twitterApiSecret){
        this.twitterApiKey = twitterAPIKey;
        this.twitterAPISecret = twitterApiSecret;
    }

    public ArrayList<TwitterTweet> getTwitterTweets(String screenName) {
        ArrayList<TwitterTweet> twitterTweetArrayList = null;
        try {
            String twitterUrlApiKey = URLEncoder.encode(twitterApiKey, "UTF-8");
            String twitterUrlApiSecret = URLEncoder.encode(twitterAPISecret, "UTF-8");
            String twitterKeySecret = twitterUrlApiKey + ":" + twitterUrlApiSecret;
            String twitterKeyBase64 = Base64.encodeToString(twitterKeySecret.getBytes(), Base64.NO_WRAP);
            TwitterAuthToken twitterAuthToken = getTwitterAuthToken(twitterKeyBase64);
            twitterTweetArrayList = getTwitterTweets(screenName, twitterAuthToken);
        } catch (UnsupportedEncodingException ex) {
        } catch (IllegalStateException ex1) {
        }
        return twitterTweetArrayList;
    }

    public ArrayList<TwitterTweet> getTwitterTweets(String screenName,
                                                     TwitterAuthToken twitterAuthToken) {
        ArrayList<TwitterTweet> twitterTweetArrayList = null;
        if (twitterAuthToken != null && twitterAuthToken.token_type.equals("bearer")) {
            HttpGet httpGet = new HttpGet(TWITTER_STREAM_URL + screenName);
            httpGet.setHeader("Authorization", "Bearer " + twitterAuthToken.access_token);
            httpGet.setHeader("Content-Type", "application/json");
            HttpUtil httpUtil = new HttpUtil();
            String twitterTweets = httpUtil.getHttpResponse(httpGet);
            twitterTweetArrayList = convertJsonToTwitterTweet(twitterTweets);
        }
        return twitterTweetArrayList;
    }

    public TwitterAuthToken getTwitterAuthToken(String twitterKeyBase64) throws UnsupportedEncodingException {
        HttpPost httpPost = new HttpPost(TWITTER_TOKEN_URL);
        httpPost.setHeader("Authorization", "Basic " + twitterKeyBase64);
        httpPost.setHeader("Content-Type", "application/x-www-form-urlencoded;charset=UTF-8");
        httpPost.setEntity(new StringEntity("grant_type=client_credentials"));
        HttpUtil httpUtil = new HttpUtil();
        String twitterJsonResponse = httpUtil.getHttpResponse(httpPost);
        return convertJsonToTwitterAuthToken(twitterJsonResponse);
    }

    private TwitterAuthToken convertJsonToTwitterAuthToken(String jsonAuth) {
        TwitterAuthToken twitterAuthToken = null;
        if (jsonAuth != null && jsonAuth.length() > 0) {
            try {
                Gson gson = new Gson();
                twitterAuthToken = gson.fromJson(jsonAuth, TwitterAuthToken.class);
            } catch (IllegalStateException ex) { }
        }
        return twitterAuthToken;
    }

    private ArrayList<TwitterTweet> convertJsonToTwitterTweet(String twitterTweets) {
        ArrayList<TwitterTweet> twitterTweetArrayList = null;
        if (twitterTweets != null && twitterTweets.length() > 0) {
            try {
                Gson gson = new Gson();
                twitterTweetArrayList =
                        gson.fromJson(twitterTweets, new TypeToken<ArrayList<TwitterTweet>>(){}.getType());
            } catch (IllegalStateException e) {
            }
        }
        return twitterTweetArrayList;
    }
    private class TwitterAuthToken {
        String token_type;
        String access_token;
    }
}

Answer 1

这是利用HttpUrlConnection的可能实现：

private static final int CONNECTION_TIMEOUT = (int) TimeUnit.SECONDS.toMillis(15);
private static final int READ_TIMEOUT = (int) TimeUnit.SECONDS.toMillis(15);

public static void main(String[] args) {
    String address = "https://twitter.com/aaroadwatch";
    System.out.println(get(address));
}

public static String get(String address) {
    String result = null;
    HttpURLConnection conn = null;
    InputStream in = null;
    try {
        // building api url
        URL url = new URL(address);
        System.out.println("GET URL " + url.toString());
        // establishing connection with server
        conn = (HttpURLConnection) url.openConnection();
        // building headers
        conn.setReadTimeout(READ_TIMEOUT);
        conn.setConnectTimeout(CONNECTION_TIMEOUT);
        conn.setRequestMethod("GET");
        if (conn.getResponseCode() == HttpURLConnection.HTTP_OK) {
            in = new BufferedInputStream(conn.getInputStream());
            // building output string from stream
            StringBuilder sb = new StringBuilder();
            int b;
            while ((b = in.read()) != -1) {
                sb.append((char) b);
            }
            String output = sb.toString().replace("\n", "");
            System.out.println("GET RES " + output);
            result = output;
        }
    } catch (MalformedURLException ex) {
        System.err.println("malformed url");
        ex.printStackTrace();
    } catch (IOException ex) {
        System.err.println("I/O exception");
        ex.printStackTrace();
    } finally {
        if (in != null) {
            try {
                in.close();
            } catch (IOException ex) {
            }
        }
        if (conn != null) {
            conn.disconnect();
        }
    }
    return result;
}

希望这会有所帮助。