我有一个简单的类写在Android Studio:
package com.mysite.myapp;
import org.apache.http.client.HttpClient;
public class Whatever {
public void headBangingAgainstTheWallExample () {
HttpClient client = new DefaultHttpClient();
}
}
从这里我得到了以下编译时错误:
无法解析HttpClient符号
HttpClient不是包含在Android Studio SDK中吗?即使不是，我也像这样把它添加到我的Gradle构建中:
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.android.support:appcompat-v7:23.0.0'
compile 'org.apache.httpcomponents:httpclient:4.5'
}
不管有没有最后一个编译行，错误都是一样的。我错过了什么?
在API 22中，它们被弃用了，在API 23中，它们被完全删除了，如果你不需要新添加的所有花哨的东西，一个简单的解决方法是简单地使用API 22之前集成的apache的。jar文件，但作为独立的。jar文件:
1. http://hc.apache.org/downloads.cgi
2. download httpclient 4.5.1, the zile file
3. unzip all files
4. drag in your project httpclient-4.5.1.jar, httpcore-4.4.3.jar and httpmime-4.5.1.jar
5. project, right click, open module settings, app, dependencies, +, File dependency and add the 3 files
6. now everything should compile properly
如前所述，org.apache.http.client.HttpClient在以下版本中不再被支持:
SDK (API级别)#23。
你必须使用java。net。httpurlconnection。
如果你想让你的代码(和生活)在使用HttpURLConnection时更容易，这里是这个类的包装器，它可以让你使用JSON对GET、POST和PUT进行简单的操作，例如，执行HTTP PUT。
HttpRequest request = new HttpRequest(API_URL + PATH).addHeader("Content-Type", "application/json");
int httpCode = request.put(new JSONObject().toString());
if (HttpURLConnection.HTTP_OK == httpCode) {
response = request.getJSONObjectResponse();
} else {
// log error
}
httpRequest.close()
请随意使用。
package com.calculistik.repository;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
/**
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
* <p>
* Copyright © 2017, Calculistik . All rights reserved.
* <p>
* Oracle and Java are registered trademarks of Oracle and/or its
* affiliates. Other names may be trademarks of their respective owners.
* <p>
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common
* Development and Distribution License("CDDL") (collectively, the
* "License"). You may not use this file except in compliance with the
* License. You can obtain a copy of the License at
* https://netbeans.org/cddl-gplv2.html or
* nbbuild/licenses/CDDL-GPL-2-CP. See the License for the specific
* language governing permissions and limitations under the License.
* When distributing the software, include this License Header
* Notice in each file and include the License file at
* nbbuild/licenses/CDDL-GPL-2-CP. Oracle designates this particular file
* as subject to the "Classpath" exception as provided by Oracle in the
* GPL Version 2 section of the License file that accompanied this code. If
* applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
* "Portions Copyrighted [year] [name of copyright owner]"
* <p>
* Contributor(s):
* Created by alejandro tkachuk @aletkachuk
* www.calculistik.com
*/
public class HttpRequest {
public static enum Method {
POST, PUT, DELETE, GET;
}
private URL url;
private HttpURLConnection connection;
private OutputStream outputStream;
private HashMap<String, String> params = new HashMap<String, String>();
public HttpRequest(String url) throws IOException {
this.url = new URL(url);
connection = (HttpURLConnection) this.url.openConnection();
}
public int get() throws IOException {
return this.send();
}
public int post(String data) throws IOException {
connection.setDoInput(true);
connection.setRequestMethod(Method.POST.toString());
connection.setDoOutput(true);
outputStream = connection.getOutputStream();
this.sendData(data);
return this.send();
}
public int post() throws IOException {
connection.setDoInput(true);
connection.setRequestMethod(Method.POST.toString());
connection.setDoOutput(true);
outputStream = connection.getOutputStream();
return this.send();
}
public int put(String data) throws IOException {
connection.setDoInput(true);
connection.setRequestMethod(Method.PUT.toString());
connection.setDoOutput(true);
outputStream = connection.getOutputStream();
this.sendData(data);
return this.send();
}
public int put() throws IOException {
connection.setDoInput(true);
connection.setRequestMethod(Method.PUT.toString());
connection.setDoOutput(true);
outputStream = connection.getOutputStream();
return this.send();
}
public HttpRequest addHeader(String key, String value) {
connection.setRequestProperty(key, value);
return this;
}
public HttpRequest addParameter(String key, String value) {
this.params.put(key, value);
return this;
}
public JSONObject getJSONObjectResponse() throws JSONException, IOException {
return new JSONObject(getStringResponse());
}
public JSONArray getJSONArrayResponse() throws JSONException, IOException {
return new JSONArray(getStringResponse());
}
public String getStringResponse() throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()));
StringBuilder response = new StringBuilder();
for (String line; (line = br.readLine()) != null; ) response.append(line + "\n");
return response.toString();
}
public byte[] getBytesResponse() throws IOException {
byte[] buffer = new byte[8192];
InputStream is = connection.getInputStream();
ByteArrayOutputStream output = new ByteArrayOutputStream();
for (int bytesRead; (bytesRead = is.read(buffer)) >= 0; )
output.write(buffer, 0, bytesRead);
return output.toByteArray();
}
public void close() {
if (null != connection)
connection.disconnect();
}
private int send() throws IOException {
int httpStatusCode = HttpURLConnection.HTTP_BAD_REQUEST;
if (!this.params.isEmpty()) {
this.sendData();
}
httpStatusCode = connection.getResponseCode();
return httpStatusCode;
}
private void sendData() throws IOException {
StringBuilder result = new StringBuilder();
for (Map.Entry<String, String> entry : params.entrySet()) {
result.append((result.length() > 0 ? "&" : "") + entry.getKey() + "=" + entry.getValue());//appends: key=value (for first param) OR &key=value(second and more)
}
sendData(result.toString());
}
private HttpRequest sendData(String query) throws IOException {
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));
writer.write(query);
writer.close();
return this;
}
}
