在JAVA中发送HTTP请求的方式有哪些？相信很多没有经验的人对此束手无策，为此本文总结了问题出现的原因和解决方法，通过这篇文章希望你能解决这个问题。
Java是什么
Java是一门面向对象编程语言，可以编写桌面应用程序、Web应用程序、分布式系统和嵌入式系统应用程序。
HttpURLConnection
使用JDK原生提供的net，无需其他jar包；
HttpURLConnection是URLConnection的子类，提供更多的方法，使用更方便。
package httpURLConnection;import java.io.BufferedReader;import java.io.InputStream;import java.io.InputStreamReader;import java.net.HttpURLConnection;import java.net.URL;public class HttpURLConnectionHelper { public static String sendRequest(String urlParam,String requestType) { HttpURLConnection con = null; BufferedReader buffer = null; StringBuffer resultBuffer = null; try { URL url = new URL(urlParam); //得到连接对象 con = (HttpURLConnection) url.openConnection(); //设置请求类型 con.setRequestMethod(requestType); //设置请求需要返回的数据类型和字符集类型 con.setRequestProperty("Content-Type", "application/json;charset=GBK"); //允许写出 con.setDoOutput(true); //允许读入 con.setDoInput(true); //不使用缓存 con.setUseCaches(false); //得到响应码 int responseCode = con.getResponseCode(); if(responseCode == HttpURLConnection.HTTP_OK){ //得到响应流 InputStream inputStream = con.getInputStream(); //将响应流转换成字符串 resultBuffer = new StringBuffer(); String line; buffer = new BufferedReader(new InputStreamReader(inputStream, "GBK")); while ((line = buffer.readLine()) != null) { resultBuffer.append(line); } return resultBuffer.toString(); } }catch(Exception e) { e.printStackTrace(); } return ""; } public static void main(String[] args) { String url ="http://int.dpool.sina.com.cn/iplookup/iplookup.php?ip=120.79.75.96"; System.out.println(sendRequest(url,"POST")); }}2. URLConnection
使用JDK原生提供的net，无需其他jar包；
建议使用HttpURLConnection
package uRLConnection;import java.io.BufferedReader;import java.io.InputStream;import java.io.InputStreamReader;import java.net.HttpURLConnection;import java.net.URL;import java.net.URLConnection;public class URLConnectionHelper { public static String sendRequest(String urlParam) { URLConnection con = null; BufferedReader buffer = null; StringBuffer resultBuffer = null; try { URL url = new URL(urlParam); con = url.openConnection(); //设置请求需要返回的数据类型和字符集类型 con.setRequestProperty("Content-Type", "application/json;charset=GBK"); //允许写出 con.setDoOutput(true); //允许读入 con.setDoInput(true); //不使用缓存 con.setUseCaches(false); //得到响应流 InputStream inputStream = con.getInputStream(); //将响应流转换成字符串 resultBuffer = new StringBuffer(); String line; buffer = new BufferedReader(new InputStreamReader(inputStream, "GBK")); while ((line = buffer.readLine()) != null) { resultBuffer.append(line); } return resultBuffer.toString(); }catch(Exception e) { e.printStackTrace(); } return ""; } public static void main(String[] args) { String url ="http://int.dpool.sina.com.cn/iplookup/iplookup.php?ip=120.79.75.96"; System.out.println(sendRequest(url)); }}3. HttpClient
使用方便，我个人偏爱这种方式，但依赖于第三方jar包，相关maven依赖如下：
<!-- https://mvnrepository.com/artifact/commons-httpclient/commons-httpclient --><dependency> <groupId>commons-httpclient</groupId> <artifactId>commons-httpclient</artifactId> <version>3.1</version></dependencypackage httpClient;import java.io.IOException;import org.apache.commons.httpclient.HttpClient;import org.apache.commons.httpclient.HttpException;import org.apache.commons.httpclient.methods.GetMethod;import org.apache.commons.httpclient.methods.PostMethod;import org.apache.commons.httpclient.params.HttpMethodParams;public class HttpClientHelper { public static String sendPost(String urlParam) throws HttpException, IOException { // 创建httpClient实例对象 HttpClient httpClient = new HttpClient(); // 设置httpClient连接主机服务器超时时间：15000毫秒 httpClient.getHttpConnectionManager().getParams().setConnectionTimeout(15000); // 创建post请求方法实例对象 PostMethod postMethod = new PostMethod(urlParam); // 设置post请求超时时间 postMethod.getParams().setParameter(HttpMethodParams.SO_TIMEOUT, 60000); postMethod.addRequestHeader("Content-Type", "application/json"); httpClient.executeMethod(postMethod); String result = postMethod.getResponseBodyAsString(); postMethod.releaseConnection(); return result; } public static String sendGet(String urlParam) throws HttpException, IOException { // 创建httpClient实例对象 HttpClient httpClient = new HttpClient(); // 设置httpClient连接主机服务器超时时间：15000毫秒 httpClient.getHttpConnectionManager().getParams().setConnectionTimeout(15000); // 创建GET请求方法实例对象 GetMethod getMethod = new GetMethod(urlParam); // 设置post请求超时时间 getMethod.getParams().setParameter(HttpMethodParams.SO_TIMEOUT, 60000); getMethod.addRequestHeader("Content-Type", "application/json"); httpClient.executeMethod(getMethod); String result = getMethod.getResponseBodyAsString(); getMethod.releaseConnection(); return result; } public static void main(String[] args) throws HttpException, IOException { String url ="http://int.dpool.sina.com.cn/iplookup/iplookup.php?ip=120.79.75.96"; System.out.println(sendPost(url)); System.out.println(sendGet(url)); }}4. Socket
使用JDK原生提供的net，无需其他jar包；
使用起来有点麻烦。
package socket;import java.io.BufferedInputStream; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.IOException; import java.io.InputStreamReader; import java.io.OutputStreamWriter; import java.net.Socket; import java.net.URLEncoder; import javax.net.ssl.SSLSocket; import javax.net.ssl.SSLSocketFactory; public class SocketForHttpTest { private int port; private String host; private Socket socket; private BufferedReader bufferedReader; private BufferedWriter bufferedWriter; public SocketForHttpTest(String host,int port) throws Exception{ this.host = host; this.port = port; // socket = new Socket(this.host, this.port); socket = (SSLSocket)((SSLSocketFactory)SSLSocketFactory.getDefault()).createSocket(this.host, this.port); } public void sendGet() throws IOException{ //String requestUrlPath = "/z69183787/article/details/17580325"; String requestUrlPath = "/"; OutputStreamWriter streamWriter = new OutputStreamWriter(socket.getOutputStream()); bufferedWriter = new BufferedWriter(streamWriter); bufferedWriter.write("GET " + requestUrlPath + " HTTP/1.1\r\n"); bufferedWriter.write("Host: " + this.host + "\r\n"); bufferedWriter.write("\r\n"); bufferedWriter.flush(); BufferedInputStream streamReader = new BufferedInputStream(socket.getInputStream()); bufferedReader = new BufferedReader(new InputStreamReader(streamReader, "utf-8")); String line = null; while((line = bufferedReader.readLine())!= null){ System.out.println(line); } bufferedReader.close(); bufferedWriter.close(); socket.close(); } public void sendPost() throws IOException{ String path = "/"; String data = URLEncoder.encode("name", "utf-8") + "=" + URLEncoder.encode("张三", "utf-8") + "&" + URLEncoder.encode("age", "utf-8") + "=" + URLEncoder.encode("32", "utf-8"); // String data = "name=zhigang_jia"; System.out.println(">>>>>>>>>>>>>>>>>>>>>"+data); OutputStreamWriter streamWriter = new OutputStreamWriter(socket.getOutputStream(), "utf-8"); bufferedWriter = new BufferedWriter(streamWriter); bufferedWriter.write("POST " + path + " HTTP/1.1\r\n"); bufferedWriter.write("Host: " + this.host + "\r\n"); bufferedWriter.write("Content-Length: " + data.length() + "\r\n"); bufferedWriter.write("Content-Type: application/x-www-form-urlencoded\r\n"); bufferedWriter.write("\r\n"); bufferedWriter.write(data); bufferedWriter.write("\r\n"); bufferedWriter.flush(); BufferedInputStream streamReader = new BufferedInputStream(socket.getInputStream()); bufferedReader = new BufferedReader(new InputStreamReader(streamReader, "utf-8")); String line = null; while((line = bufferedReader.readLine())!= null) { System.out.println(line); } bufferedReader.close(); bufferedWriter.close(); socket.close(); } public static void main(String[] args) throws Exception { //SocketForHttpTest forHttpTest = new SocketForHttpTest("www.baidu.com", 80); SocketForHttpTest forHttpTest = new SocketForHttpTest("www.baidu.com", 443); try { forHttpTest.sendGet(); // forHttpTest.sendPost(); } catch (IOException e) { e.printStackTrace(); } } }看完上述内容，你们掌握在JAVA中发送HTTP请求的方式有哪些的方法了吗？如果还想学到更多技能或想了解更多相关内容，欢迎关注编程网行业资讯频道，感谢各位的阅读！
