java的get和post方式请求：
package com.jfpay.util.http;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import org.springframework.expression.ParseException;
public class HttpRequest {
/**
* 向指定 URL 发送POST方法的请求
*
* @param url
* 发送请求的 URL
* @param param
*
* @return 所代表远程资源的响应结果
*/
public static String readPost(String url, String xml) throws ParseException, IOException{
String body = "";
//创建httpclient对象
CloseableHttpClient client = HttpClients.createDefault();
//创建post方式请求对象
HttpPost httpPost = new HttpPost(url);
//装填参数
List<NameValuePair> nvps = new ArrayList<NameValuePair>();
nvps.add(new BasicNameValuePair("xml", xml));
//设置参数到请求对象中
httpPost.setEntity(new UrlEncodedFormEntity(nvps, "utf-8"));
//设置header信息
//指定报文头【Content-type】、【User-Agent】
httpPost.setHeader("Content-type", "application/x-www-form-urlencoded;charset=utf-8");
httpPost.setHeader("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");
//执行请求操作，并拿到结果（同步阻塞）
CloseableHttpResponse response = client.execute(httpPost);
//获取结果实体
HttpEntity entity = response.getEntity();
if (entity != null) {
//按指定编码转换结果实体为String类型
body = EntityUtils.toString(entity, "utf-8");
}
EntityUtils.consume(entity);
//释放链接
response.close();
return body;
}
public static String sendPost(String url,String xml) throws IOException {
// Post请求的url，与get不同的是不需要带参数
URL postUrl = new URL(url);
// 打开连接
HttpURLConnection connection = (HttpURLConnection) postUrl.openConnection();
// 设置是否向connection输出，因为这个是post请求，参数要放在
// http正文内，因此需要设为true
connection.setDoOutput(true);
// Read from the connection. Default is true.
connection.setDoInput(true);
// 默认是 GET方式
connection.setRequestMethod("POST");
// 设置字符编码
connection.setRequestProperty("Accept-Charset", "utf-8");
// Post 请求不能使用缓存
connection.setUseCaches(false);
connection.setInstanceFollowRedirects(true);
// 配置本次连接的Content-type，配置为application/x-www-form-urlencoded的
// 意思是正文是urlencoded编码过的form参数，下面我们可以看到我们对正文内容使用URLEncoder.encode
// 进行编码
connection.setRequestProperty("Content-Type","application/x-www-form-urlencoded;charset=utf-8");
connection.setRequestProperty("contentType", "utf-8");
// 连接，从postUrl.openConnection()至此的配置必须要在connect之前完成，
// 要注意的是connection.getOutputStream会隐含的进行connect。
connection.connect();
DataOutputStream out = new DataOutputStream(connection
.getOutputStream());
// The URL-encoded contend
// 正文，正文内容其实跟get的URL中 '? '后的参数字符串一致
String content = "xml=" + URLEncoder.encode(xml, "utf-8");
// DataOutputStream.writeBytes将字符串中的16位的unicode字符以8位的字符形式写到流里面
out.writeBytes(content);
out.flush();
out.close();
BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String line;
String response = null;
while ((line = reader.readLine()) != null){
response=line;
}
reader.close();
connection.disconnect();
return response;
}
}