JAVA_GET请求URL

  1 import java.io.IOException;
  2 
  3 import net.sf.json.JSONObject;
  4 
  5 import org.apache.commons.httpclient.DefaultHttpMethodRetryHandler;
  6 import org.apache.commons.httpclient.Header;
  7 import org.apache.commons.httpclient.HttpClient;
  8 import org.apache.commons.httpclient.HttpException;
  9 import org.apache.commons.httpclient.HttpStatus;
 10 import org.apache.commons.httpclient.methods.GetMethod;
 11 import org.apache.commons.httpclient.params.HttpMethodParams;
 12 import org.apache.http.HttpEntity;
 13 import org.apache.http.HttpResponse;
 14 import org.apache.http.client.methods.HttpPost;
 15 import org.apache.http.entity.StringEntity;
 16 import org.apache.http.impl.client.DefaultHttpClient;
 17 import org.apache.http.util.EntityUtils;
 18 
 19 public class TestGetRequest {
 20 
 21     /**
 22      * @param args
 23      */
 24     public static void main(String[] args) {
 25 
 26         String url = "http://www.ecmwf.int/plots/get-map/";
 27         String param = "{\"product\":{\"product\":{\"name\":\"public_plots\",\"package\":\"medium\"},\"values\":{\"time\":[\"2016032012\",48,\"2016032212\"],\"parameter\":\"Wind 850 and mslp\",\"area\":\"Asia\"}}}";
 28         System.out.println(param);
 29         JSONObject object = JSONObject.fromObject(param);
 30         JSONObject result = doPost(url, object);
 31         System.out.println(result);
 32         JSONObject imgResult = (JSONObject) result.get("result");
 33         System.out.println(imgResult.get("url"));
 34     }
 35 
 36     public static String doGet(String url, String charset) throws Exception {
 37         /*
 38          * 使用 GetMethod 来访问一个 URL 对应的网页,实现步骤: 1:生成一个 HttpClinet 对象并设置相应的参数。
 39          * 2:生成一个 GetMethod 对象并设置响应的参数。 3:用 HttpClinet 生成的对象来执行 GetMethod 生成的Get
 40          * 方法。 4:处理响应状态码。 5:若响应正常，处理 HTTP 响应内容。 6:释放连接。
 41          */
 42         /* 1 生成 HttpClinet 对象并设置参数 */
 43         HttpClient httpClient = new HttpClient();
 44         // 设置 Http 连接超时为5秒
 45         httpClient.getHttpConnectionManager().getParams().setConnectionTimeout(
 46                 5000);
 47         /* 2 生成 GetMethod 对象并设置参数 */
 48         GetMethod getMethod = new GetMethod(url);
 49         // 设置 get 请求超时为 5 秒
 50         getMethod.getParams().setParameter(HttpMethodParams.SO_TIMEOUT, 5000);
 51         // 设置请求重试处理，用的是默认的重试处理：请求三次
 52         getMethod.getParams().setParameter(HttpMethodParams.RETRY_HANDLER,
 53                 new DefaultHttpMethodRetryHandler());
 54         String response = "";
 55         /* 3 执行 HTTP GET 请求 */
 56         try {
 57             int statusCode = httpClient.executeMethod(getMethod);
 58             /* 4 判断访问的状态码 */
 59             if (statusCode != HttpStatus.SC_OK) {
 60                 System.err.println("请求出错: " + getMethod.getStatusLine());
 61             }
 62             /* 5 处理 HTTP 响应内容 */
 63             // HTTP响应头部信息，这里简单打印
 64             Header[] headers = getMethod.getResponseHeaders();
 65             for (Header h : headers)
 66                 System.out
 67                         .println(h.getName() + "------------ " + h.getValue());
 68             // 读取 HTTP 响应内容，这里简单打印网页内容
 69             byte[] responseBody = getMethod.getResponseBody();// 读取为字节数组
 70             response = new String(responseBody, charset);
 71             System.out.println("----------response:" + response);
 72             // 读取为 InputStream，在网页内容数据量大时候推荐使用
 73             // InputStream response = getMethod.getResponseBodyAsStream();
 74         } catch (HttpException e) {
 75             // 发生致命的异常，可能是协议不对或者返回的内容有问题
 76             System.out.println("请检查输入的URL!");
 77             e.printStackTrace();
 78         } catch (IOException e) {
 79             // 发生网络异常
 80             System.out.println("发生网络异常!");
 81             e.printStackTrace();
 82         } finally {
 83             /* 6 .释放连接 */
 84             getMethod.releaseConnection();
 85         }
 86         return response;
 87     }
 88 
 89     public static JSONObject doPost(String url, JSONObject json) {
 90         DefaultHttpClient client = new DefaultHttpClient();
 91         HttpPost post = new HttpPost(url);
 92         JSONObject response = null;
 93         try {
 94             StringEntity s = new StringEntity(json.toString());
 95             s.setContentEncoding("UTF-8");
 96             s.setContentType("application/json");// 发送json数据需要设置contentType
 97             post.setEntity(s);
 98             HttpResponse res = client.execute(post);
 99             if (res.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
100                 HttpEntity entity = res.getEntity();
101                 String result = EntityUtils.toString(res.getEntity());// 返回json格式：
102                 response = JSONObject.fromObject(result);
103             }
104         } catch (Exception e) {
105             throw new RuntimeException(e);
106         }
107         return response;
108     }
109 
110 }