JAVA发送HTTP请求，返回HTTP响应内容，实例及应用

JDK 中提供了一些对无状态协议请求（HTTP ）的支持，下面我就将我所写的一个小例子（组件）进行描述：

 首先让我们先构建一个请求类（HttpRequester ）。

该类封装了 JAVA 实现简单请求的代码，如下：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.charset.Charset;
import java.util.Map;
import java.util.Vector;
 
/**
 * HTTP请求对象
 * 
 * @author YYmmiinngg
 */
public class HttpRequester {
	private String defaultContentEncoding;
 
	public HttpRequester() {
		this.defaultContentEncoding = Charset.defaultCharset().name();
	}
 
	/**
	 * 发送GET请求
	 * 
	 * @param urlString
	 *            URL地址
	 * @return 响应对象
	 * @throws IOException
	 */
	public HttpRespons sendGet(String urlString) throws IOException {
		return this.send(urlString, "GET", null, null);
	}
 
	/**
	 * 发送GET请求
	 * 
	 * @param urlString
	 *            URL地址
	 * @param params
	 *            参数集合
	 * @return 响应对象
	 * @throws IOException
	 */
	public HttpRespons sendGet(String urlString, Map<String, String> params)
			throws IOException {
		return this.send(urlString, "GET", params, null);
	}
 
	/**
	 * 发送GET请求
	 * 
	 * @param urlString
	 *            URL地址
	 * @param params
	 *            参数集合
	 * @param propertys
	 *            请求属性
	 * @return 响应对象
	 * @throws IOException
	 */
	public HttpRespons sendGet(String urlString, Map<String, String> params,
			Map<String, String> propertys) throws IOException {
		return this.send(urlString, "GET", params, propertys);
	}
 
	/**
	 * 发送POST请求
	 * 
	 * @param urlString
	 *            URL地址
	 * @return 响应对象
	 * @throws IOException
	 */
	public HttpRespons sendPost(String urlString) throws IOException {
		return this.send(urlString, "POST", null, null);
	}
 
	/**
	 * 发送POST请求
	 * 
	 * @param urlString
	 *            URL地址
	 * @param params
	 *            参数集合
	 * @return 响应对象
	 * @throws IOException
	 */
	public HttpRespons sendPost(String urlString, Map<String, String> params)
			throws IOException {
		return this.send(urlString, "POST", params, null);
	}
 
	/**
	 * 发送POST请求
	 * 
	 * @param urlString
	 *            URL地址
	 * @param params
	 *            参数集合
	 * @param propertys
	 *            请求属性
	 * @return 响应对象
	 * @throws IOException
	 */
	public HttpRespons sendPost(String urlString, Map<String, String> params,
			Map<String, String> propertys) throws IOException {
		return this.send(urlString, "POST", params, propertys);
	}
 
	/**
	 * 发送HTTP请求
	 * 
	 * @param urlString
	 * @return 响映对象
	 * @throws IOException
	 */
	private HttpRespons send(String urlString, String method,
			Map<String, String> parameters, Map<String, String> propertys)
			throws IOException {
		HttpURLConnection urlConnection = null;
 
		if (method.equalsIgnoreCase("GET") && parameters != null) {
			StringBuffer param = new StringBuffer();
			int i = 0;
			for (String key : parameters.keySet()) {
				if (i == 0)
					param.append("?");
				else
					param.append("&");
				param.append(key).append("=").append(parameters.get(key));
				i++;
			}
			urlString += param;
		}
		URL url = new URL(urlString);
		urlConnection = (HttpURLConnection) url.openConnection();
 
		urlConnection.setRequestMethod(method);
		urlConnection.setDoOutput(true);
		urlConnection.setDoInput(true);
		urlConnection.setUseCaches(false);
 
		if (propertys != null)
			for (String key : propertys.keySet()) {
				urlConnection.addRequestProperty(key, propertys.get(key));
			}
 
		if (method.equalsIgnoreCase("POST") && parameters != null) {
			StringBuffer param = new StringBuffer();
			for (String key : parameters.keySet()) {
				param.append("&");
				param.append(key).append("=").append(parameters.get(key));
			}
			urlConnection.getOutputStream().write(param.toString().getBytes());
			urlConnection.getOutputStream().flush();
			urlConnection.getOutputStream().close();
		}
 
		return this.makeContent(urlString, urlConnection);
	}
 
	/**
	 * 得到响应对象
	 * 
	 * @param urlConnection
	 * @return 响应对象
	 * @throws IOException
	 */
	private HttpRespons makeContent(String urlString,
			HttpURLConnection urlConnection) throws IOException {
		HttpRespons httpResponser = new HttpRespons();
		try {
			InputStream in = urlConnection.getInputStream();
			BufferedReader bufferedReader = new BufferedReader(
					new InputStreamReader(in));
			httpResponser.contentCollection = new Vector<String>();
			StringBuffer temp = new StringBuffer();
			String line = bufferedReader.readLine();
			while (line != null) {
				httpResponser.contentCollection.add(line);
				temp.append(line).append("\r\n");
				line = bufferedReader.readLine();
			}
			bufferedReader.close();
 
			String ecod = urlConnection.getContentEncoding();
			if (ecod == null)
				ecod = this.defaultContentEncoding;
 
			httpResponser.urlString = urlString;
 
			httpResponser.defaultPort = urlConnection.getURL().getDefaultPort();
			httpResponser.file = urlConnection.getURL().getFile();
			httpResponser.host = urlConnection.getURL().getHost();
			httpResponser.path = urlConnection.getURL().getPath();
			httpResponser.port = urlConnection.getURL().getPort();
			httpResponser.protocol = urlConnection.getURL().getProtocol();
			httpResponser.query = urlConnection.getURL().getQuery();
			httpResponser.ref = urlConnection.getURL().getRef();
			httpResponser.userInfo = urlConnection.getURL().getUserInfo();
 
			httpResponser.content = new String(temp.toString().getBytes(), ecod);
			httpResponser.contentEncoding = ecod;
			httpResponser.code = urlConnection.getResponseCode();
			httpResponser.message = urlConnection.getResponseMessage();
			httpResponser.contentType = urlConnection.getContentType();
			httpResponser.method = urlConnection.getRequestMethod();
			httpResponser.connectTimeout = urlConnection.getConnectTimeout();
			httpResponser.readTimeout = urlConnection.getReadTimeout();
 
			return httpResponser;
		} catch (IOException e) {
			throw e;
		} finally {
			if (urlConnection != null)
				urlConnection.disconnect();
		}
	}
 
	/**
	 * 默认的响应字符集
	 */
	public String getDefaultContentEncoding() {
		return this.defaultContentEncoding;
	}
 
	/**
	 * 设置默认的响应字符集
	 */
	public void setDefaultContentEncoding(String defaultContentEncoding) {
		this.defaultContentEncoding = defaultContentEncoding;
	}
}

 

 

其次我们来看看响应对象（HttpRespons ）。 响应对象其实只是一个数据BEAN ，由此来封装请求响应的结果数据，如下：

import java.util.Vector;
 
/**
 * 响应对象
 */
public class HttpRespons {
 
	String urlString;
 
	int defaultPort;
 
	String file;
 
	String host;
 
	String path;
 
	int port;
 
	String protocol;
 
	String query;
 
	String ref;
 
	String userInfo;
 
	String contentEncoding;
 
	String content;
 
	String contentType;
 
	int code;
 
	String message;
 
	String method;
 
	int connectTimeout;
 
	int readTimeout;
 
	Vector<String> contentCollection;
 
	public String getContent() {
		return content;
	}
 
	public String getContentType() {
		return contentType;
	}
 
	public int getCode() {
		return code;
	}
 
	public String getMessage() {
		return message;
	}
 
	public Vector<String> getContentCollection() {
		return contentCollection;
	}
 
	public String getContentEncoding() {
		return contentEncoding;
	}
 
	public String getMethod() {
		return method;
	}
 
	public int getConnectTimeout() {
		return connectTimeout;
	}
 
	public int getReadTimeout() {
		return readTimeout;
	}
 
	public String getUrlString() {
		return urlString;
	}
 
	public int getDefaultPort() {
		return defaultPort;
	}
 
	public String getFile() {
		return file;
	}
 
	public String getHost() {
		return host;
	}
 
	public String getPath() {
		return path;
	}
 
	public int getPort() {
		return port;
	}
 
	public String getProtocol() {
		return protocol;
	}
 
	public String getQuery() {
		return query;
	}
 
	public String getRef() {
		return ref;
	}
 
	public String getUserInfo() {
		return userInfo;
	}
 
}

 

 

最后，让我们写一个应用类，测试以上代码是否正确

import com.yao.http.HttpRequester;
import com.yao.http.HttpRespons;
 
public class Test {
	public static void main(String[] args) {
		try {
			HttpRequester request = new HttpRequester();
			HttpRespons hr = request.sendGet("http://www.csdn.net");
 
			System.out.println(hr.getUrlString());
			System.out.println(hr.getProtocol());
			System.out.println(hr.getHost());
			System.out.println(hr.getPort());
			System.out.println(hr.getContentEncoding());
			System.out.println(hr.getMethod());
			
			System.out.println(hr.getContent());
 
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}

 

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• 2008-01-09 11:26
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评论

7 楼 半倾倾 2013-09-30  

很好，发现好多网站上都有这篇文章，但这个的阅读体验最好

6 楼 v11159588 2012-08-09  

这个还不错。

5 楼 hziee 2012-05-20  

好东西啊 拿来主义

4 楼 code_lvp 2008-10-16  

太好了。谢谢楼主

3 楼 lianyarong 2008-03-27  

谢谢楼住啊，解了我的燃眉之急，十分感谢！

2 楼 lpp333 2008-01-09  

楼上的这个地址不存在

1 楼 qsky 2008-01-09  

开源项目commons-httpclient对url处理和http通信的实现已经包装好了
请看这里
http://hc.apache.org/downloads.cgi

谢谢楼下的同志