JAVA发送HTTP请求，并接受返回内容

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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：


Java代码

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 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 params,   
            Map 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 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 params,   
            Map 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 parameters, Map 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();   
            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;   
    }   
}  

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 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 params,
			Map 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 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 params,
			Map 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 parameters, Map 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();
			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： Java代码

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 contentCollection;   
    
    public String getContent() {   
        return content;   
    }   
    
    public String getContentType() {   
        return contentType;   
    }   
    
    public int getCode() {   
        return code;   
    }   
    
    public String getMessage() {   
        return message;   
    }   
    
    public Vector 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;   
    }   
    
}  

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 contentCollection;
 
	public String getContent() {
		return content;
	}
 
	public String getContentType() {
		return contentType;
	}
 
	public int getCode() {
		return code;
	}
 
	public String getMessage() {
		return message;
	}
 
	public Vector 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

Java代码

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();   
        }   
    }   
}