使用HttpClient发送http请求，并解析从服务器端返回的数据

来源：互联网发布：python 程序编辑：程序博客网时间：2024/05/01 12:37
使用Apache的httpclient包可以模拟HTTP请求的发送， get和post均可以。最方便的地方就是请求struts等web框架进行测试，省去了做测试页面的差事。
[java] view plaincopyprint?
import java.io.IOException; 
import java.io.InputStream; 
import java.util.ArrayList; 
import java.util.List; 
import java.util.Map; 
import java.util.Set; 
import org.apache.http.HttpEntity; 
import org.apache.http.HttpResponse; 
import org.apache.http.NameValuePair; 
import org.apache.http.client.ClientProtocolException; 
import org.apache.http.client.HttpClient; 
import org.apache.http.client.entity.UrlEncodedFormEntity; 
import org.apache.http.client.methods.HttpGet; 
import org.apache.http.client.methods.HttpPost; 
import org.apache.http.entity.BufferedHttpEntity; 
import org.apache.http.impl.client.DefaultHttpClient; 
import org.apache.http.message.BasicNameValuePair; 
publicclass Client { 
public String sendGet(String url) throws ClientProtocolException, IOException{ 
String result =null;
HttpClient httpClient =new DefaultHttpClient();
HttpGet get =new HttpGet(url);
InputStream in =null;
try { 
HttpResponse response = httpClient.execute(get);
HttpEntity entity = response.getEntity();
if (entity != null) { 
entity =new BufferedHttpEntity(entity);
in = entity.getContent();
byte[] read = newbyte[1024];
byte[] all = newbyte[0];
int num; 
while ((num = in.read(read)) > 0) { 
byte[] temp = newbyte[all.length + num]; 
System.arraycopy(all,0, temp,0, all.length); 
System.arraycopy(read,0, temp, all.length, num);
all = temp;
}
result =new String(all,"UTF-8");
}
}finally {
if (in != null) in.close(); 
get.abort();
}
return result; 
}
public String sendPost(String url, Map<String, String> params) throws ClientProtocolException, IOException{ 
String result =null;
HttpClient httpClient =new DefaultHttpClient();
HttpPost get =new HttpPost(url);
// 创建表单参数列表 
List<NameValuePair> qparams =new ArrayList<NameValuePair>();
Set<String> keys = params.keySet();
for (String key : keys) { 
qparams.add(new BasicNameValuePair(key, params.get(key))); 
}
// 填充表单 
get.setEntity(new UrlEncodedFormEntity(qparams,"UTF-8"));
HttpResponse response = httpClient.execute(get);
HttpEntity entity = response.getEntity();
if (entity != null) { 
entity =new BufferedHttpEntity(entity);
InputStream in = entity.getContent();
byte[] read = newbyte[1024];
byte[] all = newbyte[0];
int num; 
while ((num = in.read(read)) > 0) { 
byte[] temp = newbyte[all.length + num]; 
System.arraycopy(all,0, temp,0, all.length); 
System.arraycopy(read,0, temp, all.length, num);
all = temp;
}
result =new String(all,"UTF-8");
if (null != in) { 
in.close();
}
}
get.abort();
return result; 
}
public String sendGet(String url, Map<String, String> params) throws ClientProtocolException, IOException { 
Set<String> keys = params.keySet();
StringBuilder urlBuilder =new StringBuilder(url +"?");
for (String key : keys) { 
urlBuilder.append(key).append("=").append(params.get(key)).append("&");
}
urlBuilder.delete(urlBuilder.length() -1, urlBuilder.length());
returnthis.sendGet(urlBuilder.toString());
}
}

如果服务器返回的是XML，上面的方法返回的就是xml的字符串，如"<XML><student>......</student></XML>"。在处理xml非常管用。

上面的例子，如果使用第二种或者第三种方法，需要将参数放在Map<String, String>中