URLConnection和HTTPClient的比较

1.概念      

      HTTP 协议可能是现在 Internet 上使用得最多、最重要的协议了，越来越多的 Java 应用程序需要直接通过 HTTP 协议来访问网络资源。在 JDK 的 java.net 包中已经提供了访问 HTTP 协议的基本功能：HttpURLConnection。但是对于大部分应用程序来说，JDK 库本身提供的功能还不够丰富和灵活。

      除此之外，在Android中，androidSDK中集成了Apache的HttpClient模块，用来提供高效的、最新的、功能丰富的支持 HTTP 协议工具包，并且它支持 HTTP 协议最新的版本和建议。使用HttpClient可以快速开发出功能强大的Http程序。

2.区别

HttpClient是个很不错的开源框架，封装了访问http的请求头，参数，内容体，响应等等，

HttpURLConnection是java的标准类，什么都没封装，用起来太原始，不方便，比如重访问的自定义，以及一些高级功能等。

3.案例

URLConnection

String urlAddress = "http://192.168.1.102:8080/AndroidServer/login.do"; 
URL url; 
HttpURLConnection uRLConnection; 
public UrlConnectionToServer(){ 

}
//向服务器发送get请求
public String doGet(String username,String password){ 
String getUrl = urlAddress + "?username="+username+"&password="+password; 
try { 
url = new URL(getUrl); 
uRLConnection = (HttpURLConnection)url.openConnection(); 
InputStream is = uRLConnection.getInputStream(); 
BufferedReader br = new BufferedReader(new InputStreamReader(is)); 
String response = ""; 
String readLine = null; 
while((readLine =br.readLine()) != null){ 
//response = br.readLine(); 
response = response + readLine; 
} 
is.close(); 
br.close(); 
uRLConnection.disconnect(); 
return response; 
} catch (MalformedURLException e) { 
e.printStackTrace(); 
returnnull; 
} catch (IOException e) { 
e.printStackTrace(); 
returnnull; 
} 
} 
 
//向服务器发送post请求
public String doPost(String username,String password){ 
try { 
url = new URL(urlAddress); 
uRLConnection = (HttpURLConnection)url.openConnection(); 
uRLConnection.setDoInput(true); 
uRLConnection.setDoOutput(true); 
uRLConnection.setRequestMethod("POST"); 
uRLConnection.setUseCaches(false); 
uRLConnection.setInstanceFollowRedirects(false); 
uRLConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); 
uRLConnection.connect(); 

DataOutputStream out = new DataOutputStream(uRLConnection.getOutputStream()); 
String content = "username="+username+"&password="+password; 
out.writeBytes(content); 
out.flush(); 
out.close(); 

InputStream is = uRLConnection.getInputStream(); 
BufferedReader br = new BufferedReader(new InputStreamReader(is)); 
String response = ""; 
String readLine = null; 
while((readLine =br.readLine()) != null){ 
//response = br.readLine(); 
response = response + readLine; 
} 
is.close(); 
br.close(); 
uRLConnection.disconnect(); 
return response; 
} catch (MalformedURLException e) { 
e.printStackTrace(); 
returnnull; 
} catch (IOException e) { 
e.printStackTrace(); 
returnnull; 
} 
}

HTTPClient

String urlAddress = "http://192.168.1.102:8080/qualityserver/login.do"; 
public HttpClientServer(){ 

} 

public String doGet(String username,String password){ 
String getUrl = urlAddress + "?username="+username+"&password="+password; 
HttpGet httpGet = new HttpGet(getUrl); 
HttpParams hp = httpGet.getParams(); 
hp.getParameter("true"); 
//hp. 
//httpGet.setp 
HttpClient hc = new DefaultHttpClient(); 
try { 
HttpResponse ht = hc.execute(httpGet); 
if(ht.getStatusLine().getStatusCode() == HttpStatus.SC_OK){ 
HttpEntity he = ht.getEntity(); 
InputStream is = he.getContent(); 
BufferedReader br = new BufferedReader(new InputStreamReader(is)); 
String response = ""; 
String readLine = null; 
while((readLine =br.readLine()) != null){ 
//response = br.readLine(); 
response = response + readLine; 
} 
is.close(); 
br.close(); 

//String str = EntityUtils.toString(he); 
System.out.println("========="+response); 
return response; 
}else{ 
return "error"; 
} 
} catch (ClientProtocolException e) { 
// TODO Auto-generated catch block 
e.printStackTrace(); 
return "exception"; 
} catch (IOException e) { 
// TODO Auto-generated catch block 
e.printStackTrace(); 
return "exception"; 
} 
} 

public String doPost(String username,String password){ 
//String getUrl = urlAddress + "?username="+username+"&password="+password; 
HttpPost httpPost = new HttpPost(urlAddress); 
List params = new ArrayList(); 
NameValuePair pair1 = new BasicNameValuePair("username", username); 
NameValuePair pair2 = new BasicNameValuePair("password", password); 
params.add(pair1); 
params.add(pair2); 

HttpEntity he; 
try { 
he = new UrlEncodedFormEntity(params, "gbk"); 
httpPost.setEntity(he); 

} catch (UnsupportedEncodingException e1) { 
// TODO Auto-generated catch block 
e1.printStackTrace(); 
} 

HttpClient hc = new DefaultHttpClient(); 
try { 
HttpResponse ht = hc.execute(httpPost); 
//连接成功 
if(ht.getStatusLine().getStatusCode() == HttpStatus.SC_OK){ 
HttpEntity het = ht.getEntity(); 
InputStream is = het.getContent(); 
BufferedReader br = new BufferedReader(new InputStreamReader(is)); 
String response = ""; 
String readLine = null; 
while((readLine =br.readLine()) != null){ 
//response = br.readLine(); 
response = response + readLine; 
} 
is.close(); 
br.close(); 

//String str = EntityUtils.toString(he); 
System.out.println("=========&&"+response); 
return response; 
}else{ 
return "error"; 
} 
} catch (ClientProtocolException e) { 
// TODO Auto-generated catch block 
e.printStackTrace(); 
return "exception"; 
} catch (IOException e) { 
// TODO Auto-generated catch block 
e.printStackTrace(); 
return "exception"; 
} 
}

servlet端json转化： 

resp.setContentType("text/json"); 
resp.setCharacterEncoding("UTF-8"); 
toDo = new ToDo(); 
List<UserBean> list = new ArrayList<UserBean>(); 
list = toDo.queryUsers(mySession); 
String body; 

//设定JSON 
JSONArray array = new JSONArray(); 
for(UserBean bean : list) 
{ 
JSONObject obj = new JSONObject(); 
try
{ 
obj.put("username", bean.getUserName()); 
obj.put("password", bean.getPassWord()); 
}catch(Exception e){} 
array.add(obj); 
} 
pw.write(array.toString()); 
System.out.println(array.toString());

android端接收

String urlAddress = "http://192.168.1.102:8080/qualityserver/result.do"; 
String body = 
getContent(urlAddress); 
JSONArray array = new JSONArray(body); 
for(int i=0;i<array.length();i++) 
{ 
obj = array.getJSONObject(i); 
sb.append("用户名:").append(obj.getString("username")).append("\t"); 
sb.append("密码:").append(obj.getString("password")).append("\n"); 

HashMap<String, Object> map = new HashMap<String, Object>(); 
try { 
userName = obj.getString("username"); 
passWord = obj.getString("password"); 
} catch (JSONException e) { 
e.printStackTrace(); 
} 
map.put("username", userName); 
map.put("password", passWord); 
listItem.add(map); 

} 

} catch (Exception e) { 
// TODO Auto-generated catch block 
e.printStackTrace(); 
} 

if(sb!=null) 
{ 
showResult.setText("用户名和密码信息："); 
showResult.setTextSize(20); 
} else
extracted(); 

//设置adapter 
SimpleAdapter simple = new SimpleAdapter(this,listItem, 
android.R.layout.simple_list_item_2, 
new String[]{"username","password"}, 
newint[]{android.R.id.text1,android.R.id.text2}); 
listResult.setAdapter(simple); 

listResult.setOnItemClickListener(new OnItemClickListener() { 
@Override 
publicvoid onItemClick(AdapterView<?> parent, View view, 
int position, long id) { 
int positionId = (int) (id+1); 
Toast.makeText(MainActivity.this, "ID："+positionId, Toast.LENGTH_LONG).show(); 

} 
}); 
} 
privatevoid extracted() { 
showResult.setText("没有有效的数据！"); 
} 
//和服务器连接 
private String getContent(String url)throws Exception{ 
StringBuilder sb = new StringBuilder(); 
HttpClient client =new DefaultHttpClient(); 
HttpParams httpParams =client.getParams(); 

HttpConnectionParams.setConnectionTimeout(httpParams, 3000); 
HttpConnectionParams.setSoTimeout(httpParams, 5000); 
HttpResponse response = client.execute(new HttpGet(url)); 
HttpEntity entity =response.getEntity(); 

if(entity !=null){ 
BufferedReader reader = new BufferedReader(new InputStreamReader 
(entity.getContent(),"UTF-8"),8192); 
String line =null; 
while ((line= reader.readLine())!=null){ 
sb.append(line +"\n"); 
} 
reader.close(); 
} 
return sb.toString(); 
}