android客户端向服务器通信一般有以下选择：
1.传统的java.net.HttpURLConnection类
2.apache的httpClient框架（已纳入android.jar中，可直接使用）
3.github上的开源框架async-http(基于httpClient) ---------------------------------------------------------------------------------- 下面分别记录这三种方式的使用，
传统方式：
/**
* 以get方式向服务端发送请求，并将服务端的响应结果以字符串方式返回。如果没有响应内容则返回空字符串
*
* @param url 请求的url地址
* @param params 请求参数
* @param charset url编码采用的码表
* @return
*/
public static String getDataByGet(String url,Map<string,string> params,String charset)
{
if(url == null)
{
return ;
}
url = url.trim();
URL targetUrl = null;
try
{
if(params == null)
{
targetUrl = new URL(url);
}
else
{
StringBuilder sb = new StringBuilder(url+?);
for(Map.Entry<string,string> me : params.entrySet())
{
// 解决请求参数中含有中文导致乱码问题
sb.append(me.getKey()).append(=).append(URLEncoder.encode(me.getValue(),charset)).append(&);
}
sb.deleteCharAt(sb.length()-1);
targetUrl = new URL(sb.toString());
}
Log.i(TAG,get:url----->+targetUrl.toString());//打印log
HttpURLConnection conn = (HttpURLConnection) targetUrl.openConnection();
conn.setConnectTimeout(3000);
conn.setRequestMethod(GET);
conn.setDoInput(true);
int responseCode = conn.getResponseCode();
if(responseCode == HttpURLConnection.HTTP_OK)
{
return stream2String(conn.getInputStream(),charset);
}
} catch (Exception e)
{
Log.i(TAG,e.getMessage());
}
return ;
/**
* 以post方式向服务端发送请求，并将服务端的响应结果以字符串方式返回。如果没有响应内容则返回空字符串
* @param url 请求的url地址
* @param params 请求参数
* @param charset url编码采用的码表
* @return
*/
public static String getDataByPost(String url,Map<string,string> params,String charset)
{
if(url == null)
{
return ;
}
url = url.trim();
URL targetUrl = null;
OutputStream out = null;
try
{
targetUrl = new URL(url);
HttpURLConnection conn = (HttpURLConnection) targetUrl.openConnection();
conn.setConnectTimeout(3000);
conn.setRequestMethod(POST);
conn.setDoInput(true);
conn.setDoOutput(true);
StringBuilder sb = new StringBuilder();
if(params!=null && !params.isEmpty())
{
for(Map.Entry<string,string> me : params.entrySet())
{
// 对请求数据中的中文进行编码
sb.append(me.getKey()).append(=).append(URLEncoder.encode(me.getValue(),charset)).append(&);
}
sb.deleteCharAt(sb.length()-1);
}
byte[] data = sb.toString().getBytes();
conn.setRequestProperty(Content-Type,application/x-www-form-urlencoded);
conn.setRequestProperty(Content-Length, String.valueOf(data.length));
out = conn.getOutputStream();
out.write(data);
Log.i(TAG,post:url----->+targetUrl.toString());//打印log
int responseCode = conn.getResponseCode();
if(responseCode == HttpURLConnection.HTTP_OK)
{
return stream2String(conn.getInputStream(),charset);
}
} catch (Exception e)
{
Log.i(TAG,e.getMessage());
}
return ;
}
/**
* 将输入流对象中的数据输出到字符串中返回
* @param in
* @return
* @throws IOException
*/
private static String stream2String(InputStream in,String charset) throws IOException
{
if(in == null)
return ;
byte[] buffer = new byte[1024];
ByteArrayOutputStream bout = new ByteArrayOutputStream();
int len = 0;
while((len = in.read(buffer)) !=-1)
{
bout.write(buffer, 0, len);
}
String result = new String(bout.toByteArray(),charset);
in.close();
return result;
}</string,string></string,string></string,string></string,string>
使用httpClient：
package cn.edu.chd.httpclientdemo.http;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.StatusLine;
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.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import android.util.Log;
/**
* @author Rowand jj
*
*http工具类,发送get/post请求
*/
public final class HttpUtils
{
private static final String TAG = HttpUtils;
private static final String CHARSET = utf-8;
private HttpUtils(){}
/**
* 以get方式向指定url发送请求，将响应结果以字符串方式返回
* @param uri
* @return 如果没有响应数据返回null
*/
public static String requestByGet(String url,Map<string,string> data)
{
if(url == null)
return null;
// 构建默认http客户端对象
HttpClient client = new DefaultHttpClient();
try
{
// 拼装url,并对中文进行编码
StringBuilder sb = new StringBuilder(url+?);
if(data != null)
{
for(Map.Entry<string,string> me : data.entrySet())
{
sb.append(URLEncoder.encode(me.getKey(),CHARSET)).append(=).append(URLEncoder.encode(me.getValue(),utf-8)).append(&);
}
sb.deleteCharAt(sb.length()-1);
}
Log.i(TAG, [get]--->uri:+sb.toString());
// 创建一个get请求
HttpGet get = new HttpGet(sb.toString());
// 执行get请求，获取http响应
HttpResponse response = client.execute(get);
// 获取响应状态行
StatusLine statusLine = response.getStatusLine();
//请求成功
if(statusLine != null && statusLine.getStatusCode() == 200)
{
// 获取响应实体
HttpEntity entity = response.getEntity();
if(entity != null)
{
return readInputStream(entity.getContent());
}
}
} catch (Exception e)
{
e.printStackTrace();
}
return null;
}
/**
* 以post方式向指定url发送请求，将响应结果以字符串方式返回
* @param url
* @param data 以键值对形式表示的信息
* @return
*/
public static String requestByPost(String url,Map<string,string> data)
{
if(url == null)
return null;
HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost(url);
List<namevaluepair> params = null;
try
{
Log.i(TAG, [post]--->uri:+url);
params = new ArrayList<namevaluepair>();
if(data != null)
{
for(Map.Entry<string,string> me : data.entrySet())
{
params.add(new BasicNameValuePair(me.getKey(),me.getValue()));
}
}
// 设置请求实体
post.setEntity(new UrlEncodedFormEntity(params,CHARSET));
// 获取响应信息
HttpResponse response = client.execute(post);
StatusLine statusLine = response.getStatusLine();
if(statusLine!=null && statusLine.getStatusCode()==200)
{
HttpEntity entity = response.getEntity();
if(entity!=null)
{
return readInputStream(entity.getContent());
}
}
} catch (Exception e)
{
e.printStackTrace();
}
return null;
}
/**
* 将流中的数据写入字符串返回
* @param is
* @return
* @throws IOException
*/
private static String readInputStream(InputStream is) throws IOException
{
if(is == null)
return null;
ByteArrayOutputStream bout = new ByteArrayOutputStream();
int len = 0;
byte[] buf = new byte[1024];
while((len = is.read(buf))!=-1)
{
bout.write(buf, 0, len);
}
is.close();
return new String(bout.toByteArray());
}
/**
* 将流中的数据写入字符串返回,以指定的编码格式
* 【如果服务端返回的编码不是utf-8，可以使用此方法，将返回结果以指定编码格式写入字符串】
* @param is
* @return
* @throws IOException
*/
private static String readInputStream(InputStream is,String charset) throws IOException
{
if(is == null)
return null;
ByteArrayOutputStream bout = new ByteArrayOutputStream();
int len = 0;
byte[] buf = new byte[1024];
while((len = is.read(buf))!=-1)
{
bout.write(buf, 0, len);
}
is.close();
return new String(bout.toByteArray(),charset);
}
}</string,string></namevaluepair></namevaluepair></string,string></string,string></string,string>
3.使用async-http框架，这个如果使用的话需要导入框架的jar包或者把源码拷到工程下： 这个框架的好处是每次请求会开辟子线程，不会抛networkonmainthread异常，另外处理器类继承了Handler类，所以可以在里面更改UI。 注：这里使用的是最新的1.4.4版。 ·
?
/**
* 使用异步http框架发送get请求
* @param path get路径，中文参数需要编码（URLEncoder.encode）
*/
public void doGet(String path)
{
AsyncHttpClient httpClient = new AsyncHttpClient();
httpClient.get(path, new AsyncHttpResponseHandler(){
@Override
public void onSuccess(int statusCode, Header[] headers, byte[] responseBody)
{
if(statusCode == 200)
{
try
{
// 此处应该根据服务端的编码格式进行编码，否则会乱码
tv_show.setText(new String(responseBody,utf-8));
} catch (UnsupportedEncodingException e)
{
e.printStackTrace();
}
}
}
});
}
/**
* 使用异步http框架发送get请求
* @param path
*/
public void doPost(String path)
{
AsyncHttpClient httpClient = new AsyncHttpClient();
RequestParams params = new RequestParams();
params.put(paper,中文);//value可以是流、文件、对象等其他类型,很强大!!
httpClient.post(path, params, new AsyncHttpResponseHandler(){
@Override
public void onSuccess(int statusCode, Header[] headers, byte[] responseBody)
{
if(statusCode == 200)
{
tv_show.setText(new String(responseBody));
}
}
});
}
上面那个tv_show是一个TextView控件。
