HttpClient 连接网络的两种方法doGet和doPost

大家都知道android连接网络有两种方式，一种是HttpClient，另一种是HttpURLConnection，下面就先把我自己学习的第一种连网方式HttpClient记录下来，后一种方法有空再记录下来，好记心始终不如烂笔头啊。

android连网分HttpClient和HttpURLConnection两种，而HttpClient又分doGet和doPost两种，HttpURLConnection也分doGet和doPost两种；

一，不管是什么方式连网，都要检查网络的可用性

ConnectivityManager cm = (ConnectivityManager) getSystemService(this.CONNECTIVITY_SERVICE);
NetworkInfo info = cm.getActiveNetworkInfo();
if (info != null) {
Toast.makeText(HttpClientAsyncTaskActivity.this,
"连网正常" + info.getTypeName(), Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(HttpClientAsyncTaskActivity.this, "未连网",
Toast.LENGTH_SHORT).show();
}

在写这段代码前一定要先加权限：

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

public class HttpClientActivity extends Activity implements OnClickListener {
private TextView mTextView, mTextView1;
private Button mButton, mButton1, mButton2,mButton3;
private EditText mEditText;
private ProgressDialog pq;
private String addressurl = "http://192.168.1.196:8080/WebRoot/dogetServlet?name=admins&password=1234";
// private String addressurl = "http://www.baidu.com";

private String addressurl1 = "http://192.168.1.196:8080/WebRoot/dogetServlet";

/**
* 一get方法 通过get方法获取服务器数据的两个方式HttpClient，HttpURLConnection
* 传参直接在地址url中加上"?name=admins&password=1234" 传递的参数直接显示出来，不安全
*/
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.http_layout);

mTextView = (TextView) findViewById(R.id.httpclient_text);
mTextView1 = (TextView) findViewById(R.id.httpurl_text);
mButton = (Button) findViewById(R.id.http_httpclient_get_but);
mButton.setOnClickListener(this);
mButton1 = (Button) findViewById(R.id.http_httclient_post_but);
mButton1.setOnClickListener(this);
mButton2 = (Button) findViewById(R.id.http_httpurl_get_but);
mButton2.setOnClickListener(this);
mButton3=(Button) findViewById(R.id.http_httpurl_post_but);
mButton3.setOnClickListener(this);
mEditText=(EditText) findViewById(R.id.httpurl_edit);
}

doPost方法：

/**
* @param HttpClient POST请求
*/
public String getContentByHttpClientByPost(String httpurl) {
try {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(httpurl);
/** POST组装参数 **/
BasicNameValuePair userNamePair = new BasicNameValuePair("name",
"露西");
BasicNameValuePair passWordPair = new BasicNameValuePair(
"password", "abcd");
ArrayList<BasicNameValuePair> Pairlist = new ArrayList<BasicNameValuePair>();
Pairlist.add(userNamePair);
Pairlist.add(passWordPair);
UrlEncodedFormEntity entity = new UrlEncodedFormEntity(Pairlist,
HTTP.UTF_8);
httpPost.setEntity(entity);
httpPost.setHeader("Content-Type",
"application/x-www-form-urlencoded;charset=utf-8");

HttpResponse response = httpclient.execute(httpPost);
int statusCode = response.getStatusLine().getStatusCode();
Log.d("HttpClient  POST", "statusCode>>>>>>>: " + statusCode);
if (statusCode == HttpURLConnection.HTTP_OK) {
String content = EntityUtils.toString(response.getEntity());
Log.d("HttpClient  POST", "content>>>>>>>>: " + content);
return content;
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}

由于连接网络属于耗时操作，要实现HttpClient通信必须与AsyncTask异步机制结合，AsyncTask异步机制其实就是把线程和Handler消息机制封装的方法，当然这是系统封装好的的类；

case R.id.http_httclient_post_but:

new AsyncTask<String, Void, String>() {// 实现HttpClient通信与AsyncTask异步机制的结合
protected String doInBackground(String... params) {
String url = params[0];

return getContentByHttpClientByPost(url);
}

protected void onPostExecute(String result) {

if (result != null) {
mTextView.setText(result);
Log.v("HttpClient  POST", "onPostExecute>>post:"
+ result);
}

}
}.execute(addressurl1);
break;

doGet方法：

/**
*
* HttpClient GET请求
*
*/
public String getContentByHttpClient(String httpurl) {
InputStream in = null;
try {
HttpClient httpClient = new DefaultHttpClient();// 实例化HttpClient类
HttpGet httpGet = new HttpGet(httpurl);// 用get方法请求
HttpResponse response = httpClient.execute(httpGet);// 执行get请求方法返回
// response

int statusCode = response.getStatusLine().getStatusCode();// 通过获取状态行再获取状态码
Log.v("", "statusCode>>>>>:" + statusCode);

if (statusCode == HttpURLConnection.HTTP_OK) {// statusCode==200isok

in = response.getEntity().getContent();// 获取信息内容

BufferedReader reader = new BufferedReader(
new InputStreamReader(in, "UTF-8"));
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line);
}
Log.v("", "sb.toString():" + sb.toString());
return sb.toString();
}

} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (IllegalStateException e) {
e.printStackTrace();
} finally {
if (in != null) {
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return null;
}

同样，doGet方法也要与异步机制一起使用：

<pre class="java" name="code">case R.id.http_httpclient_get_but:
/** 参数组装 **/
// String urls="http://192.168.1.196:8080/WebRoot/dogetServlet";
// String parameter="?name=admins&password=1234";
// String urlss=urls+parameter;
// Log.v("","url>>>>:"+urlss);

new AsyncTask<String, Void, String>() {// 实现HttpClient通信与AsyncTask异步机制的结合
protected String doInBackground(String... params) {
String url = params[0];

return getContentByHttpClient(url);
}

protected void onPostExecute(String result) {

if (result != null) {
mTextView.setText(result);
// pq.dismiss();// 消除dialog
Log.v("", "onPostExecute:" + result);
}

}
}.execute(addressurl);
// pq = ProgressDialog.show(this, "请稍后。。。", "正在请求数据");
break;

权限配置：

<pre class="html" name="code">  <uses-permission android:name="android.permission.INTERNET" />