网络编程（二）
Apache的HttpClient和Java的HttpURLConnection：
自己封装的网络请求类，第三方的网络请求框架都离不开的两个类库
1.HttpClient：
Android6.0版本直接删除了HttpClient类库，采用了OKHttp。
1⃣️简要说一下HttpClient的GET请求：
（1）.创建HttpClient
private HttpClient createHttpClient() {
HttpParams mDefaultHttpParams =newBasicHttpParams();
//设置连接超时
HttpConnectionParams.setConnectionTimeout(mDefaultHttpParams,15000);
HttpConnectionParams.setTcpNoDelay(mDefaultHttpParams,true);
HttpProtocolParams.setVersion(mDefaultHttpParams, HttpVersion.HTTP_1_1);
HttpProtocolParams.setContentCharset(mDefaultHttpParams, HTTP.UTF_8);
//持续握手
HttpProtocolParams.setUseExpectContinue(mDefaultHttpParams,true);
HttpClient mHttpClient=newDefaultHttpClient(mDefaultHttpParams);
returnmHttpClient;
（2）.接下来创建HttpGet和HttpClient，请求网络并得到HttpResponse，并对HttpResponse进行处理：
private void useHttpClientGet(String url) {
HttpGet mHttpGet =newHttpGet(url);
mHttpGet.addHeader("Connection","Keep-Alive");
try{
HttpClient mHttpClient = createHttpClient();
HttpResponse mHttpResponse = mHttpClient.execute(mHttpGet);
HttpEntity mHttpEntity = mHttpResponse.getEntity();
intcode =mHttpResponse.getStatusLine().getStatusCode();
if(null!= mHttpEntity) {
InputStream mInputStream =mHttpEntity.getContent();
String respose =converStreamToString(mInputStream);
Log.i("wangshu","请求状态码:"+ code +"\n请求结果:\n"+ respose);
mInputStream.close();
}
}catch(IOException e) {
e.printStackTrace();
}
(3).converStreamToString方法将请求结果转换成String类型：
private String converStreamToString(InputStream is) throws IOException {
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
StringBuffer sb = new StringBuffer();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
String respose = sb.toString();
return respose;
}
（4）.最后我们开启线程访问百度：
new Thread(new Runnable() {
@Override
public void run() {
useHttpClientGet("http://www.baidu.com");
}
}).start();
返回结果：
返回结果
2⃣️.HttpClient的POST请求：
private void useHttpClientPost(String url) {
HttpPost mHttpPost = new HttpPost(url);
mHttpPost.addHeader("Connection", "Keep-Alive");
try {
HttpClient mHttpClient = createHttpClient();
ListpostParams = new ArrayList<>();
//要传递的参数
postParams.add(new BasicNameValuePair("username", "moon"));
postParams.add(new BasicNameValuePair("password", "123"));
mHttpPost.setEntity(new UrlEncodedFormEntity(postParams));
HttpResponse mHttpResponse = mHttpClient.execute(mHttpPost);
HttpEntity mHttpEntity = mHttpResponse.getEntity();
int code = mHttpResponse.getStatusLine().getStatusCode();
if (null != mHttpEntity) {
InputStream mInputStream = mHttpEntity.getContent();
String respose = converStreamToString(mInputStream);
Log.i("wangshu", "请求状态码:" + code + "\n请求结果:\n" + respose);
mInputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}}
2.HttpURLConnection：
在Android 6.0版本中，HttpClient库被移除了，HttpURLConnection则是以后我们唯一的选择。
HttpURLConnection的POST请求:
会了HttpURLConnection的POST请求那GET请求也就会了，所以我这里只举出POST的例子:
(1).首先我们创建一个UrlConnManager类，然后里面提供getHttpURLConnection()方法用于配置默认的参数并返回HttpURLConnection：
public static HttpURLConnection getHttpURLConnection(String url){
HttpURLConnection mHttpURLConnection=null;
try {
URL mUrl=new URL(url);
mHttpURLConnection=(HttpURLConnection)mUrl.openConnection();
//设置链接超时时间
mHttpURLConnection.setConnectTimeout(15000);
//设置读取超时时间
mHttpURLConnection.setReadTimeout(15000);
//设置请求参数
mHttpURLConnection.setRequestMethod("POST");
//添加Header
mHttpURLConnection.setRequestProperty("Connection","Keep-Alive");
//接收输入流
mHttpURLConnection.setDoInput(true);
//传递参数时需要开启
mHttpURLConnection.setDoOutput(true);
} catch (IOException e) {
e.printStackTrace();
}
return mHttpURLConnection ;
}
(2).因为我们要发送POST请求，所以在UrlConnManager类中再写一个postParams()方法用来组织一下请求参数并将请求参数写入到输出流中：
public static void postParams(OutputStream output,Listparams List) throws IOException{
StringBuilder mStringBuilder=new StringBuilder();
for (NameValuePair pair:paramsList){
if(!TextUtils.isEmpty(mStringBuilder)){
mStringBuilder.append("&");
}
mStringBuilder.append(URLEncoder.encode(pair.getName(),"UTF-8"));
mStringBuilder.append("=");
mStringBuilder.append(URLEncoder.encode(pair.getValue(),"UTF-8"));
}
BufferedWriter writer=new BufferedWriter(new OutputStreamWriter(output,"UTF-8"));
writer.write(mStringBuilder.toString());
writer.flush();
writer.close();
}
(3).接下来我们添加请求参数，调用postParams()方法将请求的参数组织好传给HttpURLConnection的输出流，请求连接并处理返回的结果：
private void useHttpUrlConnectionPost(String url) { InputStream mInputStream = null; HttpURLConnection mHttpURLConnection = UrlConnManager.getHttpURLConnection(url); try { List postParams = new ArrayList<>();
//要传递的参数
postParams.add(new BasicNameValuePair("username", "moon"));
postParams.add(new BasicNameValuePair("password", "123"));
UrlConnManager.postParams(mHttpURLConnection.getOutputStream(), postParams);
mHttpURLConnection.connect();
mInputStream = mHttpURLConnection.getInputStream();
int code = mHttpURLConnection.getResponseCode();
String respose = converStreamToString(mInputStream);
Log.i("buxq", "请求状态码:" + code + "\n请求结果:\n" + respose);
mInputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
(4).最后开启线程请求网络:
private void useHttpUrlConnectionGetThread() {
new Thread(new Runnable() {
@Override
public void run() {
useHttpUrlConnectionPost("http://www.baidu.com");
}
}).start();
}
