1. 发送请求到服务器有几种方式
（1）HttpURLConnection
（2）Httpclient 同步框架
（3）AsyncHttpClient 异步框架 （https://github.com/loopj/android-async-http 下载源码和lib包）
示例代码（3）示例 （最简便实用）
public void asyncGet(View v){
final String username = et_username.getText().toString().trim();
final String password = et_password.getText().toString().trim();
String uri = "http://192.168.1.100:8080/TestLogin/servlet/Login?"
+ "username=" + URLEncoder.encode(username)
+ "&password=" + URLEncoder.encode(password);
AsyncHttpClient client = new AsyncHttpClient();
client.get(uri, new AsyncHttpResponseHandler() {
@Override
public void onSuccess(String response) {
Toast.makeText(MainActivity.this, response, Toast.LENGTH_SHORT).show();
}
@Override
public void onFailure(Throwable error, String content) {
Toast.makeText(MainActivity.this, content, Toast.LENGTH_SHORT).show();
}
});
}
public void asyncPost(View v){
final String username = et_username.getText().toString().trim();
final String password = et_password.getText().toString().trim();
String uri = "http://192.168.1.100:8080/TestLogin/servlet/Login";
AsyncHttpClient client = new AsyncHttpClient();
RequestParams params = new RequestParams();
params.put("username", username);
params.put("password", password);
client.post(uri, params, new AsyncHttpResponseHandler() {
@Override
public void onSuccess(String response) {
Toast.makeText(MainActivity.this, response, Toast.LENGTH_SHORT).show();
}
@Override
public void onFailure(Throwable error, String content) {
Toast.makeText(MainActivity.this, content, Toast.LENGTH_SHORT).show();
}
});
}
示例代码 （1）（2）示例
public class MainActivity extends Activity {
private EditText et_password;
private EditText et_username;
public void loginByGet(View paramView) {
String str1 = this.et_password.getText().toString().trim();
String str2 = this.et_username.getText().toString().trim();
if ((TextUtils.isEmpty(str1)) || (TextUtils.isEmpty(str2))) {
Toast.makeText(this, "用户名密码不能为空", 1).show();
return;
}
try {
String str3 = String
.valueOf("http://192.168.1.100:8080/web/LoginServlet?");
StringBuilder localStringBuilder1 = new StringBuilder(str3)
.append("name=");
String str4 = URLEncoder.encode(str2, "UTF-8");
StringBuilder localStringBuilder2 = localStringBuilder1
.append(str4).append("&password=");
String str5 = URLEncoder.encode(str1, "UTF-8");
String str6 = str5;
HttpURLConnection localHttpURLConnection = (HttpURLConnection) new URL(
str6).openConnection();
localHttpURLConnection.setRequestMethod("GET");
localHttpURLConnection.setConnectTimeout(5000);
localHttpURLConnection
.setRequestProperty(
"User-Agent",
"Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET4.0C; .NET4.0E; .NET CLR 2.0.50727)");
if (localHttpURLConnection.getResponseCode() == 200) {
String str7 = StreamTools.readFromStream(localHttpURLConnection
.getInputStream());
Toast.makeText(this, str7, 1).show();
return;
}
} catch (Exception localException) {
localException.printStackTrace();
Toast.makeText(this, "登陆失败", 1).show();
return;
}
Toast.makeText(this, "登陆失败,http响应吗不正确.", 1).show();
}
public void loginByPost(View paramView) {
String str1 = this.et_password.getText().toString().trim();
String str2 = this.et_username.getText().toString().trim();
if ((TextUtils.isEmpty(str1)) || (TextUtils.isEmpty(str2))) {
Toast.makeText(this, "用户名密码不能为空", 1).show();
return;
}
try {
HttpURLConnection localHttpURLConnection = (HttpURLConnection) new URL(
"http://192.168.1.100:8080/web/LoginServlet")
.openConnection();
localHttpURLConnection.setRequestMethod("POST");
localHttpURLConnection.setRequestProperty("Content-Type",
"application/x-www-form-urlencoded");
StringBuilder localStringBuilder1 = new StringBuilder("name=");
String str3 = URLEncoder.encode(str2, "UTF-8");
StringBuilder localStringBuilder2 = localStringBuilder1
.append(str3).append("&password=");
String str4 = URLEncoder.encode(str1, "UTF-8");
String str5 = str4;
String str6 = String.valueOf(str5.length());
String str7 = str6;
localHttpURLConnection.setRequestProperty("Content-Length", str7);
//允许对外写数据
localHttpURLConnection.setDoOutput(true);
OutputStream localOutputStream = localHttpURLConnection
.getOutputStream();
byte[] arrayOfByte = str5.getBytes();
localOutputStream.write(arrayOfByte);
localOutputStream.flush();
if (localHttpURLConnection.getResponseCode() == 200) {
String str8 = StreamTools.readFromStream(localHttpURLConnection
.getInputStream());
Toast.makeText(this, str8, 1).show();
localOutputStream.close();
return;
}
} catch (Exception localException) {
Toast.makeText(this, "post登陆失败", 1).show();
return;
}
Toast.makeText(this, "post登陆失败,http响应吗不正确.", 1).show();
}
protected void onCreate(Bundle paramBundle) {
super.onCreate(paramBundle);
setContentView(R.layout.activity_main);
EditText localEditText1 = (EditText) findViewById(R.id.et_username);
this.et_username = localEditText1;
EditText localEditText2 = (EditText) findViewById(R.id.et_password);
this.et_password = localEditText2;
}
/**
* 采用httpclient的方式 用get提交数据到服务器
*/
public void loginByClientGet(View view) {
String password = et_password.getText().toString().trim();
String name = et_username.getText().toString().trim();
if (TextUtils.isEmpty(name) || TextUtils.isEmpty(password)) {
Toast.makeText(this, "用户名密码不能为空", 1).show();
return;
}
// 1.打开浏览器
HttpClient client = new DefaultHttpClient();
// 2.输入浏览器的地址
String uri = "http://192.168.1.100:8080/web/LoginServlet?" + "name="
+ URLEncoder.encode(name) + "&password="
+ URLEncoder.encode(password);
HttpGet httpGet = new HttpGet(uri);
// 3.敲回车.
try {
HttpResponse response = client.execute(httpGet);
int code = response.getStatusLine().getStatusCode();
if (code == 200) {
InputStream is = response.getEntity().getContent();
String result = StreamTools.readFromStream(is);
Toast.makeText(this, result, 1).show();
} else {
Toast.makeText(this, "服务器异常", 1).show();
}
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(this, "访问网络异常", 1).show();
}
}
/**
* 采用httpclient post数据到服务器
*/
public void loginByClientPost(View view) {
String password = et_password.getText().toString().trim();
String name = et_username.getText().toString().trim();
if (TextUtils.isEmpty(name) || TextUtils.isEmpty(password)) {
Toast.makeText(this, "用户名密码不能为空", 1).show();
return;
}
try {
// 1.创建一个浏览器
HttpClient client = new DefaultHttpClient();
// 2.准备一个连接
HttpPost post = new HttpPost(
"http://192.168.1.100:8080/web/LoginServlet");
// 要向服务器提交的数据实体
List<NameValuePair> parameters = new ArrayList<NameValuePair>();
parameters.add(new BasicNameValuePair("name", name));
parameters.add(new BasicNameValuePair("password", password));
UrlEncodedFormEntity entity = new UrlEncodedFormEntity(parameters,
"utf-8");
post.setEntity(entity);
// 3.敲回车
HttpResponse response = client.execute(post);
int code = response.getStatusLine().getStatusCode();
if (code == 200) {
InputStream is = response.getEntity().getContent();
String result = StreamTools.readFromStream(is);
Toast.makeText(this, result, 1).show();
} else {
Toast.makeText(this, "服务器异常", 1).show();
}
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(this, "client post 失败", 1).show();
}
}
}