准备条件，
编写一个web项目。编写一个servlet，若用户名为lisi,密码为123，则返回“登录成功”，否则”登录失败”。项目名为ServerItheima28。代码如下：
package com.itheima28.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class LoginServlet extends HttpServlet {
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String username = request.getParameter("username"); // 采用的编码是: iso-8859-1
String password = request.getParameter("password");
// 采用iso8859-1的编码对姓名进行逆转, 转换成字节数组, 再使用utf-8编码对数据进行转换, 字符串
username = new String(username.getBytes("iso8859-1"), "utf-8");
password = new String(password.getBytes("iso8859-1"), "utf-8");
System.out.println("姓名: " + username);
System.out.println("密码: " + password);
if("lisi".equals(username) && "123".equals(password)) {
/*
* getBytes 默认情况下, 使用的iso8859-1的编码, 但如果发现码表中没有当前字符,
* 会使用当前系统下的默认编码: GBK
*/
response.getOutputStream().write("登录成功".getBytes("utf-8"));
} else {
response.getOutputStream().write("登录失败".getBytes("utf-8"));
}
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("doPost");
doGet(request, response);
}
}
使用github上的android-async-http-master框架：
2 编写Android应用，应用截图如下：
代码结构如下：
清单文件
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.itheim28.submitdata"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="19" />
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.itheim28.submitdata.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
3 编写布局文件activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity" >
<EditText
android:id="@+id/et_username"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:hint="请输入姓名" />
<EditText
android:id="@+id/et_password"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:hint="请输入密码" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="doGet"
android:text="Get方式提交" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="doPost"
android:text="Post方式提交" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="doHttpClientOfGet"
android:text="使用HttpClient方式提交Get请求" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="doHttpClientOfPost"
android:text="使用HttpClient方式提交Post请求" />
</LinearLayout>
4 NetUtils的内容如下：
package com.itheim28.submitdata.utils;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import android.util.Log;
public class NetUtils {
private static final String TAG = "NetUtils";
/**
* 使用post的方式登录
*
* @param userName
* @param password
* @return
*/
public static String loginOfPost(String userName, String password) {
HttpURLConnection conn = null;
try {
URL url = new URL(
"http://114.215.142.191:8080/ServerItheima28/servlet/LoginServlet");
conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("POST");
conn.setConnectTimeout(10000); // 连接的超时时间
conn.setReadTimeout(5000); // 读数据的超时时间
conn.setDoOutput(true); // 必须设置此方法, 允许输出
// conn.setRequestProperty("Content-Length", 234); // 设置请求头消息,
// 可以设置多个
// post请求的参数
String data = "username=" + userName + "&password=" + password;
// 获得一个输出流, 用于向服务器写数据, 默认情况下, 系统不允许向服务器输出内容
OutputStream out = conn.getOutputStream();
out.write(data.getBytes());
out.flush();
out.close();
int responseCode = conn.getResponseCode();
if (responseCode == 200) {
InputStream is = conn.getInputStream();
String state = getStringFromInputStream(is);
return state;
} else {
Log.i(TAG, "访问失败: " + responseCode);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (conn != null) {
conn.disconnect();
}
}
return null;
}
/**
* 使用get的方式登录
*
* @param userName
* @param password
* @return 登录的状态
*/
public static String loginOfGet(String userName, String password) {
HttpURLConnection conn = null;
try {
String data = "username=" + URLEncoder.encode(userName)
+ "&password=" + URLEncoder.encode(password);
URL url = new URL(
"http://114.215.142.191:8080/ServerItheima28/servlet/LoginServlet?"
+ data);
conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET"); // get或者post必须得全大写
conn.setConnectTimeout(10000); // 连接的超时时间
conn.setReadTimeout(5000); // 读数据的超时时间
int responseCode = conn.getResponseCode();
if (responseCode == 200) {
InputStream is = conn.getInputStream();
String state = getStringFromInputStream(is);
return state;
} else {
Log.i(TAG, "访问失败: " + responseCode);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (conn != null) {
conn.disconnect(); // 关闭连接
}
}
return null;
}
/**
* 根据流返回一个字符串信息
*
* @param is
* @return
* @throws IOException
*/
private static String getStringFromInputStream(InputStream is)
throws IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len = -1;
while ((len = is.read(buffer)) != -1) {
baos.write(buffer, 0, len);
}
is.close();
String html = baos.toString(); // 把流中的数据转换成字符串, 采用的编码是: utf-8
// String html = new String(baos.toByteArray(), "GBK");
baos.close();
return html;
}
}
5 NetUtils2代码如下：
package com.itheim28.submitdata.utils;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
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;
public class NetUtils2 {
private static final String TAG = "NetUtils";
/**
* 使用post的方式登录
*
* @param userName
* @param password
* @return
*/
public static String loginOfPost(String userName, String password) {
HttpClient client = null;
try {
// 定义一个客户端
client = new DefaultHttpClient();
// 定义post方法
HttpPost post = new HttpPost(
"http://114.215.142.191:8080/ServerItheima28/servlet/LoginServlet");
// 定义post请求的参数
List<NameValuePair> parameters = new ArrayList<NameValuePair>();
parameters.add(new BasicNameValuePair("username", userName));
parameters.add(new BasicNameValuePair("password", password));
// 把post请求的参数包装了一层.
// 不写编码名称服务器收数据时乱码. 需要指定字符集为utf-8
UrlEncodedFormEntity entity = new UrlEncodedFormEntity(parameters,
"utf-8");
// 设置参数.
post.setEntity(entity);
// 设置请求头消息
// post.addHeader("Content-Length", "20");
// 使用客户端执行post方法
HttpResponse response = client.execute(post); // 开始执行post请求,
// 会返回给我们一个HttpResponse对象
// 使用响应对象, 获得状态码, 处理内容
int statusCode = response.getStatusLine().getStatusCode(); // 获得状态码
if (statusCode == 200) {
// 使用响应对象获得实体, 获得输入流
InputStream is = response.getEntity().getContent();
String text = getStringFromInputStream(is);
return text;
} else {
Log.i(TAG, "请求失败: " + statusCode);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (client != null) {
client.getConnectionManager().shutdown(); // 关闭连接和释放资源
}
}
return null;
}
/**
* 使用get的方式登录
*
* @param userName
* @param password
* @return 登录的状态
*/
public static String loginOfGet(String userName, String password) {
HttpClient client = null;
try {
// 定义一个客户端
client = new DefaultHttpClient();
// 定义一个get请求方法
String data = "username=" + userName + "&password=" + password;
HttpGet get = new HttpGet(
"http://114.215.142.191:8080/ServerItheima28/servlet/LoginServlet?" + data);
// response 服务器相应对象, 其中包含了状态信息和服务器返回的数据
// 开始执行get方法, 请求网络
HttpResponse response = client.execute(get);
// 获得响应码
int statusCode = response.getStatusLine().getStatusCode();
if (statusCode == 200) {
InputStream is = response.getEntity().getContent();
String text = getStringFromInputStream(is);
return text;
} else {
Log.i(TAG, "请求失败: " + statusCode);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (client != null) {
client.getConnectionManager().shutdown(); // 关闭连接, 和释放资源
}
}
return null;
}
/**
* 根据流返回一个字符串信息
*
* @param is
* @return
* @throws IOException
*/
private static String getStringFromInputStream(InputStream is)
throws IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len = -1;
while ((len = is.read(buffer)) != -1) {
baos.write(buffer, 0, len);
}
is.close();
String html = baos.toString(); // 把流中的数据转换成字符串, 采用的编码是: utf-8
// String html = new String(baos.toByteArray(), "GBK");
baos.close();
return html;
}
}
6 MainActivity代码如下：
package com.itheim28.submitdata;
import android.app.Activity;
import android.os.Bundle;
import android.text.TextUtils;
import android.util.Log;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;
import com.itheim28.submitdata.utils.NetUtils;
import com.itheim28.submitdata.utils.NetUtils2;
public class MainActivity extends Activity {
private static final String TAG = "MainActivity";
private EditText etUserName;
private EditText etPassword;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
etUserName = (EditText) findViewById(R.id.et_username);
etPassword = (EditText) findViewById(R.id.et_password);
}
/**
* 使用httpClient方式提交get请求
*
* @param v
*/
public void doHttpClientOfGet(View v) {
Log.i(TAG, "doHttpClientOfGet");
final String userName = etUserName.getText().toString();
final String password = etPassword.getText().toString();
new Thread(new Runnable() {
@Override
public void run() {
// 请求网络
final String state = NetUtils2.loginOfGet(userName, password);
// 执行任务在主线程中
runOnUiThread(new Runnable() {
@Override
public void run() {
// 就是在主线程中操作
Toast.makeText(MainActivity.this, state, 0).show();
}
});
}
}).start();
}
/**
* 使用httpClient方式提交post请求
*
* @param v
*/
public void doHttpClientOfPost(View v) {
Log.i(TAG, "doHttpClientOfPost");
final String userName = etUserName.getText().toString();
final String password = etPassword.getText().toString();
new Thread(new Runnable() {
@Override
public void run() {
final String state = NetUtils2.loginOfPost(userName, password);
// 执行任务在主线程中
runOnUiThread(new Runnable() {
@Override
public void run() {
// 就是在主线程中操作
Toast.makeText(MainActivity.this, state, 0).show();
}
});
}
}).start();
}
public void doGet(View v) {
final String userName = etUserName.getText().toString();
final String password = etPassword.getText().toString();
new Thread(new Runnable() {
@Override
public void run() {
// 使用get方式抓去数据
final String state = NetUtils.loginOfGet(userName, password);
// 执行任务在主线程中
runOnUiThread(new Runnable() {
@Override
public void run() {
// 就是在主线程中操作
Toast.makeText(MainActivity.this, state, 0).show();
}
});
}
}).start();
}
public void doPost(View v) {
final String userName = etUserName.getText().toString();
final String password = etPassword.getText().toString();
new Thread(new Runnable() {
@Override
public void run() {
final String state = NetUtils.loginOfPost(userName, password);
// 执行任务在主线程中
runOnUiThread(new Runnable() {
@Override
public void run() {
// 就是在主线程中操作
Toast.makeText(MainActivity.this, state, 0).show();
}
});
}
}).start();
}
}
7 MainActivity2 的代码如下：
package com.itheim28.submitdata;
import java.net.URLEncoder;
import org.apache.http.Header;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;
import com.loopj.android.http.AsyncHttpClient;
import com.loopj.android.http.AsyncHttpResponseHandler;
import com.loopj.android.http.RequestParams;
public class MainActivity2 extends Activity {
protected static final String TAG = "MainActivity2";
private EditText etUserName;
private EditText etPassword;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
etUserName = (EditText) findViewById(R.id.et_username);
etPassword = (EditText) findViewById(R.id.et_password);
}
public void doGet(View v) {
final String userName = etUserName.getText().toString();
final String password = etPassword.getText().toString();
AsyncHttpClient client = new AsyncHttpClient();
String data = "username=" + URLEncoder.encode(userName) + "&password="
+ URLEncoder.encode(password);
client.get("http://114.215.142.191:8080/ServerItheima28/servlet/LoginServlet?"
+ data, new MyResponseHandler());
}
public void doPost(View v) {
final String userName = etUserName.getText().toString();
final String password = etPassword.getText().toString();
AsyncHttpClient client = new AsyncHttpClient();
RequestParams params = new RequestParams();
params.put("username", userName);
params.put("password", password);
client.post(
"http://114.215.142.191:8080/ServerItheima28/servlet/LoginServlet",
params, new MyResponseHandler());
}
class MyResponseHandler extends AsyncHttpResponseHandler {
@Override
public void onSuccess(int statusCode, Header[] headers,
byte[] responseBody) {
// Log.i(TAG, "statusCode: " + statusCode);
Toast.makeText(
MainActivity2.this,
"成功: statusCode: " + statusCode + ", body: "
+ new String(responseBody), 0).show();
}
@Override
public void onFailure(int statusCode, Header[] headers,
byte[] responseBody, Throwable error) {
Toast.makeText(MainActivity2.this, "失败: statusCode: " + statusCode,
0).show();
}
}
}
