Android Java Web实现登录注册（一）——客户端
首先要搭建好Java Web开发环境，详细的方法请看另一篇博文点击打开链接
效果：
一、布局
布局如上图，为了控制篇幅就省略了，共用两个layout的.xml文件
二、Activity
import包的部分省略了
代码：LoginActivity.java
public class LoginActivity extends AppCompatActivity {
EditText id, password;
Button loginBtn, registerBtn;
Handler handler;
static int LOGIN_FAILED = 0;
static int LOGIN_SUCCEEDED = 1;
Dialog dialog;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
id = (EditText)findViewById(R.id.id);
password = (EditText)findViewById(R.id.password);
loginBtn = (Button)findViewById(R.id.loginBtn);
registerBtn = (Button)findViewById(R.id.registerBtn);
loginBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v){
if(isConnectingToInternet()){ //检查网络
if (id.getText().toString().equals(""))
Toast.makeText(LoginActivity.this, "请输入账号", Toast.LENGTH_SHORT).show();
else {
//启动登录Thread
dialog = new Dialog(LoginActivity.this);
dialog.setTitle("正在登录，请稍后...");
dialog.setCancelable(false);
dialog.show();
new LoginPostThread(id.getText().toString(),
password.getText().toString()).start();
}
}else{
Toast.makeText(getApplicationContext(),
"网络未连接",Toast.LENGTH_SHORT).show();
}
}
});
registerBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//跳转到注册Activity
Intent intent = new Intent(LoginActivity.this,
RegisterActivity.class);
startActivity(intent);
}
});
//Handle,Msg返回成功信息，跳转到其他Activity
handler = new Handler() {
public void handleMessage(Message msg) {
super.handleMessage(msg);
dialog.dismiss();
if (msg.what == 111) { // 处理发送线程传回的消息
if(msg.obj.toString().equals("SUCCEEDED")){
//跳转
Toast.makeText(LoginActivity.this, "模拟跳转", Toast.LENGTH_SHORT).show();
}else{
Toast.makeText(LoginActivity.this, "账号和密码不匹配", Toast.LENGTH_SHORT).show();
}
}
}
};
}
//登录Thread调用LoginPostService，返回Msg
public class LoginPostThread extends Thread {
public String id, password;
public LoginPostThread(String id, String password) {
this.id = id;
this.password = password;
}
@Override
public void run() {
// Sevice传回int
int responseInt = 0;
if(!id.equals("")) {
// 要发送的数据
List params = new ArrayList();
params.add(new BasicNameValuePair("id", id));
params.add(new BasicNameValuePair("password", password));
// 发送数据，获取对象
responseInt = LoginPostService.send(params);
Log.i("tag", "LoginActivity: responseInt = " + responseInt);
// 准备发送消息
Message msg = handler.obtainMessage();
// 设置消息默认值
msg.what = 111;
// 服务器返回信息的判断和处理
if(responseInt == LOGIN_FAILED) {
msg.obj = "FAILED";
}else if(responseInt == LOGIN_SUCCEEDED) {
msg.obj = "SUCCEEDED";
}
handler.sendMessage(msg);
}
}
}
// 检测网络状态
public boolean isConnectingToInternet() {
ConnectivityManager connectivity = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
if (connectivity != null) {
NetworkInfo[] info = connectivity.getAllNetworkInfo();
if (info != null)
for (int i = 0; i < info.length; i++)
if (info[i].getState() == NetworkInfo.State.CONNECTED)
{
return true;
}
}
return false;
}
} 其中，NameValuePair、BasicNameValuePair两个类的使用，需要为项目引入包：org.apache.http.legacy.jar。下载地址点击打开链接
代码：RegisterActivity.java
public class RegisterActivity extends AppCompatActivity {
EditText id, password;
Button loginBtn;
//Button returnBtn;
EditText password2, username;
Dialog dialog;
Handler handler;
static int LOGIN_FAILED = 0;
static int LOGIN_SUCCEEDED = 1;
static int REGISTER_FAILED = 2;
static int REGISTER_SUCCEEDED = 3;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
id = (EditText)findViewById(R.id.id);
password = (EditText)findViewById(R.id.password);
password2 = (EditText)findViewById(R.id.password2);
username = (EditText)findViewById(R.id.username);
loginBtn = (Button)findViewById(R.id.loginBtn);
//returnBtn = (Button)findViewById(R.id.returnBtn);
loginBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(checkEdit()){//检查注册信息
if(isConnectingToInternet()){ //检查网络
if (id.getText().toString().equals(""))
Toast.makeText(RegisterActivity.this, "请输入账号", Toast.LENGTH_SHORT).show();
else {
//启动登录Thread
dialog = new Dialog(RegisterActivity.this);
dialog.setTitle("正在注册，请稍后...");
dialog.setCancelable(false);
dialog.show();
new RegisterPostThread(id.getText().toString(),
username.getText().toString(),
password.getText().toString()).start();
}
}else{
Toast.makeText(getApplicationContext(),
"网络未连接",Toast.LENGTH_SHORT).show();
}
}
}
});
//Handle,Msg返回成功信息，跳转到其他Activity
handler = new Handler() {
public void handleMessage(Message msg) {
super.handleMessage(msg);
dialog.dismiss();
if (msg.what == 222) { // 处理发送线程传回的消息
if(msg.obj.toString().equals("SUCCEEDED")){
Log.i("tag", "注册模拟跳转");
//跳转
Toast.makeText(RegisterActivity.this, "模拟跳转", Toast.LENGTH_SHORT).show();
}else{
Toast.makeText(RegisterActivity.this, "账号已被注册，注册失败", Toast.LENGTH_SHORT).show();
}
}
}
};
/*
returnBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//回到登录Activity
Intent intent = new Intent(RegisterActivity.this,
LoginActivity.class);
startActivity(intent);
}
});*/
}
//注册Thread调用RegisterPostService，返回Msg
public class RegisterPostThread extends Thread {
public String id, username, password;
public RegisterPostThread(String id, String username, String password) {
this.id = id;
this.username = username;
this.password = password;
}
@Override
public void run() {
// Sevice传回int
int responseInt = 0;
if(!id.equals("")) {
// 要发送的数据
List params = new ArrayList();
params.add(new BasicNameValuePair("id", id));
params.add(new BasicNameValuePair("username", username));
params.add(new BasicNameValuePair("password", password));
// 发送数据，获取对象
responseInt = RegisterPostService.send(params);
Log.i("tag", "RegisterActivity: responseInt = " + responseInt);
// 准备发送消息
Message msg = handler.obtainMessage();
// 设置消息默认值
msg.what = 222;
// 服务器返回信息的判断和处理
if(responseInt == REGISTER_FAILED) {
msg.obj = "FAILED";
}else if(responseInt == REGISTER_SUCCEEDED) {
msg.obj = "SUCCEEDED";
}
handler.sendMessage(msg);
}
}
}
//检查注册信息
public boolean checkEdit(){
if(id.getText().toString().equals("")){
Toast.makeText(RegisterActivity.this, "账户不能为空", Toast.LENGTH_SHORT).show();
return false;
}
if(password.getText().toString().equals("")){
Toast.makeText(RegisterActivity.this, "密码不能为空", Toast.LENGTH_SHORT).show();
return false;
}
if(!password2.getText().toString().equals(password.getText().toString())){
Toast.makeText(RegisterActivity.this, "两次输入的密码不同", Toast.LENGTH_SHORT).show();
return false;
}
if(username.getText().toString().equals("")){
Toast.makeText(RegisterActivity.this, "用户名不能为空", Toast.LENGTH_SHORT).show();
return false;
}
return true;
}
// 检测网络状态
public boolean isConnectingToInternet() {
ConnectivityManager connectivity = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
if (connectivity != null) {
NetworkInfo[] info = connectivity.getAllNetworkInfo();
if (info != null)
for (int i = 0; i < info.length; i++)
if (info[i].getState() == NetworkInfo.State.CONNECTED)
{
return true;
}
}
return false;
}
}
记得在AndroidMainfest.xml中注册权限和Activity
三、PostService类
指定要连接的服务器端Servlet，（Post方法），传去数据并解析返回数据给Activity。
代码：LoginPostService.java
public class LoginPostService {
static int LOGIN_FAILED = 0;
static int LOGIN_SUCCEEDED = 1;
public static int send(List params) {
// 返回值
int responseInt = LOGIN_FAILED;
// 定位服务器的Servlet
String servlet = "LoginServlet";
// 通过 POST 方式获取 HTTP 服务器数据
String responseMsg;
responseMsg = MyHttpPost.executeHttpPost(servlet, params);
Log.i("tag", "LoginService: responseMsg = " + responseMsg);
// 解析服务器数据，返回相应 Long 值
if(responseMsg.equals("SUCCEEDED")) {
responseInt = LOGIN_SUCCEEDED;
}
return responseInt;
}
} 四、HttpPost类
前面的PostService类指定了连接的服务器端Servlet之后，把地址交给HttpPost类来真正连接服务器端并调用相应服务器端Servlet
代码：MyHttpPost.java
public class MyHttpPost {
// 服务器地址
private static String SERVER = "http://192.168.1.108:8080";
// 项目地址
private static String PROJECT = "/LYPlayerServer/";
// 请求超时
private static final int REQUEST_TIMEOUT = 0;
// 读取超时
private static final int SO_TIMEOUT = 0;
// 通过 POST 方式获取HTTP服务器数据
public static String executeHttpPost(String servlet, List params) {
String baseURL = SERVER + PROJECT + servlet;
String responseMsg = "FAILED";
try {
//连接到服务器端相应的Servlet
HttpPost request = new HttpPost(baseURL);
request.setEntity(new UrlEncodedFormEntity(params, HTTP.UTF_8));
BasicHttpParams httpParams = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(httpParams, REQUEST_TIMEOUT);
HttpConnectionParams.setSoTimeout(httpParams, SO_TIMEOUT);
HttpClient client = new DefaultHttpClient(httpParams);
HttpResponse response = client.execute(request);
if(response.getStatusLine().getStatusCode()==200)//是否成功收取信息
responseMsg = EntityUtils.toString(response.getEntity());
} catch (Exception e) {
e.printStackTrace();
}
Log.i("tag", "RegisterHttpPost: responseMsg = " + responseMsg);
return responseMsg;
}
} 实际应用中，“模拟跳转”的地方应该考虑Activity finish()的问题，跳转到app的主体部分后，用户点击home键应该不再出现登录注册界面。
在RegisterActivity中“模拟跳转”，可以finish当前Activity并把信息传给LoginActivity，让LoginActivity执行跳转并finish，以保证两个Activity都不再出现。
传递信息给LoginActivity我想到的方法有两种，一种是用有返回的Intent，另一种是用可长期保存数据的SharedPreferences。
使用SharedPreferences的好处是，我们还可以通过检查SharedPreferences的信息实现自动跳转，也就是当用户再次打开app时可以自动登录。
至此，客户端的工作完成。服务器端的工作请看下一篇。
代码下载：
客户端 http://download.csdn.net/detail/qq_24833289/9620063
服务器 http://download.csdn.net/detail/qq_24833289/9620008