Android学习之servlet登录、注册实现

服务器端是tomcat服务器+Mysql数据库，安卓客户端使用POST方法连接servlet，实现简单的登录、注册程序。该servlet在Java web开发中已经实现好了，现在拿到安卓中用。

MVC结构是模型(model)－视图(view)－控制器(controller)的缩写，一种软件设计典范，用一种业务逻辑、数据、界面显示分离的方法组织代码，将业务逻辑聚集到一个部件里面，在改进和个性化定制界面及用户交互的同时，不需要重新编写业务逻辑。

Model（模型）是应用程序中用于处理应用程序数据逻辑的部分。
　　通常模型对象负责在数据库中存取数据。

View（视图）是应用程序中处理数据显示的部分。
　　通常视图是依据模型数据创建的。

Controller（控制器）是应用程序中处理用户交互的部分。
　　通常控制器负责从视图读取数据，控制用户输入，并向模型发送数据。

servlet就是控制层，连接数据库就放在模型层上。

服务器端：

两个servlet,分别负责登录和注册，调用模型层的函数，连接数据库

登录判断，返回result：

public class AndroidLogin extends HttpServlet {    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        doGet(request, response);        //设置客户端的解码方式为utf-8        response.setContentType("text/html;charset=utf-8");        //        response.setCharacterEncoding("UTF-8");        boolean b=false;        userlogin MyPOJO=new userlogin();//新建MyPOJO类的对象myPOJO        //根据标示名获取JSP文件中表单所包含的参数        String id=request.getParameter("id");        String password=request.getParameter("password");        String result = "";        b=MyPOJO.isuserlogin(id,password);//使用模型对账号和密码进行验证，返回一个boolean类型的对象        PrintWriter out = response.getWriter();//回应请求        if(b){  //如果验证结果为真，跳转至登录成功页面            result = "success";        }        else {  //如果验证结果为假，跳转至登录失败页面            result = "fail";        }        out.write(result);        out.flush();        out.close();        System.out.println(result);    }    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {    }}

数据库模型层函数，存在返回true，不存在返回false：

import java.sql.*;public class userlogin {    String drv = "com.mysql.jdbc.Driver";    String url = "jdbc:mysql://localhost:3306/login";    String usr = "root";    String pwd = "***";    public boolean isuserlogin(String id,String password){        boolean isValid = false;        String sql="select * from ulogin where uname='"+id+"' and password='"+password+"'";        try{            Class.forName(drv).newInstance();            Connection conn = DriverManager.getConnection(url,usr,pwd);            Statement stm = conn.createStatement();            ResultSet rs = stm.executeQuery(sql);            if(rs.next()){                isValid = true;            }            rs.close();            stm.close();            conn.close();        }catch (Exception e) {            e.printStackTrace();            System.out.println(e);        }        if(isValid){//判断用户名以及密码是否与设定相符            return true;        }        else return false;    }}

注册，返回servlet:

public class androidregister extends HttpServlet {    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        doGet(request, response);        //设置客户端的解码方式为utf-8        response.setContentType("text/html;charset=utf-8");        //        response.setCharacterEncoding("UTF-8");        boolean b = false;        register myPOJO=new register();        String id=request.getParameter("id");        String password=request.getParameter("password");        String email = request.getParameter("email");        String result = "";        b=myPOJO.userregister(id,password,email);//连接数据库，插入该用户信息        PrintWriter out = response.getWriter();//回应请求        if(b){            result = "success";        }        else{            result = "fail";        }        out.write(result);        out.flush();        out.close();    }    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {    }}

数据库模型层，插入数据

public class register {    String drv = "com.mysql.jdbc.Driver";    String url = "jdbc:mysql://localhost:3306/login";    String usr = "root";    String pwd = "***";    public boolean userregister(String id,String password,String email){        boolean b = false;        String sql = "select * from ulogin where uname='"+id+"'";        try{            Class.forName(drv).newInstance();            Connection conn = DriverManager.getConnection(url,usr,pwd);            Statement stm = conn.createStatement();            ResultSet rs = stm.executeQuery(sql);            if(!rs.next()){                sql = "insert into ulogin(uname,password,email) values('"+id+"','"+password+"','"+email+"')";                stm.execute(sql);                b = true;            }            rs.close();            stm.close();            conn.close();        }catch (Exception e) {            e.printStackTrace();            System.out.println(e);        }        if(b)        {            return true;        }        else return false;    }}

web.xml配置

<servlet>        <servlet-name>AndroidLogin</servlet-name>        <servlet-class>service.AndroidLogin</servlet-class>    </servlet>    <servlet-mapping>        <servlet-name>AndroidLogin</servlet-name>        <url-pattern>/androidlogin.do</url-pattern>    </servlet-mapping>    <servlet>        <servlet-name>AndroidRegister</servlet-name>        <servlet-class>service.androidregister</servlet-class>    </servlet>    <servlet-mapping>        <servlet-name>AndroidRegister</servlet-name>        <url-pattern>/androidregister.do</url-pattern>    </servlet-mapping>

安卓客户端

在MainActivity里实现登录，耗时操作放到线程中去

页面

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="com.example.konghao.androidservletlogin.MainActivity">    <EditText        android:id="@+id/id"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentTop="true"        android:layout_centerHorizontal="true"        android:layout_marginTop="78dp"        android:ems="10"        android:inputType="textPersonName"        android:hint="用户名" />    <EditText        android:id="@+id/password"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignEnd="@+id/id"        android:layout_alignRight="@+id/id"        android:layout_below="@+id/id"        android:layout_marginTop="28dp"        android:ems="10"        android:inputType="textPassword"        android:hint="密码"/>    <Button        android:id="@+id/register"        android:text="注册"        android:layout_marginTop="20dp"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_below="@+id/password"        android:layout_alignLeft="@+id/password"/>    <Button        android:id="@+id/login"        android:text="登录"        android:layout_marginTop="20dp"        android:layout_below="@id/password"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignRight="@id/password"/></RelativeLayout>

MainActivity.java

public class MainActivity extends Activity implements View.OnClickListener{    private Button login,register;    private EditText id,password;    private final static int LOGIN_JUDGE = 1;    private int RequestCode = 1;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        login = (Button) findViewById(R.id.login);        login.setOnClickListener(this);        register = (Button) findViewById(R.id.register);        register.setOnClickListener(this);        id = (EditText) findViewById(R.id.id);        password = (EditText) findViewById(R.id.password);    }    @Override    protected void onActivityResult(int requestCode, int resultCode, Intent data) {        super.onActivityResult(requestCode, resultCode, data);        if(requestCode==1&&resultCode==2){            id.setText(data.getStringExtra("id"));            password.setText(data.getStringExtra("password"));        }    }        Handler handler = new Handler(){        @Override        public void handleMessage(Message msg){            super.handleMessage(msg);            switch (msg.what){                case LOGIN_JUDGE:{                    Bundle bundle = new Bundle();                    bundle = msg.getData();                    String result = bundle.getString("result");                    //Toast.makeText(MainActivity.this,result,Toast.LENGTH_SHORT).show();                    try {                        if (result.equals("success")) {                            Toast.makeText(MainActivity.this,"登录成功！",Toast.LENGTH_SHORT).show();                        }                    }catch (NullPointerException e){                        e.printStackTrace();                    }                }                    break;            }        }    };    @Override    public void onClick(View view) {        switch (view.getId()){            case R.id.login:{                new Thread(new Runnable() {                    @Override                    public void run() {                        //使用下面类里的函数，连接servlet，返回一个result，使用handler处理这个result                        String result = HttpLogin.LoginByPost(id.getText().toString(),password.getText().toString());                        Bundle bundle = new Bundle();                        bundle.putString("result",result);                        Message message = new Message();                        message.setData(bundle);                        message.what = LOGIN_JUDGE;                        handler.sendMessage(message);                    }                }).start();            }                break;            case R.id.register:{                Intent intent = new Intent(this,RegisterActivity.class);                startActivityForResult(intent,RequestCode);            }                break;        }    }}

注册实现，如果注册成功，则返回用户名和密码给上一个活动

public class RegisterActivity extends AppCompatActivity implements View.OnClickListener{    private int ResultCode = 2;    private final static int REGISTER_JUDGE = 2;    private Button register,back;    private EditText id,psw_1,psw_2,email;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_register);        register = (Button) findViewById(R.id.register_do);        register.setOnClickListener(this);        id = (EditText) findViewById(R.id.id_edit);        psw_1 = (EditText) findViewById(R.id.password_edit);        psw_2 = (EditText) findViewById(R.id.password_edit_1);        email = (EditText) findViewById(R.id.email_edit);    }    Handler handler = new Handler(){        @Override        public void handleMessage(Message msg){            super.handleMessage(msg);            switch (msg.what){                case REGISTER_JUDGE:{                    Bundle bundle = new Bundle();                    bundle = msg.getData();                    String result = bundle.getString("result");                    //Toast.makeText(MainActivity.this,result,Toast.LENGTH_SHORT).show();                    try {                        if (result.equals("success")) {                            Intent intent = new Intent();                            intent.putExtra("id",id.getText().toString());                            intent.putExtra("password",psw_1.getText().toString());                            setResult(ResultCode,intent);//向上一级发送数据                            finish();                        }                    }catch (NullPointerException e){                        e.printStackTrace();                    }                }                    break;            }        }    };    @Override    public void onClick(View v) {        switch (v.getId()){            case R.id.register_do:{                if( ! psw_1.getText().toString().equals(psw_2.getText().toString())){                    Toast.makeText(RegisterActivity.this,"两次密码不一致！",Toast.LENGTH_LONG).show();                }else {                    new Thread(new Runnable() {                        @Override                        public void run() {                            String result = HttpLogin.RegisterByPost(id.getText().toString(),                                    psw_1.getText().toString(),email.getText().toString());                            Bundle bundle = new Bundle();                            bundle.putString("result",result);                            Message msg = new Message();                            msg.what = REGISTER_JUDGE;                            msg.setData(bundle);                            handler.sendMessage(msg);                        }                    }).start();                }            }                break;        }    }}

布局：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="com.example.konghao.androidservletlogin.RegisterActivity">    <EditText        android:id="@+id/id_edit"        android:hint="用户名"        android:layout_marginTop="50dp"        android:layout_width="match_parent"        android:layout_height="wrap_content" />    <EditText        android:id="@+id/password_edit"        android:layout_below="@+id/id_edit"        android:hint="密码"        android:layout_marginTop="10dp"        android:layout_width="match_parent"        android:layout_height="wrap_content" />    <EditText        android:id="@+id/password_edit_1"        android:hint="确认密码"        android:layout_below="@+id/password_edit"        android:layout_marginTop="10dp"        android:layout_width="match_parent"        android:layout_height="wrap_content" />    <EditText        android:id="@+id/email_edit"        android:hint="邮箱"        android:layout_below="@+id/password_edit_1"        android:layout_marginTop="10dp"        android:layout_width="match_parent"        android:layout_height="wrap_content" />    <LinearLayout        android:layout_marginTop="20dp"        android:layout_below="@+id/email_edit"        android:layout_width="match_parent"        android:layout_height="wrap_content">        <Button            android:text="返回"            android:layout_weight="0.5"            android:id="@+id/back_edit"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:layout_below="@+id/email_edit"/>        <Button            android:id="@+id/register_do"            android:text="注册"            android:layout_weight="0.5"            android:layout_width="match_parent"            android:layout_height="wrap_content" />    </LinearLayout></RelativeLayout>

HttpLogin类，连接servlet，获取返回值

public class HttpLogin {        public static String LoginByPost(String id,String password){        String address = "http://www.khqust.top/MyWebsite/androidlogin.do";        String result = "";        try{            URL url = new URL(address);//初始化URL            HttpURLConnection conn = (HttpURLConnection) url.openConnection();            conn.setRequestMethod("POST");//请求方式            //超时信息            conn.setReadTimeout(5000);            conn.setConnectTimeout(5000);            //post方式不能设置缓存，需手动设置为false            conn.setUseCaches(false);            //我们请求的数据            String data = "id="+ URLEncoder.encode(id,"UTF-8")+                    "&password="+ URLEncoder.encode(password,"UTF-8");            //获取输出流            OutputStream out = conn.getOutputStream();            out.write(data.getBytes());            out.flush();            out.close();            conn.connect();            if (conn.getResponseCode() == 200) {                // 获取响应的输入流对象                InputStream is = conn.getInputStream();                // 创建字节输出流对象                ByteArrayOutputStream message = new ByteArrayOutputStream();                // 定义读取的长度                int len = 0;                // 定义缓冲区                byte buffer[] = new byte[1024];                // 按照缓冲区的大小，循环读取                while ((len = is.read(buffer)) != -1) {                    // 根据读取的长度写入到os对象中                    message.write(buffer, 0, len);                }                // 释放资源                is.close();                message.close();                // 返回字符串                result = new String(message.toByteArray());                //return result;            }        }catch (MalformedURLException e){            e.printStackTrace();        }catch (IOException e){            e.printStackTrace();        }        return result;    }    public static String RegisterByPost(String id,String password,String email){        String address = "http://www.khqust.top/MyWebsite/androidregister.do";        String result = "";        try{            URL url = new URL(address);//初始化URL            HttpURLConnection conn = (HttpURLConnection) url.openConnection();            conn.setRequestMethod("POST");//请求方式            //超时信息            conn.setReadTimeout(5000);            conn.setConnectTimeout(5000);            //post方式不能设置缓存，需手动设置为false            conn.setUseCaches(false);            //我们请求的数据            String data = "id="+ URLEncoder.encode(id,"UTF-8")+                    "&password="+ URLEncoder.encode(password,"UTF-8")+                    "&email="+ URLEncoder.encode(email,"UTF-8");            //获取输出流            OutputStream out = conn.getOutputStream();            out.write(data.getBytes());            out.flush();            out.close();            conn.connect();            if (conn.getResponseCode() == 200) {                // 获取响应的输入流对象                InputStream is = conn.getInputStream();                // 创建字节输出流对象                ByteArrayOutputStream message = new ByteArrayOutputStream();                // 定义读取的长度                int len = 0;                // 定义缓冲区                byte buffer[] = new byte[1024];                // 按照缓冲区的大小，循环读取                while ((len = is.read(buffer)) != -1) {                    // 根据读取的长度写入到os对象中                    message.write(buffer, 0, len);                }                // 释放资源                is.close();                message.close();                // 返回字符串                result = new String(message.toByteArray());                //return result;            }        }catch (MalformedURLException e){            e.printStackTrace();        }catch (IOException e){            e.printStackTrace();        }        return result;    }}

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