Android之登录那点事

来源：互联网发布：sai绘画软件 mac 编辑：程序博客网时间：2024/06/06 23:19

http://www.cnblogs.com/AndroidJotting/p/4944693.html

　　随着互联网的高速发展，一个应用为了保护用户的隐私，通常会通过设置用户名+密码的验证方式保证用户隐私的相对安全，我知道一般网站的登录验证，通常会设置一个二维码，通过验证二维码，防止恶意软件通过机械程序，对用户密码进行破解，那么Android设备如何实现这个功能呢？相信很多开发者对此不屑一顾，因为这样增加了用户使用的复杂性，很多软件是不会这样设计的，现在我们暂且不谈它是不是有用，今天我们重点探讨一下，如何在Android的设备上实现这个功能。本篇为大家介绍的内容包括：1、用户连续多次输错密码，增加验证码验证；2、Android如何通过http请求达到与服务器之间的通讯。好了下面开始我们今天内容的介绍，首先我们先一起来学习一下如何实现用户连续多次输错密码，增加验证码功能。

　　既然用的到二维码，那么Android如何生成二维码呢？为大家提供一个生成二维码的类：

//生成二维码的类public class BPUtil {        /**     * 用于生成二维码的字符     */    private static final char[] CHARS = {        '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',        'a','b','c','d','e','f','g','h','i','j','k','m','l','n','o','p','q','r','s','t','u','v','w','x','y','z',        'A','B','C','D','E','F','G','H','I','J','K','M','L','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'    };        private static BPUtil bpUtil;        public static BPUtil getInstance() {        if(bpUtil == null)            bpUtil = new BPUtil();        return bpUtil;    }    //            width="60" height="30" //              base_padding_left="5"//            range_padding_left="10"//            base_padding_top="15"//            range_padding_top="10"//            codeLength="4"//            line_number="3"//            font_size="20"          //default settings    private static final int DEFAULT_CODE_LENGTH = 4;    private static final int DEFAULT_FONT_SIZE = 20;    private static final int DEFAULT_LINE_NUMBER = 3;    private static final int BASE_PADDING_LEFT = 5, RANGE_PADDING_LEFT = 10, BASE_PADDING_TOP = 15, RANGE_PADDING_TOP = 10;    private static final int DEFAULT_WIDTH = 60, DEFAULT_HEIGHT = 30;        //settings decided by the layout xml    //canvas width and height    private int width = DEFAULT_WIDTH, height = DEFAULT_HEIGHT;         //random word space and pading_top    private int base_padding_left = BASE_PADDING_LEFT, range_padding_left = RANGE_PADDING_LEFT,             base_padding_top = BASE_PADDING_TOP, range_padding_top = RANGE_PADDING_TOP;        //number of chars, lines; font size    private int codeLength = DEFAULT_CODE_LENGTH, line_number = DEFAULT_LINE_NUMBER, font_size = DEFAULT_FONT_SIZE;        //variables    private String code;    private int padding_left, padding_top;    private Random random = new Random();        public Bitmap createBitmap() {        padding_left = 0;                Bitmap bp = Bitmap.createBitmap(width, height, Config.ARGB_8888);         Canvas c = new Canvas(bp);        code = createCode();                c.drawColor(Color.WHITE);        Paint paint = new Paint();        paint.setTextSize(font_size);                for (int i = 0; i < code.length(); i++) {            randomTextStyle(paint);            randomPadding();            c.drawText(code.charAt(i) + "", padding_left, padding_top, paint);        }        for (int i = 0; i < line_number; i++) {            drawLine(c, paint);        }                c.save( Canvas.ALL_SAVE_FLAG );//保存          c.restore();//        return bp;    }        public String getCode() {         return bpUtil.createCode();    }        private String createCode() {        StringBuilder buffer = new StringBuilder();        for (int i = 0; i < codeLength; i++) {            buffer.append(CHARS[random.nextInt(CHARS.length)]);        }        return buffer.toString();    }        private void drawLine(Canvas canvas, Paint paint) {        int color = randomColor();        int startX = random.nextInt(width);        int startY = random.nextInt(height);        int stopX = random.nextInt(width);        int stopY = random.nextInt(height);        paint.setStrokeWidth(1);        paint.setColor(color);        canvas.drawLine(startX, startY, stopX, stopY, paint);    }        private int randomColor() {        return randomColor(1);    }    private int randomColor(int rate) {        int red = random.nextInt(256) / rate;        int green = random.nextInt(256) / rate;        int blue = random.nextInt(256) / rate;        return Color.rgb(red, green, blue);    }        private void randomTextStyle(Paint paint) {        int color = randomColor();        paint.setColor(color);        paint.setFakeBoldText(random.nextBoolean());  //true为粗体，false为非粗体        float skewX = random.nextInt(11) / 10;        skewX = random.nextBoolean() ? skewX : -skewX;        paint.setTextSkewX(skewX); //float类型参数，负数表示右斜，整数左斜//        paint.setUnderlineText(true); //true为下划线，false为非下划//        paint.setStrikeThruText(true); //true为删除线，false为非删除    }        private void randomPadding() {        padding_left += base_padding_left + random.nextInt(range_padding_left);        padding_top = base_padding_top + random.nextInt(range_padding_top);    }}

　　有了二维码，下面我们开始设计我们的功能，这里先简单说一下，我们最终要实现的功能：1、用户正常输入用户名+密码登录；2、当用户连续3次输错密码，要求用户之后必须增加验证码输入验证。下面我们开始功能设计实现，首先是我们的布局文件：

<RelativeLayout 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"    tools:context="${relativePackage}.${activityClass}"     android:orientation="vertical"    >       <LinearLayout         android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:orientation="vertical"        >    <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_gravity="center_horizontal"        android:text="@string/yanzheng" />    <LinearLayout         android:orientation="horizontal"        android:layout_width="fill_parent"        android:layout_height="wrap_content"         >         <TextView            android:layout_weight="1"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="@string/name" />         <EditText              android:id="@+id/name"             android:layout_width="wrap_content"             android:layout_weight="6"             android:layout_height="wrap_content"             android:hint="@string/name_new"             android:singleLine="true"             />     </LinearLayout>     <LinearLayout         android:orientation="horizontal"           android:layout_width="fill_parent"        android:layout_height="wrap_content"         >         <TextView            android:layout_weight="1"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="@string/password" />         <EditText              android:id="@+id/pass"             android:layout_weight="6"             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:hint="@string/pass_new"             android:singleLine="true"             />     </LinearLayout>     <LinearLayout         android:id="@+id/layout_yanzhengma"        android:visibility="gone"        android:orientation="horizontal"        android:layout_width="fill_parent"        android:layout_height="wrap_content"         >         <TextView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="@string/yanzhengma" />         <TextView             android:id="@+id/rander"            android:layout_weight="1"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            />         <EditText             android:id="@+id/rander_input"             android:layout_weight="1"             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:singleLine="true"             />     </LinearLayout>     <LinearLayout         android:orientation="horizontal"        android:layout_width="fill_parent"        android:layout_height="wrap_content"         >         <Button            android:id="@+id/get"            android:layout_weight="1"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="@string/get" />         <Button         　　android:id="@+id/post"            android:layout_weight="1"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="@string/post" />      </LinearLayout>            </LinearLayout></RelativeLayout>

　　重点的内容来了，我们主Activity代码，大家先看一下吧：

public class MainActivity extends Activity {        private TextView mytext = null;    private EditText myname = null;//用户名    private EditText mypass = null;//密码    private EditText myrander =  null;//验证码    private Button mygetbutton = null;//Get方式发送Http请求    private Button mypostbutton = null;//Post方式发送Http请求    private LinearLayout myline = null;//控制二维码的显示        private static int n = 0;//用户输错密码次数统计        static String name = null;//用户输入的用户名    static String password = null;//用户输入的密码    private String edit;//用户输入用户输入的验证码    private String code;//验证码        @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);                mytext = (TextView)findViewById(R.id.rander);        myname = (EditText)findViewById(R.id.name);        mypass = (EditText)findViewById(R.id.pass);        myrander = (EditText)findViewById(R.id.rander_input);        mygetbutton = (Button)findViewById(R.id.get);        mypostbutton = (Button)findViewById(R.id.post);        myline = (LinearLayout)findViewById(R.id.layout_yanzhengma);                mygetbutton.setOnClickListener(new mygetbutton());        mypostbutton.setOnClickListener(new mypostbutton());            }         class mygetbutton implements OnClickListener{        public void onClick(View v) {                        name = myname.getText().toString();            password = mypass.getText().toString();                        if(n>=3){//连续三次输错密码                edit = myrander.getText().toString();                boolean boo = captcha (code , edit);                if(boo){                    new Thread(new Runnable() {                                                public void run() {                                                        final boolean flag = SendServer.getsave(name, password);                                                        runOnUiThread(new Runnable() {                                                                public void run() {                                    if(flag){                                        Toast.makeText(MainActivity.this, "登录成功", Toast.LENGTH_SHORT).show();                                        n=0;                                    }else{                                        Toast.makeText(MainActivity.this, "登录失败", Toast.LENGTH_SHORT).show();                                        n++;                                        if(n>=3){                                            myline.setVisibility(View.VISIBLE);                                        }                                    }                                }                            });                                                    }                    }).start();                }else{                    code = BPUtil.getInstance().getCode().toLowerCase();//生成新的二维码                    mytext.setText(code);//展示在用户面前                }            }else{                                new Thread(new Runnable() {                                        public void run() {                                                final boolean flag = SendServer.getsave(name, password);                                                runOnUiThread(new Runnable() {                                                        public void run() {                                if(flag){                                    Toast.makeText(MainActivity.this, "登录成功", Toast.LENGTH_SHORT).show();                                    n=0;                                }else{                                    Toast.makeText(MainActivity.this, "登录失败", Toast.LENGTH_SHORT).show();                                    n++;                                    if(n>=3){                                        myline.setVisibility(1);                                        code = BPUtil.getInstance().getCode().toLowerCase();                                        mytext.setText(code);                                    }                                }                            }                        });                                            }                }).start();                            }                    }            }        class mypostbutton implements OnClickListener{        public void onClick(View v) {                        name = myname.getText().toString();            password = mypass.getText().toString();                        new Thread(new Runnable() {                                public void run() {                                        final boolean flag = SendServer.postsave(name, password);                    runOnUiThread(new Runnable() {                                                @Override                        public void run() {                            if(flag){                                Toast.makeText(MainActivity.this, "登录成功", Toast.LENGTH_SHORT).show();                                n=0;                            }else{                                Toast.makeText(MainActivity.this, "登录失败", Toast.LENGTH_SHORT).show();                                n++;                                if(n>=3){                                    myline.setVisibility(1);                                }                            }                        }                    });                }            }).start();                    }            }        @SuppressLint("ShowToast")    private boolean captcha (String code , String edit) {                boolean flag = false;                 if (code.equals(edit)) {            flag = true;        }else {            flag = false;            Toast.makeText(MainActivity.this, " 验证码错误", 0).show();            //            imageview.setImageBitmap(bitmap);                    }        return flag;    }    protected void onRestart() {                super.onRestart();        n=0;            }    protected void onDestroy() {                super.onDestroy();        n=0;            }}

　　在这里简单介绍一下代码，因为本篇接下来要为大家分享关于Android发送GET、POST请求的知识，这里我写了两个按钮，一个用来通过使用GET方式验证，一个通过使用POST方式验证，功能上是一致的。最后请大家注意一下：红色字体部分，红色字体部分就是我们通过调用上部二维码生成类，生成二维码，然后展示在用户界面。还有就是：onRestart、onDestroy都是Activity的生命周期函数，这里将n归零，方便我们的再次登录体验。好了到这里我们的第一部分就完成了，下面我们开始进入我们本篇的下半部分。

　　关于Android服务器请求，一般有两种方式：GET、POST两种方式，接下来我们就开始一起学习吧。

public class SendServer {    //GET方式请求    public static boolean getsave(String name, String password) {                boolean flag = false;        HttpURLConnection conn = null;                try {                        //防止中文乱码            String username = URLEncoder.encode(name, "UTF-8");            String userpassword = URLEncoder.encode(password, "UTF-8");                        URL url = new URL("http://10.20.90.3:8080/Register/ManageServlet?"+"name="+username+"&password="+userpassword);            conn = (HttpURLConnection) url.openConnection();            conn.setRequestMethod("GET");            conn.setConnectTimeout(5000);            conn.setReadTimeout(5000);                        int responseCode = conn.getResponseCode();                        if(responseCode == 200){                InputStream is = conn.getInputStream();                String stu = getStringFromInputStream(is);                if(stu.equals("登录成功")){                    flag = true;                }            }                    } catch (MalformedURLException e) {            e.printStackTrace();        } catch (Exception e) {            e.printStackTrace();        } finally{            if(conn != null){                conn.disconnect();  //关闭连接            }        }                return flag;            }        //POST请求    public static boolean postsave(String name, String password) {        boolean flag = false;        HttpURLConnection conn = null;        try {            URL url = new URL("http://10.20.90.3:8080/Register/ManageServlet?");            conn = (HttpURLConnection) url.openConnection();            conn.setRequestMethod("POST");            conn.setConnectTimeout(5000);            conn.setReadTimeout(5000);                        //post请求参数            String data = "name="+name+"&password="+password;            OutputStream out = conn.getOutputStream();            out.write(data.getBytes());            out.flush();            out.close();            //            conn.setRequestProperty("Content-Length", 500);//  内容长度设置为500；请求头消息格式设置                        int respon = conn.getResponseCode();            if(respon == 200){                InputStream is = conn.getInputStream();                String stu = getStringFromInputStream(is);                if(stu.equals("登录成功")){                    flag = true;                }            }                    } catch (Exception e) {            e.printStackTrace();        }finally{            if(conn != null){                conn.disconnect();            }        }                return flag;    }            //解析服务返回的请求    private static String getStringFromInputStream(InputStream is) throws Exception{        ByteArrayOutputStream baos = new ByteArrayOutputStream();        byte[] buffer = new byte[1024*8];        int len = -1;        while((len = is.read(buffer)) != -1){            baos.write(buffer, 0, len);        }        is.close();                String html = new String(baos.toByteArray(), "GBK");//接收服务器端的数据时，防止出现中文乱码。                //String html = baos.toString();                baos.close();        return html;            }}

　　好了结束了，内容简单，大家自行了解吧。新手学习，高手交流。

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