Android之登录那点事

时间:2024-01-12 14:02:38

  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 = {
'', '', '', '', '', '', '', '', '', '',
'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 = ;
private static final int DEFAULT_FONT_SIZE = ;
private static final int DEFAULT_LINE_NUMBER = ;
private static final int BASE_PADDING_LEFT = , RANGE_PADDING_LEFT = , BASE_PADDING_TOP = , RANGE_PADDING_TOP = ;
private static final int DEFAULT_WIDTH = , DEFAULT_HEIGHT = ; //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 = ; 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 = ; i < code.length(); i++) {
randomTextStyle(paint);
randomPadding();
c.drawText(code.charAt(i) + "", padding_left, padding_top, paint);
} for (int i = ; 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 = ; 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();
paint.setColor(color);
canvas.drawLine(startX, startY, stopX, stopY, paint);
} private int randomColor() {
return randomColor();
} private int randomColor(int rate) {
int red = random.nextInt() / rate;
int green = random.nextInt() / rate;
int blue = random.nextInt() / 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() / ;
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。