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：
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//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。
以上就是本文的全部内容，希望本文的内容对大家的学习或者工作能带来一定的帮助，同时也希望多多支持移动技术网！
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