在很多的Android项目中都需要用户登录、注册。这样的话在开发中做好保护用户密码的工作就显得尤为重要。这里我把自己的密码保护方法记录下来。
这是我建了一个保存密码的文件，以便于检查自己保存密码或者上传到服务器的时候密码是否已经被保护了。这就是当我输入用户名和密码之后点击记住密码之后
保存在SD卡上的文件，打开之后可以明显的看到密码已经被保护了。
下面是我的布局文件以及主程序的代码：
1 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 2 xmlns:tools="http://schemas.android.com/tools" 3 android:layout_width="match_parent" 4 android:layout_height="match_parent" 5 android:background="#E6E6E6" 6 android:orientation="vertical"> 7 <ImageView 8 android:id="@+id/iv_head" 9 android:layout_width="150dp" 10 android:layout_height="150dp" 11 android:layout_centerHorizontal="true" 12 android:layout_marginTop="40dp" 13 android:src="@drawable/ic_launcher"/> 14 <LinearLayout 15 android:id="@+id/layout" 16 android:layout_width="match_parent" 17 android:layout_height="wrap_content" 18 android:layout_below="@+id/iv_head" 19 android:layout_margin="10dp" 20 android:background="#FFFFFF" 21 android:orientation="vertical"> 22 <RelativeLayout 23 android:id="@+id/rl_username" 24 android:layout_width="match_parent" 25 android:layout_height="wrap_content" 26 android:layout_margin="10dp"> 27 <TextView 28 android:id="@+id/tv_name" 29 android:layout_width="wrap_content" 30 android:layout_height="wrap_content" 31 android:layout_centerVertical="true" 32 android:text="账号"/> 33 <EditText 34 android:id="@+id/et_number" 35 android:layout_width="match_parent" 36 android:layout_height="wrap_content" 37 android:layout_marginLeft="5dp" 38 android:layout_toRightOf="@+id/tv_name" 39 android:background="@null"/> 40 </RelativeLayout> 41 <View 42 android:layout_width="match_parent" 43 android:layout_height="2dp" 44 android:background="#E6E6E6"/> 45 <RelativeLayout 46 android:id="@+id/rl_userpsd" 47 android:layout_width="match_parent" 48 android:layout_height="wrap_content" 49 android:layout_margin="10dp"> 50 <TextView 51 android:id="@+id/tv_psw" 52 android:layout_width="wrap_content" 53 android:layout_height="wrap_content" 54 android:layout_centerVertical="true" 55 android:text="密码"/> 56 <EditText 57 android:id="@+id/et_password" 58 android:layout_width="match_parent" 59 android:layout_height="wrap_content" 60 android:layout_marginLeft="5dp" 61 android:layout_toRightOf="@+id/tv_psw" 62 android:inputType="textPassword" 63 android:background="@null"/> 64 </RelativeLayout> 65 66 </LinearLayout> 67 <Button 68 android:id="@+id/login" 69 android:onClick="login" 70 android:layout_width="match_parent" 71 android:layout_height="40dp" 72 android:layout_below="@+id/layout" 73 android:layout_centerHorizontal="true" 74 android:layout_marginLeft="10dp" 75 android:layout_marginRight="10dp" 76 android:layout_marginTop="20dp" 77 android:background="#3C8DC4" 78 android:text="登录" 79 android:textColor="#FFFFFF"/> 80 <Button 81 android:id="@+id/signUp" 82 android:layout_width="wrap_content" 83 android:layout_height="wrap_content" 84 android:text="注册" 85 android:background="#E6E6E6" 86 android:textColor="#000000" 87 android:layout_marginTop="21dp" 88 android:layout_centerHorizontal="true" 89 android:layout_marginRight="10dp" 90 android:layout_below="@+id/login" 91 android:layout_alignParentRight="true"/> 92 93 <CheckBox 94 android:id="@+id/save" 95 android:layout_width="wrap_content" 96 android:layout_height="wrap_content" 97 android:layout_alignBaseline="@+id/signUp" 98 android:layout_alignBottom="@+id/signUp" 99 android:layout_alignLeft="@+id/login" 100 android:layout_marginLeft="14dp" 101 android:text="记住密码" /> 102 103 </RelativeLayout>
1 package com.itcast.test03; 2 import java.io.BufferedReader; 3 import java.io.IOException; 4 import java.io.InputStream; 5 import java.io.InputStreamReader; 6 import java.io.UnsupportedEncodingException; 7 import java.security.MessageDigest; 8 import java.security.NoSuchAlgorithmException; 9 import java.util.ArrayList; 10 import java.util.List; 11 import org.apache.http.HttpEntity; 12 import org.apache.http.HttpResponse; 13 import org.apache.http.NameValuePair; 14 import org.apache.http.ParseException; 15 import org.apache.http.client.ClientProtocolException; 16 import org.apache.http.client.HttpClient; 17 import org.apache.http.client.entity.UrlEncodedFormEntity; 18 import org.apache.http.client.methods.HttpPost; 19 import org.apache.http.impl.client.DefaultHttpClient; 20 import org.apache.http.message.BasicNameValuePair; 21 import org.apache.http.util.EntityUtils; 22 import org.json.JSONArray; 23 import org.json.JSONObject; 24 import android.os.Build; 25 import android.os.Bundle; 26 import android.os.StrictMode; 27 import android.annotation.SuppressLint; 28 import android.annotation.TargetApi; 29 import android.app.Activity; 30 import android.content.Intent; 31 import android.content.SharedPreferences; 32 import android.text.TextUtils; 33 import android.util.Log; 34 import android.view.Menu; 35 import android.view.View; 36 import android.view.View.OnClickListener; 37 import android.view.View.OnFocusChangeListener; 38 import android.widget.Button; 39 import android.widget.CheckBox; 40 import android.widget.EditText; 41 import android.widget.Toast; 42 43 44 public class MainActivity extends Activity implements OnClickListener { 45 private EditText et_username; 46 private EditText et_userPsd; 47 private Button login; 48 private Button signUp; 49 private CheckBox save; 50 private String user,pass; 51 @Override 52 protected void onCreate(Bundle savedInstanceState) { 53 super.onCreate(savedInstanceState); 54 setContentView(R.layout.activity_main); 55 et_username = (EditText)findViewById(R.id.et_number); 56 et_userPsd = (EditText)findViewById(R.id.et_password); 57 login=(Button)findViewById(R.id.login); 58 signUp=(Button)findViewById(R.id.signUp); 59 save = (CheckBox)findViewById(R.id.save); 60 save.setOnClickListener(new CheckBox.OnClickListener(){ 61 public void onClick(View v) { 62 SharedPreferences pre = getSharedPreferences("loginvalue", 63 MODE_WORLD_WRITEABLE); 64 pass = MD5( et_userPsd.getText().toString()); 65 user = et_username.getText().toString(); 66 if (!pass.equals("") && !user.equals("")) { 67 pre.edit().putString("username", 68 et_username.getText().toString()) 69 .putString("password", encryptmd5(pass)).commit(); 70 Toast.makeText(getApplicationContext(),"保存成功!", 71 Toast.LENGTH_SHORT).show(); 72 } else{ 73 Toast.makeText(getApplicationContext(),"密码不能为空！", 74 Toast.LENGTH_LONG).show(); 75 } 76 } 77 }); 78 login.setOnClickListener(new Button.OnClickListener() { 79 80 @Override 81 public void onClick(View v) { 82 83 SharedPreferences sp = getSharedPreferences("loginvalue",MODE_WORLD_READABLE); 84 String loginuser = sp.getString("username",null); 85 String loginpass = sp.getString("password",null); 86 87 user = et_username.getText().toString(); 88 pass = et_userPsd.getText().toString(); 89 90 String passmd5 = MD5(pass); 91 String encryptmd5 = encryptmd5(passmd5); 92 93 System.out.println("username="+ loginuser 94 + "-------------password="+ loginpass); 95 System.out.println("user=="+ user 96 + "-------------encryptmd5=="+ encryptmd5); 97 if (!user.equals("") && !pass.equals("")) { 98 if (user.equals(loginuser) && encryptmd5.equals(loginpass)) { 99 Intent intent = new Intent(); 100 intent.setClass(MainActivity.this, StudentMainActivity.class); 101 MainActivity.this.startActivity(intent); 102 finish(); 103 } else{ 104 Toast.makeText(getApplicationContext(),"密码是错误的！", 105 Toast.LENGTH_LONG).show(); 106 } 107 } else{ 108 Toast.makeText(getApplicationContext(),"密码不能为空！", 109 Toast.LENGTH_LONG).show(); 110 } 111 112 } 113 114 }); 115 initWidget();// 116 } 117 private void initWidget() 118 { 119 120 login.setOnClickListener(this); 121 signUp.setOnClickListener(this); 122 et_username.setOnFocusChangeListener(new OnFocusChangeListener() 123 { 124 125 @Override 126 public void onFocusChange(View v, boolean hasFocus) { 127 // TODO Auto-generated method stub 128 if(!hasFocus){ 129 String username=et_username.getText().toString().trim(); 130 if(username.length()<4){ 131 Toast.makeText(MainActivity.this, "用户名不能小于4个字符", Toast.LENGTH_SHORT); 132 } 133 } 134 } 135 136 }); 137 et_userPsd.setOnFocusChangeListener(new OnFocusChangeListener() 138 { 139 140 @Override 141 public void onFocusChange(View v, boolean hasFocus) { 142 // TODO Auto-generated method stub 143 if(!hasFocus){ 144 String password=et_userPsd.getText().toString().trim(); 145 if(password.length()<4){ 146 Toast.makeText(MainActivity.this, "密码不能小于4个字符", Toast.LENGTH_SHORT); 147 } 148 } 149 } 150 151 }); 152 } 153 154 155 public void onClick(View v) { 156 // TODO Auto-generated method stub 157 switch(v.getId()) 158 { 159 case R.id.login: 160 if(checkEdit()) 161 { 162 login(); 163 } 164 break; 165 case R.id.signUp: 166 Intent intent2=new Intent(MainActivity.this,SignUp.class); 167 startActivity(intent2); 168 break; 169 } 170 } 171 172 private boolean checkEdit(){ 173 if(et_username.getText().toString().trim().equals("")){ 174 Toast.makeText(MainActivity.this, "用户名不能为空", Toast.LENGTH_SHORT).show(); 175 Intent intent=new Intent(MainActivity.this,StudentMainActivity.class); 176 startActivity(intent); 177 }else if(et_userPsd.getText().toString().trim().equals("")){ 178 Toast.makeText(MainActivity.this, "密码不能为空", Toast.LENGTH_SHORT).show(); 179 }else{ 180 return true; 181 } 182 return false; 183 } 184 185 private void login(){ 186 //这个网址需要改动 187 String httpUrl="http://192.168.1.102:8080/web-test/login.jsp"; 188 HttpPost httpRequest=new HttpPost(httpUrl); 189 List<NameValuePair> params=new ArrayList<NameValuePair>(); 190 params.add(new BasicNameValuePair("username",et_username.getText().toString().trim())); 191 params.add(new BasicNameValuePair("password",et_userPsd.getText().toString().trim())); 192 HttpEntity httpentity = null; 193 try { 194 httpentity = new UrlEncodedFormEntity(params,"utf8"); 195 } catch (UnsupportedEncodingException e) { 196 // TODO Auto-generated catch block 197 e.printStackTrace(); 198 } 199 httpRequest.setEntity(httpentity); 200 HttpClient httpclient=new DefaultHttpClient(); 201 HttpResponse httpResponse = null; 202 try { 203 httpResponse = httpclient.execute(httpRequest); 204 } catch (ClientProtocolException e) { 205 // TODO Auto-generated catch block 206 e.printStackTrace(); 207 } catch (IOException e) { 208 // TODO Auto-generated catch block 209 e.printStackTrace(); 210 } 211 if(httpResponse.getStatusLine().getStatusCode()==200) 212 { 213 String strResult = null; 214 try { 215 strResult = EntityUtils.toString(httpResponse.getEntity()); 216 } catch (ParseException e) { 217 // TODO Auto-generated catch block 218 e.printStackTrace(); 219 } catch (IOException e) { 220 // TODO Auto-generated catch block 221 e.printStackTrace(); 222 } 223 Toast.makeText(MainActivity.this, strResult, Toast.LENGTH_SHORT).show(); 224 Intent intent=new Intent(MainActivity.this,StudentMainActivity.class); 225 startActivity(intent); 226 } 227 else 228 229 { 230 Toast.makeText(MainActivity.this, "登录失败！", Toast.LENGTH_SHORT).show(); 231 } 232 233 } 234 public static String MD5(String str){ 235 MessageDigest md5 = null; 236 try { 237 md5 = MessageDigest.getInstance("MD5"); 238 } catch (NoSuchAlgorithmException e) { 239 // TODO Auto-generated catch block 240 e.printStackTrace(); 241 return ""; 242 } 243 char[] charArray = str.toCharArray(); 244 byte[] byteArray = new byte[charArray.length]; 245 for (int i = 0; i < charArray.length; i++) { 246 byteArray[i] = (byte)charArray[i]; 247 } 248 byte[] md5Bytes = md5.digest(byteArray); 249 StringBuffer hexValue = new StringBuffer(); 250 for (int i = 0; i < md5Bytes.length; i++) { 251 int val = ((int)md5Bytes[i])&0xff; 252 if(val<16){ 253 hexValue.append("0"); 254 } 255 hexValue.append(Integer.toHexString(val)); 256 } 257 return hexValue.toString(); 258 } 259 public static String encryptmd5(String str){ 260 char[] a = str.toCharArray(); 261 for (int i = 0; i < a.length; i++) { 262 a[i] = (char)(a[i]^'1'); 263 } 264 String s = new String(a); 265 return s; 266 } 267 }
添加权限：
1 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> 2 <uses-permission android:name="android.permission.INTERNET" />
