Android——手机内部文件存储（作业）

作业：把用户的注册信息存储到文件里，登录成功后读出并显示出来

activity_practice2的layout文件：

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout 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"
     android:paddingBottom="@dimen/activity_vertical_margin"
     android:paddingLeft="@dimen/activity_horizontal_margin"
     android:paddingRight="@dimen/activity_horizontal_margin"
     android:paddingTop="@dimen/activity_vertical_margin"
     tools:context="com.hanqi.testapp3.PractiseActivity2"
     android:orientation="vertical">

     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:orientation="horizontal">
         <TextView
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="用户名："/>
         <EditText
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:id="@+id/et_username"/>
     </LinearLayout>
     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:orientation="horizontal">
         <TextView
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="密码："/>
         <EditText
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:id="@+id/et_password"
             android:inputType="textPassword"/>
     </LinearLayout>
     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:orientation="horizontal">
         <Button
         android:layout_width="0dp"
         android:layout_height="wrap_content"
         android:text="登陆"
         android:onClick="bt_dl_onClick"
         android:layout_weight="1"/>
         <Button
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:text="注册"
             android:onClick="bt_zc_onClick"
             android:layout_weight="1"/>
     </LinearLayout>

     <!--<Button-->
         <!--android:layout_width="match_parent"-->
         <!--android:layout_height="wrap_content"-->
         <!--android:text="fdasf"-->
         <!--android:onClick="bt_onClick"-->
         <!--android:id="@+id/bt_1"/>-->
 </LinearLayout>

activity_practice2_2的layout文件：

 <?xml version="1.0" encoding="utf-8"?>
 <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"
     android:paddingBottom="@dimen/activity_vertical_margin"
     android:paddingLeft="@dimen/activity_horizontal_margin"
     android:paddingRight="@dimen/activity_horizontal_margin"
     android:paddingTop="@dimen/activity_vertical_margin"
     tools:context="com.hanqi.testapp3.PractiseActivity2_2">

         <EditText
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:hint="用户名称"
             android:id="@+id/et_username_1"/>
         <EditText
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:hint="登陆密码"
             android:id="@+id/et_password_1"
             android:layout_below="@id/et_username_1"
             android:inputType="textPassword"/>
         <EditText
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:hint="个性签名"
             android:id="@+id/et_gxqm"
             android:layout_below="@id/et_password_1"/>

         <LinearLayout
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:layout_alignParentBottom="true">
             <Button
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:text="确定"
                 android:layout_weight="1"
                 android:onClick="bt_qd_onClick"/>
             <Button
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:text="取消"
                 android:layout_weight="1"
                 android:onClick="bt_qx_onClick"/>
         </LinearLayout>
     <!--<Button-->
         <!--android:layout_width="match_parent"-->
         <!--android:layout_height="wrap_content"-->
         <!--android:text="fdasf"-->
         <!--android:onClick="bt_onClick"-->
         <!--android:id="@+id/bt_1"-->
         <!--android:layout_below="@+id/et_gxqm"/>-->
 </RelativeLayout>

activity_practice2_3的layout文件：

 <?xml version="1.0" encoding="utf-8"?>
 <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"
     android:paddingBottom="@dimen/activity_vertical_margin"
     android:paddingLeft="@dimen/activity_horizontal_margin"
     android:paddingRight="@dimen/activity_horizontal_margin"
     android:paddingTop="@dimen/activity_vertical_margin"
     tools:context="com.hanqi.testapp3.PractiseActivity2_3">

     <TextView
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:id="@+id/tv_username"
         android:textSize="30dp"/>
     <TextView
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:id="@+id/tv_gxqm"
         android:layout_below="@id/tv_username"
         android:textSize="30dp"/>
 </RelativeLayout>

PractiseActivity2的java类：

 package com.hanqi.testapp3;

 import android.content.Intent;
 import android.os.Bundle;
 import android.support.v7.app.AppCompatActivity;
 import android.view.View;
 import android.widget.EditText;
 import android.widget.Toast;

 import java.io.FileInputStream;

 public class PractiseActivity2 extends AppCompatActivity {

     EditText et_username;
     EditText et_password;

 //    Button bt_1;
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_practise2);
         et_username = (EditText)findViewById(R.id.et_username);
         et_password = (EditText)findViewById(R.id.et_password);
         //bt_1 = (Button)findViewById(R.id.bt_1);
     }
     public void bt_zc_onClick(View v)
     {
         Intent intent = new Intent(this,PractiseActivity2_2.class);
         startActivity(intent);
     }

     public void bt_dl_onClick(View v)
     {
         String str1 = "";
         String str2 = "";
         String str3 = "";
         String uc = et_username.getText().toString();
         String pw = et_password.getText().toString();

         try {
             FileInputStream fis = openFileInput("practise2-1.txt");
             byte[] b = new byte[1024];
             int i;

             while ((i=fis.read(b))>0)
             {
                 String str = new String(b,0,i);
                 str1 += str;
             }
             fis.close();

             FileInputStream fis2 = openFileInput("practise2-2.txt");
             byte[] b2 = new byte[1024];
             int i2 = 0;
             while ((i2=fis2.read(b2))>0)
             {
                 String str = new String(b2,0,i2);
                 str2 += str;
             }
             fis2.close();

             FileInputStream fis3 = openFileInput("practise2-3.txt");
             byte[] b3 = new byte[1024];
             int i3 = 0;
             while ((i3=fis3.read(b3))>0)
             {
                 String str = new String(b3,0,i3);
                 str3 += str;
             }
             fis3.close();
         }
        catch (Exception e)
        {

        }
         if (uc.trim().length()==0||pw.trim().length()==0)
         {
             Toast.makeText(PractiseActivity2.this, "用户名和密码不能为空", Toast.LENGTH_SHORT).show();
             return;
         }
         if (str1 ==null||(str1!=null&&!str1.equals(uc)))
         {
             Toast.makeText(PractiseActivity2.this, "用户未注册", Toast.LENGTH_SHORT).show();
             return;
         }
         if (!str2.equals(pw))
         {
             Toast.makeText(PractiseActivity2.this, "密码错误", Toast.LENGTH_SHORT).show();
             return;
         }
         else
         {
             Toast.makeText(PractiseActivity2.this, "用户验证成功", Toast.LENGTH_SHORT).show();
             Intent intent = new Intent(this,PractiseActivity2_3.class);
             startActivity(intent);
             finish();
         }
     }
 //    public void bt_onClick(View v)
 //    {
 //        try {
 //            FileInputStream fis = openFileInput("practise2-1.txt");
 //            byte[] b = new byte[1024];
 //            int i;
 //
 //            while ((i=fis.read(b))>0)
 //            {
 //                String str = new String(b,0,i);
 //                str1 += str;
 //            }
 //
 //            fis.close();
 //        }
 //        catch (Exception e)
 //        {
 //
 //        }
 //        bt_1.setText(str1);
 //    }
 }

PractiseActivity2_2的java类：

 package com.hanqi.testapp3;

 import android.content.Intent;
 import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
 import android.view.View;
 import android.widget.EditText;
 import android.widget.Toast;

 import java.io.FileOutputStream;
 import java.io.PrintStream;

 public class PractiseActivity2_2 extends AppCompatActivity {

     EditText et_username_1;
     EditText et_password_1;
     EditText et_gxqm;
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_practise2_2);
         et_username_1 = (EditText)findViewById(R.id.et_username_1);
         et_password_1 = (EditText)findViewById(R.id.et_password_1);
         et_gxqm = (EditText)findViewById(R.id.et_gxqm);
     }
     public void bt_qd_onClick(View v)
     {
         String username = et_username_1.getText().toString();
         if (username ==null||username.trim().length()==0)
         {
             Toast.makeText(PractiseActivity2_2.this, "请填写用户名", Toast.LENGTH_SHORT).show();
             return;
         }
         String password = et_password_1.getText().toString();
         if (password ==null||password.trim().length()==0)
         {
             Toast.makeText(PractiseActivity2_2.this, "请填写密码", Toast.LENGTH_SHORT).show();
             return;
         }
         String gxqm = et_gxqm.getText().toString();
         if (gxqm ==null||gxqm.trim().length()==0)
         {
             Toast.makeText(PractiseActivity2_2.this, "个性签名为必填内容", Toast.LENGTH_SHORT).show();
             return;
         }
         try {
             FileOutputStream fos = openFileOutput("practise2-1.txt",MODE_PRIVATE);
             PrintStream ps = new PrintStream(fos);
             ps.print(username);
             FileOutputStream fos2 = openFileOutput("practise2-2.txt",MODE_PRIVATE);
             PrintStream ps2 = new PrintStream(fos2);
             ps2.print(password);
             FileOutputStream fos3 = openFileOutput("practise2-3.txt",MODE_PRIVATE);
             PrintStream ps3 = new PrintStream(fos3);
             ps3.print(gxqm);
             ps.close();
             ps2.close();
             ps3.close();
             fos.close();
             Toast.makeText(PractiseActivity2_2.this, "保存成功", Toast.LENGTH_SHORT).show();
         }
         catch (Exception e)
         {

         }
         Intent intent = new Intent(this,PractiseActivity2.class);
         startActivity(intent);
         finish();
     }
     public void bt_qx_onClick(View v)
     {
         setResult(RESULT_CANCELED, null);
         finish();
     }

 }

PractiseActivity2_3的java类：

 package com.hanqi.testapp3;

 import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
 import android.widget.TextView;

 import java.io.FileInputStream;

 public class PractiseActivity2_3 extends AppCompatActivity {

     TextView tv_username;
     TextView tv_gxqm;

     String str1 = "";
     String str3 = "";
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_practise2_3);
         tv_username = (TextView)findViewById(R.id.tv_username);
         tv_gxqm = (TextView)findViewById(R.id.tv_gxqm);

         try {
             FileInputStream fis = openFileInput("practise2-1.txt");
             byte[] b = new byte[1024];
             int i;

             while ((i=fis.read(b))>0)
             {
                 String str = new String(b,0,i);
                 str1 += str;
             }

             fis.close();

             FileInputStream fis3 = openFileInput("practise2-3.txt");
             byte[] b3 = new byte[1024];
             int i3 = 0;
             while ((i3=fis3.read(b3))>0)
             {
                 String str = new String(b3,0,i3);
                 str3 += str;
             }
             fis3.close();
         }
         catch (Exception e)
         {

         }
         tv_username.setText("用户名是：" + str1);
         tv_gxqm.setText("个性签名是："+str3);
     }
 }

效果为：