FileSaveQQ.java
package njitt.software.saveqq;import android.content.Context;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.util.HashMap;import java.util.Map;public class FileSaveQQ {//保存QQ账号和登录密码到data.txt文件中public static boolean saveUserInfo(Context context, String account, Stringpassword) {FileOutputStream fos = null;try {//获取文件的输出流对象fosfos = context.openFileOutput("data.txt",Context.MODE_PRIVATE);//将数据转换为字节码的形式写入data.txt文件中fos.write((account + ":" + password).getBytes());return true;} catch (Exception e) {e.printStackTrace();return false;}finally {try {if(fos != null){fos.close();}} catch (IOException e) {e.printStackTrace();}}}//从data.txt文件中获取存储的QQ账号和密码public static Map<String, String> getUserInfo(Context context) {String content = "";FileInputStream fis = null;try {//获取文件的输入流对象fisfis = context.openFileInput("data.txt");//将输入流对象中的数据转换为字节码的形式byte[] buffer = new byte[fis.available()];fis.read(buffer);//通过read()方法读取字节码中的数据content = new String(buffer); //将获取的字节码转换为字符串Map<String, String> userMap = new HashMap<String, String>();String[] infos = content.split(":");//将字符串以“：”分隔后形成一个数组的形式userMap.put("account", infos[0]); //将数组中的第一个数据放入userMap集合中userMap.put("password", infos[1]); //将数组中的第二个数据放入userMap集合中return userMap;} catch (Exception e) {e.printStackTrace();return null;}finally {try {if(fis != null){fis.close();}} catch (IOException e) {e.printStackTrace();}}}}
MainActivity.java
package njitt.software.saveqq;import androidx.appcompat.app.AppCompatActivity;import android.os.Bundle;import android.text.TextUtils;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.Toast;import java.util.Map;public class MainActivity extends AppCompatActivity implements View.OnClickListener{private EditText et_account; //账号输入框private EditText et_password; //密码输入框private Button btn_login;//登录按钮@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);initView();//通过工具类FileSaveQQ中的getUserInfo()方法获取QQ账号和密码信息// Map<String, String> userInfo = FileSaveQQ.getUserInfo(this);Map<String, String> userInfo = SPSaveQQ.getUserInfo(this);if (userInfo != null) {et_account.setText(userInfo.get("account")); //将获取的账号显示到界面上et_password.setText(userInfo.get("password")); //将获取的密码显示到界面上}}private void initView() {et_account = (EditText) findViewById(R.id.et_account);et_password = (EditText) findViewById(R.id.et_password);btn_login = (Button) findViewById(R.id.btn_login);//设置按钮的点击监听事件btn_login.setOnClickListener(this);}@Overridepublic void onClick(View v) {switch (v.getId()) {case R.id.btn_login://当点击登录按钮时，获取界面上输入的QQ账号和密码String account = et_account.getText().toString().trim();String password = et_password.getText().toString();//检验输入的账号和密码是否为空if (TextUtils.isEmpty(account)) {Toast.makeText(this, "请输入QQ账号", Toast.LENGTH_SHORT).show();return;}if (TextUtils.isEmpty(password)) {Toast.makeText(this, "请输入密码", Toast.LENGTH_SHORT).show();return;}Toast.makeText(this, "登录成功", Toast.LENGTH_SHORT).show();//保存用户信息boolean isSaveSuccess = FileSaveQQ.saveUserInfo(this, account,password);/* boolean isSaveSuccess = SPSaveQQ.saveUserInfo(this, account, password);*/if (isSaveSuccess) {Toast.makeText(this, "保存成功", Toast.LENGTH_SHORT).show();} else {Toast.makeText(this, "保存失败", Toast.LENGTH_SHORT).show();}break;}}}
SPSaveQQ.java
package njitt.software.saveqq;import android.content.Context;import android.content.SharedPreferences;import java.util.HashMap;import java.util.Map;public class SPSaveQQ{// 保存QQ账号和登录密码到data.xml文件中public static boolean saveUserInfo(Context context, String account,String password) {SharedPreferences sp = context.getSharedPreferences("data",Context.MODE_PRIVATE);SharedPreferences.Editor edit = sp.edit();edit.putString("userName", account);edit.putString("pwd", password);mit();return true;}//从data.xml文件中获取存储的QQ账号和密码public static Map<String, String> getUserInfo(Context context) {SharedPreferences sp = context.getSharedPreferences("data",Context.MODE_PRIVATE);String account = sp.getString("userName", null);String password = sp.getString("pwd", null);Map<String, String> userMap = new HashMap<String, String>();userMap.put("account", account);userMap.put("password", password);return userMap;}}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="/apk/res/android"android:layout_width="match_parent"android:layout_height="match_parent"android:background="#E6E6E6"android:orientation="vertical"android:padding="10dp"><ImageViewandroid:layout_width="70dp"android:layout_height="70dp"android:layout_centerHorizontal="true"android:layout_gravity="center_horizontal"android:layout_marginTop="30dp"android:src="@drawable/head" /><LinearLayoutandroid:layout_width="match_parent"android:layout_height="wrap_content"android:layout_marginTop="15dp"android:background="@android:color/white"android:orientation="horizontal"><TextViewandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:padding="10dp"android:text="账号:"android:textColor="#000"android:textSize="20sp" /><EditTextandroid:id="@+id/et_account"android:layout_width="match_parent"android:layout_height="wrap_content"android:layout_marginLeft="5dp"android:background="@null"android:padding="10dp" /></LinearLayout><LinearLayoutandroid:layout_width="match_parent"android:layout_height="wrap_content"android:layout_marginTop="10dp"android:background="@android:color/white"android:orientation="horizontal"><TextViewandroid:id="@+id/tv_password"android:layout_width="wrap_content"android:layout_height="wrap_content"android:padding="10dp"android:text="密码:"android:textColor="#000"android:textSize="20sp" /><EditTextandroid:id="@+id/et_password"android:layout_width="match_parent"android:layout_height="wrap_content"android:layout_marginLeft="5dp"android:background="@null"android:inputType="textPassword"android:padding="10dp" /></LinearLayout><Buttonandroid:id="@+id/btn_login"android:layout_width="match_parent"android:layout_height="wrap_content"android:layout_marginTop="25dp"android:background="#3C8DC4"android:text="登录"android:textColor="@android:color/white"android:textSize="20sp" /></LinearLayout>
实现效果如下：
