基于Android的短信管理系统

环境；Android studio3.4+
sqlite数据库基本的增删该查

在这里插入图片描述

package com.admin.sms;

import android.annotation.SuppressLint;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * @desc 登录界面
 * @author 小强程序设计
 * @QQ   2103752102
 */
public class LoginActivity extends AppCompatActivity implements View.OnClickListener {
    private EditText et_username;
    private EditText et_password;
    private Button btn_login;
    private Button btn_register;
    // 数据库的名字
    public static String dbName = "before.db";
    // 数据库在手机里的路径
    @SuppressLint("SdCardPath")
    private static String DATABASE_PATH = "/data/data/com.admin.sms/databases/";


    public boolean checkDataBase() {
        SQLiteDatabase checkDB = null;
        try {
            String databaseFilename = DATABASE_PATH + dbName;
            checkDB = SQLiteDatabase.openDatabase(databaseFilename, null,
                    SQLiteDatabase.OPEN_READONLY);
        } catch (SQLiteException e) {
        }
        if (checkDB != null) {
            checkDB.close();
        }
        return checkDB != null ? true : false;
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        initView();
        initData();

//        initDB();
    }

    private void initDB() {
        boolean dbExist = checkDataBase();
        if (dbExist) {
        } else {// 不存在就把raw里的数据库写入手机
            try {
                copyDataBase();
            } catch (IOException e) {
                throw new Error("Error copying database");
            }
        }
    }

    /**
     * 复制数据库到手机指定文件夹下 * @throwsIOException
     */
    public void copyDataBase() throws IOException {
        String databaseFilenames = DATABASE_PATH + dbName;
        File dir = new File(DATABASE_PATH);
        if (!dir.exists())// 判断文件夹是否存在，不存在就新建一个
            dir.mkdir();
        FileOutputStream os = null;
        try {
            os = new FileOutputStream(databaseFilenames);// 得到数据库文件的写入流
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        InputStream is = getResources() .openRawResource(R.raw.before);
        byte[] buffer = new byte[8192];
        int count = 0;
        try {
            while ((count = is.read(buffer)) > 0) {
                os.write(buffer, 0, count);
                os.flush();
            }
        } catch (IOException e) {

        }
        try {
            is.close();
            os.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

    private void initData() {
        SharedPreferences sp = getSharedPreferences("user", Context.MODE_PRIVATE);
        String username = sp.getString("username", "");
        String password = sp.getString("password", "");
        et_username.setText(username);
        et_password.setText(password);
    }

    private void initView() {
        et_username = (EditText) findViewById(R.id.et_username);
        et_password = (EditText) findViewById(R.id.et_password);
        btn_login = (Button) findViewById(R.id.btn_login);
        btn_register = (Button) findViewById(R.id.btn_register);

        btn_login.setOnClickListener(this);
        btn_register.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn_login:
                submit();
                break;
            case R.id.btn_register:
                startActivity(new Intent(LoginActivity.this, RegisterActivity.class));
                break;
        }
    }

    private void submit() {
        String username = et_username.getText().toString().trim();
        if (TextUtils.isEmpty(username)) {
            Toast.makeText(this, "账号不能为空", Toast.LENGTH_SHORT).show();
            return;
        }

        String password = et_password.getText().toString().trim();
        if (TextUtils.isEmpty(password)) {
            Toast.makeText(this, "密码不能为空", Toast.LENGTH_SHORT).show();
            return;
        }

        User user = SqliteHelper.login(new SqliteHelper(this), username, password);

        if (user != null) {
            SharedPreferences sp = getSharedPreferences("user", Context.MODE_PRIVATE);
            SharedPreferences.Editor edit = sp.edit();
            edit.putInt("id", user.getId());
            edit.putString("username", username);
            edit.putString("password", password);
            edit.putString("name", user.getName());
            edit.putString("phone", user.getPhone());
            edit.putInt("sex", user.getSex());
            edit.commit();
            startActivity(new Intent(this, MainActivity.class));
            finish();
        } else {
            Toast.makeText(this, "账号或密码错误", Toast.LENGTH_SHORT).show();
        }

    }
}

有需要完整代码的请加Q ： 2103752102