用android的sqllite数据库写一个古诗词的增、删、查、改，写清楚布局文件、Java文件等相关代码

好的，下面是一个简单的古诗词增删查改的示例，使用 SQLite 数据库存储数据。

首先，需要在 Android Studio 中创建一个新项目，然后在 app 目录下的 build.gradle 文件中添加以下依赖项：

implementation 'androidx.recyclerview:recyclerview:1.2.0'
implementation 'com.google.android.material:material:1.3.0'
implementation 'androidx.cardview:cardview:1.0.0'
implementation 'androidx.appcompat:appcompat:1.2.0'
implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
implementation 'androidx.sqlite:sqlite:2.1.0'

接下来，我们需要创建一个数据库帮助类 DBHelper.java，用于创建数据库和表格，并提供增删查改操作。

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class DBHelper extends SQLiteOpenHelper {

    private static final String DB_NAME = "poetry.db";
    private static final int DB_VERSION = 1;

    public DBHelper(Context context) {
        super(context, DB_NAME, null, DB_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        String sql = "CREATE TABLE IF NOT EXISTS poetry (_id INTEGER PRIMARY KEY AUTOINCREMENT, title TEXT, author TEXT, content TEXT)";
        db.execSQL(sql);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS poetry");
        onCreate(db);
    }

    public void insert(String title, String author, String content) {
        SQLiteDatabase db = getWritableDatabase();
        String sql = "INSERT INTO poetry (title, author, content) VALUES (?, ?, ?)";
        db.execSQL(sql, new String[]{title, author, content});
        db.close();
    }

    public void delete(int id) {
        SQLiteDatabase db = getWritableDatabase();
        String sql = "DELETE FROM poetry WHERE _id=?";
        db.execSQL(sql, new Object[]{id});
        db.close();
    }

    public void update(int id, String title, String author, String content) {
        SQLiteDatabase db = getWritableDatabase();
        String sql = "UPDATE poetry SET title=?, author=?, content=? WHERE _id=?";
        db.execSQL(sql, new Object[]{title, author, content, id});
        db.close();
    }

    public Cursor queryAll() {
        SQLiteDatabase db = getReadableDatabase();
        String sql = "SELECT * FROM poetry";
        Cursor cursor = db.rawQuery(sql, null);
        return cursor;
    }

}

接下来，我们需要创建一个显示诗词列表的界面 PoetryListActivity.java，以及一个用于显示每首诗词的界面 PoetryDetailActivity.java。

public class PoetryListActivity extends AppCompatActivity {

    private RecyclerView mRecyclerView;
    private PoetryListAdapter mAdapter;
    private List<Poetry> mDataList = new ArrayList<>();
    private DBHelper mDBHelper;

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

        mRecyclerView = findViewById(R.id.recycler_view);
        mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
        mAdapter = new PoetryListAdapter(this, mDataList);
        mRecyclerView.setAdapter(mAdapter);

        mDBHelper = new DBHelper(this);

        loadData();
    }

    private void loadData() {
        mDataList.clear();
        Cursor cursor = mDBHelper.queryAll();
        while (cursor.moveToNext()) {
            int id = cursor.getInt(cursor.getColumnIndex("_id"));
            String title = cursor.getString(cursor.getColumnIndex("title"));
            String author = cursor.getString(cursor.getColumnIndex("author"));
            String content = cursor.getString(cursor.getColumnIndex("content"));
            Poetry poetry = new Poetry(id, title, author, content);
            mDataList.add(poetry);
        }
        mAdapter.notifyDataSetChanged();
    }

    public void onAddClick(View view) {
        startActivity(new Intent(this, PoetryDetailActivity.class));
    }

    @Override
    protected void onResume() {
        super.onResume();
        loadData();
    }

}

public class PoetryDetailActivity extends AppCompatActivity {

    private EditText mTitleEditText;
    private EditText mAuthorEditText;
    private EditText mContentEditText;
    private DBHelper mDBHelper;
    private int mPoetryId;

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

        mTitleEditText = findViewById(R.id.title_edit_text);
        mAuthorEditText = findViewById(R.id.author_edit_text);
        mContentEditText = findViewById(R.id.content_edit_text);

        mDBHelper = new DBHelper(this);

        mPoetryId = getIntent().getIntExtra("poetry_id", -1);
        if (mPoetryId != -1) {
            Cursor cursor = mDBHelper.queryById(mPoetryId);
            if (cursor.moveToFirst()) {
                String title = cursor.getString(cursor.getColumnIndex("title"));
                String author = cursor.getString(cursor.getColumnIndex("author"));
                String content = cursor.getString(cursor.getColumnIndex("content"));
                mTitleEditText.setText(title);
                mAuthorEditText.setText(author);
                mContentEditText.setText(content);
            }
        }
    }

    public void onSaveClick(View view) {
        String title = mTitleEditText.getText().toString();
        String author = mAuthorEditText.getText().toString();
        String content = mContentEditText.getText().toString();

        if (mPoetryId == -1) {
            mDBHelper.insert(title, author, content);
        } else {
            mDBHelper.update(mPoetryId, title, author, content);
        }

        finish();
    }

    public void onDeleteClick(View view) {
        if (mPoetryId != -1) {
            mDBHelper.delete(mPoetryId);
        }
        finish();
    }

}

最后，我们需要在布局文件中添加以下内容：

activity_poetry_list.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
        android:id="@+id/add_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="16dp"
        android:onClick="onAddClick"
        android:text="添加诗词" />

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

activity_poetry_detail.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <EditText
        android:id="@+id/title_edit_text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="题目" />

    <EditText
        android:id="@+id/author_edit_text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="作者" />

    <EditText
        android:id="@+id/content_edit_text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="内容" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <Button
            android:id="@+id/save_button"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:onClick="onSaveClick"
            android:text="保存" />

        <Button
            android:id="@+id/delete_button"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:onClick="onDeleteClick"
            android:text="删除" />

    </LinearLayout>

</LinearLayout>

最后，我们需要创建一个用于显示诗词列表的适配器 PoetryListAdapter.java。

public class PoetryListAdapter extends RecyclerView.Adapter<PoetryListAdapter.ViewHolder> {

    private Context mContext;
    private List<Poetry> mDataList;

    public PoetryListAdapter(Context context, List<Poetry> dataList) {
        mContext = context;
        mDataList = dataList;
    }

    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(mContext).inflate(R.layout.item_poetry, parent, false);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        final Poetry poetry = mDataList.get(position);
        holder.titleTextView.setText(poetry.getTitle());
        holder.authorTextView.setText(poetry.getAuthor());
        holder.contentTextView.setText(poetry.getContent());
        holder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(mContext, PoetryDetailActivity.class);
                intent.putExtra("poetry_id", poetry.getId());
                mContext.startActivity(intent);
            }
        });
    }

    @Override
    public int getItemCount() {
        return mDataList.size();
    }

    static class ViewHolder extends RecyclerView.ViewHolder {

        TextView titleTextView;
        TextView authorTextView;
        TextView contentTextView;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            titleTextView = itemView.findViewById(R.id.title_text_view);
            authorTextView = itemView.findViewById(R.id.author_text_view);
            contentTextView = itemView.findViewById(R.id.content_text_view);
        }

    }

}

最后，我们在 res/values/styles.xml 文件中添加以下样式：

<style name="AppTheme" parent="Theme.MaterialComponents.Light.NoActionBar">
    <item name="colorPrimary">@color/purple_500</item>
    <item name="colorPrimaryVariant">@color/purple_700</item>
    <item name="colorOnPrimary">@color/white</item>
    <item name="colorSecondary">@color/teal_200</item>
    <item name="colorSecondaryVariant">@color/teal_700</item>
    <item name="colorOnSecondary">@color/black</item>
    <item name="android:fontFamily">@font/roboto</item>
</style>

最后，我们还需要在 AndroidManifest.xml 文件中添加以下权限：

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />