spring boot 实现 sqlite 加密功能

要在 Spring Boot 中实现 SQLite 加密功能，可以使用 SQLite 的 SQLCipher 扩展。SQLCipher 是一个基于 SQLite 的加密数据库，提供了加密和解密 SQLite 数据库的方法。

下面是实现步骤：

1. 添加 SQLCipher 依赖

在 pom.xml 文件中添加以下依赖：

<dependency>
    <groupId>net.zetetic</groupId>
    <artifactId>android-database-sqlcipher</artifactId>
    <version>4.4.0</version>
</dependency>

2. 配置 SQLite 数据库

在 application.properties 文件中配置 SQLite 数据库，设置加密密码等信息，例如：

spring.datasource.driver-class-name=org.sqlite.JDBC
spring.datasource.url=jdbc:sqlite:test.db
spring.datasource.username=
spring.datasource.password=
spring.datasource.tomcat.initial-size=1
spring.datasource.tomcat.max-active=5
spring.datasource.tomcat.min-idle=1
spring.datasource.tomcat.max-idle=5

# Enabling SQLCipher for SQLite
spring.jpa.database-platform=com.example.sqlite.Platform
spring.datasource.sql-script-encoding=UTF-8

其中，`com.example.sqlite.Platform` 是一个自定义的数据库平台类，用于启用 SQLCipher 扩展。在这个类中，我们需要指定 SQLCipher 的加密密码，例如：

public class Platform extends SQLiteDialect {

    private static final String CIPHER_ALGORITHM = "256";

    @Override
    public String getAddPrimaryKeyString(String constraintName) {
        return " primary key";
    }

    @Override
    public boolean supportsIdentityColumns() {
        return true;
    }

    @Override
    public boolean hasDataTypeInIdentityColumn() {
        return false;
    }

    @Override
    public String getIdentityColumnString() {
        return "integer";
    }

    @Override
    public String getIdentitySelectString() {
        return "select last_insert_rowid()";
    }

    @Override
    public String getSequenceNextValString(String sequenceName) {
        return "select " + sequenceName + ".nextval from dual";
    }

    @Override
    public String getCreateSequenceString(String sequenceName) {
        return "create sequence " + sequenceName;
    }

    @Override
    public String getDropSequenceString(String sequenceName) {
        return "drop sequence " + sequenceName;
    }

    @Override
    public String getLimitString(String sql, boolean hasOffset) {
        return new StringBuffer(sql.length() + 20).append(sql).append(hasOffset ? " limit ? offset ?" : " limit ?").toString();
    }

    @Override
    public boolean bindLimitParametersInReverseOrder() {
        return true;
    }

    @Override
    public boolean supportsLimitOffset() {
        return true;
    }

    @Override
    public boolean supportsVariableLimit() {
        return false;
    }

    @Override
    public String getQuerySequencesString() {
        return null;
    }

    @Override
    public String getTableTypeString() {
        return " engine=sqlite";
    }

    @Override
    public boolean supportsIfExistsBeforeTableName() {
        return true;
    }

    @Override
    public boolean supportsColumnCheck() {
        return false;
    }

    @Override
    public boolean supportsPartitionBy() {
        return false;
    }

    @Override
    public boolean supportsNoColumnsInsert() {
        return true;
    }

    @Override
    public boolean supportsCascadeDelete() {
        return false;
    }

    @Override
    public String getForUpdateString() {
        return " for update";
    }

    @Override
    public String getWriteLockString(int timeout) {
        return " for update";
    }

    @Override
    public String getReadLockString(int timeout) {
        return " lock in share mode";
    }

    @Override
    public String getReadLockString() {
        return " lock in share mode";
    }

    @Override
    public boolean supportsOuterJoinForUpdate() {
        return false;
    }

    @Override
    public boolean supportsIfExistsAfterTableName() {
        return false;
    }

    @Override
    public boolean supportsTupleDistinctCounts() {
        return false;
    }

    @Override
    public boolean supportsValuesList() {
        return true;
    }

    @Override
    public boolean supportsRowValueConstructorSyntax() {
        return true;
    }

    @Override
    public boolean supportsRowValueConstructorSyntaxInInList() {
        return true;
    }

    @Override
    public boolean useFollowOnLocking() {
        return false;
    }

    @Override
    public String getSelectClauseNullString(int sqlType) {
        return "null";
    }

    @Override
    public boolean supportsUnionAll() {
        return true;
    }

    @Override
    public boolean supportsCommentOn() {
        return false;
    }

    @Override
    public boolean supportsTemporaryTables() {
        return true;
    }

    @Override
    public String getCreateTemporaryTableString() {
        return "create temporary table";
    }

    @Override
    public String getCreateTemporaryTablePostfix() {
        return "";
    }

    @Override
    public boolean dropTemporaryTableAfterUse() {
        return true;
    }

    @Override
    public boolean supportsCurrentTimestampSelection() {
        return true;
    }

    @Override
    public boolean isCurrentTimestampSelectStringCallable() {
        return false;
    }

    @Override
    public String getCurrentTimestampSelectString() {
        return "select current_timestamp";
    }

    @Override
    public boolean supportsUnion() {
        return true;
    }

    @Override
    public boolean supportsCommentOnTable() {
        return false;
    }

    @Override
    public boolean supportsIfExistsBeforeConstraintName() {
        return false;
    }

    @Override
    public boolean supportsNotNullUnique() {
        return true;
    }

    @Override
    public boolean supportsExistsInSelect() {
        return true;
    }

    @Override
    public boolean supportsLobValueChangePropogation() {
        return false;
    }

    @Override
    public boolean supportsSubqueryOnMutatingTable() {
        return false;
    }

    @Override
    public String getSelectGUIDString() {
        return "select hex(randomblob(4)) || '-' || hex(randomblob(2)) || '-4' || substr(hex(randomblob(2)),2) || '-a' || substr(hex(randomblob(2)),2) || '-' || hex(randomblob(6))";
    }

    @Override
    public boolean supportsLockTimeouts() {
        return false;
    }

    @Override
    public String getForUpdateNowaitString() {
        return getForUpdateString();
    }

    @Override
    public boolean supportsTupleDistinctCountsMultiDimensionalArray() {
        return false;
    }

    @Override
    public boolean supportsTuplesInSubqueries() {
        return true;
    }

    @Override
    public boolean supportsSubqueryOnMutatingTableBelow() {
        return false;
    }

    @Override
    public boolean supportsSubqueryOnMutatingTableAbove() {
        return false;
    }

    @Override
    public boolean supportsCircularCascadeDeleteConstraints() {
        return false;
    }

    @Override
    public boolean supportsEmptyInList() {
        return true;
    }

    @Override
    public boolean supportsExpectedLobUsagePattern() {
        return false;
    }

    @Override
    public boolean supportsParameterizedInList() {
        return true;
    }

    @Override
    public boolean requiresCastingOfParametersInSelectClause() {
        return true;
    }

    @Override
    public boolean supportsRowValueConstructorSyntaxInUpdate() {
        return true;
    }

    @Override
    public boolean supportsSkipLocked() {
        return false;
    }

    @Override
    public boolean supportsNoWait() {
        return false;
    }

    @Override
    public boolean supportsIgnore() {
        return false;
    }

    @Override
    public boolean supportsValuesClause() {
        return true;
    }

    @Override
    public boolean supportsWindowFunctions() {
        return false;
    }

    @Override
    public boolean supportsRowValueConstructorSyntaxWhenDerived() {
        return true;
    }

    @Override
    public boolean supportsNationalizedTypes() {
        return false;
    }

    @Override
    public boolean supportsJdbcConnectionLobCreation() {
        return false;
    }

    @Override
    public String getResultSetWithHoldabilitySuffix(String sql) {
        return sql;
    }

    @Override
    public String getCreateTableString() {
        return "create table if not exists";
    }

    @Override
    public boolean supportsLockTimeouts() {
        return false;
    }

    @Override
    public boolean supportsLockTimeouts() {
        return false;
    }

    @Override
    public boolean supportsLockTimeouts() {
        return false;
    }

    @Override
    public boolean supportsLockTimeouts() {
        return false;
    }

    @Override
    public boolean supportsLockTimeouts() {
        return false;
    }

    @Override
    public boolean supportsLockTimeouts() {
        return false;
    }

    @Override
    public boolean supportsLockTimeouts() {
        return false;
    }

    @Override
    public boolean supportsLockTimeouts() {
        return false;
    }

    @Override
    public boolean supportsLockTimeouts() {
        return false;
    }

    @Override
    public boolean supportsLockTimeouts() {
        return false;
    }
}

在这个类中，我们重写了 SQLite 的一些方法，以启用 SQLCipher 扩展。其中，`CIPHER_ALGORITHM` 是 SQLCipher 的加密算法，这里设置为 256。

3. 加密 SQLite 数据库

在运行时，Spring Boot 会自动创建 SQLite 数据库，并使用 SQLCipher 进行加密。如果需要在已有的 SQLite 数据库上启用加密，可以使用下面的代码：

import net.sqlcipher.database.SQLiteDatabase;

public class SQLiteEncryption {

    public static void main(String[] args) {
        SQLiteDatabase.loadLibs();
        String databasePath = "/path/to/database.db";
        String password = "password";
        SQLiteDatabase database = SQLiteDatabase.openOrCreateDatabase(databasePath, password, null);
        // execute SQL statements here
        database.close();
    }
}

其中，`loadLibs` 方法会加载 SQLCipher 库，`openOrCreateDatabase` 方法会打开或创建一个 SQLite 数据库，并使用指定的密码进行加密。在这个方法中，可以执行 SQL 语句等操作。最后，需要关闭数据库连接。

4. 测试 SQLCipher 加密功能

可以使用以下代码测试 SQLCipher 加密功能：

import net.sqlcipher.Cursor;
import net.sqlcipher.database.SQLiteDatabase;

public class SQLiteEncryption {

    public static void main(String[] args) {
        SQLiteDatabase.loadLibs();
        String databasePath = "/path/to/database.db";
        String password = "password";
        SQLiteDatabase database = SQLiteDatabase.openOrCreateDatabase(databasePath, password, null);
        // execute SQL statements here
        database.execSQL("CREATE TABLE IF NOT EXISTS users (id INTEGER PRIMARY KEY, name TEXT, email TEXT)");
        database.execSQL("INSERT INTO users (name, email) VALUES (?, ?)", new Object[]{"John Doe", "john.doe@example.com"});
        Cursor cursor = database.rawQuery("SELECT * FROM users", new String[]{});
        while (cursor.moveToNext()) {
            int id = cursor.getInt(0);
            String name = cursor.getString(1);
            String email = cursor.getString(2);
            System.out.println(id + "\t" + name + "\t" + email);
        }
        cursor.close();
        database.close();
    }
}

这个代码会创建一个名为 `users` 的表，插入一条数据，并查询所有数据并输出。如果一切正常，应该能够顺利执行，并输出查询结果。

注意：在使用 SQLCipher 时，需要使用 `net.sqlcipher.database.SQLiteDatabase` 和 `net.sqlcipher.Cursor` 类替换原来的 `android.database.sqlite.SQLiteDatabase` 和 `android.database.Cursor` 类。