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refactor(MySQLEntityRepository): Use Gson library to serialize and de…
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…serialize entities

from and to the database. Add table name to the constructor.
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@GeorgeV220
GeorgeV220 committed Jul 27, 2024
1 parent 2548a43 commit 201708d
Showing 1 changed file with 54 additions and 107 deletions.
161 changes: 54 additions & 107 deletions database/src/main/java/com/georgev22/library/utilities/MySQLEntityRepository.java
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Original file line number Diff line number Diff line change
@@ -1,14 +1,11 @@
package com.georgev22.library.utilities;

import com.georgev22.library.database.sql.Database;
import com.georgev22.library.maps.HashObjectMap;
import com.georgev22.library.maps.ObjectMap;
import com.georgev22.library.maps.ObservableObjectMap;
import com.georgev22.library.utilities.exceptions.NoSuchConstructorException;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import java.lang.reflect.InvocationTargetException;
import java.math.BigInteger;
import java.sql.Connection;
import java.sql.PreparedStatement;
Expand All @@ -33,6 +30,7 @@ public class MySQLEntityRepository<V extends Entity> implements EntityRepository
private final Logger logger;
private final Class<V> entityClass;
private final String tableName;
private final Gson gson;

/**
* Constructs a MySQLEntityRepository with the specified database, logger, and entity class.
Expand All @@ -46,7 +44,7 @@ public MySQLEntityRepository(Database database, Logger logger, Class<V> entityCl
}

/**
* Constructs a MySQLEntityRepository with the specified database, logger, and entity class.
* Constructs a MySQLEntityRepository with the specified database, logger, entity class, and table name.
*
* @param database The database to be used.
* @param logger The logger for handling log messages.
Expand All @@ -58,6 +56,7 @@ public MySQLEntityRepository(Database database, Logger logger, Class<V> entityCl
this.logger = logger;
this.entityClass = entityClass;
this.tableName = tableName;
this.gson = new GsonBuilder().create();
}

/**
Expand All @@ -68,57 +67,30 @@ public MySQLEntityRepository(Database database, Logger logger, Class<V> entityCl
@Override
public CompletableFuture<V> save(@NotNull V entity) {
return exists(entity._id(), true, false).thenApplyAsync(exists -> {
ObjectMap<String, Object> values = getValuesMap(entity);
String statement;
String entityId = escapeSql(entity._id());
String json = gson.toJson(entity);
String statement;
if (exists) {
statement = this.database.buildUpdateStatement(this.tableName, values, "_id = '" + entityId + "'");
statement = "UPDATE " + tableName + " SET data = ? WHERE _id = ?";
} else {
statement = this.database.buildInsertStatement(this.tableName, new HashObjectMap<String, Object>().append("_id", "'" + entityId + "'").append(values));
statement = "INSERT INTO " + tableName + " (_id, data) VALUES (?, ?)";
}

if (statement.isEmpty()) {
try (Connection connection = this.database.getConnection();
PreparedStatement preparedStatement = connection.prepareStatement(statement)) {
preparedStatement.setString(1, json);
preparedStatement.setString(2, entityId);
preparedStatement.executeUpdate();
} catch (SQLException | ClassNotFoundException e) {
this.logger.log(Level.SEVERE, "[EntityRepository]:", e);
return null;
}

this.executeStatement(statement);

this.loadedEntities.append(entity._id(), entity);
return entity;
});
}

/**
* Executes the provided SQL statement using the repository's database connection.
*
* @param statement The SQL statement to be executed.
*/
private void executeStatement(String statement) {
try (Connection connection = this.database.getConnection()) {
if (connection == null || connection.isClosed()) {
try (Connection newConnection = this.database.openConnection()) {
newConnection.prepareStatement(statement).executeUpdate();
}
} else {
connection.prepareStatement(statement).executeUpdate();
}
} catch (SQLException | ClassNotFoundException e) {
this.logger.log(Level.SEVERE, "[EntityRepository]:", e);
}
}

private @Nullable PreparedStatement querySQL(String statement) {
try {
Connection connection = this.database.getConnection();
if (connection == null || connection.isClosed()) {
connection = this.database.openConnection();
}
return connection.prepareStatement(statement);
} catch (SQLException | ClassNotFoundException e) {
this.logger.log(Level.SEVERE, "[EntityRepository]:", e);
return null;
}
}

/**
* Loads an entity from the database based on the specified entity ID.
*
Expand All @@ -131,31 +103,18 @@ public CompletableFuture<V> load(@NotNull String entityId) {
return CompletableFuture.completedFuture(loadedEntities.get(entityId));
}
return CompletableFuture.supplyAsync(() -> {
String statement = "SELECT * FROM " + this.tableName + " WHERE _id = '" + escapeSql(entityId) + "'";
try (PreparedStatement stmt = querySQL(statement)) {
if (stmt == null) {
this.logger.log(Level.SEVERE, "Failed to create statement for entity ID: " + entityId);
return null;
}
try (ResultSet resultSet = stmt.executeQuery()) {
if (resultSet == null) {
this.logger.log(Level.SEVERE, "Failed to load entity with ID: " + entityId + " because the result set was null.");
return null;
}
String statement = "SELECT data FROM " + this.tableName + " WHERE _id = '" + escapeSql(entityId) + "'";
try (Connection connection = this.database.getConnection();
PreparedStatement preparedStatement = connection.prepareStatement(statement)) {
try (ResultSet resultSet = preparedStatement.executeQuery()) {
if (resultSet.next()) {
this.checkForConstructorWithSingleString(this.entityClass);
V entity = this.entityClass.getConstructor(String.class).newInstance(entityId);
for (int i = 0; i < resultSet.getMetaData().getColumnCount(); i++) {
String columnName = resultSet.getMetaData().getColumnName(i + 1);
Object columnValue = resultSet.getObject(i + 1);
entity.setValue(columnName, columnValue);
}
String json = resultSet.getString("data");
V entity = gson.fromJson(json, entityClass);
this.loadedEntities.append(entityId, entity);
return entity;
}
}
} catch (SQLException | NoSuchMethodException | InvocationTargetException | InstantiationException |
IllegalAccessException | NoSuchConstructorException e) {
} catch (SQLException | ClassNotFoundException e) {
this.logger.log(Level.SEVERE, "[EntityRepository]:", e);
}

Expand Down Expand Up @@ -193,21 +152,13 @@ public CompletableFuture<Boolean> exists(@NotNull String entityId, boolean check
}
if (checkDb) {
String statement = "SELECT COUNT(*) FROM " + this.tableName + " WHERE _id = '" + escapeSql(entityId) + "'";
try (PreparedStatement stmt = querySQL(statement)) {
if (stmt == null) {
this.logger.log(Level.SEVERE, "Failed to create statement for entity ID: " + entityId);
return false;
}
try (ResultSet resultSet = stmt.executeQuery()) {
if (resultSet == null) {
this.logger.log(Level.SEVERE, "Failed to check if entity with ID: " + entityId + " exists because the result set was null.");
return false;
}
resultSet.next();
int count = resultSet.getInt(1);
return forceLoad ? this.load(entityId) != null : count > 0;
}
} catch (SQLException e) {
try (Connection connection = this.database.getConnection();
PreparedStatement preparedStatement = connection.prepareStatement(statement);
ResultSet resultSet = preparedStatement.executeQuery()) {
resultSet.next();
int count = resultSet.getInt(1);
return forceLoad ? this.load(entityId) != null : count > 0;
} catch (SQLException | ClassNotFoundException e) {
this.logger.log(Level.SEVERE, "[EntityRepository]:", e);
return false;
}
Expand All @@ -228,12 +179,14 @@ public CompletableFuture<Void> delete(@NotNull String entityId) {
this.logger.log(Level.WARNING, "[EntityRepository]: Entity with ID " + entityId + " does not exist.");
return;
}
String statement = this.database.buildDeleteStatement(
this.tableName,
"_id = '" + escapeSql(entityId) + "'"
);
String statement = "DELETE FROM " + this.tableName + " WHERE _id = '" + escapeSql(entityId) + "'";

this.executeStatement(statement);
try (Connection connection = this.database.getConnection();
PreparedStatement preparedStatement = connection.prepareStatement(statement)) {
preparedStatement.executeUpdate();
} catch (SQLException | ClassNotFoundException e) {
this.logger.log(Level.SEVERE, "[EntityRepository]:", e);
}
this.loadedEntities.remove(entityId);
}));
}
Expand All @@ -244,33 +197,27 @@ public CompletableFuture<Void> delete(@NotNull String entityId) {
@Override
public CompletableFuture<BigInteger> loadAll() {
return CompletableFuture.supplyAsync(() -> {
String statement = "SELECT * FROM " + this.tableName;
String statement = "SELECT _id, data FROM " + this.tableName;
List<CompletableFuture<Void>> futures = new ArrayList<>();
AtomicReference<BigInteger> count = new AtomicReference<>(BigInteger.ZERO);

try (PreparedStatement preparedStatement = this.querySQL(statement)) {
if (preparedStatement == null) {
this.logger.log(Level.SEVERE, "Failed to create statement for loading all entities.");
return CompletableFuture.completedFuture(BigInteger.ZERO);
}
try (ResultSet resultSet = preparedStatement.executeQuery()) {
if (resultSet == null) {
this.logger.log(Level.SEVERE, "Failed to load all entities because the result set was null.");
return CompletableFuture.completedFuture(BigInteger.ZERO);
}
while (resultSet.next()) {
String id = resultSet.getString("_id");
CompletableFuture<Void> future = load(id).thenAccept(v -> {
if (v != null) {
count.updateAndGet(current -> current.add(BigInteger.ONE));
}
});
futures.add(future);
}
try (Connection connection = this.database.getConnection();
PreparedStatement preparedStatement = connection.prepareStatement(statement);
ResultSet resultSet = preparedStatement.executeQuery()) {
while (resultSet.next()) {
String id = resultSet.getString("_id");
String json = resultSet.getString("data");
CompletableFuture<Void> future = CompletableFuture.runAsync(() -> {
V entity = gson.fromJson(json, entityClass);
if (entity != null) {
this.loadedEntities.append(id, entity);
count.updateAndGet(current -> current.add(BigInteger.ONE));
}
});
futures.add(future);
}
} catch (SQLException e) {
} catch (SQLException | ClassNotFoundException e) {
this.logger.log(Level.SEVERE, "[EntityRepository]:", e);
return CompletableFuture.completedFuture(BigInteger.ZERO);
}

CompletableFuture<Void> allOf = CompletableFuture.allOf(futures.toArray(new CompletableFuture[0]));
Expand Down

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