我正在尝试为我的Java项目创建一个DAO类。 我只有一个表“USER”的SQLite数据库。 架构是：
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Person other = (Person) obj;
if (personName == null) {
if (other.personName != null)
return false;
} else if (!personName.equals(other.personName))
return false;
return true;
}
我的UserDAOImpl类有findAll（），findByNickname（字符串昵称），插入，更新，删除方法。
我使用 CREATE TABLE USER(
username VARCHAR(20) NOT NULL PRIMARY KEY,
password VARCHAR NOT NULL,
total_matches INTEGER DEFAULT 0,
victories INTEGER DEFAULT 0,
times_alien INTEGER DEFAULT 0,
times_human INTEGER DEFAULT 0,
total_steps INTEGER DEFAULT 0,
humans_killed INTEGER DEFAULT 0,
aliens_killed INTEGER DEFAULT 0,
kills_as_human INTEGER DEFAULT 0,
kills_as_alien INTEGER DEFAULT 0,
total_escapes INTEGER DEFAULT 0,
total_broken_hatches INTEGER DEFAULT 0,
total_noises INTEGER DEFAULT 0,
online_status VARCHAR(5) NOT NULL DEFAULT "false");
来阻止SQL注入。
我的问题是，如果我调用insert（User toInsert）方法然后遍历findAll（）结果，我可以看到正确的插入。
但是，如果我使用SQLite命令行进入终端并打开数据库，当我执行“SELECT * FROM USER”时，前一个插入不会显示。
数据库类：
PreparedStatementDAO课程是：
/**
* The Class DB.
* Gives a connection to the game Database.
*/
public class DB {
/** the singleton instance of the Database. */
private static DB instance = new DB();
/** the path to the database. */
private static final String DBPath = "db/eftaios_DB.db";
/**
* Istantiates a new Database.
*/
private DB(){
/*
*
*/
}
/**
* Create a connection between this class and the database files.
*
* @return the database connection.
* @throws SQLException the SQL exception
*/
public Connection connect() throws SQLException{
Connection dbConnection = null;
try {
Class.forName("org.sqlite.JDBC");
String dbPath = DB.class.getClassLoader().getResource(DBPath).getPath();
dbConnection = DriverManager.getConnection("jdbc:sqlite:"+dbPath);
} catch (ClassNotFoundException e) {
/*
* do nothing, the class is imported in the maven dependencies
*/
} catch (SQLException e) {
throw new SQLException();
}
return dbConnection;
}
我的测试主要方法是：
/**
* The class UserDAOImpl implements the UserDAOInterface
* It implements a DAO (Data Access Object) for the User table.
* It gives access to the User table on the Database.
* With this class you can perform queries like find, insert, delete and update on the USER table.
*/
public class UserDAOImpl implements UserDAOInterface {
/** the database connection used to query it. */
private Connection dbConnection;
/** the result of a query to the database. */
private ResultSet queryResult;
/** the statement to execute to perform db queries. */
private Statement queryStatement;
/** the prepared statement to execute mysql injection secure queryes. */
private PreparedStatement queryPreparedStatement;
/** the name of the database user's table. */
private static final String USER_TABLE = "USER";
/**
* To user list.
*
* @param qryResult the qry result
* @return the list
* @throws SQLException the SQL exception
*/
private List<User> toUserList(ResultSet qryResult) throws SQLException{
List<User> result = new ArrayList<User>();
/* forall user in result, populate the new user and add it to the users list */
while(qryResult.next()){
User record = new User();
record.setNickname(qryResult.getString(User.NICKNAME_COL_NAME));
record.setPassword(qryResult.getString(User.PASSWORD_COL_NAME));
record.setAliensKilled(qryResult.getInt(User.ALIENS_KILLED_COL_NAME));
record.setHumansKilled(qryResult.getInt(User.HUMANS_KILLED_COL_NAME));
record.setKillsAsAlien(qryResult.getInt(User.KILLS_AS_ALIEN_COL_NAME));
record.setKillsAsHuman(qryResult.getInt(User.KILLS_AS_HUMAN_COL_NAME));
record.setOnlineStatus(qryResult.getBoolean(User.ONLINE_STATUS_COL_NAME));
record.setTimesAlien(qryResult.getInt(User.TIMES_ALIEN_COL_NAME));
record.setTimesHuman(qryResult.getInt(User.TIMES_HUMAN_COL_NAME));
record.setTotalBrokenHatches(qryResult.getInt(User.TOTAL_BROKEN_HATCHES_COL_NAME));
record.setTotalEscapes(qryResult.getInt(User.TOTAL_ESCAPES_COL_NAME));
record.setTotalMatches(qryResult.getInt(User.TOTAL_MATCHES_COL_NAME));
record.setTotalNoises(qryResult.getInt(User.TOTAL_NOISES_COL_NAME));
record.setTotalSteps(qryResult.getInt(User.TOTAL_STEPS_COL_NAME));
record.setVictories(qryResult.getInt(User.VICTORIES_COL_NAME));
result.add(record);
}
return result;
}
/*
* (non-Javadoc)
* @see it.polimi.ingsw.deolacremona.server.model.database.UserDAOInterface#findAll()
*/
@Override
public List<User> findAll() throws SQLException {
String findAllQuery = "SELECT * FROM "+USER_TABLE;
List<User> users = new ArrayList<User>();
this.dbConnection = DB.getDatabase().connect();
this.dbConnection.setAutoCommit(false);
this.queryStatement = this.dbConnection.createStatement();
this.queryResult = this.queryStatement.executeQuery(findAllQuery);
users = this.toUserList(queryResult);
this.dbConnection.commit();
this.queryResult.close();
this.queryStatement.close();
this.dbConnection.close();
return users;
}
/*
* (non-Javadoc)
* @see it.polimi.ingsw.deolacremona.server.model.database.UserDAOInterface#findByNickname(java.lang.String)
*/
@Override
public List<User> findByNickname(String userNickname) throws SQLException {
String findByNicknameQuery = "SELECT * FROM "+USER_TABLE+" WHERE "+User.NICKNAME_COL_NAME+"=?";
List<User> users = new ArrayList<User>();
this.dbConnection = DB.getDatabase().connect();
this.dbConnection.setAutoCommit(false);
/* preparing the statement to prevent sql injection */
this.queryPreparedStatement = this.dbConnection.prepareStatement(findByNicknameQuery);
this.queryPreparedStatement.setString(1, userNickname);
/* now get the result */
this.queryResult = this.queryPreparedStatement.executeQuery();
users = this.toUserList(queryResult);
this.dbConnection.commit();
this.queryPreparedStatement.close();
this.queryResult.close();
this.dbConnection.close();
return users;
}
/*
* (non-Javadoc)
* @see it.polimi.ingsw.deolacremona.server.model.database.UserDAOInterface#insert(it.polimi.ingsw.deolacremona.server.model.database.User)
*/
@Override
public boolean insert(User toInsert) throws SQLException {
boolean result = false;
MD5Hasher hasher = new MD5Hasher();
String md5Password = hasher.md5(toInsert.getPassword());
String insertQuery =
"INSERT INTO "+USER_TABLE+" ("+User.NICKNAME_COL_NAME+","+User.PASSWORD_COL_NAME+") VALUES (?,?)";
this.dbConnection = DB.getDatabase().connect();
this.dbConnection.setAutoCommit(false);
/* preparing the statement to prevent sql injection */
this.queryPreparedStatement = this.dbConnection.prepareStatement(insertQuery);
this.queryPreparedStatement.setString(1, toInsert.getNickname());
this.queryPreparedStatement.setString(2, md5Password);
if(this.queryPreparedStatement.executeUpdate()==1)
result = true;
this.queryPreparedStatement.close();
this.dbConnection.commit();
this.dbConnection.close();
return result;
}
/*
* (non-Javadoc)
* @see it.polimi.ingsw.deolacremona.server.model.database.UserDAOInterface#update(it.polimi.ingsw.deolacremona.server.model.database.User)
*/
@Override
public boolean update(User toUpdate) throws SQLException {
boolean result = false;
String updateQuery = "UPDATE "+USER_TABLE+" SET "
+ User.ALIENS_KILLED_COL_NAME +"=?,"
+ User.HUMANS_KILLED_COL_NAME +"=?,"
+ User.KILLS_AS_ALIEN_COL_NAME +"=?,"
+ User.KILLS_AS_HUMAN_COL_NAME +"=?,"
+ User.ONLINE_STATUS_COL_NAME +"=?,"
+ User.TIMES_ALIEN_COL_NAME +"=?,"
+ User.TIMES_HUMAN_COL_NAME +"=?,"
+ User.TOTAL_BROKEN_HATCHES_COL_NAME +"=?,"
+ User.TOTAL_ESCAPES_COL_NAME +"=?,"
+ User.TOTAL_MATCHES_COL_NAME +"=?,"
+ User.TOTAL_NOISES_COL_NAME +"=?,"
+ User.TOTAL_STEPS_COL_NAME +"=?,"
+ User.VICTORIES_COL_NAME +"=?"
+ " WHERE "+User.NICKNAME_COL_NAME+"=?";
/* preparing the sql statement to prevent sql injection */
this.dbConnection = DB.getDatabase().connect();
this.dbConnection.setAutoCommit(false);
this.queryPreparedStatement = this.dbConnection.prepareStatement(updateQuery);
this.queryPreparedStatement.setInt (1, toUpdate.getAliensKilled());
this.queryPreparedStatement.setInt (2, toUpdate.getHumansKilled());
this.queryPreparedStatement.setInt (3, toUpdate.getKillsAsAlien());
this.queryPreparedStatement.setInt (4, toUpdate.getKillsAsHuman());
this.queryPreparedStatement.setBoolean(5, toUpdate.isOnlineStatus());
this.queryPreparedStatement.setInt (6, toUpdate.getTimesAlien());
this.queryPreparedStatement.setInt (7, toUpdate.getTimesHuman());
this.queryPreparedStatement.setInt (8, toUpdate.getTotalBrokenHatches());
this.queryPreparedStatement.setInt (9, toUpdate.getTotalEscapes());
this.queryPreparedStatement.setInt (10, toUpdate.getTotalMatches());
this.queryPreparedStatement.setInt (11, toUpdate.getTotalNoises());
this.queryPreparedStatement.setInt (12, toUpdate.getTotalSteps());
this.queryPreparedStatement.setInt (13, toUpdate.getVictories());
this.queryPreparedStatement.setString (14, toUpdate.getNickname());
if(this.queryPreparedStatement.executeUpdate()==1){
result = true;
}
this.queryPreparedStatement.close();
this.dbConnection.commit();
this.dbConnection.close();
return result;
}
/*
* (non-Javadoc)
* @see it.polimi.ingsw.deolacremona.server.model.database.UserDAOInterface#updateAdder(it.polimi.ingsw.deolacremona.server.model.database.User)
*/
@Override
public boolean updateAdder(User toUpdate) {
// TODO Auto-generated method stub
return false;
}
/*
* (non-Javadoc)
* @see it.polimi.ingsw.deolacremona.server.model.database.UserDAOInterface#delete(it.polimi.ingsw.deolacremona.server.model.database.User)
*/
@Override
public boolean delete(User toDelete) throws SQLException {
boolean result = false;
String deleteQuery = "DELETE FROM "+USER_TABLE+" WHERE username=?";
this.dbConnection = DB.getDatabase().connect();
this.dbConnection.setAutoCommit(false);
this.queryPreparedStatement = this.dbConnection.prepareStatement(deleteQuery);
this.queryPreparedStatement.setString(1, toDelete.getNickname());
if(this.queryPreparedStatement.executeUpdate()==1){
result = true;
}
this.queryPreparedStatement.close();
this.dbConnection.commit();
this.dbConnection.close();
return result;
}
}
感谢您的时间。
编辑：当我剪切数据库并将其放入另一个目录时，退出eclipse，将数据库移回其先前的目录并重新打开eclipse，然后Java完成的所有更改都将丢失。 -答案 0 :(得分：1)
已解决：在Maven项目中，所有资源都会在＆＃34; build＆＃34;之后复制到另一个目录中。命令。我正在阅读错误的数据库。