This suggests that your clients.db
file couldn't be found. Try locating that file more appropriately. Scroll down to the section entitled "How to Specify Database Files".
I downloaded the SQLite JAR, put it in my CLASSPATH, and found a tutorial here that worked perfectly in less than five minutes. It put test.db in my project root, as expected.
I've rewritten that tutorial the way I'd do it. It works. Don't say it brings nothing.
package sqlite;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
public class Test
{
private static final String DEFAULT_DRIVER = "org.sqlite.JDBC";
private static final String DEFAULT_URL = "jdbc:sqlite:data/test.db";
public static void main(String[] args)
{
Connection conn = null;
try
{
conn = createConnection(DEFAULT_DRIVER, DEFAULT_URL);
createTable(conn);
List<Person> people = new ArrayList<Person>();
people.add(new Person("Gandhi", "politics"));
people.add(new Person("Wittgenstein", "philosophy"));
people.add(new Person("Turing", "computers"));
saveAll(conn, people);
List<Person> rows = findAll(conn);
System.out.println(rows);
}
catch (ClassNotFoundException e)
{
e.printStackTrace();
}
catch (SQLException e)
{
e.printStackTrace();
}
finally
{
close(conn);
}
}
private static List<Person> findAll(Connection conn) throws SQLException
{
List<Person> rows = new ArrayList<Person>();
ResultSet rs = null;
Statement stat = null;
try
{
stat = conn.createStatement();
rs = stat.executeQuery("select * from people;");
while (rs.next())
{
rows.add(new Person(rs.getString("name"), rs.getString("occupation")));
}
}
finally
{
close(stat);
close(rs);
}
return rows;
}
private static void saveAll(Connection conn, List<Person> people) throws SQLException
{
PreparedStatement prep = null;
try
{
prep = conn.prepareStatement("insert into people values (?, ?);");
for (Person person : people)
{
prep.setString(1, person.getName());
prep.setString(2, person.getOccupation());
prep.addBatch();
}
conn.setAutoCommit(false);
prep.executeBatch();
conn.setAutoCommit(true);
}
finally
{
close(prep);
}
}
private static void createTable(Connection conn) throws SQLException
{
Statement stat = null;
try
{
stat = conn.createStatement();
stat.executeUpdate("drop table if exists people;");
stat.executeUpdate("create table people (name, occupation);");
}
finally
{
close(stat);
}
}
private static Connection createConnection(String driver, String url) throws ClassNotFoundException, SQLException
{
Class.forName(DEFAULT_DRIVER);
Connection conn = DriverManager.getConnection(DEFAULT_URL);
return conn;
}
private static void close(Connection conn)
{
try
{
if (conn != null)
{
conn.close();
}
}
catch (Exception e)
{
e.printStackTrace();
}
}
private static void close(Statement stat)
{
try
{
if (stat != null)
{
stat.close();
}
}
catch (Exception e)
{
e.printStackTrace();
}
}
private static void close(ResultSet rs)
{
try
{
if (rs != null)
{
rs.close();
}
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
class Person
{
private String name;
private String occupation;
Person(String name, String occupation)
{
this.name = name;
this.occupation = occupation;
}
public String getName()
{
return this.name;
}
public String getOccupation()
{
return this.occupation;
}
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append("{ name: ").append(this.name).append(", occupation: ").append(this.occupation).append(" }");
return sb.toString();
}
}
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…