这是我为数据库连接编写的代码:
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
class StockReduzido {
// Select "jdbc:postgresql://localhost/tbd" if using a local database
private static final String LIGACAO ="jdbc:postgresql://localhost:5432/postgres"; //URL
private static final String UTILIZADOR = "postgres"; //USER
private static final String SENHA = "meio5"; //PASS
private static final String INTERROGACAO = "SELECT ref, desig,stock " + "FROM produto WHERE (stock < 5) ORDER BY stock ASC";
public static void main(String args[])
throws SQLException {
Connection objLigacao = null;
Statement objComando = null;
ResultSet objResultado = null;
int intRef = 0;
String strDesig = "";
int intStock = 0;
try {
Class.forName("org.postgresql.Driver");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
objLigacao = DriverManager.getConnection(LIGACAO,
UTILIZADOR, SENHA);
objComando = objLigacao.createStatement();
objResultado = objComando.executeQuery(INTERROGACAO);
while (objResultado.next()) {
intRef = objResultado.getInt("ref");
strDesig = objResultado.getString("desig");
intStock = objResultado.getInt("stock");
System.out.println("Ref=" + intRef + "; " +
"Desig=" + strDesig + "; " +
"Stock=" + intStock + ";");
}
objResultado.close();
objComando.close();
objLigacao.close();
}
}
然后我收到此错误:
java.lang.ClassNotFoundException: org.postgresql.Driver
at java.lang.Class.forNameImpl(Native Method)
at java.lang.Class.forName(Class.java:273)
at StockReduzido.main(StockReduzido.java:24)
Exception in thread "main" java.sql.SQLException: No suitable driver found for jdbc:postgresql://localhost:5432/postgres
at java.sql.DriverManager.getConnection(DriverManager.java:700)
at java.sql.DriverManager.getConnection(DriverManager.java:258)
at StockReduzido.main(StockReduzido.java:28)
我的postgres服务器是localhost:5432
。但是我的数据库名称是“postgres
”。我是否需要在URL连接中进行一些更改?