Java使用JDBC连接postgresql数据库示例

package tool;

import java.sql.connection;

import java.sql.drivermanager;

import java.sql.preparedstatement;

import java.sql.resultset;

import java.sql.sqlexception;

public class psqlconnectiontool {

  private string url = "jdbc:postgresql://xxx.xxx.xxx.xxx:5432/testdb" ;

  private string username = "postgres" ;

  private string password = "postgres" ;

  private connection connection = null ;

  public connection getconn() {

   try {

    class .forname( "org.postgresql.driver" ).newinstance();

    connection = drivermanager.getconnection(url, username, password);

   } catch (instantiationexception e) {

    // todo auto-generated catch block

    e.printstacktrace();

   } catch (illegalaccessexception e) {

    // todo auto-generated catch block

    e.printstacktrace();

   } catch (classnotfoundexception e) {

    // todo auto-generated catch block

    e.printstacktrace();

   } catch (sqlexception e) {

    // todo auto-generated catch block

    e.printstacktrace();

   }

   return connection;

  }

  public resultset query(connection conn, string sql) {

   preparedstatement pstatement = null ;

   resultset rs = null ;

   try {

    pstatement = conn.preparestatement(sql);

    rs = pstatement.executequery();

   } catch (sqlexception e) {

    e.printstacktrace();

   }

   return rs;

  }

  public boolean queryupdate(connection conn, string sql) {

   preparedstatement pstatement = null ;

   int rs = 0 ;

   try {

    pstatement = conn.preparestatement(sql);

    rs = pstatement.executeupdate();

   } catch (sqlexception e) {

    // todo auto-generated catch block

    e.printstacktrace();

   }

   if (rs > 0 ) {

    return true ;

   }

   return false ;

  }

  public static void main(string[] args) throws sqlexception {

   psqlconnectiontool pgtool = new psqlconnectiontool();

   connection myconn = pgtool.getconn();

   pgtool.queryupdate(myconn, "insert into test values (1,'smoon','man')" );

   resultset rs = pgtool.query(myconn, "select * from test" );

   while (rs.next()){

    int id = rs.getint( "id" );

    string name = rs.getstring( "name" );

    string gender = rs.getstring( "gender" );

    system.out.println( "id:" +id+ " 姓名：" +name+ " 性别：" +gender);

    myconn.close();

   }

  }

}