jdbc使用DataSource连接mysql,postgresql,oracle的代码

jdbc连接数据库，使用DataSource是推荐的方式

(jdbc驱动是当然要放进classpath里的,官网一般都有下载)

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;

import org.postgresql.ds.PGSimpleDataSource;

import oracle.jdbc.pool.OracleDataSource;

import com.mysql.jdbc.jdbc2.optional.MysqlDataSource;

public class DBConnection {

    /**
     * @param args
     * @throws SQLException
     */
    public static void main(String[] args) throws SQLException {
        // TODO Auto-generated method stub
        MysqlDataSource mysqlDataSource = new MysqlDataSource();
        // mysqlDataSource.setPassword("dev");
        // mysqlDataSource.setUser("dev");
        mysqlDataSource
                .setURL("jdbc:mysql://localhost/forJava?user=dev&password=dev");
        Connection conn = mysqlDataSource.getConnection();
        Statement stmt = conn.createStatement();
        stmt.executeUpdate("create table if not exists web\n" + "(\n"
                + "        id int not null primary key,\n" + "        name varchar(100),\n"
                + "        created timestamp,\n" + "        content blob\n" + ");\n" + "");
        for (int i = 0; i < 1; i++) {
            stmt.executeUpdate("insert into web (name,content) values ('HL','frgertrhrtnthtohioh')");
        }
        showResultSet(stmt.executeQuery("select * from web limit 10"));

        // Driver driver = new com.mysql.jdbc.Driver();
        // driver.connect("jdbc:mysql://localhost/forJava?user=dev&password=dev",
        // null);

        PGSimpleDataSource pgSimpleDataSource = new PGSimpleDataSource();
        pgSimpleDataSource.setServerName("localhost");
        pgSimpleDataSource.setDatabaseName("dev");
        pgSimpleDataSource.setUser("dev");
        pgSimpleDataSource.setPassword("dev");
        conn = pgSimpleDataSource.getConnection();
        // conn =
        // DriverManager.getConnection("jdbc:postgresql://localhost/test",
        // "dev", "dev");
        showResultSet(conn.createStatement().executeQuery("select * from cities"));

        OracleDataSource oraDataSource = new OracleDataSource();
        // oraDataSource.setServerName("127.0.0.1");
        // oraDataSource.setDatabaseName("HR");
        // oraDataSource.setUser("HR");
        // oraDataSource.setPassword("HR");
        oraDataSource.setURL("jdbc:oracle:thin:hr/hr@//localhost:1521/XE");
        conn = oraDataSource.getConnection();
        stmt = conn.createStatement();
        stmt.execute("select * from tab");
        showResultSet(stmt.getResultSet());
        stmt.execute("select * from jobs");
        showResultSet(stmt.getResultSet());
        stmt.execute("select * from DEPARTMENTS");
        showResultSet(stmt.getResultSet());
    }

    static void showResultSet(ResultSet resultSet) throws SQLException {
        ResultSetMetaData resultSetMetaData = resultSet.getMetaData();
        int num = resultSetMetaData.getColumnCount();
        while (resultSet.next()) {
            for (int i = 1; i <= num; i++) {
                System.out.print(resultSetMetaData.getCatalogName(i) + " "
                        + resultSet.getString(i));
            }
            System.out.println();
        }
    }
}

import java.sql.Connection; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.SQLException; import java.sql.Statement; import org.postgresql.ds.PGSimpleDataSource; import oracle.jdbc.pool.OracleDataSource; import com.mysql.jdbc.jdbc2.optional.MysqlDataSource; public class DBConnection { /** * @param args * @throws SQLException */ public static void main(String[] args) throws SQLException { // TODO Auto-generated method stub MysqlDataSource mysqlDataSource = new MysqlDataSource(); // mysqlDataSource.setPassword("dev"); // mysqlDataSource.setUser("dev"); mysqlDataSource .setURL("jdbc:mysql://localhost/forJava?user=dev&password=dev"); Connection conn = mysqlDataSource.getConnection(); Statement stmt = conn.createStatement(); stmt.executeUpdate("create table if not exists web\n" + "(\n" + " id int not null primary key,\n" + " name varchar(100),\n" + " created timestamp,\n" + " content blob\n" + ");\n" + ""); for (int i = 0; i < 1; i++) { stmt.executeUpdate("insert into web (name,content) values ('HL','frgertrhrtnthtohioh')"); } showResultSet(stmt.executeQuery("select * from web limit 10")); // Driver driver = new com.mysql.jdbc.Driver(); // driver.connect("jdbc:mysql://localhost/forJava?user=dev&password=dev", // null); PGSimpleDataSource pgSimpleDataSource = new PGSimpleDataSource(); pgSimpleDataSource.setServerName("localhost"); pgSimpleDataSource.setDatabaseName("dev"); pgSimpleDataSource.setUser("dev"); pgSimpleDataSource.setPassword("dev"); conn = pgSimpleDataSource.getConnection(); // conn = // DriverManager.getConnection("jdbc:postgresql://localhost/test", // "dev", "dev"); showResultSet(conn.createStatement().executeQuery("select * from cities")); OracleDataSource oraDataSource = new OracleDataSource(); // oraDataSource.setServerName("127.0.0.1"); // oraDataSource.setDatabaseName("HR"); // oraDataSource.setUser("HR"); // oraDataSource.setPassword("HR"); oraDataSource.setURL("jdbc:oracle:thin:hr/hr@//localhost:1521/XE"); conn = oraDataSource.getConnection(); stmt = conn.createStatement(); stmt.execute("select * from tab"); showResultSet(stmt.getResultSet()); stmt.execute("select * from jobs"); showResultSet(stmt.getResultSet()); stmt.execute("select * from DEPARTMENTS"); showResultSet(stmt.getResultSet()); } static void showResultSet(ResultSet resultSet) throws SQLException { ResultSetMetaData resultSetMetaData = resultSet.getMetaData(); int num = resultSetMetaData.getColumnCount(); while (resultSet.next()) { for (int i = 1; i <= num; i++) { System.out.print(resultSetMetaData.getCatalogName(i) + " " + resultSet.getString(i)); } System.out.println(); } } }

呃，在自己电脑上同时安装了mysql, postgresql,oracle,db2,sqlite的人是不是很蛋疼？