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)
1 import java.sql.Connection;
2 import java.sql.ResultSet;
3 import java.sql.ResultSetMetaData;
4 import java.sql.SQLException;
5 import java.sql.Statement;
6
7 import org.postgresql.ds.PGSimpleDataSource;
8
9 import oracle.jdbc.pool.OracleDataSource;
10
11 import com.mysql.jdbc.jdbc2.optional.MysqlDataSource;
12
13 public class DBConnection {
14
15 /**
16 * @param args
17 * @throws SQLException
18 */
19 public static void main(String[] args) throws SQLException {
20 // TODO Auto-generated method stub
21 MysqlDataSource mysqlDataSource = new MysqlDataSource();
22 // mysqlDataSource.setPassword("dev");
23 // mysqlDataSource.setUser("dev");
24 mysqlDataSource
25 .setURL("jdbc:mysql://localhost/forJava?user=dev&password=dev");
26 Connection conn = mysqlDataSource.getConnection();
27 Statement stmt = conn.createStatement();
28 stmt.executeUpdate("create table if not exists web\n" + "(\n"
29 + " id int not null primary key,\n" + " name varchar(100),\n"
30 + " created timestamp,\n" + " content blob\n" + ");\n" + "");
31 for (int i = 0; i < 1; i++) {
32 stmt.executeUpdate("insert into web (name,content) values ('HL','frgertrhrtnthtohioh')");
33 }
34 showResultSet(stmt.executeQuery("select * from web limit 10"));
35
36 // Driver driver = new com.mysql.jdbc.Driver();
37 // driver.connect("jdbc:mysql://localhost/forJava?user=dev&password=dev",
38 // null);
39
40 PGSimpleDataSource pgSimpleDataSource = new PGSimpleDataSource();
41 pgSimpleDataSource.setServerName("localhost");
42 pgSimpleDataSource.setDatabaseName("dev");
43 pgSimpleDataSource.setUser("dev");
44 pgSimpleDataSource.setPassword("dev");
45 conn = pgSimpleDataSource.getConnection();
46 // conn =
47 // DriverManager.getConnection("jdbc:postgresql://localhost/test",
48 // "dev", "dev");
49 showResultSet(conn.createStatement().executeQuery("select * from cities"));
50
51 OracleDataSource oraDataSource = new OracleDataSource();
52 // oraDataSource.setServerName("127.0.0.1");
53 // oraDataSource.setDatabaseName("HR");
54 // oraDataSource.setUser("HR");
55 // oraDataSource.setPassword("HR");
56 oraDataSource.setURL("jdbc:oracle:thin:hr/hr@//localhost:1521/XE");
57 conn = oraDataSource.getConnection();
58 stmt = conn.createStatement();
59 stmt.execute("select * from tab");
60 showResultSet(stmt.getResultSet());
61 stmt.execute("select * from jobs");
62 showResultSet(stmt.getResultSet());
63 stmt.execute("select * from DEPARTMENTS");
64 showResultSet(stmt.getResultSet());
65 }
66
67 static void showResultSet(ResultSet resultSet) throws SQLException {
68 ResultSetMetaData resultSetMetaData = resultSet.getMetaData();
69 int num = resultSetMetaData.getColumnCount();
70 while (resultSet.next()) {
71 for (int i = 1; i <= num; i++) {
72 System.out.print(resultSetMetaData.getCatalogName(i) + " "
73 + resultSet.getString(i));
74 }
75 System.out.println();
76 }
77 }
78 }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？