import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class MainSql {
// JDBC 驱动名及数据库 URL static final String JDBC_DRIVER = "com.mysql.jdbc.Driver" ; static final String DB_URL = "jdbc:mysql://localhost:3306/chat" ; // 数据库的用户名与密码,需要根据自己的设置 static final String USER = "root" ; static final String PASS = "" ; public static void main(String[] args) {
// TODO Auto-generated method stub Connection conn = null ; Statement stmt = null ; try {
Class.forName(JDBC_DRIVER); System.out.println( "链接数据库.." ); conn = DriverManager.getConnection(DB_URL,USER,PASS); stmt = conn.createStatement(); String sql = "SELECT * FROM users" ; ResultSet rs = stmt.executeQuery(sql); while (rs.next()){
// 通过字段检索 String id = rs.getString( "id" ); String password = rs.getString( "passwd" ); // 输出数据 System.out.println( "用户名: " + id); System.out.println( "密码: " + password); } rs.close(); stmt.close(); conn.close(); } catch (SQLException se){
// 处理 JDBC 错误 se.printStackTrace(); } catch (Exception e){
// 处理 Class.forName 错误 e.printStackTrace(); } finally {
// 关闭资源 try {
if (stmt!= null ) stmt.close(); } catch (SQLException se2){
} // 什么都不做 try {
if (conn!= null ) conn.close(); } catch (SQLException se){
se.printStackTrace(); } } System.out.println( "Goodbye!" ); } } |