dbutil+c3p0

package cn.itcast.web.jdbc; import java.sql.Connection; import java.sql.ResultSet; import java.sql.Statement; import org.junit.Test; //基于JDBC的CURD操作 public class Crud { @Test public void create2(){ Connection conn = null; Statement stmt = null; ResultSet rs = null; String sql = "insert into t_user(username) values('丝丝')"; try { conn = JdbcUtil.getMySqlConnection(); stmt = conn.createStatement(); int i = stmt.executeUpdate(sql); System.out.println(i>0?"成功":"失败"); } catch (Exception e) { e.printStackTrace(); }finally{ JdbcUtil.close(rs); JdbcUtil.close(stmt); JdbcUtil.close(conn); } } @Test public void read(){ Connection conn = null; Statement stmt = null; ResultSet rs = null; String sql = "select * from user where gender='male'"; try { conn = JdbcUtil.getMySqlConnection(); stmt = conn.createStatement(); rs = stmt.executeQuery(sql); while(rs.next()){ String name = rs.getString("name"); String gender = rs.getString("gender"); System.out.println(name+":"+gender); } } catch (Exception e) { e.printStackTrace(); }finally{ JdbcUtil.close(rs); JdbcUtil.close(stmt); JdbcUtil.close(conn); } } @Test public void update(){ Connection conn = null; Statement stmt = null; ResultSet rs = null; String sql = "update user set gender='female' where id = 8"; try { conn = JdbcUtil.getMySqlConnection(); stmt = conn.createStatement(); int i = stmt.executeUpdate(sql); System.out.println(i>0?"成功":"失败"); } catch (Exception e) { e.printStackTrace(); }finally{ JdbcUtil.close(rs); JdbcUtil.close(stmt); JdbcUtil.close(conn); } } @Test public void delete(){ Connection conn = null; Statement stmt = null; ResultSet rs = null; String sql = "delete from user where salary IS NULL"; try { conn = JdbcUtil.getMySqlConnection(); stmt = conn.createStatement(); int i = stmt.executeUpdate(sql); System.out.println(i>0?"成功":"失败"); } catch (Exception e) { e.printStackTrace(); }finally{ JdbcUtil.close(rs); JdbcUtil.close(stmt); JdbcUtil.close(conn); } } @Test public void read(String name){ Connection conn = null; Statement stmt = null; ResultSet rs = null; String sql = "select * from user where name='"+name+"'"; System.out.println("sql="+sql); try { conn = JdbcUtil.getMySqlConnection(); stmt = conn.createStatement(); rs = stmt.executeQuery(sql); while(rs.next()){ //while(rs!=null) name = rs.getString("name"); String gender = rs.getString("gender"); System.out.println(name+":"+gender); } } catch (Exception e) { e.printStackTrace(); }finally{ JdbcUtil.close(rs); JdbcUtil.close(stmt); JdbcUtil.close(conn); } } public void createTable(String tableName){ } public void dropTable(String tableName){ } }