JDBC

JAVA Database Connectivity?

java數據庫

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sun公司提供的一種數據庫訪問規則，規范，由于數據庫種類較多，并且java語言使用比較廣泛，sun就通過了一種規范，讓其他的數據庫提供商去實現的訪問規則

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JDBC的基本步驟

1.注冊驅動

2.建立連接

3.創建statement

4.執行sql，得到ResultSet

5.遍歷結果集

6.釋放資源

package tan.jung.test;import java.sql.Connection; import java.sql.Driver; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement;import tan.jung.JDBCUtil;public class MianTest {public static void main(String[] args) {Connection conn = null;Statement st = null;ResultSet rs =null;try {//注冊驅動DriverManager.registerDriver(new com.mysql.jdbc.Driver());//建立連接conn = DriverManager.getConnection("jdbc:mysql://localhost/student", "root", "root");//創建statementst= conn.createStatement();//得到結果集String sql="select * from tab_belong";rs = st.executeQuery(sql);//遍歷查詢每一條記錄while(rs.next()){int id = rs.getInt("id");String belong = rs.getString("belong");System.out.println("id="+id+",belong="+belong);}} catch (SQLException e) {e.printStackTrace();}finally {JDBCUtil.release(conn, st, rs); }}}//第二個包 package tan.jung;import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement;public class JDBCUtil {public static void release(Connection conn,Statement st,ResultSet rs){closers(rs);closest(st);closeconn(conn);}private static void closers(ResultSet rs){try {if(rs !=null){rs.close();}} catch (SQLException e) {e.printStackTrace(); }finally {rs=null;}}private static void closest(Statement st){try {if(st !=null){st.close();}} catch (SQLException e) {e.printStackTrace(); }finally {st=null;}}private static void closeconn(Connection conn){try {if(conn !=null){conn.close();}} catch (SQLException e) {e.printStackTrace(); }finally {conn=null;}} }

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JDBC　工具類構建

1.資源釋放工作的整合

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2.驅動防二次注冊

?Class.forName("com.mysql.jdbc.Driver");

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3.使用properties配置文件

package tan.jung.test;import java.sql.Connection; import java.sql.Driver; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement;import tan.jung.JDBCUtil;public class MianTest {public static void main(String[] args) {Connection conn = null;Statement st = null;ResultSet rs =null;try {conn =JDBCUtil.getConn();//創建statementst= conn.createStatement();//得到結果集String sql="select * from tab_belong";rs = st.executeQuery(sql);//遍歷查詢每一條記錄while(rs.next()){int id = rs.getInt("id");String belong = rs.getString("belong");System.out.println("id="+id+",belong="+belong);}} catch (Exception e) {e.printStackTrace();}finally {JDBCUtil.release(conn, st, rs); }}}//第二個包package tan.jung;import java.io.FileInputStream; import java.io.InputStream; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.Properties;public class JDBCUtil {static String driverClass = null;static String url=null;static String name=null;static String password=null;static{try {//1.創建一個屬性配置對象Properties properties = new Properties();//InputStream is =new FileInputStream("jdbc.properties");InputStream is =JDBCUtil.class.getClassLoader().getResourceAsStream("jdbc.properties"); //導入輸出流 properties.load(is);//讀取屬性driverClass=properties.getProperty("driverClass");url=properties.getProperty("url");name=properties.getProperty("name");password=properties.getProperty("password");} catch (Exception e) {e.printStackTrace();}}public static Connection getConn(){Connection conn =null;try {Class.forName(driverClass);//建立連接conn = DriverManager.getConnection(url, name, password); } catch (Exception e) {e.printStackTrace();}return conn;}public static void release(Connection conn,Statement st,ResultSet rs){closers(rs);closest(st);closeconn(conn);}private static void closers(ResultSet rs){try {if(rs !=null){rs.close();}} catch (SQLException e) {e.printStackTrace(); }finally {rs=null;}}private static void closest(Statement st){try {if(st !=null){st.close();}} catch (SQLException e) {e.printStackTrace(); }finally {st=null;}}private static void closeconn(Connection conn){try {if(conn !=null){conn.close();}} catch (SQLException e) {e.printStackTrace(); }finally {conn=null;}} } 案例

創建jdbc.properties文件

driverClass=com.mysql.jdbc.Driver url=jdbc:mysql://127.0.0.1/student name=root password=root 案例

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轉載于:https://www.cnblogs.com/JungTan0113/p/11037491.html

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