封装

package util; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException;    /** * @author sawyer 2014下午1:20:16 *  */    public class JdbcUtil {     private Connection conn = null;     private PreparedStatement stmt = null;     private ResultSet rs = null;     private static String driver = "com.mysql.jdbc.Driver";     private String url = "jdbc:mysql://localhost:3306/Student";     private String user = "root";     private String password = "root";        /**     * Get the driver     */     static {        }     /**     * Connect the database     */     public Connection getCon() {         try {             Class.forName(driver);         } catch (ClassNotFoundException e) {             e.printStackTrace();         }         try {             conn = (Connection) DriverManager                     .getConnection(url, user, password);         } catch (SQLException e) {             e.printStackTrace();         }         return conn;     }        /**     * @param sql     * @param obj     *Update     */    public int update(String sql, Object... obj) {        int count = 0;        conn = getCon();        try {            stmt = conn.prepareStatement(sql);            if (obj != null) {                for (int i = 0; i < obj.length; i++) {                    stmt.setObject(i + 1, obj[i]);                }            }            count = stmt.executeUpdate();        } catch (SQLException e) {            e.printStackTrace();        } finally {            close();        }        return count;    }      /**     * @param sql     * @param obj     * Query     */    public ResultSet Query(String sql, Object... obj) {        conn = getCon();        try {            stmt = conn.prepareStatement(sql);            while (obj != null) {                for (int i = 0; i < obj.length; i++) {                    stmt.setObject(i + 1, obj[i]);                }            }            rs = stmt.executeQuery();        } catch (SQLException e) {            e.printStackTrace();        } finally {            close();        }        return rs;    }       /**     * CLose the resource     */     public void close() {         try {             if (rs != null) {                 rs.close();             }         } catch (SQLException e) {             e.printStackTrace();         } finally {             try {                 if (stmt != null) {                     stmt.close();                 }             } catch (SQLException e) {                 e.printStackTrace();             } finally {                 if (conn != null) {                     try {                         conn.close();                     } catch (SQLException e) {                         e.printStackTrace();                     }                 }             }         }     } }

model

package model; import java.io.Serializable; public class Student implements Serializable{    private int id;    private int age;    private String name;         public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public int getAge() {        return age;    }    public void setAge(int age) {        this.age = age;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }}

测试

package model; import java.sql.ResultSet;import java.sql.SQLException; import util.JdbcUtil; public class Test {    public static void main(String[] args) {        testInsert();        testQuery();    }    public static void testInsert(){        Student s=new Student();        s.setId(12);        s.setAge(23);        s.setName("xxt");        JdbcUtil u=new JdbcUtil();        String sql="insert into T_Student(id,age,name) values( ?,?,?)";        int result=u.update(sql, s.getId(),s.getAge(),s.getName());        System.out.println(result);    }    public static void testQuery(){        String sql="select * from T_Student where age=?";        Student s=new Student();        s.setAge(23);        JdbcUtil u=new JdbcUtil();        ResultSet rs=u.Query(sql, s.getAge());        try {            if(rs.next()){                //s.setName(rs.getString("name"));                System.out.println(rs.getString("name"));//s.getName(rs.getString("name"))            }        } catch (SQLException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }}

jdbc工具类封装