第1个回答 2011-08-17
给你个连接数据库的DB封装类
import java.sql.*;
public class DB {
public static Connection getConn() {
Connection conn = null;
try {
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection("jdbc:mysql://localhost/这里写你的数据库名?user=root&password=这里是你设置的数据库密码");
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
return conn;
}
public static PreparedStatement prepare(Connection conn, String sql) {
PreparedStatement pstmt = null;
try {
if(conn != null) {
pstmt = conn.prepareStatement(sql);
}
} catch (SQLException e) {
e.printStackTrace();
}
return pstmt;
}
public static PreparedStatement prepare(Connection conn, String sql, int autoGenereatedKeys) {
PreparedStatement pstmt = null;
try {
if(conn != null) {
pstmt = conn.prepareStatement(sql, autoGenereatedKeys);
}
} catch (SQLException e) {
e.printStackTrace();
}
return pstmt;
}
public static Statement getStatement(Connection conn) {
Statement stmt = null;
try {
if(conn != null) {
stmt = conn.createStatement();
}
} catch (SQLException e) {
e.printStackTrace();
}
return stmt;
}
public static ResultSet getResultSet(Statement stmt, String sql) {
ResultSet rs = null;
try {
if(stmt != null) {
rs = stmt.executeQuery(sql);
}
} catch (SQLException e) {
e.printStackTrace();
}
return rs;
}
public static void executeUpdate(Statement stmt, String sql) {
try {
if(stmt != null) {
stmt.executeUpdate(sql);
}
} catch (SQLException e) {
e.printStackTrace();
}
}
public static void close(Connection conn) {
try {
if(conn != null) {
conn.close();
conn = null;
}
} catch (SQLException e) {
e.printStackTrace();
}
}
public static void close(Statement stmt) {
try {
if(stmt != null) {
stmt.close();
stmt = null;
}
} catch (SQLException e) {
e.printStackTrace();
}
}
public static void close(ResultSet rs) {
try {
if(rs != null) {
rs.close();
rs = null;
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
下面几句话是连接数据库,并处理的语句:
Connection conn = null;
PreparedStatement pstmt = null;
try {
conn = DB.getConn();
/**
这里写处理数据库的语句
例如插入删除等
*/
pstmt.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
} finally {
DB.close(pstmt);
DB.close(conn);
}