标签：
DBHelper连接数据库代码如下
package tools;
import java.io.Console;
import java.sql.*;
import java.util.Enumeration;
//import java.util.logging.*;
//import javax.swing.table.*;
/**
* SQL 鍩烘湰鎿嶄綔
* 閫氳繃瀹?鍙互寰堣交鏉剧殑浣跨敤 JDBC 鏉ユ搷绾垫暟鎹簱
* @author Null
*/
public class DBHelper
{
/**
* 椹卞姩
*/
//public static String driver = "com.microsoft.jdbc.sqlserver.SQLServerDriver";
public static String driver = "com.mysql.jdbc.Driver";
/**
* 杩炴帴瀛楃涓?
*/
//public static String url = "jdbc:microsoft:sqlserver://127.0.0.1:1433;DatabaseName=st";
public static String url = "jdbc:mysql://localhost:3306/test";
/**
* 鐢ㄦ埛鍚?
*/
public static String user = "root";
/**
* 瀵嗙爜
*/
public static String password = "root";
/**
* 涓嶅厑璁稿疄渚嬪寲璇ョ被
*/
private DBHelper()
{
}
/**
* 鑾峰彇涓?釜鏁版嵁搴撹繛鎺?
* 閫氳繃璁剧疆绫荤殑 driver / url / user / password 杩欏洓涓潤鎬佸彉閲忔潵 璁剧疆鏁版嵁搴撹繛鎺ュ睘鎬?
* @return 鏁版嵁搴撹繛鎺?
*/
public static Connection getConnection()
{
try
{
//鑾峰彇椹卞姩
Class.forName(driver);
} catch (ClassNotFoundException ex)
{
//Logger.getLogger(DBHelper.class.getName()).log(Level.SEVERE, null, ex);
System.out.println(ex.getMessage());
}
try
{
return DriverManager.getConnection(url, user, password);
} catch (SQLException ex)
{
//Logger.getLogger(DBHelper.class.getName()).log(Level.SEVERE, null, ex);
System.out.println(ex.getMessage());
return null;
}
}
/**
* 鑾峰彇涓?釜 Statement
* 璇?Statement 宸茬粡璁剧疆鏁版嵁闆?鍙互婊氬姩,鍙互鏇存柊
* @return 濡傛灉鑾峰彇澶辫触灏嗚繑鍥?null,璋冪敤鏃惰寰楁鏌ヨ繑鍥炲?
*/
public static Statement getStatement()
{
Connection conn = getConnection();
if (conn == null)
{
return null;
}
try
{
return conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,
ResultSet.CONCUR_UPDATABLE);
// 閻犱礁澧介悿鍡涘极閻楀牆绁﹂梻鍡楁瑜板弶绂掗妷锔炬硦闁告棑鎷烽柛娆樺灟娴滄帡寮寸?妯荤厐
} catch (SQLException ex)
{
//Logger.getLogger(DBHelper.class.getName()).log(Level.SEVERE, null, ex);
System.out.println(ex.getMessage());
close(conn);
}
return null;
}
/**
* 鑾峰彇涓?釜 Statement
* 璇?Statement 宸茬粡璁剧疆鏁版嵁闆?鍙互婊氬姩,鍙互鏇存柊
* @param conn 鏁版嵁搴撹繛鎺?
* @return 濡傛灉鑾峰彇澶辫触灏嗚繑鍥?null,璋冪敤鏃惰寰楁鏌ヨ繑鍥炲?
*/
public static Statement getStatement(Connection conn)
{
if (conn == null)
{
return null;
}
try
{
return conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE);
// 璁剧疆鏁版嵁闆嗗彲浠ユ粴鍔?鍙互鏇存柊
} catch (SQLException ex)
{
//Logger.getLogger(DBHelper.class.getName()).log(Level.SEVERE, null, ex);
System.out.println(ex.getMessage());
return null;
}
}
/**
* 鑾峰彇涓?釜甯﹀弬鏁扮殑 PreparedStatement
* 璇?PreparedStatement 宸茬粡璁剧疆鏁版嵁闆?鍙互婊氬姩,鍙互鏇存柊
* @param cmdText 闇? ? 鍙傛暟鐨?SQL 璇彞
* @param cmdParams SQL 璇彞鐨勫弬鏁拌〃
* @return 濡傛灉鑾峰彇澶辫触灏嗚繑鍥?null,璋冪敤鏃惰寰楁鏌ヨ繑鍥炲?
*/
public static PreparedStatement getPreparedStatement(String cmdText, Object[] cmdParams)
{
Connection conn = getConnection();
if (conn == null)
{
return null;
}
PreparedStatement pstmt = null;
try
{
pstmt = conn.prepareStatement(cmdText, ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE);
int i = 1;
for (Object item : cmdParams) //java foreach閬嶅巻闆嗗悎,瑕佹眰闆嗗悎绫诲疄鐜癊numeration鎺ュ彛
{
pstmt.setObject(i, item);
i++;
}
} catch (SQLException e)
{
e.printStackTrace();
close(conn);
}
return pstmt;
}
/**
* 鑾峰彇涓?釜甯﹀弬鏁扮殑 PreparedStatement
* 璇?PreparedStatement 宸茬粡璁剧疆鏁版嵁闆?鍙互婊氬姩,鍙互鏇存柊
* @param conn 鏁版嵁搴撹繛鎺?
* @param cmdText 闇? ? 鍙傛暟鐨?SQL 璇彞
* @param cmdParams SQL 璇彞鐨勫弬鏁拌〃
* @return 濡傛灉鑾峰彇澶辫触灏嗚繑鍥?null,璋冪敤鏃惰寰楁鏌ヨ繑鍥炲?
*/
public static PreparedStatement getPreparedStatement(Connection conn, String cmdText, Object[] cmdParams)
{
if (conn == null)
{
return null;
}
PreparedStatement pstmt = null;
try
{
pstmt = conn.prepareStatement(cmdText, ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE);
int i = 1;
for (Object item : cmdParams)
{
pstmt.setObject(i, item);
i++;
}
} catch (SQLException ex)
{
System.out.println(ex.getMessage());
//ex.printStackTrace();
close(pstmt);
}
return pstmt;
}
/**
* 鎵ц SQL 璇彞,杩斿洖缁撴灉涓烘暣鍨?
* 涓昏鐢ㄤ簬鎵ц闈炴煡璇㈣鍙?
* @param cmdText SQL 璇彞
* @return 闈炶礋鏁?姝ｅ父鎵ц; -1:鎵ц閿欒; -2:杩炴帴閿欒
*/
public static int ExecSql(String cmdText)
{
Statement stmt = getStatement();
if (stmt == null)
{
return -2;
}
int i;
try
{
i = stmt.executeUpdate(cmdText);
} catch (SQLException ex)
{
//Logger.getLogger(DBHelper.class.getName()).log(Level.SEVERE, null,ex);
System.out.println(ex.getMessage());
i = -1;
}
closeConnection(stmt);
return i;
}
/**
* 鎵ц SQL 璇彞,杩斿洖缁撴灉涓烘暣鍨?
* 涓昏鐢ㄤ簬鎵ц闈炴煡璇㈣鍙?
* @param cmdText SQL 璇彞
* @return 闈炶礋鏁?姝ｅ父鎵ц; -1:鎵ц閿欒; -2:杩炴帴閿欒
*/
public static int ExecSql(Connection conn, String cmdText)
{
Statement stmt = getStatement(conn);
if (stmt == null)
{
return -2;
}
int i;
try
{
i = stmt.executeUpdate(cmdText);
} catch (SQLException ex)
{
//Logger.getLogger(DBHelper.class.getName()).log(Level.SEVERE, null, ex);
System.out.println(ex.getMessage());
i = -1;
}
close(stmt);
return i;
}
/**
* 鎵ц SQL 璇彞,杩斿洖缁撴灉涓烘暣鍨?
* 涓昏鐢ㄤ簬鎵ц闈炴煡璇㈣鍙?
* @param cmdText 闇? ? 鍙傛暟鐨?SQL 璇彞
* @param cmdParams SQL 璇彞鐨勫弬鏁拌〃
* @return 闈炶礋鏁?姝ｅ父鎵ц; -1:鎵ц閿欒; -2:杩炴帴閿欒
*/
public static int ExecSql(String cmdText, Object[] cmdParams)
{
PreparedStatement pstmt = getPreparedStatement(cmdText, cmdParams);
if (pstmt == null)
{
return -2;
}
int i;
try
{
i = pstmt.executeUpdate();
} catch (SQLException ex)
{
//Logger.getLogger(DBHelper.class.getName()).log(Level.SEVERE, null, ex);
System.out.println(ex.getMessage());
i = -1;
}
closeConnection(pstmt);
return i;
}
/**
* 鎵ц SQL 璇彞,杩斿洖缁撴灉涓烘暣鍨?
* 涓昏鐢ㄤ簬鎵ц闈炴煡璇㈣鍙?
* @param conn 鏁版嵁搴撹繛鎺?
* @param cmdText 闇? ? 鍙傛暟鐨?SQL 璇彞
* @param cmdParams SQL 璇彞鐨勫弬鏁拌〃
* @return 闈炶礋鏁?姝ｅ父鎵ц; -1:鎵ц閿欒; -2:杩炴帴閿欒
*/
public static int ExecSql(Connection conn, String cmdText, Object[] cmdParams)
{
PreparedStatement pstmt = getPreparedStatement(conn, cmdText, cmdParams);
if (pstmt == null)
{
return -2;
}
int i;
try
{
i = pstmt.executeUpdate();
} catch (SQLException ex)
{
//Logger.getLogger(DBHelper.class.getName()).log(Level.SEVERE, null, ex);
System.out.println(ex.getMessage());
i = -1;
}
close(pstmt);
return i;
}
/**
* 杩斿洖缁撴灉闆嗙殑绗竴琛岀殑涓?垪鐨勫?,鍏朵粬蹇界暐
* @param cmdText SQL 璇彞
* @return
*/
public static Object ExecScalar(String cmdText)
{
ResultSet rs = getResultSet(cmdText);
Object obj = getScalar(rs);
closeConnection(rs);
return obj;
}
/**
* 杩斿洖缁撴灉闆嗙殑绗竴琛岀殑涓?垪鐨勫?,鍏朵粬蹇界暐
* @param conn 鏁版嵁搴撹繛鎺?
* @param cmdText SQL 璇彞
* @return
*/
public static Object ExecScalar(Connection conn, String cmdText)
{
ResultSet rs = getResultSet(conn, cmdText);
Object obj = getScalar(rs);
closeEx(rs);
return obj;
}
/**
* 杩斿洖缁撴灉闆嗙殑绗竴琛岀殑涓?垪鐨勫?,鍏朵粬蹇界暐
* @param cmdText 闇? ? 鍙傛暟鐨?SQL 璇彞
* @param cmdParams SQL 璇彞鐨勫弬鏁拌〃
* @return
*/
public static Object ExecScalar(String cmdText, Object[] cmdParams)
{
ResultSet rs = getResultSet(cmdText, cmdParams);
Object obj = getScalar(rs);
closeConnection(rs);
return obj;
}
/**
* 杩斿洖缁撴灉闆嗙殑绗竴琛岀殑涓?垪鐨勫?,鍏朵粬蹇界暐
* @param conn 鏁版嵁搴撹繛鎺?
* @param cmdText 闇? ? 鍙傛暟鐨?SQL 璇彞
* @param cmdParams SQL 璇彞鐨勫弬鏁拌〃
* @return
*/
public static Object ExecScalar(Connection conn, String cmdText, Object[] cmdParams)
{
ResultSet rs = getResultSet(conn, cmdText, cmdParams);
Object obj = getScalar(rs);
closeEx(rs);
return obj;
}
/**
* 杩斿洖涓?釜 ResultSet
* @param cmdText SQL 璇彞
* @return
*/
public static ResultSet getResultSet(String cmdText)
{
Statement stmt = getStatement();
if (stmt == null)
{
return null;
}
try
{
return stmt.executeQuery(cmdText);
} catch (SQLException ex)
{
//Logger.getLogger(DBHelper.class.getName()).log(Level.SEVERE, null, ex);
System.out.println(ex.getMessage());
closeConnection(stmt);
}
return null;
}
/**
* 杩斿洖涓?釜 ResultSet
* @param conn
* @param cmdText SQL 璇彞
* @return
*/
public static ResultSet getResultSet(Connection conn, String cmdText)
{
Statement stmt = getStatement(conn);
if (stmt == null)
{
return null;
}
try
{
return stmt.executeQuery(cmdText);
} catch (SQLException ex)
{
//Logger.getLogger(DBHelper.class.getName()).log(Level.SEVERE, null, ex);
System.out.println(ex.getMessage());
close(stmt);
}
return null;
}
/**
* 杩斿洖涓?釜 ResultSet
* @param cmdText 闇? ? 鍙傛暟鐨?SQL 璇彞
* @param cmdParams SQL 璇彞鐨勫弬鏁拌〃
* @return
*/
public static ResultSet getResultSet(String cmdText, Object[] cmdParams)
{
PreparedStatement pstmt = getPreparedStatement(cmdText, cmdParams);
if (pstmt == null)
{
return null;
}
try
{
return pstmt.executeQuery();
} catch (SQLException ex)
{
//Logger.getLogger(DBHelper.class.getName()).log(Level.SEVERE, null, ex);
System.out.println(ex.getMessage());
closeConnection(pstmt);
}
return null;
}
/**
* 杩斿洖涓?釜 ResultSet
* @param conn 鏁版嵁搴撹繛鎺?
* @param cmdText 闇? ? 鍙傛暟鐨?SQL 璇彞
* @param cmdParams SQL 璇彞鐨勫弬鏁拌〃
* @return
*/
public static ResultSet getResultSet(Connection conn, String cmdText, Object[] cmdParams)
{
PreparedStatement pstmt = getPreparedStatement(conn, cmdText, cmdParams);
if (pstmt == null)
{
return null;
}
try
{
return pstmt.executeQuery();
} catch (SQLException ex)
{
//Logger.getLogger(DBHelper.class.getName()).log(Level.SEVERE, null, ex);
System.out.println(ex.getMessage());
close(pstmt);
}
return null;
}
public static Object getScalar(ResultSet rs)
{
if (rs == null)
{
return null;
}
Object obj = null;
try
{
if (rs.next())
{
obj = rs.getObject(1);
}
} catch (SQLException ex)
{
//Logger.getLogger(DBHelper.class.getName()).log(Level.SEVERE, null, ex);
System.out.println(ex.getMessage());
}
return obj;
}
private static void close(Object obj)
{
if (obj == null)
{
return;
}
try
{
if (obj instanceof Statement)
{
((Statement) obj).close();
} else if (obj instanceof PreparedStatement)
{
((PreparedStatement) obj).close();
} else if (obj instanceof ResultSet)
{
((ResultSet) obj).close();
} else if (obj instanceof Connection)
{
((Connection) obj).close();
}
} catch (SQLException ex)
{
//Logger.getLogger(DBHelper.class.getName()).log(Level.SEVERE, null, ex);
System.out.println(ex.getMessage());
}
}
private static void closeEx(Object obj)
{
if (obj == null)
{
return;
}
try
{
if (obj instanceof Statement)
{
((Statement) obj).close();
} else if (obj instanceof PreparedStatement)
{
((PreparedStatement) obj).close();
} else if (obj instanceof ResultSet)
{
((ResultSet) obj).getStatement().close();
} else if (obj instanceof Connection)
{
((Connection) obj).close();
}
} catch (SQLException ex)
{
//Logger.getLogger(DBHelper.class.getName()).log(Level.SEVERE, null, ex);
System.out.println(ex.getMessage());
}
}
private static void closeConnection(Object obj)
{
if (obj == null)
{
return;
}
try
{
if (obj instanceof Statement)
{
((Statement) obj).getConnection().close();
} else if (obj instanceof PreparedStatement)
{
((PreparedStatement) obj).getConnection().close();
} else if (obj instanceof ResultSet)
{
((ResultSet) obj).getStatement().getConnection().close();
} else if (obj instanceof Connection)
{
((Connection) obj).close();
}
} catch (SQLException ex)
{
//Logger.getLogger(DBHelper.class.getName()).log(Level.SEVERE, null, ex);
System.out.println(ex.getMessage());
}
}
}
实现实体类代码如下
package entity;
public class User{
private String userID;
private String userName;
private String password;
public void setUserID(String userID){
this.userID=userID;
}
public String getUserID(){
return userID;
}
public void setUserName(String userName){
this.userName=userName;
}
public String getUserName(){
return userName;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
写完
private String userID;
private String userName;
private String password;
getset即可
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原文地址：http://www.cnblogs.com/1125963739-qq/p/5286605.html
