baseDAO数据库链接

package org.xiaotian.BaseDAO;


import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.PreparedStatement;
import java.util.ArrayList;
import java.util.SortedMap;


import javax.servlet.jsp.jstl.sql.Result;
import javax.servlet.jsp.jstl.sql.ResultSupport;


/**
 * 操作数据库
 * @author Administrator
 *
 */
public class BaseDAO {

public static final String DRIVER = "com.mysql.jdbc.Driver";
public static final String URL ="jdbc:mysql:/localhost:3306/db?useUnicode=true&characterEncoding=utf-8";
public static final String USERNAME = "root";
public static final String USERPWD="123456";

/*
* 拿连接
*/
public static Connection getConn() throws Exception {
Class.forName(DRIVER);
return DriverManager.getConnection(URL, USERNAME, USERPWD);
}

/*
* 关闭数据库连接
*/
public static void closeConn(Connection conn, ResultSet rs) {
try {
if (rs != null) {
rs.close();
}
if (conn != null && !conn.isClosed()) {
conn.close();
}
} catch(Exception e) {
e.printStackTrace();
}
}

public static void theSameCode(PreparedStatement ps, Object[] params) throws Exception{
if (params != null && params.length > 0) {
for (int i=0; i<params.length; i++) {
ps.setObject(i+1, params[i]);
}
}
}

/*
* 对数据库执行增加，删除，修改操作
*/
public static boolean runUpdate(String sql, Object[] params) {
int count = 0;
try {
Connection conn = getConn();
PreparedStatement ps = conn.prepareStatement(sql);
theSameCode(ps, params);
count = ps.executeUpdate();
closeConn(conn, null);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

return count > 0;
}

/*
* 查询
*/
public static Result runSelect(String sql, Object[] params) {
Result result = null;
try {
Connection conn = getConn();
PreparedStatement ps = conn.prepareStatement(sql);
theSameCode(ps, params);
ResultSet rs = ps.executeQuery();
result = ResultSupport.toResult(rs);
closeConn(conn, rs);
} catch (Exception e) {
e.printStackTrace();
}
return result;
}



}