这是小编刚开始学java的时候老师教的一个web程序链接数据库的应用类，献给有需要的一些朋友，也希望大神们不要嫌弃
package com.aaa.util;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class BaseDao {
static String url="jdbc:oracle:thin:@localhost:1521:orcl";
static String driver="oracle.jdbc.OracleDriver";
static String user="scott";
static String password="tiger";
Connection conn=null;
PreparedStatement ps = null;
ResultSet rs= null;
//加载驱动
static{
try {
Class.forName(driver);
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
//获取连接
public static Connection getConnection() {
Connection conn=null;
try {
conn = DriverManager.getConnection(url, user, password);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return conn;
}
//关闭连接
public static void closeAllConnection(Connection conn ,PreparedStatement ps ,ResultSet rs) {
if(rs!=null){
try {
rs.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if(ps!=null){
try {
ps.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if(conn!=null){
try {
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
//设置方法
public PreparedStatement setParams(PreparedStatement ps ,Object[] params) {
if(params!=null){
for (int i = 0; i < params.length; i++) {
try {
ps.setObject(i+1, params[i]);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
return ps;
}
//公共增，删除，修改方法
public boolean executeUpdate(String sql,Object[] params) throws SQLException {
conn=getConnection();
ps=conn.prepareStatement(sql);
ps=setParams(ps, params);
int ret=ps.executeUpdate();
if(ret>0){
System.out.println("success!");
return true;
}else
{
System.out.println("fail!");
}
closeAllConnection(conn, ps, null);
return false;
}
//公共查询方法
public List<Map<String,Object>> executeQuery(String sql,Object[] params) {
conn=getConnection();
List<Map<String,Object>> objectList=new ArrayList<Map<String,Object>>();
try {
ps=conn.prepareStatement(sql);
ps=setParams(ps, params);
rs=ps.executeQuery();
ResultSetMetaData rsmd=rs.getMetaData();
while(rs.next()){//遍历所有的行
Map<String,Object> rowMap=new HashMap<String, Object>();
for (int i = 0; i < rsmd.getColumnCount(); i++) {//遍历所有的列
rowMap.put(rsmd.getColumnName(i+1).toLowerCase(), rs.getObject(i+1));
}
objectList.add(rowMap);
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
closeAllConnection(conn, ps, rs);
}
return objectList;
}
//此处是用来测试链接是否成功
/* public static void main(String[] args) {BaseDao bd = new BaseDao();
List<Map<String,Object>> objectList= bd.executeQuery("select *from(select rownum r ,PID,PNAME,SEX,BIRTHDAY,PATH FROM TBL_PERSON) e WHERE r<10 and r>4", null);
for (Map<String, Object> map : objectList) {
System.out.println(map.toString());
}
}*/
}