Java JDBC数据库 之 DBUtil 封装类
http://www.verejava.com/?id=16998460142640
下载 Oracle 或者 Mysql Jar 驱动
mysql-connector-java-3.0.10-stable-bin.jar
ojdbc14.jar
package com.db;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class DBUtil
{
private Connection conn;//数据库的链接对象
public DBUtil()
{
//加载驱动
try
{
Class.forName("oracle.jdbc.driver.OracleDriver");
} catch (ClassNotFoundException e)
{
e.printStackTrace();
}
}
//打开数据的链接
public Connection openConnection()
{
try
{
conn=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:orcl", "myspace", "myspace123");
} catch (SQLException e)
{
e.printStackTrace();
}
return conn;
}
//执行 INSERT DELETE UPDATE 的方法
public boolean executeUpdate(String sql)
{
//打开数据库
openConnection();
//创建执行 sql 的对象
try
{
Statement stmt=conn.createStatement();
//执行sql 语句
if(stmt.executeUpdate(sql)>0)
{
return true;
}
} catch (SQLException e)
{
e.printStackTrace();
}
finally
{
DBClose();
}
return false;
}
//执行 sql 的 查找 SELECT 的方法
public ResultSet executeQuery(String sql)
{
//打开数据库链接
openConnection();
//创建执行sql 的对象
Statement stmt=null;
ResultSet rs=null;
try
{
stmt = conn.createStatement();
rs=stmt.executeQuery(sql);
} catch (SQLException e)
{
e.printStackTrace();
}
return rs;
}
//绑定的sql INSERT DELETE UPDATE 方法
public boolean executeUpdate(String sql,Object[] params)
{
//打开数据库
openConnection();
//创建绑定对象
try
{
PreparedStatement pstmt=conn.prepareStatement(sql);
//填充 ？ 的值
for(int i=0;params!=null&&i<params.length;i++)
{
if(params[i] instanceof Integer)
{
pstmt.setInt(i+1, Integer.parseInt(params[i].toString()));
continue;
}
if(params[i] instanceof Float)
{
pstmt.setFloat(i+1, Float.parseFloat(params[i].toString()));
continue;
}
if(params[i] instanceof Double)
{
pstmt.setDouble(i+1, Double.parseDouble(params[i].toString()));
continue;
}
if(params[i] instanceof String)
{
pstmt.setString(i+1, params[i].toString());
}
//java.sql.Date, java.util.Date
if(params[i] instanceof java.util.Date)
{
//将 java.util.Date 转成 java.sql.Date
java.util.Date javaDate=(java.util.Date)params[i];
java.sql.Date sqlDate=new java.sql.Date(javaDate.getTime());
pstmt.setDate(i+1, sqlDate);
continue;
}
if(params[i] instanceof java.util.Timestamp)
{
//将 java.util.Date 转成 java.sql.Date
java.util.Date javaDate=(java.util.Date)params[i];
java.sql.Timestamp timestamp=new java.sql.Timestamp(javaDate.getTime());
pstmt.setTimestamp(i+1, timestamp);
continue;
}
}
//执行 绑定的 sql 语句
if(pstmt.executeUpdate()>0)
{
return true;
}
} catch (SQLException e)
{
e.printStackTrace();
}
finally
{
DBClose();
}
return false;
}
//绑定的sql 查找 SELECT 方法
public ResultSet executeQuery(String sql,Object[] params)
{
//打开数据库
openConnection();
//创建绑定对象
try
{
PreparedStatement pstmt=conn.prepareStatement(sql);
//填充 ？ 的值
for(int i=0;params!=null&&i<params.length;i++)
{
if(params[i] instanceof Integer)
{
pstmt.setInt(i+1, Integer.parseInt(params[i].toString()));
continue;
}
if(params[i] instanceof Float)
{
pstmt.setFloat(i+1, Float.parseFloat(params[i].toString()));
continue;
}
if(params[i] instanceof Double)
{
pstmt.setDouble(i+1, Double.parseDouble(params[i].toString()));
continue;
}
if(params[i] instanceof String)
{
pstmt.setString(i+1, params[i].toString());
}
//java.sql.Date, java.util.Date
if(params[i] instanceof java.util.Date)
{
//将 java.util.Date 转成 java.sql.Date
java.util.Date javaDate=(java.util.Date)params[i];
java.sql.Date sqlDate=new java.sql.Date(javaDate.getTime());
pstmt.setDate(i+1, sqlDate);
continue;
}
if(params[i] instanceof java.util.Timestamp)
{
//将 java.util.Date 转成 java.sql.Date
java.util.Date javaDate=(java.util.Date)params[i];
java.sql.Timestamp timestamp=new java.sql.Timestamp(javaDate.getTime());
pstmt.setTimestamp(i+1, timestamp);
continue;
}
}
//执行 绑定的 sql 语句
return pstmt.executeQuery();
} catch (SQLException e)
{
e.printStackTrace();
}
return null;
}
//关闭数据库链接
public void DBClose()
{
if(conn!=null)
{
try
{
conn.close();
} catch (SQLException e)
{
e.printStackTrace();
}
}
}
}
package com.db.test;
import com.db.DBUtil;
public class TestAdd
{
public static void main(String[] args)
{
DBUtil db=new DBUtil();
String sql="INSERT INTO dept(id,name)VALUES(3,'IT')";
if(db.executeUpdate(sql))
{
System.out.println("执行成功");
}
else
{
System.out.println("执行失败");
}
}
}
package com.db.test;
import com.db.DBUtil;
public class TestDelete
{
public static void main(String[] args)
{
DBUtil db=new DBUtil();
String sql="DELETE FROM dept WHERE id=3";
if(db.executeUpdate(sql))
{
System.out.println("执行成功");
}
else
{
System.out.println("执行失败");
}
}
}
package com.db.test;
import com.db.DBUtil;
public class TestUpdate
{
public static void main(String[] args)
{
DBUtil db=new DBUtil();
String sql="UPDATE dept SET name='指尖不' WHERE id=3";
if(db.executeUpdate(sql))
{
System.out.println("执行成功");
}
else
{
System.out.println("执行失败");
}
}
}
package com.db.test;
import java.sql.ResultSet;
import java.sql.SQLException;
import com.db.DBUtil;
public class TestFind
{
public static void main(String[] args)
{
DBUtil db=new DBUtil();
String sql="SELECT * FROM dept";
ResultSet rs=db.executeQuery(sql);
try
{
while(rs.next())
{
int id=rs.getInt("id");
String name=rs.getString("name");
System.out.println(id+","+name);
}
} catch (SQLException e)
{
e.printStackTrace();
}
finally
{
db.DBClose();
}
}
}
