數據庫鏈接及操做實例

一、如下數據庫鏈接及操做實例

package properties;



import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;

public class test {
public static void main(String[] args) {
	/*FileWriter fw;

		fw = new FileWriter("tt.txt",true);//加上 true參數，表明是往這個文件中添加 內容，不是覆蓋原文件的內容
		fw.write("this is my");
		fw.write("stu");
		fw.write("dent");
		fw.write(".");
		fw.write("txt");
		fw.write("這是個人文件");
		fw.close();*/
	/*URL aurl=new URL("http://www.googel.com:80");
	System.out.println("protocol="+aurl.getProtocol());
	System.out.println("Authority="+aurl.getAuthority());
	System.out.println("Host="+aurl.getHost());
	System.out.println("Port="+aurl.getPort());*/
	add_update_del("update t_Accepted_Cert_Info t set t.custname='顏麗' where t.mobileno ='13536703748'");
	query("select * from t_Accepted_Cert_Info info where info.mobileno ='13536703748'");
}
public static Properties getProperties() {
	Properties prop = new Properties();//Properties 類表示了一個持久的屬性集。Properties 可保存在流中或從流中加載。屬性列表中每一個鍵及其對應值都是一個字符串
	try {
		// /加載屬性列表
		//InputStream in = new BufferedInputStream(new FileInputStream(
				//"D:\\myselenium\\config.properties"));
		//讀取當前工程下的配置文件
		  InputStream in =test.class.getResourceAsStream("/properties/config.properties");// getResourceAsStream查找具備給定名稱的資源,返回一個InputStream對象
		prop.load(in);//從流中加載
		return prop;
	} catch (Exception e) {
		e.printStackTrace();
		return null;
	}
	
}
public static Connection getConnection(){
	Connection conn=null;
	String driverName=getProperties().getProperty("orcal.driverName");
	String url=getProperties().getProperty("PA18dburl");
	String username=getProperties().getProperty("PA18dbuser");
	String pwd=getProperties().getProperty("PA18sdbpsw");
	try {
		Class.forName(driverName);
		conn=DriverManager.getConnection(url,username,pwd);
		
		if (conn!=null){
			System.out.println("數據庫鏈接成功");			
		}
		return conn;
	} catch (Exception e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
		return null;
	}
	
}
public static void add_update_del(String sql){
	Connection conn=getConnection();
	
	int x;
	try {
		Statement st=conn.createStatement();
		x = st.executeUpdate(sql);
		System.out.println("操做成功"+x);
	} catch (SQLException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	}
	
}
public static void query(String sql){
	try{
		Connection conn=getConnection();
		Statement st=conn.createStatement();
		ResultSet rs=st.executeQuery(sql);
		//當返回的結果集不爲空時，而且還有記錄時
		while(rs!=null && rs.next()){
			int id=rs.getInt(1);//獲取當前記錄的第一個字段的值
			String name=rs.getString("custname");
			String addr=rs.getString("addr");
			System.out.println("id"+id+"\t"+"name"+name+"\t"+"addr"+addr+"\t");
			
		}
		}catch(Exception e){
			e.printStackTrace();
	}
		
}
}