java通过配置文件（Properties类）连接Oracle数据库代码示例

Posted 2020-10-01 云上咖啡

  1 import java.io.FileInputStream;
  2 import java.io.IOException;
  3 import java.io.InputStream;
  4 import java.sql.Connection;
  5 import java.sql.DriverManager;
  6 import java.sql.ResultSet;
  7 import java.sql.SQLException;
  8 import java.sql.Statement;
  9 import java.util.Properties;
 10 
 11 public class JdbcDemo {
 12     //创建对象关联配置文件
 13     private Properties pro = new Properties();
 14     private String driver;
 15     private String url;
 16     private String user;
 17     private String psw;
 18     
 19     public JdbcDemo(){
 20         try {
 21             //通过反射获取数据流
 22             pro.load(this.getClass().getResourceAsStream("MyOrcDb.properties"));
 23             //获取配置文件数据
 24             this.setDriver(pro.getProperty("driver"));
 25             this.setUrl(pro.getProperty("url"));
 26             this.setUser(pro.getProperty("user"));
 27             this.setPsw(pro.getProperty("psw"));
 28         } catch (IOException e) {
 29             e.printStackTrace();
 30         }
 31     }
 32     
 33     private void minSalName(){
 34         
 35         //连接数据库
 36         try {
 37             Class.forName(driver);
 38             //获取连接
 39             Connection con;
 40             con = DriverManager.getConnection(url,user,psw);
 41             //sql语句载入数据库
 42             Statement st = con.createStatement();
 43             //读取各部门最低工资名单
 44             //关闭数据库
 45             String sql = "SELECT emp.deptno,emp.ename,emp.sal from emp,"
 46                     + "(SELECT deptno,min(sal) minSal from emp GROUP BY deptno) a "
 47                     + "where emp.deptno = a.deptno "
 48                     + "and emp.sal = a.minsal";
 49             //获得结果集
 50             ResultSet rst = st.executeQuery(sql );
 51             //获得结果集的列数
 52             int n = rst.getMetaData().getColumnCount();
 53             //遍历结果集
 54             String str = "";
 55             for(;rst.next();){
 56                 for(int i=1;i<=n;i++){
 57                     str += rst.getString(i)+"\t";
 58                 }
 59                 str += "\n";
 60             }
 61             System.out.println(str);
 62             //关闭JDBC（先开后关）
 63             rst.close();
 64             st.close();
 65             con.close();
 66         } catch (ClassNotFoundException e) {
 67             e.printStackTrace();
 68         }
 69         catch (SQLException e) {
 70             e.printStackTrace();
 71         }
 72     }
 73         public String getDriver() {
 74         return driver;
 75     }
 76     public void setDriver(String driver) {
 77         this.driver = driver;
 78     }
 79     public String getUrl() {
 80         return url;
 81     }
 82     public void setUrl(String url) {
 83         this.url = url;
 84     }
 85     public String getUser() {
 86         return user;
 87     }
 88     public void setUser(String user) {
 89         this.user = user;
 90     }
 91     public String getPsw() {
 92         return psw;
 93     }
 94     public void setPsw(String psw) {
 95         this.psw = psw;
 96     }
 97     public static void main(String[] args) {
 98         JdbcDemo jdbc = new JdbcDemo();
 99         jdbc.minSalName();
100     }
101 
102 }