java调用数据库如何保证敏感字段的安全性

现实生活中，我们会看到电话号码等敏感信息隐藏显示的情况，eg.137****7924，那怎么才能保证敏感字段的安全性呢？
步骤 ：
step1:通过sql语句保证敏感信息的安全性
step2:建立视图
step3:java调用视图
sql语句如下：

create view customer_info1 as
select replace(initiative_phone,SUBSTR(initiative_phone,4,4),'****'),customer_id,call_time,sum_time,call_result from crm

或者

create view customer_info as
select concat(left(initiative_phone,3),'****',right(initiative_phone,4))'tel',customer_id,call_time,sum_time,call_result from crm

结果如图：

已经创建好包含敏感信息的视图customer_info，在java中直接调用视图就可以了，万变不离其宗，前面已经写过如何用java调用表了，调用视图是一样的。
具体代码如下所示：

DBUtil类：用来java程序与数据库的连接

package NoSensitiveSelect;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class DBUtil {
    
    
    static{
    
    
        //加载驱动
        try {
    
    
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
    
    
            e.printStackTrace();
        }
    }
    static Connection con=null;

    //构造方法私有化
    private DBUtil(){
    
    

    }
    //开始连接
    public static Connection getConnection() throws SQLException {
    
    
        con= DriverManager.getConnection("jdbc:mysql://localhost:3306/class?","root","root");
        return con;
    }

    //关闭连接
    public static void closeConnection() throws SQLException {
    
    
        con.close();
    }
}

DBService:实现具体的操作

package NoSensitiveSelect;

import java.sql.*;
import java.util.ArrayList;
import java.util.List;

public class DBService {
    
    
    String sql=null;
    PreparedStatement PS;
    ResultSet res;
    List<Customer> list  = new ArrayList<Customer>();
    public List<Customer> select() throws SQLException {
    
    
        //编写sql语句
        sql="select * from customer_info";
        //编译
        PS=DBUtil.getConnection().prepareStatement(sql);
        //执行
       res =  PS.executeQuery();
       while(res.next()){
    
    
          Customer cu = new Customer();
          String phone = res.getString("concat(left(initiative_phone,3),'****',right(initiative_phone,4))");
          int id = res.getInt("customer_id");
          Timestamp call_time = res.getTimestamp("call_time");
          int sum_time = res.getInt("sum_time");
          int call_result = res.getInt("call_result");
          cu.setInitiative_phone(phone);
          cu.setCustomer_id(id);
          cu.setCall_time(call_time);
          cu.setSum_time(sum_time);
          cu.setCall_result(call_result);

          list.add(cu);
       }
        return  list;
    }

}

Customer类：实体类，用来存储信息

package NoSensitiveSelect;

import java.sql.Date;
import java.sql.Time;
import java.sql.Timestamp;

public class Customer {
    
    

    private String initiative_phone;
    private int customer_id;
    private Timestamp call_time;
    private int sum_time;
    private int call_result;


    public Customer(){
    
    

    }
    public Customer(String initiative_phone, int customer_id, Timestamp call_time, int sum_time, int call_result) {
    
    
        this.initiative_phone = initiative_phone;
        this.customer_id = customer_id;
        this.call_time = call_time;
        this.sum_time = sum_time;
        this.call_result = call_result;
    }

    public String getInitiative_phone() {
    
    
        return initiative_phone;
    }

    public void setInitiative_phone(String initiative_phone) {
    
    
        this.initiative_phone = initiative_phone;
    }

    public int getCustomer_id() {
    
    
        return customer_id;
    }

    public void setCustomer_id(int customer_id) {
    
    
        this.customer_id = customer_id;
    }

    public Timestamp getCall_time() {
    
    
        return call_time;
    }

    public void setCall_time(Timestamp call_time) {
    
    
        this.call_time = call_time;
    }

    public int getSum_time() {
    
    
        return sum_time;
    }

    public void setSum_time(int sum_time) {
    
    
        this.sum_time = sum_time;
    }

    public int getCall_result() {
    
    
        return call_result;
    }

    public void setCall_result(int call_result) {
    
    
        this.call_result = call_result;
    }

    @Override
    public String toString() {
    
    
        return
                "客户电话：" + initiative_phone + '\'' +
                ",客户编号" + customer_id +
                ", 电话时间：" + call_time +
                ", 通话总时长：" + sum_time +
                ", 业务：" + call_result+"\n";
    }


}

Test类：测试类

package NoSensitiveSelect;

import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;

public class Test {
    
    

    public static void main(String[] args) throws SQLException {
    
    
        //1.建立连接
        Connection con = DBUtil.getConnection();

        //2.调用查询方法
        DBService service = new DBService();
        List list = service.select();
        System.out.println(list);

        //关闭连接
        DBUtil.closeConnection();
    }
}

结果如下图所示：