2016年3月17日Android学习笔记

1.Java.io.ByteArrayOutputStream.writeTo()方法实例

java.io.ByteArrayOutputStream.writeTo(OutputStream out) 方法写入该字节数组输出流的内容到指定的输出流参数。

2.xiecheng的数据库都是用的Mysql，不用Oracle。不用SQLServer，因为SQLServer有漏洞，不安全。

3.数据库等连接必须关闭。

参考：

package com;

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

public class TestPreparedStatement {
    public static void main(String[] args) {
        Connection con = null;
        PreparedStatement pst = null;
        try {
            Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");

            String url = "jdbc:sqlserver://127.0.0.1:1433;databaseName=userManager";
            con = DriverManager.getConnection(url, "as", "");
           

            String sql = "insert into myuser (userName,pwd) values (? , ?)";
            pst = con.prepareStatement(sql);
           

            pst.setString(1, "张三");  //也可以用setObject()
            pst.setString(2, "123");
            pst.addBatch();
   
            pst.setString(1, "李四");
            pst.setString(2, "456");
            pst.addBatch();
   
            pst.executeBatch();
   
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
           try {
               if (pst != null) {
                   pst.close();
                   pst = null;
               }
               if (con != null) {
                   con.close();
                   con = null;
               }
           } catch (SQLException e) {
               e.printStackTrace();
           }
       }
    }
}

参考：http://blog.sina.com.cn/s/blog_6fd9615d01010e2h.html
4.

5.