解决方法：
1、将所有的涉及到编码的都设置为 utf8（utf-8）；
设置数据库编码：命令行执行：
mysql> show variables like 'character%';
可以查看是否为utf8
mysql> show variables like 'character%';
+--------------------------+------------------------------------------------------+
| Variable_name | Value |
+--------------------------+------------------------------------------------------+
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | utf8 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | latin1 |
| character_set_system | utf8 |
| character_sets_dir | D:Program Filesmysql-5.6.20-winx64sharecharsets |
+--------------------------+------------------------------------------------------+
character_set_server项不知道如何设置，不过不影响。修改数据库编码执行命令：
mysql> alter database db_name character set utf8;
修改其他编码：
mysql> set names 'utf8';
设置JSP页面编码：在页面顶部添加
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
修改数据库连接DriverManager.getConnection(url, usr, pwd)的url：
String url = "jdbc:mysql://localhost:3306/db_name?useUnicode=true&characterEncoding=utf-8";
2、post传输方式
在发送页面和接收页面顶部都添加以下代码：
<% request.setCharacterEncoding("UTF-8");
response.setCharacterEncoding("UTF-8");
response.setContentType("text/html; charset=utf-8");
%>
