最后一次解决mysql中文乱码！！！（
适用于简单的JSP页面之间传递中文，100%好使
String name=new String(roleform.getName().getBytes("ISO-8859-1"),"GB2312");
最简便的方法
配置个spring内置的过滤器：
<filter>
<filter-name>Spring character encoding filter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>GBK</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>Spring character encoding filter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
注意：该过滤器是老大，必须放在所有过滤器的前面
为了说的明白一些，我觉个例子：
很简单，就是从html中接受两个输入，然后由jsp处理写到mysql且从数据库返回这个结果显示出来。
Mysql_jstl.html
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接下来就是创建数据库，名字为sample
然后建立一个table: employee,内容如下（其中应该是email,可是我不小心在建数据库打错了，将错就错了）：
+-------------+------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+------------------+------+-----+---------+----------------+
| employee_id | int(10) unsigned | NO | PRI | NULL | auto_increment |
| last_name | varchar(20) | YES | | NULL | |
| first_name | varchar(20) | YES | | NULL | |
| birth | date | YES | | NULL | |
| sex | enum('m','f') | YES | | m | |
| emmail | varchar(39) | YES | | NULL | |
+-------------+------------------+------+-----+---------+----------------+
如果只是这样的话，就会出现这样的错误：报告的错误是：sqle=com.mysql.jdbc.MysqlDataTruncation:
Data truncation: Data too long
for column 'last_name' at row 1 .而且select last_name from employee.来看也出现了如下的情况：
| last_name |
+-------------+
| ?? |
| 54243654321 |
| ?? |
| ?? |
+-------------+
出现问号！
前面我们已经说过了，mysql默认的编码是latin1,不是我们所需要的gbk,所以我们要修改成为utf8，因为若要正确显示中文繁、简、日文、韩文 使用utf8，修改方法如下：
ALTER DATABASE sample ####这里修改整个数据库的编码
CHARACTER SET utf8
DEFAULT CHARACTER SET utf8
COLLATE utf8_general_ci
DEFAULT COLLATE utf8_general_ci;
当然了，你也可在在建数据库的时候指定编码，比如：
CREATE DATABASE sample
CHARACTER SET utf8
DEFAULT CHARACTER SET utf8
COLLATE utf8_general_ci
DEFAULT COLLATE utf8_general_ci ;
接下来要做的是打开mysql所在的目录下的my.nin
在[mysqld]段加入一下代码改成：
default-character-set=utf8
启动mysql，输入：
执行下列语句，看看结果是不是下面的：
mysql> show variables like '%character%';
+--------------------------+-------------------------------------------+
| Variable_name | Value |
+--------------------------+-------------------------------------------+
| character_set_client | latin1 |
| character_set_connection | latin1 |
| character_set_database | utf8 |
| character_set_results | latin1 |
| character_set_server | utf8
| character_set_system | utf8 |
| character_sets_dir | C:/MySQL/MySQL Server 5.0/share/charsets/ |
+--------------------------+-------------------------------------------+
mysql> show variables like '%collation%';
+----------------------+-------------------+
| Variable_name | Value |
+----------------------+-------------------+
| collation_connection | latin1_swedish_ci |
| collation_database | utf8_general_ci |
| collation_server | utf8_general_ci |
+----------------------+-------------------+
接着你再看看执行那个Mysql.html 文件：这回你可以看到的是
mysql> select * from employee;
+-------------+-----------+------------+------------+------+--------------+
| employee_id | last_name | first_name | birth | sex | emmail |
+-------------+-----------+------------+------------+------+--------------+
| 12 | ? | ?? | 1978-12-11 | f | [email protected] |
| 13 | ? | ?? | 1978-12-11 | f | [email protected] |
| 14 | ? | ?? | 1978-12-11 | f | [email protected] |
| 15 | ? | ?? | 1978-12-11 | f | [email protected] |
| 16 | ? | ?? | 1978-12-11 | f | [email protected] |
| 17 | ? | ?? | 1978-12-11 | f | [email protected] |
+-------------+-----------+------------+------------+------+--------------+
这当然不是我们希望看到的，我们需要的现实完美正确的中文：
我们还有最后一招：
mysql> SET NAMES 'gbk' ;
Query OK, 0 rows affected (0.00 sec)
因为我们需要的是gbk.
看看mysql中的character设置情况：
mysql> SHOW VARIABLES LIKE '%character%' ;
+--------------------------+-------------------------------------------+
| Variable_name | Value |
+--------------------------+-------------------------------------------+
| character_set_client | gbk |
| character_set_connection | gbk |
| character_set_database | utf8 |
| character_set_results | gbk |
| character_set_server | utf8 |
| character_set_system | utf8 |
| character_sets_dir | C:/MySQL/MySQL Server 5.0/share/charsets/ |
+--------------------------+-------------------------------------------+
7 rows in set (0.00 sec)
mysql> SHOW VARIABLES LIKE '%collation%' ;
+----------------------+-----------------+
| Variable_name | Value |
+----------------------+-----------------+
| collation_connection | gbk_chinese_ci |
| collation_database | utf8_general_ci |
| collation_server | utf8_general_ci |
+----------------------+-----------------+
这个才是我们最终需要的。
在来查看执行完Mysql_jstl.jsp后的数据库中的结果：
mysql> select * from employee;
| 14 | 王 | 彭给 | 1978-12-11 | f | [email protected] |
| 15 | 田 | 王光 | 1978-12-11 | f | [email protected] |
| 16 | 息 | 存入 | 1978-12-11 | f | [email protected] |
| 17 | 往 | 小杯 | 1978-12-11 | f | [email protected] |
+-------------+-----------+------------+------------+------+--------------+
可以高兴得看到了中文，并且在浏览器中也显示正确。
但是仅仅这样的话，当你重新启动mysql的时候
所有的设置又失效了。
mysql> show variables like '%character%';
+--------------------------+-------------------------------------------+
| Variable_name | Value |
+--------------------------+-------------------------------------------+
| character_set_client | latin1 |
| character_set_connection | latin1 |
| character_set_database | utf8 |
| character_set_results | latin1 |
| character_set_server | utf8 |
| character_set_system | utf8 |
| character_sets_dir | C:/MySQL/MySQL Server 5.0/share/charsets/ |
+--------------------------+-------------------------------------------+
mysql> SHOW VARIABLES LIKE '%collation%' ;
+----------------------+-------------------+
| Variable_name | Value |
+----------------------+-------------------+
| collation_connection | latin1_swedish_ci |
| collation_database | utf8_general_ci |
| collation_server | utf8_general_ci |
+----------------------+-------------------+
重新读取又出现乱码：
mysql> select * from employee;
+-------------+-----------+------------+------------+--
| employee_id | last_name | first_name | birth | s
+-------------+-----------+------------+------------+--
| 12 | ? | ?? | 1978-12-11 | f
| 13 | ? | ?? | 1978-12-11 | f
| 14 | ? | ?? | 1978-12-11 | f
| 15 | ? | ?? | 1978-12-11 | f
| 16 | ? | ?? | 1978-12-11 | f
| 17 | ? | ?? | 1978-12-11 | f
+-------------+-----------+------------+------------+--
所以我们需要在客户端设置系统能识别中文的编码gbk并没有保存到my.ini文件中。所以要修改my.ini文件
在[mysql]段加入一下代码改成：default-character-set=gbk 这样设置就得到保存了。
重启就可以了。
mysql> show variables like '%character%';
+--------------------------+----------------
| Variable_name | Value
+--------------------------+----------------
| character_set_client | gbk
| character_set_connection | gbk
| character_set_database | utf8
| character_set_results | gbk
| character_set_server | utf8
| character_set_system | utf8
| character_sets_dir | C:/MySQL/MySQL
+--------------------------+----------------
mysql> SHOW VARIABLES LIKE '%collation%' ;
+----------------------+-----------------+
| Variable_name | Value |
+----------------------+-----------------+
| collation_connection | gbk_chinese_ci |
| collation_database | utf8_general_ci |
| collation_server | utf8_general_ci |