解決亂碼最好的方法是在項目設計之初，統一所有的字符集，例如頁面、request對象以及數據庫等等。

一、 幾種常見的亂碼現象：

1、頁面亂碼

單純的頁面亂碼是很好解決的，只要修改頭部適合的字符集即可，如果頁面中文顯示亂碼，你可以把字符集修改為：gb2312或gbk。

2、頁面之間傳遞的參數是亂碼

頁面之間傳遞參數出現的亂碼，就要解決頁面編碼和requset的字符集問題，在參數傳進傳出時重新設置相應的字符集。比如：request.setCharacterEncoding("UTF-8");

3、數據庫亂碼(下面詳細介紹)

二、數據庫亂碼解決方法(Mysql)

頁面和頁面傳值都沒有問題，結果發現存儲在數據庫中的數據出現了亂碼，則問題是出現在數據庫的編碼問題。

下面我已MySql數據庫為例說明解決方法：

如果你安裝數據庫的時候字符集使用的默認選項：latin1

DOS命令下進入數據庫show 一下字符集(命令：show variables like"%char%"; )顯示如下：

Java代碼 

+--------------------------+---------------+

| Variable_name            | Value         |

+--------------------------+---------------+

| character_set_client     | latin1        |

| character_set_connection | latin1        |

| character_set_database   | latin1        |

| character_set_filesystem | binary        |

| character_set_results    | latin1        |

| character_set_server     | latin1        |

| character_set_system     | utf8          |

+--------------------------+---------------+

+--------------------------+---------------+| Variable_name | Value |+--------------------------+---------------+| character_set_client | latin1 || character_set_connection | latin1 || character_set_database | latin1 || character_set_filesystem | binary || character_set_results | latin1 || character_set_server | latin1 || character_set_system | utf8 |+--------------------------+---------------+

1、修改數據庫默認字符集：

打開C:\Program Files\MySQL\MySQL Server 5.0里面的my.ini文件找到這段文字：

引用

# The default character set that will be used when a new schema or table is

# created and no character set is defined

default-character-set=latin1

把default-character-set=latin1改為default-character-set=gbk

這時候show 一下字符集(重新啟動mysql服務 ，命令：show variables like"%char%"; )顯示如下：

Java代碼 

+--------------------------+---------------+

| Variable_name            | Value         |

+--------------------------+---------------+

| character_set_client     | latin1        |

| character_set_connection | latin1        |

| character_set_database   | gbk           |

| character_set_filesystem | binary

| character_set_results    | latin1        |

| character_set_server     | latin1        |

| character_set_system     | utf8          |

+--------------------------+---------------+

+--------------------------+---------------+| Variable_name | Value |+--------------------------+---------------+| character_set_client | latin1 || character_set_connection | latin1 || character_set_database | gbk || character_set_filesystem | binary || character_set_results | latin1 || character_set_server | latin1 || character_set_system | utf8 |+--------------------------+---------------+

2、如果你是導入的數據庫，需要對my.ini做如下修改找到

引用

[client]

port=3306

[mysql]

default-character-set=latin1

把 default-character-set=latin1改為default-character-set=gbk

引用

# SERVER SECTION

# ----------------------------------------------------------------------

#

# The following options will be read by the MySQL Server. Make sure that

# you have installed the server correctly (see above) so it reads this

# file.

#

[mysqld]

找到

增加default-character-set=gbk

然后在設置一下你導入的數據庫字符集即可：

命令:alter database  你的數據庫名 charset = gbk;

重新啟動mysql服務,show 一下字符集(，命令：show variables like"%char%"; )顯示如下：

Java代碼 

+--------------------------+---------------+

| Variable_name            | Value         |

+--------------------------+---------------+

| character_set_client     | gbk           |

| character_set_connection | gbk           |

| character_set_database   | gbk           |

| character_set_filesystem | binary        |

| character_set_results    | gbk           |

| character_set_server     | gbk           |

| character_set_system     | utf8          |

+--------------------------+---------------+

+--------------------------+---------------+| Variable_name | Value |+--------------------------+---------------+| character_set_client | gbk || character_set_connection | gbk || character_set_database | gbk || character_set_filesystem | binary || character_set_results | gbk || character_set_server | gbk || character_set_system | utf8 |+--------------------------+---------------+