解决mysql的中文乱码

首先：打开你的MySql安装目录，找到一个my.ini文件，打开。建议用Editplus打开，因为可以看到第几行：打开如下:

# MySQL Server Instance Configuration File
# ----------------------------------------------------------------------
# Generated by the MySQL Server Instance Configuration Wizard
#
#
# Installation Instructions
# ----------------------------------------------------------------------
#
# On Linux you can copy this file to /etc/my.cnf to set global options,
# mysql-data-dir/my.cnf to set server-specific options
# (@localstatedir@ for this installation) or to
# ~/.my.cnf to set user-specific options.
#
# On Windows you should keep this file in the installation directory 
# of your server (e.g. C:Program FilesMySQLMySQL Server X.Y). To
# make sure the server reads the config file use the startup option 
# "--defaults-file". 
#
# To run run the server from the command line, execute this in a 
# command line shell, e.g.
# mysqld --defaults-file="C:Program FilesMySQLMySQL Server X.Ymy.ini"
#
# To install the server as a Windows service manually, execute this in a 
# command line shell, e.g.
# mysqld --install MySQLXY --defaults-file="C:Program FilesMySQLMySQL Server X.Ymy.ini"
#
# And then execute this in a command line shell to start the server, e.g.
# net start MySQLXY
#
#
# Guildlines for editing this file
# ----------------------------------------------------------------------
#
# In this file, you can use all long options that the program supports.
# If you want to know the options a program supports, start the program
# with the "--help" option.
#
# More detailed information about the individual options can also be
# found in the manual.
#
#
# CLIENT SECTION
# ----------------------------------------------------------------------
#
# The following options will be read by MySQL client applications.
# Note that only client applications shipped by MySQL are guaranteed
# to read this section. If you want your own MySQL client program to
# honor these values, you need to specify it as an option during the
# MySQL client library initialization.
#
[client]

port=3306

[mysql]

[i][b]default-character-set=utf8[/b][/i]

# 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]

# The TCP/IP Port the MySQL Server will listen on
port=3306


#Path to installation directory. All paths are usually resolved relative to this.
basedir="C:/Program Files/MySQL/MySQL Server 5.0/"

#Path to the database root
datadir="C:/Program Files/MySQL/MySQL Server 5.0/Data/"

# The default character set that will be used when a new schema or table is
# created and no character set is defined
[i][b]default-character-set=utf8[/b][/i]

# The default storage engine that will be used when create new tables when
default-storage-engine=INNODB

# Set the SQL mode to strict
sql-mode="STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"

# The maximum amount of concurrent sessions the MySQL server will
# allow. One of these connections will be reserved for a user with
# SUPER privileges to allow the administrator to login even if the
# connection limit has been reached.
max_connections=100

# Query cache is used to cache SELECT results and later return them
# without actual executing the same query once again. Having the query
# cache enabled may result in significant speed improvements, if your
# have a lot of identical queries and rarely changing tables. See the
# "Qcache_lowmem_prunes" status variable to check if the current value
# is high enough for your load.
# Note: In case your tables change very often or if your queries are
# textually different every time, the query cache may result in a
# slowdown instead of a performance improvement.
query_cache_size=0

# The number of open tables for all threads. Increasing this value
# increases the number of file descriptors that mysqld requires.
# Therefore you have to make sure to set the amount of open files
# allowed to at least 4096 in the variable "open-files-limit" in
# section [mysqld_safe]
table_cache=256

# Maximum size for internal (in-memory) temporary tables. If a table
# grows larger than this value, it is automatically converted to disk
# based table This limitation is for a single table. There can be many
# of them.
tmp_table_size=5M


# How many threads we should keep in a cache for reuse. When a client
# disconnects, the client's threads are put in the cache if there aren't
# more than thread_cache_size threads from before.  This greatly reduces
# the amount of thread creations needed if you have a lot of new
# connections. (Normally this doesn't give a notable performance
# improvement if you have a good thread implementation.)
thread_cache_size=8

#*** MyISAM Specific options

# The maximum size of the temporary file MySQL is allowed to use while
# recreating the index (during REPAIR, ALTER TABLE or LOAD DATA INFILE.
# If the file-size would be bigger than this, the index will be created
# through the key cache (which is slower).
myisam_max_sort_file_size=100G

# If the temporary file used for fast index creation would be bigger
# than using the key cache by the amount specified here, then prefer the
# key cache method.  This is mainly used to force long character keys in
# large tables to use the slower key cache method to create the index.
myisam_sort_buffer_size=8M

# Size of the Key Buffer, used to cache index blocks for MyISAM tables.
# Do not set it larger than 30% of your available memory, as some memory
# is also required by the OS to cache rows. Even if you're not using
# MyISAM tables, you should still set it to 8-64M as it will also be
# used for internal temporary disk tables.
key_buffer_size=8M

# Size of the buffer used for doing full table scans of MyISAM tables.
# Allocated per thread, if a full scan is needed.
read_buffer_size=64K
read_rnd_buffer_size=256K

# This buffer is allocated when MySQL needs to rebuild the index in
# REPAIR, OPTIMZE, ALTER table statements as well as in LOAD DATA INFILE
# into an empty table. It is allocated per thread so be careful with
# large settings.
sort_buffer_size=212K


#*** INNODB Specific options ***


# Use this option if you have a MySQL server with InnoDB support enabled
# but you do not plan to use it. This will save memory and disk space
# and speed up some things.
#skip-innodb

# Additional memory pool that is used by InnoDB to store metadata
# information.  If InnoDB requires more memory for this purpose it will
# start to allocate it from the OS.  As this is fast enough on most
# recent operating systems, you normally do not need to change this
# value. SHOW INNODB STATUS will display the current amount used.
innodb_additional_mem_pool_size=2M

# If set to 1, InnoDB will flush (fsync) the transaction logs to the
# disk at each commit, which offers full ACID behavior. If you are
# willing to compromise this safety, and you are running small
# transactions, you may set this to 0 or 2 to reduce disk I/O to the
# logs. Value 0 means that the log is only written to the log file and
# the log file flushed to disk approximately once per second. Value 2
# means the log is written to the log file at each commit, but the log
# file is only flushed to disk approximately once per second.
innodb_flush_log_at_trx_commit=1

# The size of the buffer InnoDB uses for buffering log data. As soon as
# it is full, InnoDB will have to flush it to disk. As it is flushed
# once per second anyway, it does not make sense to have it very large
# (even with long transactions).
innodb_log_buffer_size=1M

# InnoDB, unlike MyISAM, uses a buffer pool to cache both indexes and
# row data. The bigger you set this the less disk I/O is needed to
# access data in tables. On a dedicated database server you may set this
# parameter up to 80% of the machine physical memory size. Do not set it
# too large, though, because competition of the physical memory may
# cause paging in the operating system.  Note that on 32bit systems you
# might be limited to 2-3.5G of user level memory per process, so do not
# set it too high.
innodb_buffer_pool_size=8M

以上用蓝色标注的就是要修改后的。

其次：在你建表的时候记得选择：utf8字符集。

第三：你可以在每个页面中都使用：charset=utf-8,但是本人认为这种方法太笨了。而且工作量也很大，其实完全可以使用一个过滤器Filter实现，简单容易操作：步骤如下

第一：在项目文件src下新建一个Filters包，哦，我是说拿我做的案例作为参考。

第二：在包里面新建一个servlet类。记住类的接口一定要为：Filter-javax.servlet类的名称为I18NSupport.java

内容如下：

package filters;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class I18NSupport implements Filter {
 
 private String encoding;
 private String contentType;

 public void destroy() {
  // TODO Auto-generated method stub

 }

 public void doFilter(ServletRequest request, ServletResponse response,
   FilterChain chain) throws IOException, ServletException {
         request.setCharacterEncoding(encoding);
         response.setCharacterEncoding(encoding);
         response.setContentType(contentType);
         chain.doFilter(request, response);
 }

 public void init(FilterConfig conf) throws ServletException {
  encoding=conf.getInitParameter("encoding");
  contentType=conf.getInitParameter("contentType");
 }

}

# Size of each log file in a log group. You should set the combined size
# of log files to about 25%-100% of your buffer pool size to avoid
# unneeded buffer pool flush activity on log file overwrite. However,
# note that a larger logfile size will increase the time needed for the
# recovery process.
innodb_log_file_size=10M

# Number of threads allowed inside the InnoDB kernel. The optimal value
# depends highly on the application, hardware as well as the OS
# scheduler properties. A too high value may lead to thread thrashing.
innodb_thread_concurrency=8
最后还要在项目下的wed-inf/web.xml下写下配置文件：

<filter>
     <filter-name>I18NSupport</filter-name>
     <filter-class>filters.I18NSupport</filter-class>
     <init-param>
         <param-name>encoding</param-name>
         <param-value>utf-8</param-value>
     </init-param>
     <init-param>
       <param-name>contentType</param-name>
       <param-value>text/html;charset=utf-8</param-value>
     </init-param>
  </filter>
  <filter-mapping>
     <filter-name>I18NSupport</filter-name>
     <url-pattern>/*</url-pattern>
  </filter-mapping>
 

   
    这就差不多了。

哦，差点就忘记了最关键的，那就是在tomcat下修改配置：D:Program Filesapache-tomcat-5.5.17conf\server.xml

打开后

<!-- Define a non-SSL HTTP/1.1 Connector on port 8080 -->
    <Connector [i][b]URIEcoding="utf-8"[/b][/i] port="8686" maxHttpHeaderSize="8192"
               maxThreads="150" minSpareThreads="25" maxSpareThreads="75"
               enableLookups="false" redirectPort="8443" acceptCount="100"
               connectionTimeout="20000" disableUploadTimeout="true" />
    <!-- Note : To disable connection timeouts, set connectionTimeout value
     to 0 -->

加粗斜体部分是我添加的，这样就完美解决了中文乱码。