Java连接MySQL中文乱码处理

原文出处：http://busybox.is-programmer.com/posts/23596.html

最近学习MySQL时又遇到了一个烦人的问题，中文编码，虽然在建立数据库时设置的字符编码为utf8，在MySQL的console上执行insert插入中文时没问题，可是在java代码中插入中文到mysql中就是??了，就是代码中的realName

 /************************************************************
     * Add resident
     ************************************************************
     */
    public boolean addResident(String userID,String realName,String gender,
            String birth,String addr,String tel,String email,String checkin) {
        Connection conn = this.getConnection();
        CallableStatement stmt = null;
        Date birthDate = null;
        Date checkinDate = null;
        if(birth!=null && (!birth.equals(""))) {
            birthDate = Date.valueOf(birth);
        }
        if(checkin!=null && (!checkin.equals(""))) {
            checkinDate = Date.valueOf(checkin);
        }
        try {
            stmt = conn.prepareCall("{call ICommunity.addResident(?,?,?,?,?,?,?,?,?)}");
            stmt.setString(1, userID);
            stmt.setString(2, realName);
            stmt.setString(3, gender);
            stmt.setDate(4, birthDate);
            stmt.setString(5, addr);
            stmt.setString(6, tel);
            stmt.setString(7, email);
            stmt.setDate(8, checkinDate);
            
            stmt.registerOutParameter(9, Types.BOOLEAN);
            stmt.execute();
            return stmt.getBoolean(9);
            
            
        }catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            return false;
        }
        finally {
            try {
                conn.close();
                stmt.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

差了好多资料，可还是没有解决根本问题，不管在代码里怎么改变字符编码，到数据库中显示的还是乱码

 

最后一篇很给力的文章解决了问题：http://developer.51cto.com/art/200906/130425.htm，需要设置一下mysql的配置文件中的client和server的默认编码。

在linux下这个配置文件在/etc/mysql/my.cnf，编辑之后的文件内容为：

[client]
port        = 3306
socket      = /var/run/mysqld/mysqld.sock
default-character-set=utf8
# Here is entries for some specific programs
# The following values assume you have at least 32M ram

# This was formally known as [safe_mysqld]. Both versions are currently parsed.
[mysqld_safe]
socket      = /var/run/mysqld/mysqld.sock
nice        = 0

[mysqld]
#
# * Basic Settings
#

default-character-set=utf8

就是分别在[client]和[mysqld]下添加设置默认编码的语句。

然后重启mysql，sudo /etc/init.d/mysql restart

结果就正常了。。。

还有一篇介绍字符编码的文章也很给力：http://www.regexlab.com/zh/encoding.htm