java数据库等——乱码问题解决办法

中文乱码解决方案：
数据库乱码:
UTF-8对中文用3个字节来表示
String s =”飞翔”;
byte[] utf8 = s.getBytes(“utf-8”);//获得utf-8编码的字节值
System….(new String(utf8,”gbk”);//用GBK编码格式对UTF-8编码格式的字节数组进行解码，将产生乱码。
 
查看数据库的字符集
show variables like 'character\_set\_%';
show variables like 'collation_%';
--设置数据库字符编码
set names 'GBK'
alter database payment character set GBK;
create database mydb character set GBK;
set character_set_client=gbk;
set character_set_connection=gbk;
set character_set_database=gbk;
set character_set_results=gbk;
set character_set_server=gbk;
set character_set_system=gbk;
set collation_connection=gbk;
set collation_database=gbk;
set collation_server=gbk;
Servlet解决服务器端传给客户端产生的乱码问题
添加GB2312编码
向服务器输出中文时出现乱码或“？”最常用的解决方案：
service(HttpServletRequest request,HttpServletResponse response){
String s =” 中文”;
response.setContentType(“text/html;charset=utf-8”);
PrintWriter out = response.getWriter();
out.println(s);
}
以上方法有时候会失灵，所以使用下面试试：
service(){
String s = “中文”;
PrintWriter out = response.getWriter();
response.setHeader(“Content-Type”,”text/html;charset=utf-8”);//设置Conten-Type响应头
out.println(new String(s.getByte(“utf-8”),”iso-8859-1”));
}//获得utf-8编码的字节数组后，将其按原样保存在String对象中
}
1struts:      
String name =request.getParameter("username");
      String username;
      try {
username=new String(request.getParameter("username").getBytes("ISO-8859-1"), "gb2312" );
 
username = new String(username.getBytes(“ISO8859-1”),”GBK”);
 
2 struts2
HttpServletRequest request=ServletActionContext.getRequest();String
str=new Strin