jsp頁面轉後台，出現中文亂碼

1、jsp頁面設置的<%@ page language="java" import="java.util.*" pageEncoding="GBK"%>

2、後台

System.out.println("==="+baseSVo.getVName());
  String str = baseSVo.getVName();
  try {
   str=new String(str.getBytes("ISO8859-1"),"GBK");
  } catch (UnsupportedEncodingException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
  System.out.println("str==="+str);

打印結果：

===???
str===???

3、頁面的查詢事件：以FORM表單來提交

  $('#search').click(function(){//查詢
        document.searchform.action="mealdate_mealdateSearch";
        document.searchform.method="post";
           document.searchform.submit();
    });

4、新增或修改 使用的是ajax 方式

$('#save').click(function(){//新增保存 返回主界面
         var editdDate=$('#edit_dDate').val();
         if (editdDate==''){
            alert("請選擇日期");
            return false;
         }
         $.ajax({
         url:'mealdateupdcheck',
              dataType:'json',
              type:'post',
              beforeSend:function(){},
              data:{
                  'baseVo.mdateId':$('#edit_mdateId').val(),
                  'baseVo.dDate':$('#edit_dDate').val(),
                  'baseVo.mstId':$('#edit_mstId').val(),
                  'userSNoPassWord':$('#userSNoPassWord').val()
             },
             success:function(data){
                if(data=='true'){
                    document.editform.action="mealdate_mealdateSearch";
                    document.searchform.method="post";
                  document.editform.submit();
                }else if(data=='false'){
                   alert('操作失敗');
                   return false;
                }else{
                   alert(data);
                   return false;
                }
             }
        });
    });