js加密参数传给后台，后台解密base64

前台js

// base64加密开始
var keyStr = "ABCDEFGHIJKLMNOP" + "QRSTUVWXYZabcdef" + "ghijklmnopqrstuv"
                + "wxyz0123456789+/" + "=";

function encode64(input) {
        var output = "";
        var chr1, chr2, chr3 = "";
        var enc1, enc2, enc3, enc4 = "";
        var i = 0;
        do {
                chr1 = input.charCodeAt(i++);
                chr2 = input.charCodeAt(i++);
                chr3 = input.charCodeAt(i++);
                enc1 = chr1 >> 2;
                enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
                enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
                enc4 = chr3 & 63;
                if (isNaN(chr2)) {
                        enc3 = enc4 = 64;
                } else if (isNaN(chr3)) {
                        enc4 = 64;
                }
                output = output + keyStr.charAt(enc1) + keyStr.charAt(enc2)
                                + keyStr.charAt(enc3) + keyStr.charAt(enc4);
                chr1 = chr2 = chr3 = "";
                enc1 = enc2 = enc3 = enc4 = "";
        } while (i < input.length);

        return output;
}
// base64加密结束

// 提交from到答题页面
function mfzsub(){
    var uri = $('#mfz').attr('action');
    inputhide();
    if(getexport() == "IE"){
        window.open('../'+uri+'?PAPERBANK_ID='+encode64($('#PAPERBANK_ID').val())+'&ORDERID='+encode64($('#ORDERID').val())+"&CLASSTYPE=" + encodeURI(encodeURI($('#CLASSTYPE').val())) + "&title=" + $('#title').val() +"&type=" + $('#type').val(),'');
    }else{
        window.open(uri+'?PAPERBANK_ID='+encode64($('#PAPERBANK_ID').val())+'&ORDERID='+encode64($('#ORDERID').val())+"&CLASSTYPE=" + encodeURI(encodeURI($('#CLASSTYPE').val())) + "&title=" + $('#title').val() +"&type=" + $('#type').val(),'');
    }
    
}

后台java处理

pd.put("CLASSTYPE", URLDecoder.decode(pd.getString("CLASSTYPE")));
            pd.put("PAPERBANK_ID", Base.decode(pd.getString("PAPERBANK_ID")));
//            pd.put("title", URLDecoder.decode(pd.getString("title")));
//            pd.put("type", URLDecoder.decode(pd.getString("type")));
            pd.put("ORDERID", Base.decode(pd.getString("ORDERID")));

base.java

package com.fh.util;

import java.io.ByteArrayOutputStream;

public class Base {

    private static byte[] base64DecodeChars = new byte[] { -1, -1, -1, -1, -1,
            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
            -1, -1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59,
            60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
            10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1,
            -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37,
            38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1,
            -1, -1 };

    /**
     * 解密
     * 
     * @param str
     * @return
     */
    public static String decode(String str) {
        byte[] data = str.getBytes();
        int len = data.length;
        ByteArrayOutputStream buf = new ByteArrayOutputStream(len);
        int i = 0;
        int b1, b2, b3, b4;

        while (i < len) {
            do {
                b1 = base64DecodeChars[data[i++]];
            } while (i < len && b1 == -1);
            if (b1 == -1) {
                break;
            }

            do {
                b2 = base64DecodeChars[data[i++]];
            } while (i < len && b2 == -1);
            if (b2 == -1) {
                break;
            }
            buf.write((int) ((b1 << 2) | ((b2 & 0x30) >>> 4)));

            do {
                b3 = data[i++];
                if (b3 == 61) {
                    return new String(buf.toByteArray());
                }
                b3 = base64DecodeChars[b3];
            } while (i < len && b3 == -1);
            if (b3 == -1) {
                break;
            }
            buf.write((int) (((b2 & 0x0f) << 4) | ((b3 & 0x3c) >>> 2)));

            do {
                b4 = data[i++];
                if (b4 == 61) {
                    return new String(buf.toByteArray());
                }
                b4 = base64DecodeChars[b4];
            } while (i < len && b4 == -1);
            if (b4 == -1) {
                break;
            }
            buf.write((int) (((b3 & 0x03) << 6) | b4));
        }
        return new String(buf.toByteArray());
    }

}