Java解码网站post字符串(swich case用法和乱码判断)

对网站post字符串进行解码，用常见字符集试验，用了switch case并对乱码做判断，如果是js加密且ContentType文件类型是text/octet纯二进制就无法解码。具体代码如下：

public class DPIPost {
//判断是否是乱码
private static boolean isMessyCode(String strName) {
try {
Pattern p = Pattern.compile("\\s*|\t*|\r*|\n*");
Matcher m = p.matcher(strName);
String after = m.replaceAll("");
String temp = after.replaceAll("\\p{P}", "");
char[] ch = temp.trim().toCharArray();

int length = (ch != null) ? ch.length : 0;
for (int i = 0; i < length; i++) {
char c = ch[i];
if (!Character.isLetterOrDigit(c)) {
String str = "" + ch[i];
//if (!str.matches("[\u4e00-\u9fa5]+")) {
if (!str.matches("[0-9a-zA-Z\\u4e00-\\u9fa5]+")){
return true;
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return false;
}
@SuppressWarnings("finally")
public static String decodePostData(String postdata) throws UnsupportedEncodingException{
String charSet="Base64";//字符集
String retPostdata=postdata;//返回值
try{
switch(charSet){
case "Base64"://base64解码
byte[] bEncode=postdata.getBytes();//获取post串的字节
byte[] bDecode= it.sauronsoftware.base64.Base64.decode(bEncode);//用base64解码
String strBase64=new String(bDecode);
if(strBase64.contains("&") && strBase64.contains("=") && !strBase64.contains("%")){//解码成功的标志
String str1=strBase64.replaceAll("&", "a");
String str2=str1.replaceAll("=", "b");
if(!DPIPost.isMessyCode(str2)) {//不含有乱码
retPostdata= strBase64;
break;
}
}else if(strBase64.contains("%")) {//需URL解码
postdata=strBase64;
}
charSet="UTF-8";
case "UTF-8":
String strUTF8=URLDecoder.decode(postdata,charSet);
if(strUTF8.contains("&") && strUTF8.contains("=")){//解码成功的标志
String str1=strUTF8.replaceAll("&", "a");
String str2=str1.replaceAll("=", "b");
if(!DPIPost.isMessyCode(str2)) {//不含有乱码
retPostdata= strUTF8;
break;
}
}
charSet="UTF-16";
case "UTF-16":
String strUTF16=URLDecoder.decode(postdata,charSet);
if(strUTF16.contains("&") && strUTF16.contains("=")){//解码成功的标志
String str1=strUTF16.replaceAll("&", "a");
String str2=str1.replaceAll("=", "b");
if(!DPIPost.isMessyCode(str2)) {//不含有乱码
retPostdata= strUTF16;
break;
}
}
charSet="GBK";
case "GBK":
String strGBK=URLDecoder.decode(postdata,charSet);
if(strGBK.contains("&") && strGBK.contains("=")){//解码成功的标志
String str1=strGBK.replaceAll("&", "a");
String str2=str1.replaceAll("=", "b");
if(!DPIPost.isMessyCode(str2)) {//不含有乱码
retPostdata= strGBK;
break;
}
}
charSet="GB2312";
case "GB2312":
String strGB2312=URLDecoder.decode(postdata,charSet);
if(strGB2312.contains("&") && strGB2312.contains("=")){//解码成功的标志
String str1=strGB2312.replaceAll("&", "a");
String str2=str1.replaceAll("=", "b");
if(!DPIPost.isMessyCode(str2)) {//不含有乱码
retPostdata= strGB2312;
break;
}
}
charSet="GB18030";
case "GB18030":
String strGB18030=URLDecoder.decode(postdata,charSet);
if(strGB18030.contains("&") && strGB18030.contains("=")){//解码成功的标志
String str1=strGB18030.replaceAll("&", "a");
String str2=str1.replaceAll("=", "b");
if(!DPIPost.isMessyCode(str2)) {//不含有乱码
retPostdata= strGB18030;
break;
}
}
charSet="UNICODE";
case "UNICODE":
String strUnicode=URLDecoder.decode(postdata,charSet);
if(strUnicode.contains("&") && strUnicode.contains("=")){//解码成功的标志
String str1=strUnicode.replaceAll("&", "a");
String str2=str1.replaceAll("=", "b");
if(!DPIPost.isMessyCode(str2)) {//不含有乱码
retPostdata= strUnicode;
break;
}
}
charSet="BIG5";
case "BIG5":
String strBig5=URLDecoder.decode(postdata,charSet);
if(strBig5.contains("&") && strBig5.contains("=")){//解码成功的标志
String str1=strBig5.replaceAll("&", "a");
String str2=str1.replaceAll("=", "b");
if(!DPIPost.isMessyCode(str2)) {//不含有乱码
retPostdata= strBig5;
break;
}
}
charSet="ISO-8859-1";
case "ISO-8859-1":
String strISO88591=URLDecoder.decode(postdata,charSet);
if(strISO88591.contains("&") && strISO88591.contains("=")){//解码成功的标志
String str1=strISO88591.replaceAll("&", "a");
String str2=str1.replaceAll("=", "b");
if(!DPIPost.isMessyCode(str2)) {//不含有乱码
retPostdata= strISO88591;
break;
}
}
default:
retPostdata=postdata;
break;
}
}catch(IOException e){e.printStackTrace();}
finally {
return retPostdata;
}

}

public static void main(String[] args) throws Exception {
//String postdata="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";
//String postdata="YXBwa2V5PThjMDAyYzVjMzBkNSZkZXZpY2U9NDBjZmIyMjg2OTY5ODExZmYyZTQ1NGI5OWRlOGUyYmZkN2Y2YmZmYiZwbGF0PTEmYXBwcGtnPWNvbS5kZXdtb2JpbGUua3VhaXlhJmFwcHZlcj0xNDQmc2RrdmVyPTYwMDU2Jm5ldHdvcmt0eXBlPXdpZmk=";
String postdata="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";
String retPostData=DPIPost.decodePostData(postdata);
if(retPostData != postdata) System.out.println(retPostData);
}
}