//String转inputStream
1. String --> InputStream
InputStream String2InputStream(String str){
    ByteArrayInputStream stream = new ByteArrayInputStream(str.getBytes());
    return stream;
}

2. InputStream --> String
String inputStream2String(InputStream is){
    BufferedReader in = new BufferedReader(new InputStreamReader(is));
    StringBuffer buffer = new StringBuffer();
    String line = "";
    while ((line = in.readLine()) != null){
      buffer.append(line);
    }
    return buffer.toString();

InputStream inputStream =
postMethod.getResponseBodyAsStream();
BufferedReader in = new BufferedReader(new InputStreamReader(inputStream));
String xml = FileCopyUtils.copyToString(in);

====================================

   try {
    int len = request.getContentLength();
    byte buffer[];
    buffer = new byte[len];
    ServletInputStream in = request.getInputStream();
    int total = 0;
    for (int once = 0; total < len && once >= 0; total += once) {
     once = in.readLine(buffer, total, len);
    }
System.out.println(new String(buffer,"utf-8"));

======================

*
   try {
    InputStream is = request.getInputStream();
    byte buf[] = new byte[3000];
    is.read(buf);
System.out.println(new String(buf,"utf-8"));
   } catch (IOException e) {
   
   }

=============================

        int len = request.getContentLength();
        byte buffer[];
        buffer = new byte[len];
        ServletInputStream in = request.getInputStream();
        int total = 0;
        for (int once = 0; total < len && once >= 0; total += once) {
         once = in.readLine(buffer, total, len);
        }
       
        String temp=new String(buffer,"utf-8");

============================

/**********************************************************************/  
   ByteArrayOutputStream byteOutput= new ByteArrayOutputStream();
        try {       
        BufferedInputStream bufferInput = null;
        bufferInput = new BufferedInputStream(is);
            if(bufferInput==null){
            System.out.println("No data!");
            }
            int length;
            int size = 4096;           
            byte buf[] = new byte[size];
            byteOutput.reset();
            while ((length = bufferInput.read(buf, 0, size)) != -1) {
             byte[] temp = new byte[length];
             for (int i = 0; i < length; i++) {
                 temp[i] = buf[i];
             }
            byteOutput.write(temp);
            }
        } catch (Exception e) {
           e.printStackTrace();
        }      

        String data=byteOutput.toString();