1、String –> InputStream

InputStrem is = new ByteArrayInputStream(str.getBytes());  或者  ByteArrayInputStream stream= new ByteArrayInputStream(str.getBytes());

2、InputStream–>String

inputStream input = null;    StringBuffer out = new StringBuffer();       byte[] b = new byte[4096];       for (int n; (n = input.read(b)) != -1;) {            out.append(new String(b, 0, n));       }  return out.toString();

3、Reader –>String

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

4、String–>Reader

Reader reader = null;  BufferedReader r = new BufferedReader(reader);  StringBuilder b = new StringBuilder();  String line;  while((line=r.readLine())!=null) {       b.append(line);       b.append(“\r\n”);  }  return b.toString();