Java输入流与字符串之间的转换方法-

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();
}

今天从网上看到了另一种方法，特拿来分享

String all_content=null;
    try {
      all_content =new String();

      InputStream ins = 获取的输入流;

      ByteArrayOutputStream outputstream = new ByteArrayOutputStream();
      byte[] str_b = new byte[1024];
      int i = -1;
      while ((i=ins.read(str_b)) > 0) {
          outputstream.write(str_b,0,i);
      }
      all_content = outputstream.toString();
   } catch (Exception e) {
     e.printStackTrace();
   }

此两种方法上面一种更快，但是比较耗内存，后者速度慢，耗资源少

3、File --> InputStream

InputStream in = new InputStream(new FileInputStream(File));

4、InputStream --> File

public void inputstreamtofile(InputStream ins,File file){
    OutputStream os = new FileOutputStream(file);
    int bytesRead = 0;
    byte[] buffer = new byte[8192];
    while ((bytesRead = ins.read(buffer, 0, 8192)) != -1) {
        os.write(buffer, 0, bytesRead);
    }
    os.close();
    ins.close();
}

转自：http://apps.hi.baidu.com/share/detail/19357535