问题描述：服务器接收后台返回的报文时，提示java.lang.NegativeArraySizeException

分析：这种异常返回的原因，一般情况下没有报文提示为返回空报文，初步分析是响应报文流长度出了问题

百度一下类似的情况：https://stackoverflow.com/questions/11207897/negative-array-size-exception

节选部分内容：

try{
connection = (HttpConnection)Connector.open("http://someurl.xml",Connector.READ_WRITE);
URLEncodedPostData postData = new URLEncodedPostData(URLEncodedPostData.DEFAULT_CHARSET, false);
postData.append("username", "loginapi");
postData.append("password", "myapilogin");
postData.append("term", word);

 connection.setRequestMethod(HttpConnection.POST);  
 connection.setRequestProperty("Content-Type","application/x-www-form-urlencoded");  
 connection.setRequestProperty("User-Agent","Profile/MIDP-2.0 Configuration/CLDC-1.0");  
 requestOut = connection.openOutputStream();  
 requestOut.write(postData.getBytes());  
 String contentType = connection.getHeaderField("Content-type");  
 detailIn = connection.openInputStream();  
 int length = (int) connection.getLength();  
 ByteArrayOutputStream baos = new ByteArrayOutputStream();  
 if(length > 0){//这里长度没有判定的情况下，byte array长度若为-1会产生错误  
     byte info\[\] = new byte\[length\];  
     int bytesRead = detailIn.read(info);  
     while(bytesRead > 0) {  
         baos.write(info, 0, bytesRead);  
         bytesRead = detailIn.read(info);  
         }  
     baos.close();  
     connection.close();  
     requestSuceeded(baos.toByteArray(), contentType);

     detailIn.read(info);  
 }  
 else  
 {  
      System.out.println("Negative array size");  
 }  
       requestOut.close();  
       detailIn.close();  
       connection.close();  
}

　　结论：HTTP服务器在返回响应报文的时候，没有进行content.length长度判断，按照常规流程响应了错误长度的报文，导致了接收方报文长度异常