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
