Question

我有一个查看android资产的函数，如果资产存在则加载。如果不然后查看文件系统。如果找到它，它会加载它 - 如果文件不是零字节。如果在文件系统上找不到它，则会尝试从服务器获取它。除非文件已经存在并且大小为0，否则所有这些都有效 - 并且它在某些“原始”java逻辑测试中失败。我不明白这里有什么问题，并探讨它是否是我自己代码之外的错误的可能性。

问题发生在

if (lenoffile>1){  // always fails

其中对0的任何此int检查都会导致函数返回而不执行预期的流。

private String readQuestions(String xml_file){
    Log.i(TAG2,"readQuestions");
    List<String> mapList = null;
    String xmlString = null;
    int lenoffile =0;
    AssetManager am = this.getAssets();
    try {
        mapList = Arrays.asList(am.list(""));
        if (mapList.contains(xml_file)){
            InputStream is = am.open(xml_file);
            int length = is.available();
            byte[] data = new byte[length];
            is.read(data);
            xmlString = new String(data);
            return xmlString;
        } 
    } catch (IOException e1) {
        Log.i(TAG,"Failed in ReadQuestions() from assets");
    //  e1.printStackTrace();
        //return null;
    }
    Log.i(TAG2,"File not an asset. Must be on FS");
    if (me.FileExists(Environment.getExternalStorageDirectory().getAbsolutePath() + APPDIR +"/"+xml_file)) 
        xmlString = m.fileLoader(xml_file);

    if (xmlString != null){
        lenoffile = xmlString.length();
        Log.i(TAG2,"Length of file found=" + lenoffile);
        if (lenoffile>1){ // below never gets executed even with lenoffile==0
            Log.i(TAG2,"Returning here with a file of length "+ lenoffile);
            return xmlString; // assume the full file exists and validate
        }
    }   // if else then there is a null situation
    else{   // look on FS and load accordingly          
            DownloadFileAsync Z = new DownloadFileAsync();

迹：

06-09 12:26:58.197: I/SRCFILE(11792): readQuestions
06-09 12:27:08.822: I/SRCFILE(11792): File not an asset. Must be on FS
06-09 12:27:15.197: I/SRCFILE(11792): Length of file found=0

提前致谢。

凯文

逻辑分解 - 意外行为测试值

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