Question

我的应用程序正在运行。如果它们不存在，我需要在SDCard中创建XML文件和目录。

我使用此代码从Assets

获取XML文件

public  Document abrirArchivo()
{       
    Document internalDom = null;
    //Cargo el archivo xml en una variable Document
    try
    {                   
    AssetManager assManager = context.getAssets();

    DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
    DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();    
    internalDom = dBuilder.parse(assManager.open("gastos.xml"));
    }
    catch (Exception e) {
        e.printStackTrace();
        }
    return internalDom;
}

然后将此文档保存到SdCard中的文件

public void crearArchivo(){

            String pathDirectorio=android.os.Environment.getExternalStorageDirectory().toString()+"/AdministradorGastos/";
            File directorio= new File(pathDirectorio);
            File archivoExiste= new File(path);
            directorio.mkdirs();
            if(!archivoExiste.exists())
            {   
                Document dom= abrirArchivo();
                try
                {
                    Transformer transformer = TransformerFactory.newInstance().newTransformer();
                    transformer.setOutputProperty(OutputKeys.INDENT, "yes");
                    StreamResult streamResult = new StreamResult(new File(pathDirectorio+"gastos.xml"));
                    DOMSource source = new DOMSource(dom);
                    transformer.transform(source, streamResult);                   
                }
                catch (Exception e) {
                    e.printStackTrace();
                }
            }

        }

问题是我在SDCard中获取一个空的xml文件，而我在Assets中的XML文件是这样的：

<?xml version="1.0"?>
<gastos>   
    <gasto>
        <descripcion>Default</descripcion>
        <monto>0</monto> 
        <fecha>01/01/1900</fecha>
    </gasto>
</gastos>

Answer 1

检查您的AndroidManifest文件是否有必要的权限：

 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

将此放置在应用程序标记内。我的代码中没有看到任何其他错误。

Answer 2

而不是创建文件将文件从资产复制到SD卡。检查以下代码

private void CopyAssets() {
        AssetManager assetManager = getAssets();
        String[] files = null;
        try {
            files = assetManager.list("Files");
        } catch (IOException e) {
            Log.e("tag", e.getMessage());
        }

        for(String filename : files) {
            System.out.println("File name => "+filename);
            InputStream in = null;
            OutputStream out = null;
            try {
              in = assetManager.open("Files/"+filename);   // if files resides inside the "Files" directory itself
              out = new FileOutputStream(Environment.getExternalStorageDirectory().toString() +"/" + filename);
              copyFile(in, out);
              in.close();
              in = null;
              out.flush();
              out.close();
              out = null;
            } catch(Exception e) {
                Log.e("tag", e.getMessage());
            }
        }
    }

    private void copyFile(InputStream in, OutputStream out) throws IOException {
        byte[] buffer = new byte[1024];
        int read;
        while((read = in.read(buffer)) != -1){
          out.write(buffer, 0, read);
        }
    }

使用以下权限：

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

Android，如果不存在，则无法在SD中创建文件

2 个答案: