public class Utils {
public static List<Message> getMessages() {
//File file = new File("file:///android_asset/helloworld.txt");
AssetManager assetManager = getAssets();
InputStream ims = assetManager.open("helloworld.txt");
}
}
我正在使用这段代码试图从资产读取文件。我尝试了两种方法。首先，当使用文件时，我收到FileNotFoundException，当使用资产管理器getAssets()方法不被识别。 有什么解决办法吗?
当前回答
ExceptionProof
It maybe too late but for the sake of others who look for the peachy answers.loadAssetFile()方法返回资产的纯文本，如果有任何错误，则返回defaultValue参数。
public static String loadAssetFile(Context context, String fileName, String defaultValue) {
String result=defaultValue;
InputStreamReader inputStream=null;
BufferedReader bufferedReader=null;
try {
inputStream = new InputStreamReader(context.getAssets().open(fileName));
bufferedReader = new BufferedReader(inputStream);
StringBuilder out= new StringBuilder();
String line = bufferedReader.readLine();
while (line != null) {
out.append(line);
line = bufferedReader.readLine();
}
result=out.toString();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
Objects.requireNonNull(inputStream).close();
} catch (Exception e) {
e.printStackTrace();
}
try {
Objects.requireNonNull(bufferedReader).close();
} catch (Exception e) {
e.printStackTrace();
}
}
return result;
}
其他回答
您可以从文件中加载内容。考虑文件在资产文件夹中。
public static InputStream loadInputStreamFromAssetFile(Context context, String fileName){
AssetManager am = context.getAssets();
try {
InputStream is = am.open(fileName);
return is;
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
public static String loadContentFromFile(Context context, String path){
String content = null;
try {
InputStream is = loadInputStreamFromAssetFile(context, path);
int size = is.available();
byte[] buffer = new byte[size];
is.read(buffer);
is.close();
content = new String(buffer, "UTF-8");
} catch (IOException ex) {
ex.printStackTrace();
return null;
}
return content;
}
现在可以通过调用函数来获取内容，如下所示
String json= FileUtil.loadContentFromFile(context, "data.json");
考虑到数据。json存储在Application\app\src\main\assets\data.json中
AssetManager assetManager = getAssets();
InputStream inputStream = null;
try {
inputStream = assetManager.open("helloworld.txt");
}
catch (IOException e){
Log.e("message: ",e.getMessage());
}
ExceptionProof
It maybe too late but for the sake of others who look for the peachy answers.loadAssetFile()方法返回资产的纯文本，如果有任何错误，则返回defaultValue参数。
public static String loadAssetFile(Context context, String fileName, String defaultValue) {
String result=defaultValue;
InputStreamReader inputStream=null;
BufferedReader bufferedReader=null;
try {
inputStream = new InputStreamReader(context.getAssets().open(fileName));
bufferedReader = new BufferedReader(inputStream);
StringBuilder out= new StringBuilder();
String line = bufferedReader.readLine();
while (line != null) {
out.append(line);
line = bufferedReader.readLine();
}
result=out.toString();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
Objects.requireNonNull(inputStream).close();
} catch (Exception e) {
e.printStackTrace();
}
try {
Objects.requireNonNull(bufferedReader).close();
} catch (Exception e) {
e.printStackTrace();
}
}
return result;
}
getAssets()方法将在Activity类内部调用时工作。
如果你在非Activity类中调用这个方法，那么你需要从Context中调用这个方法，这个Context是从Activity类中传递过来的。下面是可以访问该方法的行。
ContextInstance.getAssets();
ContextInstance可以作为Activity类的this传递。
@HpTerm答案Kotlin版本:
private fun getDataFromAssets(activity: Activity): String {
var bufferedReader: BufferedReader? = null
var data = ""
try {
bufferedReader = BufferedReader(
InputStreamReader(
activity?.assets?.open("Your_FILE.html"),
"UTF-8"
)
) //use assets? directly if inside the activity
var mLine:String? = bufferedReader.readLine()
while (mLine != null) {
data+= mLine
mLine=bufferedReader.readLine()
}
} catch (e: Exception) {
e.printStackTrace()
} finally {
try {
bufferedReader?.close()
} catch (e: Exception) {
e.printStackTrace()
}
}
return data
}
