如何从 Android Studio 中的资产读取文本文件?
How to read a text file from assets in Android Studio?
我在 Android Studio 的资产文件目录中可能有 wifi2.txt 文件。但是,当我尝试访问它时,我不断收到 NULLPointException。我的代码如下:(提前致谢)
//CSV FILE READING
File file = null;
try {
FileInputStream is = new FileInputStream(file);
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(getAssets().open("wifi2.txt")));
String line;
Log.e("Reader Stuff",reader.readLine());
while ((line = reader.readLine()) != null) {
Log.e("code",line);
String[] RowData = line.split(",");
LatLng centerXY = new LatLng(Double.valueOf(RowData[1]), Double.valueOf(RowData[2]));
if (RowData.length == 4) {
mMap.addMarker(new MarkerOptions().position(centerXY).title(String.valueOf(RowData[0]) + String.valueOf(RowData[3])).icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN)));
}
}
} catch (IOException ex) {
ex.printStackTrace();
} finally {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
//Done with CSV File Reading
用法: String yourData = LoadData("wifi2.txt");
假设 wifi2.txt 位于 assets
public String LoadData(String inFile) {
String tContents = "";
try {
InputStream stream = getAssets().open(inFile);
int size = stream.available();
byte[] buffer = new byte[size];
stream.read(buffer);
stream.close();
tContents = new String(buffer);
} catch (IOException e) {
// Handle exceptions here
}
return tContents;
}
Reference
从资产中读取文件的方法:
public static String readFile(AssetManager mgr, String path) {
String contents = "";
InputStream is = null;
BufferedReader reader = null;
try {
is = mgr.open(path);
reader = new BufferedReader(new InputStreamReader(is));
contents = reader.readLine();
String line = null;
while ((line = reader.readLine()) != null) {
contents += '\n' + line;
}
} catch (final Exception e) {
e.printStackTrace();
} finally {
if (is != null) {
try {
is.close();
} catch (IOException ignored) {
}
}
if (reader != null) {
try {
reader.close();
} catch (IOException ignored) {
}
}
}
return contents;
}
File file = null;
try {
FileInputStream is = new FileInputStream(file);
实际上您并没有在任何地方使用 FileInputStream。只需使用这段代码
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(getAssets().open("wifi2.txt")));
String line;
Log.e("Reader Stuff",reader.readLine());
while ((line = reader.readLine()) != null) {
Log.e("code",line);
String[] RowData = line.split(",");
LatLng centerXY = new LatLng(Double.valueOf(RowData[1]), Double.valueOf(RowData[2]));
if (RowData.length == 4) {
mMap.addMarker(new MarkerOptions().position(centerXY).title(String.valueOf(RowData[0]) + String.valueOf(RowData[3])).icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN)));
}
}
} catch (IOException ex) {
ex.printStackTrace();
}
在 Kotlin 中,我们可以实现这一点:-
val string = requireContext().assets.open("wifi2.txt").bufferedReader().use {
it.readText()
}
我使用 kotlin 从资产文件加载文本的解决方案
object AssetsLoader {
fun loadTextFromAsset(context: Context, file: String): String {
return context.assets.open(file).bufferedReader().use { reader ->
reader.readText()
}
}
}
像这样使用它:
val text = AssetsLoader.loadTextFromAsset(context, "test.json")
我在 Android Studio 的资产文件目录中可能有 wifi2.txt 文件。但是,当我尝试访问它时,我不断收到 NULLPointException。我的代码如下:(提前致谢)
//CSV FILE READING
File file = null;
try {
FileInputStream is = new FileInputStream(file);
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(getAssets().open("wifi2.txt")));
String line;
Log.e("Reader Stuff",reader.readLine());
while ((line = reader.readLine()) != null) {
Log.e("code",line);
String[] RowData = line.split(",");
LatLng centerXY = new LatLng(Double.valueOf(RowData[1]), Double.valueOf(RowData[2]));
if (RowData.length == 4) {
mMap.addMarker(new MarkerOptions().position(centerXY).title(String.valueOf(RowData[0]) + String.valueOf(RowData[3])).icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN)));
}
}
} catch (IOException ex) {
ex.printStackTrace();
} finally {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
//Done with CSV File Reading
用法: String yourData = LoadData("wifi2.txt");
假设 wifi2.txt 位于 assets
public String LoadData(String inFile) {
String tContents = "";
try {
InputStream stream = getAssets().open(inFile);
int size = stream.available();
byte[] buffer = new byte[size];
stream.read(buffer);
stream.close();
tContents = new String(buffer);
} catch (IOException e) {
// Handle exceptions here
}
return tContents;
}
Reference
从资产中读取文件的方法:
public static String readFile(AssetManager mgr, String path) {
String contents = "";
InputStream is = null;
BufferedReader reader = null;
try {
is = mgr.open(path);
reader = new BufferedReader(new InputStreamReader(is));
contents = reader.readLine();
String line = null;
while ((line = reader.readLine()) != null) {
contents += '\n' + line;
}
} catch (final Exception e) {
e.printStackTrace();
} finally {
if (is != null) {
try {
is.close();
} catch (IOException ignored) {
}
}
if (reader != null) {
try {
reader.close();
} catch (IOException ignored) {
}
}
}
return contents;
}
File file = null;
try {
FileInputStream is = new FileInputStream(file);
实际上您并没有在任何地方使用 FileInputStream。只需使用这段代码
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(getAssets().open("wifi2.txt")));
String line;
Log.e("Reader Stuff",reader.readLine());
while ((line = reader.readLine()) != null) {
Log.e("code",line);
String[] RowData = line.split(",");
LatLng centerXY = new LatLng(Double.valueOf(RowData[1]), Double.valueOf(RowData[2]));
if (RowData.length == 4) {
mMap.addMarker(new MarkerOptions().position(centerXY).title(String.valueOf(RowData[0]) + String.valueOf(RowData[3])).icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN)));
}
}
} catch (IOException ex) {
ex.printStackTrace();
}
在 Kotlin 中,我们可以实现这一点:-
val string = requireContext().assets.open("wifi2.txt").bufferedReader().use {
it.readText()
}
我使用 kotlin 从资产文件加载文本的解决方案
object AssetsLoader {
fun loadTextFromAsset(context: Context, file: String): String {
return context.assets.open(file).bufferedReader().use { reader ->
reader.readText()
}
}
}
像这样使用它:
val text = AssetsLoader.loadTextFromAsset(context, "test.json")