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
public String ReadFromfile(String fileName, Context context) {
StringBuilder returnString = new StringBuilder();
InputStream fIn = null;
InputStreamReader isr = null;
BufferedReader input = null;
try {
fIn = context.getResources().getAssets()
.open(fileName, Context.MODE_WORLD_READABLE);
isr = new InputStreamReader(fIn);
input = new BufferedReader(isr);
String line = "";
while ((line = input.readLine()) != null) {
returnString.append(line);
}
} catch (Exception e) {
e.getMessage();
} finally {
try {
if (isr != null)
isr.close();
if (fIn != null)
fIn.close();
if (input != null)
input.close();
} catch (Exception e2) {
e2.getMessage();
}
}
return returnString.toString();
}
其他回答
kotlin的一行解决方案:
fun readFileText(fileName: String): String {
return assets.open(fileName).bufferedReader().use { it.readText() }
}
此外，您可以使用它作为扩展函数无处不在
fun Context.readTextFromAsset(fileName : String) : String{
return assets.open(fileName).bufferedReader().use {
it.readText()}
}
简单地调用任何上下文类
context.readTextFromAsset("my file name")
读取和写入文件总是冗长且容易出错。避免这些答案，使用Okio即可:
public void readLines(File file) throws IOException {
try (BufferedSource source = Okio.buffer(Okio.source(file))) {
for (String line; (line = source.readUtf8Line()) != null; ) {
if (line.contains("square")) {
System.out.println(line);
}
}
}
}
public String ReadFromfile(String fileName, Context context) {
StringBuilder returnString = new StringBuilder();
InputStream fIn = null;
InputStreamReader isr = null;
BufferedReader input = null;
try {
fIn = context.getResources().getAssets()
.open(fileName, Context.MODE_WORLD_READABLE);
isr = new InputStreamReader(fIn);
input = new BufferedReader(isr);
String line = "";
while ((line = input.readLine()) != null) {
returnString.append(line);
}
} catch (Exception e) {
e.getMessage();
} finally {
try {
if (isr != null)
isr.close();
if (fIn != null)
fIn.close();
if (input != null)
input.close();
} catch (Exception e2) {
e2.getMessage();
}
}
return returnString.toString();
}
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;
}
