java文件是在
应用程序/ SRC /主/爪哇/ nate.marxBros / QuoteBank.java
txt文件位于
应用程序/ src目录/主/资产/ Quotes.txt
代码是
File file = new File("assets/QuotesMonkeyBusiness.txt");
Scanner input = null;
try {
input = new Scanner(file);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
不应该像其他任何java程序一样工作吗？但它给文件找不到异常
我在这个网站上尝试过很多东西
Android Studio Reading from Raw Resource Text File
但该方法不起作用,因为我不知道如何传递上下文
谢谢你的帮助
更新的代码
public class QuoteBank {
private ArrayList<ArrayList<QuoteBank>> bank;
private Context mContext;
private ArrayList<QuoteQuestion> monkeyBuisness;
public QuoteBank(Context context){
mContext = context;
InputStream is = null;
try {
is = mContext.getAssets().open("QuotesMonkeyBusiness.txt");
} catch (IOException e) {
e.printStackTrace();
}
ArrayList<QuoteQuestion> monkeyBuisness = parseFileToBank(is);
}
主要活动
public class MainActivity extends ActionBarActivity {
QuoteBank b = new QuoteBank(MainActivity.this);
解决方法
在QuoteBank.java中设置一个私有变量：
private Context mContext;
设置构造函数：
public QuoteBank(Context context) {
this.mContext = context;
}
然后在你的活动中实例化它,
QuoteBank quoteBank = new QuoteBank(context);
可以通过this命令或Activity.this在活动中调用上下文变量,其中将“Activity”替换为您的活动名称.或者,如果您在片段内,则可以从onCreateView(…)方法中的View对象获取上下文.通常通过调用view.getContext().
现在,在您抓取资产的方法中,您可以使用上下文：
InputStream is = mContext.getAssets().open("QuotesMonkeyBusiness.txt")
既然您正在使用android studio,您可以创建一个main(String [] args){…}方法并运行它或者只是启动模拟器并让它使用Log.d(…)来显示来自文件.
或者,您也可以使用以下方法：
AssetManager am = mContext.getAssets();
InputStream is = am.open("QuotesMonkeyBusiness.txt");
将QuoteBank作为单例实例也可能有意义,这可能会提高效率,尽管这完全取决于您的要求,可能是这样的：
List<String> allTextLines = QuoteBank.readFromFile(context,path_to_file);
然后在QuoteBank.java类中,您可以使用如下方法：
/**
* Created by AndyRoid on 5/23/15.
*/
public class QuoteBank {
private Context mContext;
public QuoteBank(Context context) {
this.mContext = context;
}
public List<String> readLine(String path) {
List<String> mLines = new ArrayList<>();
AssetManager am = mContext.getAssets();
try {
InputStream is = am.open(path);
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
String line;
while ((line = reader.readLine()) != null)
mLines.add(line);
} catch (IOException e) {
e.printStackTrace();
}
return mLines;
}
}
然后在我的MainActivity.java类中,我有以下内容：
/**
* Created by AndyRoid on 5/23/15.
*/
public class MainActivity extends AppCompatActivity {
public static final String TAG = MainActivity.class.getSimpleName();
public static final String mPath = "adventur.txt";
private QuoteBank mQuoteBank;
private List<String> mLines;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mQuoteBank = new QuoteBank(this);
mLines = mQuoteBank.readLine(mPath);
for (String string : mLines)
Log.d(TAG,string);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main,menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button,so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
这是我的项目结构：
这是我的日志输出：
更新：为什么你不应该在Android中使用扫描仪
从官方文档：
http://developer.android.com/reference/java/util/Scanner.html
This class is not as useful as it might seem. It’s very inefficient for communicating between machines; you should use JSON,protobufs,or even XML for that. Very simple uses might get away with split(String). For input from humans,the use of locale-specific regular expressions make it not only expensive but also somewhat unpredictable.
The Scanner class is not thread-safe.
最后注意：
我强烈建议您阅读此处使用的所有对象的文档,以便您了解该过程.
