我该如何在我的android代码中修复此致命异常？

Question

我已经在MainActivity.java中使用textSplitter和一些代码编写了一个类，但是却遇到了致命的运行时异常。

public class textSplitter {

    public String myText(BufferedReader bufferedReader,StringBuilder stringBuilder,String line,String fin) throws IOException {

        while ((line=bufferedReader.readLine()) != null) {
            stringBuilder.append(line);
            stringBuilder.append('\n');
        }
        fin = stringBuilder.toString();
        return fin;
    }

    public String[] txtConverter(String[] text,String fin) {
        text = fin.split("\\$");
        return text;
    }
}

主要活动：

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        InputStream is = this.getResources().openRawResource(R.raw.text1);
        InputStreamReader isr = new InputStreamReader(is);
        BufferedReader br = new BufferedReader(isr);
        StringBuilder stringBuilder = new StringBuilder();
        String line = null;
        String fin = null;
        String[] text = null;
        textSplitter myClass = new textSplitter();
        try {
            myClass.myText(br,stringBuilder,line,fin);
            myClass.txtConverter(text,fin);

            TextView myText = (TextView) findViewById(R.id.text);
            myText.setText(text.toString());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Answer 1

你的问题在这里

myClass.myText(br,stringBuilder,line,fin);

因为您永远不会将fin的值设置为结果。 尝试

fin = myClass.myText(br,stringBuilder,line,fin);

这样做时应避免NPE

text = fin.split("\\$");