錯誤與未報告的異常異常增加時，加密代碼

Question

我在這條線上這個錯誤

Error:(27, 57) error: unreported exception Exception; must be caught or declared to be thrown

：

public String encrypted = MCrypt.bytesToHex(mcrypt.encrypt("Text to Encrypt")); 

，並試圖用try和catch周圍，但沒有奏效。

package com.example.user.test14; 

import android.app.Activity; 
import android.os.AsyncTask; 
import android.os.Bundle; 
import android.util.Log; 


import org.apache.http.HttpEntity; 
import org.apache.http.HttpResponse; 
import org.apache.http.NameValuePair; 
import org.apache.http.client.entity.UrlEncodedFormEntity; 
import org.apache.http.client.methods.HttpPost; 
import org.apache.http.impl.client.DefaultHttpClient; 
import org.apache.http.message.BasicNameValuePair; 
import org.apache.http.protocol.HTTP; 
import org.json.JSONException; 
import org.json.JSONObject; 

import java.io.BufferedReader; 
import java.io.InputStream; 
import java.io.InputStreamReader; 
import java.util.ArrayList; 
import java.util.List; 
public class MainActivity extends Activity { 
MCrypt mcrypt = new MCrypt(); 
public String encrypted = MCrypt.bytesToHex(mcrypt.encrypt("Text to Encrypt")); 

@Override 
protected void onCreate(Bundle savedInstanceState) { 

    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    new MyTask().execute(); 
} 

private class MyTask extends AsyncTask<String, String, Boolean> { 
    @Override 
    protected void onPreExecute() { 
     super.onPreExecute(); 
    } 

    @Override 
    protected Boolean doInBackground(String... params) { 
     List<NameValuePair> params1 = new ArrayList<NameValuePair>(); 
     params1.add(new BasicNameValuePair("id","1")); 
     params1.add(new BasicNameValuePair("temp",encrypted)); 
     params1.add(new BasicNameValuePair("pulse","sheri")); 
     params1.add(new BasicNameValuePair("motion","a")); 
     String link="http://192.168.0.21/insert_data.php"; 
     boolean success = false; 
     try { 

      JSONObject json = makeHttpRequest(link, "POST", params1); 
      success = json.getBoolean("success"); 

     } catch (Exception e) { 
      // TODO: handle exception 
     } 

     return success; 
    } 

    @Override 
    protected void onPostExecute(Boolean result) { 
     super.onPostExecute(result); 
     if (result) { 
      Log.e("result","true"); 
     } else { 
      Log.e("result","false"); 
     } 
    } 
} 

private JSONObject makeHttpRequest(String url, String method,List<NameValuePair> params) { 
    InputStream is = null; 
    JSONObject jObj = null; 
    String json = ""; 
    DefaultHttpClient httpClient = new DefaultHttpClient(); 
    HttpPost httpPost = new HttpPost(url); 
    try { 
     httpPost.setEntity(new UrlEncodedFormEntity(params)); 

     HttpResponse httpResponse = httpClient.execute(httpPost); 
     HttpEntity httpEntity = httpResponse.getEntity(); 
     is = httpEntity.getContent(); 
    } catch (Exception e1) { 
     // TODO Auto-generated catch block 
     e1.printStackTrace(); 
    } 

    try { 
     BufferedReader reader = new BufferedReader(new InputStreamReader(is, HTTP.UTF_8), 8); 
     StringBuilder sb = new StringBuilder(); 
     String line = null; 
     while ((line = reader.readLine()) != null) { 
      sb.append(line + "\n"); 
     } 
     is.close(); 
     json = sb.toString(); 
    } catch (Exception e) { 
     Log.e("Buffer Error", "Error converting result " + e.toString()); 
    } 

    // try parse the string to a JSON object 
    try { 
     Log.e("json", json); 
     jObj = new JSONObject(json); 
    } catch (JSONException e) { 
     Log.e("JSON Parser", "Error parsing data " + e.toString()); 
    } 

    // return JSON String 
    return jObj; 
} 
} 

任何人都可以幫忙嗎？我很感激。

Answer 1

通過更換兩個相應的行添加下面的構造方法類

MCrypt mcrypt; 
public String encrypted; 
public MainActivity(){ 
    try{ 
    mcrypt = new MCrypt(); 
    encrypted = MCrypt.bytesToHex(mcrypt.encrypt("Text to Encrypt")); 
    } catch(Exception e){ 
    e.printStackTrace(); 
    } 
} 

。

Answer 2

如果你想用try-catch包圍它，代碼需要在構造函數中。或者，像這樣做：

public class MainActivity extends Activity { 
    public String encrypted = bytesToHex(); 

    private static String bytesToHex() { 
     try { 
      MCrypt mcrypt = new MCrypt(); 
      return MCrypt.bytesToHex(mcrypt.encrypt("Text to Encrypt")); 
     } 
     catch (Exception e) { 
      e.printStackTrace(); 
      return null; 
     } 
    }