方法compareScores（int，int，int）应该返回一个int值。 还有其他错误。我已经研究过这个错误，但我似乎无法纠正这个错误..
这是logcat：
01-06 09:14:22.838: E/AndroidRuntime(27362): FATAL EXCEPTION: main
01-06 09:14:22.838: E/AndroidRuntime(27362): java.lang.NumberFormatException: Invalid int: "null"
01-06 09:14:22.838: E/AndroidRuntime(27362): at java.lang.Integer.invalidInt(Integer.java:138)
01-06 09:14:22.838: E/AndroidRuntime(27362): at java.lang.Integer.parseInt(Integer.java:355)
01-06 09:14:22.838: E/AndroidRuntime(27362): at java.lang.Integer.parseInt(Integer.java:332)
01-06 09:14:22.838: E/AndroidRuntime(27362): at com.example.plearnyforparent.DiagnosticFour$2.onClick(DiagnosticFour.java:104)
01-06 09:14:22.838: E/AndroidRuntime(27362): at android.view.View.performClick(View.java:4278)
01-06 09:14:22.838: E/AndroidRuntime(27362): at android.view.View$PerformClick.run(View.java:17429)
01-06 09:14:22.838: E/AndroidRuntime(27362): at android.os.Handler.handleCallback(Handler.java:725)
01-06 09:14:22.838: E/AndroidRuntime(27362): at android.os.Handler.dispatchMessage(Handler.java:92)
01-06 09:14:22.838: E/AndroidRuntime(27362): at android.os.Looper.loop(Looper.java:137)
01-06 09:14:22.838: E/AndroidRuntime(27362): at android.app.ActivityThread.main(ActivityThread.java:5099)
01-06 09:14:22.838: E/AndroidRuntime(27362): at java.lang.reflect.Method.invokeNative(Native Method)
01-06 09:14:22.838: E/AndroidRuntime(27362): at java.lang.reflect.Method.invoke(Method.java:511)
01-06 09:14:22.838: E/AndroidRuntime(27362): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:803)
01-06 09:14:22.838: E/AndroidRuntime(27362): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:570)
01-06 09:14:22.838: E/AndroidRuntime(27362): at dalvik.system.NativeStart.main(Native Method)
这是我的DiagnosticFour.java：
package com.example.plearnyforparent;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
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.json.JSONException;
import org.json.JSONObject;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.Bundle;
import android.os.StrictMode;
import android.os.StrictMode.ThreadPolicy;
import android.util.SparseBooleanArray;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;
public class DiagnosticFour extends Activity{
ProgressDialog mProgressDialog;
ListView listview;
Button next;
int a4Score, level;
String score, score2, score3, score4, childid;
Functions function = new Functions();
SessionManager session;
Address add = new Address();
String page = add.add+"throw/editchildlevel.php";
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.diagnostic_screen);
session = new SessionManager(getApplicationContext());
String[] questions = getResources().getStringArray(R.array.diag_3);
listview = (ListView) findViewById(R.id.android_qlist);
listview.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_multiple_choice, questions));
listview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// TODO Auto-generated method stub
a4Score=0;
int len = listview.getCount();
SparseBooleanArray checked = listview.getCheckedItemPositions();
for(int i=0 ; i<len ; i++){
if (checked.get(i)==true)
a4Score++;
}
}
});
next = (Button)findViewById(R.id.btnNext);
next.setOnClickListener(new View.OnClickListener() {
@SuppressLint("NewApi") @Override
public void onClick(View v) {
HashMap<String, String> child = session.getLevel();
level= Integer.parseInt(child.get(SessionManager.CLICKED_CHILDLEVEL));
session.saveScore(Integer.toString(a4Score), level);
HashMap<String, String> user = session.getScores();
score2 = user.get(SessionManager.KEY_SCORE2);
score3 = user.get(SessionManager.KEY_SCORE3);
score4 = user.get(SessionManager.KEY_SCORE4);
level = function.compareScores(Integer.parseInt(score2), Integer.parseInt(score3), Integer.parseInt(score4));
mProgressDialog = new ProgressDialog(DiagnosticFour.this);
mProgressDialog.setMessage("Getting data");
mProgressDialog.setIndeterminate(false);
mProgressDialog.show();
HashMap<String, String> childData = session.getChild();
childid = childData.get(SessionManager.CLICKED_CHILD);
// TODO Auto-generated method stub
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(page);
ThreadPolicy tp = ThreadPolicy.LAX;
StrictMode.setThreadPolicy(tp);
String result = "";
InputStream isr = null;
try {
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
nameValuePairs.add(new BasicNameValuePair("child_id", childid));
nameValuePairs.add(new BasicNameValuePair("child_level", String.valueOf(level)));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
isr = entity.getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(isr,"iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
isr.close();
result=sb.toString();
int mark;
JSONObject json = new JSONObject(result);
mark = json.getInt("success");
mProgressDialog.dismiss();
if (mark == 1){
Toast.makeText(getBaseContext(),"Child Level: "+level,Toast.LENGTH_SHORT).show();
//account = new Account();
//account.setID(json.getString("uID"));
//account.setfName(json.getString("uFname"));
//account.setmName(json.getString("uMname"));
//account.setlName(json.getString("uLname"));
//accountSave.add(account);
/*child_id = json.getString("child_id");
child_name = json.getString("child_name");
child_parent = json.get("child_parent");*/
/*session.createLoginSession(ID, fName, mName,lName, bday, user, pass, pic,email,contact,address);*/
/*Intent i = new Intent(getApplicationContext(),Children.class);
startActivity(i);
finish();*/
}
if (mark == 0){
Toast.makeText(getBaseContext(),"Error in Saving Data",Toast.LENGTH_SHORT).show();
}
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
} catch (IOException e) {
// TODO Auto-generated catch block
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
/*Intent i = new Intent(getApplicationContext(), Result.class);
startActivity(i);*/
}
});
}
}
SessionManager.java：
package com.example.plearnyforparent;
import java.util.HashMap;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
public class SessionManager {
// Shared Preferences
SharedPreferences pref;
// Editor for Shared preferences
Editor editor;
// Context
Context _context;
// Shared pref mode
int PRIVATE_MODE = 0;
// Sharedpref file name
private static final String PREF_NAME = "PlearnyPref";
// All Shared Preferences Keys
private static final String IS_LOGIN = "IsLoggedIn";
public static final String CLICKED_CHILD = "child";
public static final String CLICKED_CHILDAGE = "child_age";
public static final String CLICKED_CHILDLEVEL = "child_level";
public static final String KEY_ID = "parent_id";
public static final String KEY_NAME = "parent_name";
public static final String KEY_USER = "parent_username";
public static final String KEY_PASS = "parent_password";
public static final String KEY_SCORE2 = "child_score2";
public static final String KEY_SCORE3 = "child_score3";
public static final String KEY_SCORE4 = "child_score4";
public static final String KEY_SCORE = "child_score";
// Constructor
public SessionManager(Context context){
this._context = context;
pref = _context.getSharedPreferences(PREF_NAME, PRIVATE_MODE);
editor = pref.edit();
}
/**
* Create login session
* */
public void createLoginSession(String ID, String name, String username){
// Storing login value as TRUE
editor.putBoolean(IS_LOGIN, true);
editor.putString(KEY_ID, ID);
editor.putString(KEY_NAME, name);
editor.putString(KEY_USER, username);
// commit changes
editor.commit();
}
/**
* Check login method wil check user login status
* If false it will redirect user to login page
* Else won't do anything
* */
public void checkLogin(){
// Check login status
if(this.isLoggedIn()){
Intent i = new Intent(_context, Children.class);
// Closing all the Activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
// Add new Flag to start new Activity
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
// Staring Login Activity
_context.startActivity(i);
}
}
public void saveScore(String score, int level){
if (level==2)
editor.putString(KEY_SCORE2, score);
if (level==3)
editor.putString(KEY_SCORE3, score);
if (level==4)
editor.putString(KEY_SCORE4, score);
editor.commit();
}
/**
* Get stored session data
* */
public HashMap<String, String> getUserDetails(){
HashMap<String, String> user = new HashMap<String, String>();
user.put(KEY_ID, pref.getString(KEY_ID, null));
user.put(KEY_NAME, pref.getString(KEY_NAME, null));
user.put(KEY_USER, pref.getString(KEY_USER, null));
user.put(KEY_PASS, pref.getString(KEY_PASS, null));
// return user
return user;
}
public HashMap<String, String> getScores(){
HashMap<String, String> score = new HashMap<String, String>();
score.put(KEY_SCORE2, pref.getString(KEY_SCORE2, null));
score.put(KEY_SCORE3, pref.getString(KEY_SCORE3, null));
score.put(KEY_SCORE4, pref.getString(KEY_SCORE4, null));
/*score.put(KEY_SCORE3, pref.getString(KEY_SCORE3, null));
score.put(KEY_SCORE4, pref.getString(KEY_SCORE4, null));*/
return score;
}
public HashMap<String, String> getChild(){
HashMap<String, String> child = new HashMap<String, String>();
child.put(CLICKED_CHILDAGE, pref.getString(CLICKED_CHILDAGE, null));
child.put(CLICKED_CHILD, pref.getString(CLICKED_CHILD, null));
return child;
}
/**
* Clear session details
* */
public void logoutUser(){
// Clearing all data from Shared Preferences
editor.clear();
editor.commit();
// After logout redirect user to Loing Activity
Intent i = new Intent(_context, MainActivity.class);
// Closing all the Activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
// Add new Flag to start new Activity
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
// Staring Login Activity
_context.startActivity(i);
}
public void addedChild(String child_id, String child_age, int level){
editor.putString(CLICKED_CHILD, child_id);
editor.putString(CLICKED_CHILDAGE, child_age);
editor.putString(CLICKED_CHILDLEVEL, String.valueOf(level));
editor.commit();
}
public void changeLevel(int level){
level ++;
editor.putString(CLICKED_CHILDLEVEL, String.valueOf(level));
editor.commit();
}
public HashMap<String, String> getLevel(){
HashMap<String, String> child = new HashMap<String, String>();
child.put(CLICKED_CHILDLEVEL, pref.getString(CLICKED_CHILDLEVEL, null));
return child;
}
/**
* Quick check for login
* **/
// Get Login State
public boolean isLoggedIn(){
return pref.getBoolean(IS_LOGIN, false);
}
}
Functions.java：
package com.example.plearnyforparent;
public class Functions {
public int compareScores(int score2, int score3, int score4){
int scores[]={score2, score3, score4};
int level=0, maxscore= scores[0];
for(int i =0 ; i<3; i++)
{
if(scores[i] > maxscore){
maxscore = scores[i];
level = i++;
}
}
return level;
}
}
答案 0 :(得分：2)
在compareScores功能中，您会收到int个参数。但是当你调用这个函数时，你正在使用Integer。请注意，Integer可以是null但int可以。{/ p>
我建议在使用之前验证您的输入，如下所示：
if (myString != null && !myString.isEmpty()) {
myNumber = Integer.parseInt(a);
} else {
myNumber = 0;
}