IllegalStateException: 找不到只有一个 (Context) 参数的辅助类 null 的构造函数 [英] IllegalStateException: Could not find constructor that hast just a (Context) argument for helper class null

问题描述

我的 logcat 出现错误:

08-12 12:49:07.095: E/AndroidRuntime(4151): 致命异常: main08-12 12:49:07.095:E/AndroidRuntime(4151):java.lang.RuntimeException:无法启动活动组件信息{com.kns.expense.activty/com.kns.expense.activty.AddExpenseActivity}:java.lang.IllegalStateException: 找不到只有一个 (Context) 参数的辅助类 null 的构造函数08-12 12:49:07.095: E/AndroidRuntime(4151): 在 android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)08-12 12:49:07.095: E/AndroidRuntime(4151): 在 android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)08-12 12:49:07.095:E/AndroidRuntime(4151):在 android.app.ActivityThread.access$600(ActivityThread.java:141)08-12 12:49:07.095: E/AndroidRuntime(4151): 在 android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)08-12 12:49:07.095: E/AndroidRuntime(4151): 在 android.os.Handler.dispatchMessage(Handler.java:99)08-12 12:49:07.095: E/AndroidRuntime(4151): 在 android.os.Looper.loop(Looper.java:137)08-12 12:49:07.095: E/AndroidRuntime(4151): 在 android.app.ActivityThread.main(ActivityThread.java:5041)08-12 12:49:07.095: E/AndroidRuntime(4151): 在 java.lang.reflect.Method.invokeNative(Native Method)08-12 12:49:07.095: E/AndroidRuntime(4151): 在 java.lang.reflect.Method.invoke(Method.java:511)08-12 12:49:07.095:E/AndroidRuntime(4151):在 com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)08-12 12:49:07.095: E/AndroidRuntime(4151): 在 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)08-12 12:49:07.095: E/AndroidRuntime(4151): at dalvik.system.NativeStart.main(Native Method)08-12 12:49:07.095: E/AndroidRuntime(4151): 引起: java.lang.IllegalStateException: 找不到只有一个 (Context) 参数的辅助类 null 的构造函数08-12 12:49:07.095: E/AndroidRuntime(4151): 在 com.j256.ormlite.android.apptools.OpenHelperManager.constructHelper(OpenHelperManager.java:210)08-12 12:49:07.095: E/AndroidRuntime(4151): 在 com.j256.ormlite.android.apptools.OpenHelperManager.loadHelper(OpenHelperManager.java:165)08-12 12:49:07.095: E/AndroidRuntime(4151): 在 com.j256.ormlite.android.apptools.OpenHelperManager.getHelper(OpenHelperManager.java:75)08-12 12:49:07.095: E/AndroidRuntime(4151): 在 com.kns.expense.db.DatabaseManager.getHelper(DatabaseManager.java:18)08-12 12:49:07.095:E/AndroidRuntime(4151):在 com.kns.expense.db.Repo.(Repo.java:13)08-12 12:49:07.095: E/AndroidRuntime(4151): 在 com.kns.expense.activty.AddExpenseActivity.onCreate(AddExpenseActivity.java:48)08-12 12:49:07.095: E/AndroidRuntime(4151): 在 android.app.Activity.performCreate(Activity.java:5104)08-12 12:49:07.095: E/AndroidRuntime(4151): 在 android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)08-12 12:49:07.095: E/AndroidRuntime(4151): 在 android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)08-12 12:49:07.095: E/AndroidRuntime(4151): ... 11 更多08-12 12:49:07.095:E/AndroidRuntime(4151):由:java.lang.NullPointerException 引起08-12 12:49:07.095: E/AndroidRuntime(4151): 在 com.j256.ormlite.android.apptools.OpenHelperManager.constructHelper(OpenHelperManager.java:208)08-12 12:49:07.095: E/AndroidRuntime(4151): ... 19 更多08-12 12:49:10.305:D/dalvikvm(4175):GC_CONCURRENT 释放 63K，7% 释放 2776K/2984K，暂停 74ms+3ms，总共 207ms

在 Repo 代码内部调用时:

public Repo(Context context) { {DatabaseManager<DatabaseHelper>manager = new DatabaseManager();db = manager.getHelper(context, DatabaseHelper.class);//这里出现错误用户 = 新 RepoUsers(db);}

DatabaseHelper 是

公共类 DatabaseHelper 扩展 OrmLiteSqliteOpenHelper{private static final String DATABASE_NAME = "ezexpense.sqlite";私有静态最终 int DATABASE_VERSION = 1;private Dao<EzExpenseProject, String>userDao = null;private RuntimeExceptionDaouserRuntimeDao = null;公共数据库助手(上下文上下文){超级(上下文，DATABASE_NAME，空，DATABASE_VERSION)；DatabaseInitializer initializer = new DatabaseInitializer(context);尝试 {initializer.createDatabase();初始化程序关闭()；} catch (IOException e) {e.printStackTrace();}}

请帮助我如何克服这个错误?

解决方案

有时在你的 App 的 gradle 文件中使用 Proguard 会发生这种情况可以通过裁判来解决使用proguard for ormLite

Hi i am getting the error my logcat is:

08-12 12:49:07.095: E/AndroidRuntime(4151): FATAL EXCEPTION: main
08-12 12:49:07.095: E/AndroidRuntime(4151): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.kns.expense.activty/com.kns.expense.activty.AddExpenseActivity}: java.lang.IllegalStateException: Could not find constructor that hast just a (Context) argument for helper class null
08-12 12:49:07.095: E/AndroidRuntime(4151):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
08-12 12:49:07.095: E/AndroidRuntime(4151):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
08-12 12:49:07.095: E/AndroidRuntime(4151):     at android.app.ActivityThread.access$600(ActivityThread.java:141)
08-12 12:49:07.095: E/AndroidRuntime(4151):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
08-12 12:49:07.095: E/AndroidRuntime(4151):     at android.os.Handler.dispatchMessage(Handler.java:99)
08-12 12:49:07.095: E/AndroidRuntime(4151):     at android.os.Looper.loop(Looper.java:137)
08-12 12:49:07.095: E/AndroidRuntime(4151):     at android.app.ActivityThread.main(ActivityThread.java:5041)
08-12 12:49:07.095: E/AndroidRuntime(4151):     at java.lang.reflect.Method.invokeNative(Native Method)
08-12 12:49:07.095: E/AndroidRuntime(4151):     at java.lang.reflect.Method.invoke(Method.java:511)
08-12 12:49:07.095: E/AndroidRuntime(4151):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
08-12 12:49:07.095: E/AndroidRuntime(4151):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
08-12 12:49:07.095: E/AndroidRuntime(4151):     at dalvik.system.NativeStart.main(Native Method)
08-12 12:49:07.095: E/AndroidRuntime(4151): Caused by: java.lang.IllegalStateException: Could not find constructor that hast just a (Context) argument for helper class null
08-12 12:49:07.095: E/AndroidRuntime(4151):     at com.j256.ormlite.android.apptools.OpenHelperManager.constructHelper(OpenHelperManager.java:210)
08-12 12:49:07.095: E/AndroidRuntime(4151):     at com.j256.ormlite.android.apptools.OpenHelperManager.loadHelper(OpenHelperManager.java:165)
08-12 12:49:07.095: E/AndroidRuntime(4151):     at com.j256.ormlite.android.apptools.OpenHelperManager.getHelper(OpenHelperManager.java:75)
08-12 12:49:07.095: E/AndroidRuntime(4151):     at com.kns.expense.db.DatabaseManager.getHelper(DatabaseManager.java:18)
08-12 12:49:07.095: E/AndroidRuntime(4151):     at com.kns.expense.db.Repo.<init>(Repo.java:13)
08-12 12:49:07.095: E/AndroidRuntime(4151):     at com.kns.expense.activty.AddExpenseActivity.onCreate(AddExpenseActivity.java:48)
08-12 12:49:07.095: E/AndroidRuntime(4151):     at android.app.Activity.performCreate(Activity.java:5104)
08-12 12:49:07.095: E/AndroidRuntime(4151):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
08-12 12:49:07.095: E/AndroidRuntime(4151):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
08-12 12:49:07.095: E/AndroidRuntime(4151):     ... 11 more
08-12 12:49:07.095: E/AndroidRuntime(4151): Caused by: java.lang.NullPointerException
08-12 12:49:07.095: E/AndroidRuntime(4151):     at com.j256.ormlite.android.apptools.OpenHelperManager.constructHelper(OpenHelperManager.java:208)
08-12 12:49:07.095: E/AndroidRuntime(4151):     ... 19 more
08-12 12:49:10.305: D/dalvikvm(4175): GC_CONCURRENT freed 63K, 7% free 2776K/2984K, paused 74ms+3ms, total 207ms

When calling inside the Repo code:

public Repo(Context context) {  {
        DatabaseManager<DatabaseHelper> manager = new DatabaseManager<DatabaseHelper>();
        db = manager.getHelper(context, DatabaseHelper.class);// here getting error
        Users = new RepoUsers(db);
    }   

And DatabaseHelper is

public class DatabaseHelper extends OrmLiteSqliteOpenHelper{

    private static final String DATABASE_NAME = "ezexpense.sqlite";
    private static final int DATABASE_VERSION = 1;

    private Dao<EzExpenseProject, String> userDao = null;
    private RuntimeExceptionDao<EzExpenseProject, String> userRuntimeDao = null;

    public DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);

        DatabaseInitializer initializer = new DatabaseInitializer(context);
        try {
            initializer.createDatabase();
            initializer.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

Please help me how to overcome this error?

解决方案

sometimes it's occurred for using Proguard in gradle file of Your App can fix by refereeing use proguard for ormLite

这篇关于IllegalStateException: 找不到只有一个 (Context) 参数的辅助类 null 的构造函数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！