最近在学服务组件的时候写的一个银行项目,在存款的时候报了空指针异常和反射异常,应该怎么解决?

1.MainActivity代码

package com.example.banktestdemo;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "MainActivity";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    public  void NormalUserClick(View view){
        Log.d(TAG,"点击用户按钮");
        startActivity(new Intent(this,NormalUserActivity.class));
    }
    public  void BankWorkerClick(View view){
        startActivity(new Intent(this,BankWorkerActivity.class));
    }
    public void BossClick(View view){
        startActivity(new Intent(this,BankBossActivity.class));
    }
}

2.NormalUserAction_impl代码(实现类)

package com.example.banktestdemo.impl;
import android.os.Binder;
import android.util.Log;
import com.example.banktestdemo.Interfaces.INormalUserAction;
public class NormalUserAction extends Binder implements INormalUserAction  {
    //这里要继承binder
    private static final String TAG = "NormalUserAction";
    @Override
    public void savemoney(float money) {
        Log.d(TAG, "savemoney is ---" + money);

    }
    @Override
    public float getmoney() {
        Log.d(TAG, "getmoney is ---100.00");
        return 100.00f;
    }
    @Override
    public float loanmoney() {
        Log.d(TAG, "loanmoney is 100.00");
        return 100.00f;
    }
}

3.NormalUser的接口代码

ackage com.example.banktestdemo.Interfaces;

public interface INormalUserAction {

    void savemoney(float money);
    float getmoney();
    float loanmoney();

}

4.NormalUserActivity代码

package com.example.banktestdemo;
import android.app.Activity;
import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;

import android.os.Binder;
import android.os.IBinder;
import android.util.Log;
import android.view.View;

import androidx.annotation.Nullable;

import com.example.banktestdemo.Interfaces.INormalUserAction;
public class NormalUserActivity extends Activity {

    private static final String TAG = "NormalUserActivity";
    private NormalUserConnection mnormalUserConnection;
    private boolean mIsBind;
    private INormalUserAction mnormalUserAction;
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_user);
        doBindService();//写一个绑定服务的方法
    }
    private void doBindService() {
        Log.d(TAG,"执行doBindService");
        Intent intent =new Intent();
        intent.setAction("com.example.ACTION_NORMAL_USER");
        intent.addCategory(Intent.CATEGORY_DEFAULT);//理解这步
        intent.setPackage(this.getPackageName());//必须声明包名,否则会报错
        mnormalUserConnection = new NormalUserConnection();
        mIsBind = bindService(intent, mnormalUserConnection, BIND_AUTO_CREATE);
    }
    private class NormalUserConnection implements ServiceConnection {
        private INormalUserAction mnormalUserAction;
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
           //通过接口来转换,等于这个方法里面的IBinder 的service;这样写就能获取对方的控制权
            Log.d(TAG,"Service connected"+name);
            mnormalUserAction = (INormalUserAction) service;
        }
        @Override
        public void onServiceDisconnected(ComponentName name) {
            Log.d(TAG,"Service disconnected"+name);
        }
    }
    public  void  saveClick(View view){
        Log.d(TAG,"savemoney");
        mnormalUserAction.savemoney(100000);//走到这一步开始出错,反射异常和空指针异常
    }
    public  void  getClick(View view){
Log.d(TAG,"get money");
mnormalUserAction.getmoney();
    }
    public  void  loanClick(View view){
     Log.d(TAG,"loan money");
     mnormalUserAction.loanmoney();
    }
    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (mIsBind&&mnormalUserConnection!=null){
            unbindService(mnormalUserConnection);
            mnormalUserConnection = null;
            mIsBind = false;
        }
    }
}

5.BankService代码

package com.example.banktestdemo;

import android.app.Service;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;
import android.text.TextUtils;
import android.util.Log;

import androidx.annotation.Nullable;

import com.example.banktestdemo.Interfaces.INormalUserAction;
import com.example.banktestdemo.impl.BankBossAction;
import com.example.banktestdemo.impl.BankWorkerAction;
import com.example.banktestdemo.impl.NormalUserAction;

public class BankServices extends Service {


    private static final String TAG = "BankServices";

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {

        String action = intent.getAction();
        if (!TextUtils.isEmpty(action)){
            Log.d(TAG,"进行回调");
            if ("com.example.ACTION_NORMAL_USER".equals(action)) {
                Log.d(TAG,"符合用户Action");
                     return  new NormalUserAction();
            }else if ("com.example.ACTION_BANK_WORKER".equals(action)){
                     return new BankWorkerAction();
            }else if ("com.example.ACTION_BANK_BOSS".equals(action)){
                     return new BankBossAction();
            }
        }
        Log.d(TAG, "走到这里");
        return new NormalUserAction();
    }
}

6.log报错部分

E/AndroidRuntime: FATAL EXCEPTION: main

  Process: com.example.banktestdemo, PID: 6127

  java.lang.IllegalStateException: Could not execute method of the activity

    at android.view.View$1.onClick(View.java:4020)

    at android.view.View.performClick(View.java:4780)

    at android.view.View$PerformClick.run(View.java:19866)

    at android.os.Handler.handleCallback(Handler.java:739)

    at android.os.Handler.dispatchMessage(Handler.java:95)

    at android.os.Looper.loop(Looper.java:135)

    at android.app.ActivityThread.main(ActivityThread.java:5254)

    at java.lang.reflect.Method.invoke(Native Method)

    at java.lang.reflect.Method.invoke(Method.java:372)

    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)

    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

   Caused by: java.lang.reflect.InvocationTargetException

    at java.lang.reflect.Method.invoke(Native Method)

    at java.lang.reflect.Method.invoke(Method.java:372)

    at android.view.View$1.onClick(View.java:4015)

    at android.view.View.performClick(View.java:4780) 

    at android.view.View$PerformClick.run(View.java:19866) 

    at android.os.Handler.handleCallback(Handler.java:739) 

    at android.os.Handler.dispatchMessage(Handler.java:95) 

    at android.os.Looper.loop(Looper.java:135) 

    at android.app.ActivityThread.main(ActivityThread.java:5254) 

    at java.lang.reflect.Method.invoke(Native Method) 

    at java.lang.reflect.Method.invoke(Method.java:372) 

    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) 

    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698) 

   Caused by: java.lang.NullPointerException: Attempt to invoke interface method 'void com.example.banktestdemo.Interfaces.INormalUserAction.savemoney(float)' on a null object reference

    at com.example.banktestdemo.NormalUserActivity.saveClick(NormalUserActivity.java:60)

    at java.lang.reflect.Method.invoke(Native Method) 

    at java.lang.reflect.Method.invoke(Method.java:372) 

    at android.view.View$1.onClick(View.java:4015) 

    at android.view.View.performClick(View.java:4780) 

    at android.view.View$PerformClick.run(View.java:19866) 

    at android.os.Handler.handleCallback(Handler.java:739) 

    at android.os.Handler.dispatchMessage(Handler.java:95) 

    at android.os.Looper.loop(Looper.java:135) 

    at android.app.ActivityThread.main(ActivityThread.java:5254) 

    at java.lang.reflect.Method.invoke(Native Method) 

    at java.lang.reflect.Method.invoke(Method.java:372) 

    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) 

    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)