1.加入依赖：

implementation 'com.journeyapps:zxing-android-embedded:4.3.0'

2.CaptureActivity

package com.jsyj.android_p1;

import android.annotation.SuppressLint;
import android.os.Bundle;
import android.view.KeyEvent;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

import com.journeyapps.barcodescanner.CaptureManager;
import com.journeyapps.barcodescanner.DecoratedBarcodeView;

public class CaptureActivity extends AppCompatActivity {

    private CaptureManager capture;
    private DecoratedBarcodeView barcodeScannerView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_capture);// 自定义布局

        barcodeScannerView = (DecoratedBarcodeView) findViewById(R.id.dbv_custom);

        capture = new CaptureManager(this, barcodeScannerView);
        capture.initializeFromIntent(getIntent(), savedInstanceState);
        capture.decode();
    }

    @Override
    protected void onResume() {
        super.onResume();
        capture.onResume();
    }

    @Override
    protected void onPause() {
        super.onPause();
        capture.onPause();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        capture.onDestroy();
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        capture.onSaveInstanceState(outState);
    }

    @SuppressLint("MissingSuperCall")
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String permissions[], @NonNull int[] grantResults) {
        capture.onRequestPermissionsResult(requestCode, permissions, grantResults);
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        return barcodeScannerView.onKeyDown(keyCode, event) || super.onKeyDown(keyCode, event);
    }
}

3.activity_capture.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center_horizontal"
    android:orientation="vertical">

    <com.journeyapps.barcodescanner.DecoratedBarcodeView
        android:id="@+id/dbv_custom"
        android:layout_width="match_parent"
        android:layout_height="235dp"
        android:layout_marginLeft="20dp"
        android:layout_marginTop="50dp"
        android:layout_marginRight="20dp"
        app:zxing_preview_scaling_strategy="fitXY" />

</LinearLayout>

4.MainActivity

package com.jsyj.android_p1;

import androidx.appcompat.app.AppCompatActivity;


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

import com.google.zxing.integration.android.IntentIntegrator;
import com.google.zxing.integration.android.IntentResult;


public class MainActivity extends AppCompatActivity {


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.sm).setOnClickListener(view -> initScan());

    }

    public void initScan() {
        IntentIntegrator integrator = new IntentIntegrator(this);
        // 设置要扫描的条码类型，ONE_D_CODE_TYPES：一维码，QR_CODE_TYPES-二维码
        integrator.setDesiredBarcodeFormats();
        integrator.setCaptureActivity(CaptureActivity.class); //设置打开摄像头的Activity
        integrator.setPrompt("请对准二维码"); //底部的提示文字，设为""可以置空
        integrator.setCameraId(0); //前置或者后置摄像头
        integrator.setBeepEnabled(false); //扫描成功的「哔哔」声，默认开启
        integrator.setBarcodeImageEnabled(true);
        integrator.initiateScan();
    }


    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
        super.onActivityResult(requestCode, resultCode, intent);
        if (requestCode == IntentIntegrator.REQUEST_CODE) {
            IntentResult scanResult = IntentIntegrator.parseActivityResult(requestCode, resultCode, intent);
            if (scanResult != null && scanResult.getContents() != null) {
                String result = scanResult.getContents();
                Log.d("扫码返回: ", result);
            }
        }
    }


}

5.权限：

 <uses-permission android:name="android.permission.INTERNET"/>
 <uses-permission android:name="android.permission.CAMERA" />
 <uses-permission android:name="android.permission.VIBRATE" />
 <uses-permission android:name="android.permission.FLASHLIGHT" />