添加依赖

    debugImplementation 'com.squareup.leakcanary:leakcanary-android:1.6.1'
    releaseImplementation 'com.squareup.leakcanary:leakcanary-android-no-op:1.6.1'
    // Optional, if you use support library fragments:
    debugImplementation 'com.squareup.leakcanary:leakcanary-support-fragment:1.6.1'

创建自定义的Application

public class ExampleApplication extends Application {

    @Override public void onCreate() {
        super.onCreate();
        if (LeakCanary.isInAnalyzerProcess(this)) {
            // This process is dedicated to LeakCanary for heap analysis.
            // You should not init your app in this process.
            return;
        }
        LeakCanary.install(this);
        // Normal app init code...
    }
}

在AndroidManifest.xml的appication标签中添加如下

android:name=".ExampleApplication"

测试

创建一个secondActivity

public class secondActivity extends AppCompatActivity {

    static Demo demo;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);

        if(demo==null)
        {
            demo=new Demo();
        }

        finish();
    }

    class Demo
    {

    }
}

MainActivity

public class MainActivity extends AppCompatActivity {



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Intent intent=new Intent(MainActivity.this,secondActivity.class);
        startActivity(intent);

    }


}