LeakingActivity.java

package com.novoda.example.MemoryLeaker;

import android.app.Activity;
import android.os.Bundle;
import android.os.Debug;
import android.view.View;
import android.widget.TextView;

import java.io.File;
import java.io.IOException;

public class LeakingActivity extends Activity
{
    private static final int BYTES_IN_A_MEGABYTE = 1024 * 1024;
    private static final int BYTES_TO_ALLOCATE = BYTES_IN_A_MEGABYTE;
    private static final String HPROF_DUMP_BASENAME = "LeakingActivity.hprof";

    private byte[] byteArray;

    private TextView heapSizeTextView;

    private void updateHeapSize() {
        heapSizeTextView.setText(Runtime.getRuntime().totalMemory() / BYTES_IN_A_MEGABYTE + "mb");
    }

    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        heapSizeTextView = (TextView)findViewById(R.id.tv_heap_size);

        findViewById(R.id.btn_gc).setOnClickListener(
                new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        System.gc();
                    }
                }
        );
        findViewById(R.id.btn_heap).setOnClickListener(
                new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        dumpHprofData();
                    }
                }
        );

        byteArray = new byte[BYTES_TO_ALLOCATE];
    }

    private void dumpHprofData() {
        String absPath = new File(getApplicationInfo().dataDir, HPROF_DUMP_BASENAME).getAbsolutePath();
        try {
            // this'll cause a collection
            Debug.dumpHprofData(absPath);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void onResume() {
        super.onResume();
        updateHeapSize();
    }
}