主要是通过内容提供器来获取通讯录的联系人信息，还演示了动态权限的申请过程。

Manifest：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.leo.getcontacts">
    <!--读取联系人权限-->
    <uses-permission android:name="android.permission.READ_CONTACTS" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

MainActivity：

/**
 * 该项目演示了获取系统的联系人 主要是练习内容提供器的使用
 */
public class MainActivity extends AppCompatActivity {
    private List<String> list;
    private ListView listView;
    private ArrayAdapter<String> arrayAdapter;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        list = new ArrayList<>();
        listView = findViewById(R.id.listview);
        arrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, list);
        listView.setAdapter(arrayAdapter);
        //检查是否有权限
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_CONTACTS) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_CONTACTS}, 1);
        } else {
            readContacts();
        }
    }

    /***
     * 获取联系人数据
     */
    private void readContacts() {
        Cursor cursor = null;
        try {
            cursor = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null, null, null, null);
            if (cursor != null) {
                while (cursor.moveToNext()) {
                    String displayName = cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
                    String number = cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
                    list.add(displayName + "\n" + number);
                }
                arrayAdapter.notifyDataSetChanged();
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (cursor != null) {
                cursor.close();
            }
        }
    }

    /***
     * 不管是否获取了权限 都会调用此方法
     * @param requestCode
     * @param permissions
     * @param grantResults
     */
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        switch (requestCode) {
            case 1:
//                如果有权限 则读取联系人
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    readContacts();
                } else {//否则退出程序或者弹出提示
                    Toast.makeText(this, "未获得联系人权限！", Toast.LENGTH_SHORT).show();
                }
                break;
        }
    }
}