《Android源码设计模式解析和实战》工厂模式

工厂模式适用于复杂对象的创建：

工厂：
<pre>
public abstract class Factory {
public abstract <T extends Product> T getProduct(Class<T> cls);
}
public class RunningFactory extends Factory {
private static final String TAG = "RunningFactory";

@Override
public <T extends Product> T getProduct(Class<T> cls) {
    Product p = null;
    try {
        p = (Product) Class.forName(cls.getName()).newInstance();
    } catch (Exception e) {
        Log.i(TAG, "getProduct: " + e.getMessage());
        e.printStackTrace();
    }
    return (T) p;
}

}

</pre>
产品：
<pre>
public abstract class Product {
public abstract void start();
public abstract void end();
}

public class AProduct extends Product {
private static final String TAG = "AProduct";

@Override
public void start() {
    Log.i(TAG, "start: ");
}

@Override
public void end() {
    Log.i(TAG, "end: ");
}

}
public class BProduct extends Product {
private static final String TAG = "BProduct";
@Override
public void start() {
Log.i(TAG, "start: ");
}

@Override
public void end() {
    Log.i(TAG, "end: ");
}

}
</pre>
使用：
<pre>
public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    RunningFactory factory = new RunningFactory();
    AProduct a = factory.getProduct(AProduct.class);
    BProduct b = factory.getProduct(BProduct.class);
    a.start();
    b.start();
    a.end();
    b.end();
}

}
</pre>

log：
<pre>
03-06 19:11:34.111 26572-26572/? I/AProduct: start:
03-06 19:11:34.111 26572-26572/? I/BProduct: start:
03-06 19:11:34.111 26572-26572/? I/AProduct: end:
03-06 19:11:34.111 26572-26572/? I/BProduct: end:
</pre>