エレガントな解決ツールクラス設計

82154 ワード
プログラミング

目次

  • エレガントなケース
  • クラスを使用して論理
    • をカプセル化する.
  • ポリシー統合
  • エレガントなケース2
  • デコレーション拡張機能
  • エレガントなケース3

    • エレガントなケース1


    問題思考:設計ツールクラスを考えるとき、ほとんどの場合、私はクラスに関連し、静的メソッドを定義し、この静的メソッドを呼び出して多重化することに慣れています.大体次のようになります.
    例:タイプ変換ツールクラス、beanとmapの変換、2つのシーンを説明します.
  • bean 2 mapはbean変換mapの実装であり、私たちの多くはこのように設計されたツールクラス
    • である.
  • map 2 Beanとmap 2 Bean 2はmapステアリングbeanの2つの異なる実装であり、機能は一致する
    • である.
    public class PropertyUtils {
	public static Map<String, Object> bean2Map(Object object)
			throws IntrospectionException, IllegalAccessException, InstantiationException, InvocationTargetException {
		BeanInfo beanInfo = Introspector.getBeanInfo(object.getClass());
		PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();

		Map<String, Object> map = new HashMap<>();
		for (PropertyDescriptor pd : propertyDescriptors) {
			if (pd.getPropertyType().isAssignableFrom(Class.class)) {
				continue;
			}
			String propertyName = pd.getName();
			Method readMethod = pd.getReadMethod();
			if (!readMethod.isAccessible()) {
				readMethod.setAccessible(true);
			}
			Object propertyValue = readMethod.invoke(object);
			map.put(propertyName, propertyValue);
		}
		return map;
	}

	public static <T> T map2Bean(Class<T> type, Map<String, Object> map)
			throws IntrospectionException, IllegalAccessException, InstantiationException, InvocationTargetException {
		BeanInfo beanInfo = Introspector.getBeanInfo(type);
		PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
		T obj = type.newInstance();
		for (PropertyDescriptor pd : propertyDescriptors) {
			if (pd.getPropertyType().isAssignableFrom(Class.class)) {
				continue;
			}
			String propertyName = pd.getName();
			if (map.containsKey(propertyName)) {
				Object value = map.get(propertyName);
				Method setter = pd.getWriteMethod();
				if (!setter.isAccessible()) {
					setter.setAccessible(true);
				}
				setter.invoke(obj, value);
			}
		}
		return obj;
	}

	public static <T> T map2Bean2(Class<T> type, Map<String, Object> map)
			throws IntrospectionException, IllegalAccessException, InstantiationException, InvocationTargetException {
		T obj = type.newInstance();
		for (Entry<String, Object> entry : map.entrySet()) {
			String key = entry.getKey();
			Object value = entry.getValue();
			PropertyDescriptor pd = new PropertyDescriptor(key, type);
			Method writeMethod = pd.getWriteMethod();
			if (!writeMethod.isAccessible()) {
				writeMethod.setAccessible(true);
			}
			writeMethod.invoke(obj, value);
		}
		return obj;
	}
}

    クラスを使用して論理をカプセル化


    bean 2 mapの問題に対して、タイプの転換なため、私達はとても容易に適当な者の思想を思い付きます ， 抽象インタフェース
    /**
 * Created by it
 * Created in 2019 3 26 
 * Description:  
 */
public abstract class AbstracAdapter<T, D> {
	
	protected T t;
	
	public AbstracAdapter(T t) {
		this.t = t;
	}
	
	public abstract D conver() throws Exception;
	
}

    具体的には、ここでは拡張を残すことができ、Bean 2 map Adapterは他の方法を追加することができる.
    /**
 * Created by it
 * Created in 2019 3 26 
 * Description:  
 */
public class Bean2MapAdapter extends AbstracAdapter<Object, Map<String, Object>> {
	
	public Bean2MapAdapter(Object t) {
		super(t);
	}
	
	public Map<String, Object> conver() throws IntrospectionException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
		Map<String, Object> map = new HashMap<>();
		BeanInfo beanInfo = Introspector.getBeanInfo(t.getClass());
		PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();

		for (PropertyDescriptor pd : propertyDescriptors) {
			if (pd.getPropertyType().isAssignableFrom(Class.class)) {
				continue;
			}
			String propertyName = pd.getName();
			Method readMethod = pd.getReadMethod();
			if (!readMethod.isAccessible()) {
				readMethod.setAccessible(true);
			}
			Object propertyValue = readMethod.invoke(t);
			map.put(propertyName, propertyValue);
		}
		return map;
	}
	
}

    エレガントなパッケージツールクラスを
    /**
 * 
 * Created by it
 * Created in 2019 3 25 
 * Description:  bean 
 */
public class PropertyUtils {
	
	/**
	 * bean -> Map
	 */
	public static Map<String, Object> bean2Map(Object object) {
		Bean2MapAdapter adapter = new Bean2MapAdapter(object);
		try {
			return adapter.conver();
		} catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException | IntrospectionException e) {
			throw new RuntimeException(e);
		}
	}
}

    戦略者の統合


    map 2 Beanとmap 2 Bean 2の2つの異なる実装に対して,異なる実装パッケージクラスに対して戦略者モードを容易に考えることができる.
    ちゅうしょうしゅつインタフェース
    public interface AbstractMap2Bean {
	<T> T map2Bean(Class<T> type, Map<String, Object> map) throws Exception;
}

    具体的には、ここでは2種類、任意の種類を拡張することもできます
    /**
 * Created by it
 * Created in 2019 3 26 
 * Description:  
 */
public class Bean2MapAdapter extends AbstracAdapter<Object, Map<String, Object>> {
	
	public Bean2MapAdapter(Object t) {
		super(t);
	}
	
	public Map<String, Object> conver() throws IntrospectionException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
		Map<String, Object> map = new HashMap<>();
		BeanInfo beanInfo = Introspector.getBeanInfo(t.getClass());
		PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();

		for (PropertyDescriptor pd : propertyDescriptors) {
			if (pd.getPropertyType().isAssignableFrom(Class.class)) {
				continue;
			}
			String propertyName = pd.getName();
			Method readMethod = pd.getReadMethod();
			if (!readMethod.isAccessible()) {
				readMethod.setAccessible(true);
			}
			Object propertyValue = readMethod.invoke(t);
			map.put(propertyName, propertyValue);
		}
		return map;
	}
	
}

    エレガントなパッケージツールクラスを
    /**
 * 
 * Created by it
 * Created in 2019 3 25 
 * Description:  bean 
 */
public class PropertyUtils {
	
	/**
	 * bean -> Map
	 */
	public static Map<String, Object> bean2Map(Object object) {
		Bean2MapAdapter adapter = new Bean2MapAdapter(object);
		try {
			return adapter.conver();
		} catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException | IntrospectionException e) {
			throw new RuntimeException(e);
		}
	}
}

    元のツールクラスメソッドmap 2 Beanを次の2つにカプセル化
    /**
 * Created by it
 * Created in 2019 3 26 
 * Description:  bean 
 */
public class DefaultMap2Bean implements AbstractMap2Bean {

	@Override
	public <T> T map2Bean(Class<T> type, Map<String, Object> map) throws IntrospectionException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
		BeanInfo beanInfo = Introspector.getBeanInfo(type);
		PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
		T obj = type.newInstance();
		for (PropertyDescriptor pd : propertyDescriptors) {
			if (pd.getPropertyType().isAssignableFrom(Class.class)) {
				continue;
			}
			String propertyName = pd.getName();
			if (map.containsKey(propertyName)) {
				Object value = map.get(propertyName);
				Method setter = pd.getWriteMethod();
				if (!setter.isAccessible()) {
					setter.setAccessible(true);
				}
				setter.invoke(obj, value);
			}
		}
		return obj;
	}

}

    第2種
    /**
 * Created by it
 * Created in 2019 3 26 
 * Description:  map 
 */
public class PriorityMap4Map2Bean implements AbstractMap2Bean {

	@Override
	public <T> T map2Bean(Class<T> type, Map<String, Object> map) throws IntrospectionException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
		T obj = type.newInstance();
		for (Entry<String, Object> entry : map.entrySet()) {
			String key = entry.getKey();
			Object value = entry.getValue();
			PropertyDescriptor pd = new PropertyDescriptor(key, type);
			Method writeMethod = pd.getWriteMethod();
			if (!writeMethod.isAccessible()) {
				writeMethod.setAccessible(true);
			}
			writeMethod.invoke(obj, value);
		}
		return obj;
	}
	
}

    工具類を修正して、ここでは前を優雅にして、 spring ， spring ， 
    /**
 * Created by it
 * Created in 2019 3 26 
 * Description:  bean 
 */
public class PropertyUtils {

	/**
	 * Map -> bean
	 */
	public static <T> T map2Bean(Class<T> type, Map<String, Object> map) {
		try {
			AbstractMap2Bean delegate = new DefaultMap2Bean();
			return delegate.map2Bean(type, map);
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
	}

	/**
	 * Map -> bean
	 */
	public static <T> T map2Bean2(Class<T> type, Map<String, Object> map) {
		try {
			AbstractMap2Bean delegate = new PriorityMap4Map2Bean();
			return delegate.map2Bean(type, map);
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
	}
}

    複数の実装クラスの選択に対して、ここでは委任エージェントクラスを導入するために最適化することもできます.
    /**
 * Created by it
 * Created in 2019 3 26 
 * Description:  ， 
 */
public class RouteMap2Bean implements AbstractMap2Bean {
	
	private AbstractMap2Bean delegate;
	
	public RouteMap2Bean() {
		this(false);
	}

	/**
	 *  
	 */
	public RouteMap2Bean(boolean mapPriority) {
		if (mapPriority) {
			this.delegate = new PriorityMap4Map2Bean();
		} else {
			this.delegate = new DefaultMap2Bean();
		}
	}

	@Override
	public <T> T map2Bean(Class<T> type, Map<String, Object> map) throws Exception {
		return delegate.map2Bean(type, map);
	}
	
}

    修正ツールクラスは次のとおりです.
    /**
 * Created by it
 * Created in 2019 3 26 
 * Description:  bean 
 */
public class PropertyUtils {

	/**
	 * Map -> bean
	 */
	public static <T> T map2Bean(Class<T> type, Map<String, Object> map) {
		return map2Bean(type, map, false);
	}
	
	public static <T> T map2Bean(Class<T> type, Map<String, Object> map, boolean mapPriority) {
		try {
			AbstractMap2Bean delegate = new RouteMap2Bean(mapPriority);
			return delegate.map2Bean(type, map);
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
	}
}

    エレガントなケース2


    デコレーション拡張機能


    装飾者が元のオブジェクトの機能を動的に強化することによって、ファイルの復号化を実現し、復号化を包装オブジェクトにカプセル化し、対外的に包装オブジェクトを提供して復号化し、 ， 暗号化の実装
    /**
 * 
 * Created by it
 * Created in 2019 3 31 
 * Description:  
 */
public class DesEncryptOutputStream extends FilterOutputStream{
	
	public DesEncryptOutputStream(OutputStream out) {
		super(out);
	}
	
	public void encrypt(byte[] buffers) throws IOException {
		try {
			String encrypt = AESUtil.encrypt(new String(buffers), Keys.DES);
			super.write(encrypt.getBytes());
		} catch (IOException e) {
			throw new RuntimeException(e);
		}
	}
}

    暗号化の実装
    /**
 * 
 * Created by it
 * Created in 2019 3 31 
 * Description:  
 */
public class DesDecryptptInputStream extends FilterInputStream {
	
	protected DesDecryptptInputStream(InputStream in) {
		super(in);
	}
	
	public byte[] decrypt() {
		try {
			//  
			int size = in.available();
			byte[] data = new byte[size];
			super.read(data);
			//  
			String decrypt = AESUtil.decrypt(new String(data), Keys.DES);
			return decrypt.getBytes();
		} catch (IOException e) {
			throw new RuntimeException(e);
		}
	}
}

    mainテストコード、 
    public class Test {

	public static void main(String[] args) throws Exception {
		String name = " kjkjlk 12345";
		//  
		DesEncryptOutputStream outputStream = new DesEncryptOutputStream(new FileOutputStream("1.txt"));
		outputStream.encrypt(name.getBytes());
		outputStream.close();

		//  
		DesDecryptptInputStream inputStream = new DesDecryptptInputStream(new FileInputStream("1.txt"));
		byte[] decrypt = inputStream.decrypt();
		System.out.println(new String(decrypt));
		inputStream.close();
	}

}

    エレガントなケース3


    前に書いたコードをもう一つ挙げます
    優雅なツールクラス実装.TimeUnitの実装を参考にする
    public enum CompressUtil {
	DEFLATER {
		Compress compress = new DeflaterCompress();

		public byte[] compress(byte[] data) throws IOException {
			return compress.compress(data);
		}

		public byte[] uncompress(byte[] data) throws IOException {
			return compress.uncompress(data);
		}
	},
	BZIP2 {
		Compress compress = new LzoCompress();

		public byte[] compress(byte[] data) throws IOException {
			return compress.compress(data);
		}

		public byte[] uncompress(byte[] data) throws IOException {
			return compress.uncompress(data);
		}
	},
	GZIP {
		Compress compress = new GzipCompress();

		public byte[] compress(byte[] data) throws IOException {
			return compress.compress(data);
		}

		public byte[] uncompress(byte[] data) throws IOException {
			return compress.uncompress(data);
		}
	},
	LZ4 {
		Compress compress = new Lz4Compress();

		public byte[] compress(byte[] data) throws IOException {
			return compress.compress(data);
		}

		public byte[] uncompress(byte[] data) throws IOException {
			return compress.uncompress(data);
		}
	},
	LZO {
		Compress compress = new LzoCompress();

		public byte[] compress(byte[] data) throws IOException {
			return compress.compress(data);
		}

		public byte[] uncompress(byte[] data) throws IOException {
			return compress.uncompress(data);
		}
	},
	SNAPPY {
		Compress compress = new SnappyCompress();

		public byte[] compress(byte[] data) throws IOException {
			return compress.compress(data);
		}

		public byte[] uncompress(byte[] data) throws IOException {
			return compress.uncompress(data);
		}
	};

	public byte[] compress(byte[] data) throws IOException {
		throw new AbstractMethodError();
	}

	public byte[] uncompress(byte[] data) throws IOException {
		throw new AbstractMethodError();
	}
}

    2つの異なる呼び出しが優雅です
    	CompressUtil.GZIP.compress(bytes);
	CompressUtil.LZ4.compress(bytes);

    JAvaでよく使われる圧縮と解凍の具体的な実現:https://blog.csdn.net/dengjili/article/details/86554012
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