/*** 内容*/
public class Context {private String text;public Context(String text) {super();this.text = text;}public String getText() {return text;}public void setText(String text) {this.text = text;}
}

/*** 抽象父类*/
public abstract class AbstractExpression {public void Interpret(Context context) {if (null != context.getText() && context.getText().length() > 0) {String keyValue = context.getText().substring(0, 2);String key = keyValue.substring(0, 1);String value = keyValue.substring(1, 2);excute(key, value);if (context.getText().length() > 2) {context.setText(context.getText().substring(3));} else {context.setText("");}}}public abstract void excute(String key, String value);
}

/*** 大写字母转义*/
public class CharacterExpression extends AbstractExpression{@Overridepublic void excute(String key, String value) {System.out.print(key.getBytes()[0] + Integer.parseInt(value) + " ");}
}

/*** 小写字母转义*/
public class SmallExpression extends AbstractExpression {@Overridepublic void excute(String key, String value) {int tar = key.getBytes()[0] + Integer.parseInt(value);System.out.print((char)tar + " ");}
}

/*** 客户端*/
public class Text {public static void main(String[] args) {Context context = new Context("A1 B2 C3 D4 a1 b1 c1 d2");AbstractExpression expression = null;while(context.getText().length() > 0) {String first = context.getText().substring(0, 1);if (Character.isLowerCase(first.charAt(0))) {expression = new SmallExpression();} else {expression = new CharacterExpression();}expression.Interpret(context);}}
}

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