stringmixerprocessor.java

JAVA编程思想第四版英文原版习题答案. pdf原版的

// interfaces/interfaceprocessor/StringMixerProcessor.java
// TIJ4 Chapter Interfaces, Exercise 11, page 324
/* Create a class with a method that takes a String argument and produces a result
* that swaps each pair of characters in that argument. Adapt the class so that it
* works with interfaceprocessor.Apply.process().
*/
/* Solution includes, in same package:
* package interfaces.interfaceprocessor;

* public class StringMixer {
*	static String process(String s) {
*		char[] ca = new char[s.length()];
*		if((s.length())%2 == 0) {
*			for(int i = 0; i < s.length(); i += 2) {
*				ca[i] = s.charAt(i + 1);
*				ca[i + 1] = s.charAt(i);			
*			}		
*			return new String(ca);
*		}
*		else {
*		for(int i = 0; i < s.length() - 1; i += 2) {
*				ca[i] = s.charAt(i + 1);
*				ca[i + 1] = s.charAt(i);			
*			}
*			ca[s.length() - 1] = s.charAt(s.length() - 1);		
*			return new String(ca);
*		}
*	}	
* }
*/
// program takes command line String argument:
package interfaces.interfaceprocessor;

class StringMixerAdapter implements Processor {
	public String name() { return "StringMixerAdapter"; }
	StringMixer stringMixer;
	public StringMixerAdapter(StringMixer stringMixer) {
		this.stringMixer = stringMixer;
	}
	public String process(Object input) {
		return stringMixer.process((String)input);
	}	
}

public class StringMixerProcessor {
	public static void main(String[] args) {
		String s = new String(args[0]);
		Apply.process(new StringMixerAdapter(new StringMixer()), s);
	}
}