Java设计模式（7）—— 装饰器

public interface ILogger {
void logger(String info);
}
public class ConsoleLogger implements ILogger {
public void logger(String info) {
System.out.println(info);
}

}
public class FileLogger implements ILogger {
private PrintWriter writer;

public FileLogger(String path) {
File file = new File(path);
FileOutputStream output;
try {
output = new FileOutputStream(file);
writer = new PrintWriter(output);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}

public void logger(String info) {
if (writer == null) {
System.out.println("FileLogger init failure");
} else {
writer.write(info);
writer.flush();
}
}
}
public abstract class DecoratorLogger implements ILogger {

protected ILogger delegate;
public DecoratorLogger(ILogger delegate) {
this.delegate = delegate;
}
abstract public void logger(String info);
}
public class EncryptLogger extends DecoratorLogger {
public EncryptLogger(ILogger delegate) {
super(delegate);
}
public void logger(String info) {
String temp = encrypt(info);
delegate.logger(temp);
}

private String encrypt(String info) {
// encrypt algorithm
// ...
return info;
}
}