编辑“︁责任链模式（Chain of Responsibility Pattern）”︁（章节）

== 代码示例 ==
以下是一个简单的责任链模式实现示例，模拟不同级别的日志记录器：

<syntaxhighlight lang="java">
// 抽象处理者
abstract class Logger {
    public static int INFO = 1;
    public static int DEBUG = 2;
    public static int ERROR = 3;
    
    protected int level;
    protected Logger nextLogger; // 责任链中的下一个元素
    
    public void setNextLogger(Logger nextLogger) {
        this.nextLogger = nextLogger;
    }
    
    public void logMessage(int level, String message) {
        if (this.level <= level) {
            write(message);
        }
        if (nextLogger != null) {
            nextLogger.logMessage(level, message);
        }
    }
    
    abstract protected void write(String message);
}

// 具体处理者1
class ConsoleLogger extends Logger {
    public ConsoleLogger(int level) {
        this.level = level;
    }
    
    @Override
    protected void write(String message) {
        System.out.println("Standard Console::Logger: " + message);
    }
}

// 具体处理者2
class ErrorLogger extends Logger {
    public ErrorLogger(int level) {
        this.level = level;
    }
    
    @Override
    protected void write(String message) {
        System.out.println("Error Console::Logger: " + message);
    }
}

// 具体处理者3
class FileLogger extends Logger {
    public FileLogger(int level) {
        this.level = level;
    }
    
    @Override
    protected void write(String message) {
        System.out.println("File::Logger: " + message);
    }
}

// 客户端代码
public class ChainPatternDemo {
    private static Logger getChainOfLoggers() {
        Logger errorLogger = new ErrorLogger(Logger.ERROR);
        Logger fileLogger = new FileLogger(Logger.DEBUG);
        Logger consoleLogger = new ConsoleLogger(Logger.INFO);
        
        errorLogger.setNextLogger(fileLogger);
        fileLogger.setNextLogger(consoleLogger);
        
        return errorLogger;
    }
    
    public static void main(String[] args) {
        Logger loggerChain = getChainOfLoggers();
        
        loggerChain.logMessage(Logger.INFO, "This is an information.");
        loggerChain.logMessage(Logger.DEBUG, "This is a debug level information.");
        loggerChain.logMessage(Logger.ERROR, "This is an error information.");
    }
}
</syntaxhighlight>

'''输出结果：'''
<pre>
Standard Console::Logger: This is an information.
File::Logger: This is a debug level information.
Standard Console::Logger: This is a debug level information.
Error Console::Logger: This is an error information.
File::Logger: This is an error information.
Standard Console::Logger: This is an error information.
</pre>