✨ 14. 점진적인 개선 - 리팩토링 완료 (목록 14-1~7)

src/main/java/chapter14/Application.java

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+package chapter14;
+
+import chapter14.args.Args;
+import chapter14.args.ArgsException;
+
+class Application {
+
+    public static void main(String[] args) {
+        try {
+            Args arg = new Args("l,p#,d*", args);
+            boolean logging = arg.getBoolean('l');
+            int port = arg.getInt('p');
+            String directory = arg.getString('d');
+            executeApplication(logging, port, directory);
+        } catch (ArgsException e) {
+            System.out.printf("Argument error: %s\n", e.errorMessage());
+        }
+    }
+
+    // stub
+    private static void executeApplication(boolean logging, int port, String directory) {
+        System.out.printf("logging: %b, port: %d, directory: %s\n", logging, port, directory);
+    }
+}

src/main/java/chapter14/args/Args.java

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+package chapter14.args;
+
+import java.util.*;
+
+import static chapter14.args.ArgsException.ErrorCode.*;
+
+public class Args {
+    private Map<Character, ArgumentMarshaler> marshalers;
+    private Set<Character> argsFound;
+    private ListIterator<String> currentArgument;
+
+    public Args(String schema, String[] args) throws ArgsException {
+        marshalers = new HashMap<>();
+        argsFound = new HashSet<>();
+
+        parseSchema(schema);
+        parseArgumentStrings(Arrays.asList(args));
+    }
+
+    private void parseSchema(String schema) throws ArgsException {
+        for (String element : schema.split(",")) {
+            if (element.length() > 0) {
+                parseSchemaElement(element.trim());
+            }
+        }
+    }
+
+    private void parseSchemaElement(String element) throws ArgsException {
+        char elementId = element.charAt(0);
+        String elementTail = element.substring(1);
+        validateSchemaElementId(elementId);
+        if (elementTail.length() == 0)
+            marshalers.put(elementId, new BooleanArgumentMarshaler());
+        else if (elementTail.equals("*"))
+            marshalers.put(elementId, new StringArgumentMarshaler());
+        else if (elementTail.equals("#"))
+            marshalers.put(elementId, new IntegerArgumentMarshaler());
+        else if (elementTail.equals("##"))
+            marshalers.put(elementId, new DoubleArgumentMarshaler());
+        else
+            throw new ArgsException(INVALID_ARGUMENT_FORMAT, elementId, elementTail);
+
+    }
+
+    private void validateSchemaElementId(char elementId) throws ArgsException {
+        if (!Character.isLetter(elementId)) {
+            throw new ArgsException(INVALID_ARGUMENT_NAME, elementId, null);
+        }
+    }
+
+    private void parseArgumentStrings(List<String> argsList) throws ArgsException {
+        for (currentArgument = argsList.listIterator(); currentArgument.hasNext(); ) {
+            String argString = currentArgument.next();
+            if (argString.startsWith("-")) {
+                parseArgumentCharacters(argString.substring(1));
+            } else {
+                currentArgument.previous();
+                break;
+            }
+        }
+    }
+
+    private void parseArgumentCharacters(String argChars) throws ArgsException {
+        for (int i = 0; i < argChars.length(); i++) {
+            parseArgumentCharacter(argChars.charAt(i));
+        }
+    }
+
+    private void parseArgumentCharacter(char argChar) throws ArgsException {
+        ArgumentMarshaler m = marshalers.get(argChar);
+        if (m == null) {
+            throw new ArgsException(UNEXPECTED_ARGUMENT, argChar, null);
+        } else {
+            argsFound.add(argChar);
+            try {
+                m.set(currentArgument);
+            } catch (ArgsException e) {
+                e.setErrorArgumentId(argChar);
+                throw e;
+            }
+        }
+    }
+
+    public boolean has(char arg) {
+        return argsFound.contains(arg);
+    }
+
+    public int nextArgument() {
+        return currentArgument.nextIndex();
+    }
+
+    public boolean getBoolean(char arg) {
+        return BooleanArgumentMarshaler.getValue(marshalers.get(arg));
+    }
+
+    public String getString(char arg) {
+        return StringArgumentMarshaler.getValue(marshalers.get(arg));
+    }
+
+    public int getInt(char arg) {
+        return IntegerArgumentMarshaler.getValue(marshalers.get(arg));
+    }
+
+    public double getDouble(char arg) {
+        return DoubleArgumentMarshaler.getValue(marshalers.get(arg));
+    }
+}

src/main/java/chapter14/args/ArgsException.java

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+package chapter14.args;
+
+public class ArgsException extends Exception {
+    private char errorArgumentId = '\0';
+    private String errorParameter = "TILT";
+    private ErrorCode errorCode = ErrorCode.OK;
+
+    public ArgsException() {
+    }
+
+    public ArgsException(String message) {
+        super(message);
+    }
+
+    public ArgsException(ErrorCode errorCode) {
+        this.errorCode = errorCode;
+    }
+
+    public ArgsException(ErrorCode errorCode, String errorParameter) {
+        this.errorCode = errorCode;
+        this.errorParameter = errorParameter;
+    }
+
+    public ArgsException(ErrorCode errorCode, char errorArgumentId, String errorParameter) {
+        this.errorCode = errorCode;
+        this.errorArgumentId = errorArgumentId;
+        this.errorParameter = errorParameter;
+    }
+
+    public char getErrorArgumentId() {
+        return errorArgumentId;
+    }
+
+    public void setErrorArgumentId(char errorArgumentId) {
+        this.errorArgumentId = errorArgumentId;
+    }
+
+    public String getErrorParameter() {
+        return errorParameter;
+    }
+
+    public void setErrorParameter(String errorParameter) {
+        this.errorParameter = errorParameter;
+    }
+
+    public ErrorCode getErrorCode() {
+        return errorCode;
+    }
+
+    public void setErrorCode(ErrorCode errorCode) {
+        this.errorCode = errorCode;
+    }
+
+    public String errorMessage() {
+        switch (errorCode) {
+            case OK:
+                return "TILT: Should not get here.";
+            case UNEXPECTED_ARGUMENT:
+                return String.format("Argument(s) -%c unexpected.", errorArgumentId);
+            case MISSING_STRING:
+                return String.format("Could not find string parameter for -%c.",
+                        errorArgumentId);
+            case INVALID_INTEGER:
+                return String.format("Argument -%c expects an integer but was '%s'.",
+                        errorArgumentId, errorParameter);
+            case MISSING_INTEGER:
+                return String.format("Could not find integer parameter for -%c.",
+                        errorArgumentId);
+            case INVALID_DOUBLE:
+                return String.format("Argument -%c expects an double but was '%s'.",
+                        errorArgumentId, errorParameter);
+            case MISSING_DOUBLE:
+                return String.format("Could not find double parameter for -%c.",
+                        errorArgumentId);
+            case INVALID_ARGUMENT_NAME:
+                return String.format("'%c' is not a valid argument name.",
+                        errorArgumentId);
+            case INVALID_ARGUMENT_FORMAT:
+                return String.format("'%s' is not a valid argument format.",
+                        errorParameter);
+        }
+        return "";
+    }
+
+    public enum ErrorCode {
+        OK, INVALID_ARGUMENT_FORMAT, UNEXPECTED_ARGUMENT,
+        INVALID_ARGUMENT_NAME,
+        MISSING_STRING,
+        MISSING_INTEGER, INVALID_INTEGER,
+        MISSING_DOUBLE, INVALID_DOUBLE
+    }
+}

src/main/java/chapter14/args/ArgumentMarshaler.java

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+package chapter14.args;
+
+import java.util.Iterator;
+
+public interface ArgumentMarshaler {
+    void set(Iterator<String> currentArgument) throws ArgsException;
+}

src/main/java/chapter14/args/BooleanArgumentMarshaler.java

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+package chapter14.args;
+
+import java.util.Iterator;
+
+public class BooleanArgumentMarshaler implements ArgumentMarshaler {
+    private boolean booleanValue = false;
+
+    @Override
+    public void set(Iterator<String> currentArgument) throws ArgsException {
+        booleanValue = true;
+    }
+
+    public static boolean getValue(ArgumentMarshaler am) {
+        if (am != null && am instanceof BooleanArgumentMarshaler) {
+            return ((BooleanArgumentMarshaler) am).booleanValue;
+        } else {
+            return false;
+        }
+    }
+}

src/main/java/chapter14/args/DoubleArgumentMarshaler.java

@@ -0,0 +1,32 @@
+package chapter14.args;
+
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+import static chapter14.args.ArgsException.ErrorCode.INVALID_DOUBLE;
+import static chapter14.args.ArgsException.ErrorCode.MISSING_DOUBLE;
+
+public class DoubleArgumentMarshaler implements ArgumentMarshaler {
+    private double doubleValue = 0;
+
+    @Override
+    public void set(Iterator<String> currentArgument) throws ArgsException {
+        String parameter = null;
+        try {
+            parameter = currentArgument.next();
+            doubleValue = Double.parseDouble(parameter);
+        } catch (NoSuchElementException e) {
+            throw new ArgsException(MISSING_DOUBLE);
+        } catch (NumberFormatException e) {
+            throw new ArgsException(INVALID_DOUBLE, parameter);
+        }
+    }
+
+    public static double getValue(ArgumentMarshaler am) {
+        if (am != null && am instanceof DoubleArgumentMarshaler) {
+            return ((DoubleArgumentMarshaler) am).doubleValue;
+        } else {
+            return 0.0;
+        }
+    }
+}

src/main/java/chapter14/args/IntegerArgumentMarshaler.java

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+package chapter14.args;
+
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+import static chapter14.args.ArgsException.ErrorCode.INVALID_INTEGER;
+import static chapter14.args.ArgsException.ErrorCode.MISSING_INTEGER;
+
+public class IntegerArgumentMarshaler implements ArgumentMarshaler {
+    private int intValue = 0;
+
+    @Override
+    public void set(Iterator<String> currentArgument) throws ArgsException {
+        String parameter = null;
+        try {
+            parameter = currentArgument.next();
+            intValue = Integer.parseInt(parameter);
+        } catch (NoSuchElementException e) {
+            throw new ArgsException(MISSING_INTEGER);
+        } catch (NumberFormatException e) {
+            throw new ArgsException(INVALID_INTEGER, parameter);
+        }
+    }
+
+    public static int getValue(ArgumentMarshaler am) {
+        if (am != null && am instanceof IntegerArgumentMarshaler) {
+            return ((IntegerArgumentMarshaler) am).intValue;
+        } else {
+            return 0;
+        }
+    }
+}

src/main/java/chapter14/args/StringArgumentMarshaler.java

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+package chapter14.args;
+
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+import static chapter14.args.ArgsException.ErrorCode.MISSING_STRING;
+
+public class StringArgumentMarshaler implements ArgumentMarshaler {
+    private String stringValue = "";
+
+    @Override
+    public void set(Iterator<String> currentArgument) throws ArgsException {
+        try {
+            stringValue = currentArgument.next();
+        } catch (NoSuchElementException e) {
+            throw new ArgsException(MISSING_STRING);
+        }
+    }
+
+    public static String getValue(ArgumentMarshaler am) {
+        if (am != null && am instanceof StringArgumentMarshaler) {
+            return ((StringArgumentMarshaler) am).stringValue;
+        } else {
+            return "";
+        }
+    }
+}