Question

我有不同的类，每个都接收字符串并将其转换为不同的html格式。然后我有一个chooser类，其中我有转换案例以转移字符串，例如我将字符串发送到chooser和stylename，就像这样

Chooser chooser = new Chooser();
String text = chooser.format(sometext, stylename);

Chooser类是这样的：

public String format(String sometext, String stylename) {
    switch (stylename) {
        case "NewStyle":
            NewStyle ns = new NewStyle();
            str = ns.refprocess(sometext);
            break;
        case "Anotherstyle":
            Anotherstyle as = new Anotherstyle();
            str = as.refprocess(sometext);
            break;
        case "Tet_Letters":
            Turk_J_Chem tet_letters = new Turk_J_Chem();
            str = tet_letters.refprocess(sometext);
            break;
    }
}

它有什么简短的方法吗？这样当我将stylename作为String发送时，它会转换为Class，制作其对象，然后仅将sometext发送到该类？

Answer 1

我假设你有一个界面：

static interface Style {
    String refprocess(String text);
}

和3个实现：

static class NewStyle implements Style {
    @Override
    public String refprocess(final String text) {
        return "new style of " + text;
    }
}

static class Anotherstyle implements Style {
    @Override
    public String refprocess(final String text) {
        return "Another style of " + text;
    }
}

static class Turk_J_Chem implements Style {

    @Override
    public String refprocess(final String text) {
        return "Turk_J_Chem's style of " + text;
    }
}

然后你可以创建一个类的枚举，并使用枚举格式化

enum Styles1 {
    NEW(NewStyle.class, "NewStyle"),
    ANOTHER(Anotherstyle.class, "Anotherstyle"),
    TET_LETTERS(Turk_J_Chem.class, "Tet_Letters");
    String str;
    Class<? extends Style> clazz;

    Styles1(final Class<? extends Style> clazz, final String str) {
        this.clazz = clazz;
        this.str = str;
    }

}

static String formatUsingEnum1(final String sometext, final String stylename) {
    for (final Styles1 style : Styles1.values()) {
        if (style.str.equals(stylename)) {
            try {
                return style.clazz.newInstance().refprocess(sometext);
            } catch (final Exception e) {
                break;
            }
        }
    }
    throw new NotImplementedException(stylename);
}

或者您可以使用实例填充枚举：

enum Styles2 {
    NEW(new NewStyle(), "NewStyle"),
    ANOTHER(new Anotherstyle(), "Anotherstyle"),
    TET_LETTERS(new Turk_J_Chem(), "Tet_Letters");
    String str;
    Style style;

    Styles2(final Style instance, final String str) {
        style = instance;
        this.str = str;
    }

}

static String formatUsingEnum2(final String sometext, final String stylename) {
    for (final Styles2 style : Styles2.values()) {
        if (style.str.equals(stylename)) {
            try {
                return style.style.refprocess(sometext);
            } catch (final Exception e) {
                break;
            }
        }
    }
    throw new NotImplementedException(stylename);
}

但是你可以在enum中插入一个抽象函数，并为所有实例提供内联实现：

enum Styles3 {
    NewStyle() {
        @Override
        String refprocess(final String text) {
            return "new style of " + text;
        }
    },
    Anotherstyle {
        @Override
        String refprocess(final String text) {
            return "Another style of " + text;
        }
    },
    TET_LETTERS {
        @Override
        String refprocess(final String text) {
            return "Turk_J_Chem's style of " + text;
        }
    };
    abstract String refprocess(String text);
}

static String formatUsingEnum3(final String sometext, final String stylename) {
    for (final Styles3 style : Styles3.values()) {
        if (style.name().equalsIgnoreCase(stylename)) {
            try {
                return style.refprocess(sometext);
            } catch (final Exception e) {
                break;
            }
        }
    }
    throw new NotImplementedException(stylename);
}

...享受

从java中的字符串创建类的对象

1 个答案: