从Java中的属性文件创建具有嵌套字段的映射或对象

我需要从带有嵌套字段的属性文件创建JSON？ 例如，我们有以下属性文件：

student.name="John"
student.exam.math=5
teacher.skills=10

我需要输出以下JSON文件：

Properties : {
    student : {
        name : "John",
        exam : {
            math : 5
        }
    },
    teacher : {
       skills : 10
    }
}

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JSON代码可以使用FLEX-JSON序列化程序或GSON库生成，这不是问题。主要问题是解析属性并生成具有嵌套属性的Java对象或映射。有允许这样做的图书馆吗？谢谢

顺便说一句，目前还没有知名的图书馆可以做到这一点。但你可以用一种简单的方式来做：

 public String propertiesToJson(Properties p) {
    Map tree = new LinkedHashMap();

    for (String name : p.stringPropertyNames()) {
        String[] parts = name.split("\\.");
        Map nextTree = tree;
        for (int i = 0, partsLength = parts.length; i < partsLength; i++) {
            String part = parts[i];
            Object v = nextTree.get(part);
            if (v == null) {
                if (i < partsLength - 1) {
                    Map newNextTree = new LinkedHashMap();
                    nextTree.put(part, newNextTree);
                    nextTree = newNextTree;
                } else {
                    nextTree.put(part, p.getProperty(name));
                }
            } else {
                if (i < partsLength - 1) {
                    nextTree = (Map) v;
                }
            }
        }
    }


    StringBuilder sb = new StringBuilder();
    sb.append("Properties : {\n");
    recursive(tree, sb, 1);
    sb.append("}");

    return sb.toString();
}

private void recursive(Map tree, StringBuilder sb, int deep) {
    boolean first = true;
    for (Object key : tree.keySet()) {
        if (!first) sb.append(",\n");
        else first = false;
        for (int t = 0; t < deep; t++) sb.append("\t");
        sb.append(key + " : ");
        Object v = tree.get(key);
        if (v instanceof Map) {
            sb.append("{\n");
            recursive((Map) v, sb, deep+1);
            for (int t = 0; t < deep; t++) sb.append("\t");
            sb.append("}");
        } else {
            sb.append(v);
        }
    }
    sb.append("\n");
}

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顺便说一句，没有知名的图书馆可以这样做。但你可以用一种简单的方式来做：

 public String propertiesToJson(Properties p) {
    Map tree = new LinkedHashMap();

    for (String name : p.stringPropertyNames()) {
        String[] parts = name.split("\\.");
        Map nextTree = tree;
        for (int i = 0, partsLength = parts.length; i < partsLength; i++) {
            String part = parts[i];
            Object v = nextTree.get(part);
            if (v == null) {
                if (i < partsLength - 1) {
                    Map newNextTree = new LinkedHashMap();
                    nextTree.put(part, newNextTree);
                    nextTree = newNextTree;
                } else {
                    nextTree.put(part, p.getProperty(name));
                }
            } else {
                if (i < partsLength - 1) {
                    nextTree = (Map) v;
                }
            }
        }
    }


    StringBuilder sb = new StringBuilder();
    sb.append("Properties : {\n");
    recursive(tree, sb, 1);
    sb.append("}");

    return sb.toString();
}

private void recursive(Map tree, StringBuilder sb, int deep) {
    boolean first = true;
    for (Object key : tree.keySet()) {
        if (!first) sb.append(",\n");
        else first = false;
        for (int t = 0; t < deep; t++) sb.append("\t");
        sb.append(key + " : ");
        Object v = tree.get(key);
        if (v instanceof Map) {
            sb.append("{\n");
            recursive((Map) v, sb, deep+1);
            for (int t = 0; t < deep; t++) sb.append("\t");
            sb.append("}");
        } else {
            sb.append(v);
        }
    }
    sb.append("\n");
}

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尽管这篇文章比较老，但一个非常简单的解决方案是使用Jackson JavaPropsMapper：

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尽管这篇文章比较老，但一个非常简单的解决方案是使用Jackson JavaPropsMapper：

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谢谢我来试试。谢谢！我想试试这个。