如何操作 JSON 树的叶子

Question

我想使用 JAVA 将 JSON 树中的稀有词替换为 _RARE_。

我的稀有词列表包含

late  
populate
convicts

所以对于下面的 JSON

["S", ["PP", ["ADP", "In"], ["NP", ["DET", "the"], ["NP", ["ADJ", "late"], ["NOUN", "1700<s"]]]], ["S", ["NP", ["ADJ", "British"], ["NOUN", "convicts"]], ["S", ["VP", ["VERB", "were"], ["VP", ["VERB", "used"], ["S+VP", ["PRT", "to"], ["VP", ["VERB", "populate"], ["WHNP", ["DET", "which"], ["NOUN", "colony"]]]]]], [".", "?"]]]]

我应该得到

["S", ["PP", ["ADP", "In"], ["NP", ["DET", "the"], ["NP", ["ADJ", "_RARE_"], ["NOUN", "1700<s"]]]], ["S", ["NP", ["ADJ", "British"], ["NOUN", "_RARE_"]], ["S", ["VP", ["VERB", "were"], ["VP", ["VERB", "used"], ["S+VP", ["PRT", "to"], ["VP", ["VERB", "populate"], ["WHNP", ["DET", "which"], ["NOUN", "colony"]]]]]], [".", "?"]]]]

注意方法

["ADJ","late"]

被替换为

["ADJ","_RARE_"]

到目前为止，我的代码如下：

我递归地遍历树，一旦找到稀有词，我就创建一个新的 JSON 数组并尝试用它替换现有树的节点。请参阅下面的// this Doesn't work，这就是我卡住的地方。树在此函数之外保持不变。

public static void traverseTreeAndReplaceWithRare(JsonArray tree){   

        //System.out.println(tree.getAsJsonArray()); 

        for (int x = 0; x < tree.getAsJsonArray().size(); x++)
        {
            if(!tree.get(x).isJsonArray())
            {
                if(tree.size()==2)
                {   
                //beware it will get here twice for same word
                 String word= tree.get(1).toString();  
                 word=word.replaceAll("\"", ""); // removing double quotes

                 if(rareWords.contains(word))
                 {
                 JsonParser parser = new JsonParser();                   

                             //This works perfectly 
                             System.out.println("Orig:"+tree);
                 JsonElement jsonElement = parser.parse("["+tree.get(0)+","+"_RARE_"+"]");

                 JsonArray newRareArray = jsonElement.getAsJsonArray();

                             //This works perfectly 
                             System.out.println("New:"+newRareArray);

                 tree=newRareArray; // this Doesn't work
                 }                 

                }               
                continue;   
            }
            traverseTreeAndReplaceWithRare(tree.get(x).getAsJsonArray());
        }
    }

上面的调用代码，我用google的gson

JsonParser parser = new JsonParser();
JsonElement jsonElement = parser.parse(strJSON);
JsonArray tree = jsonElement.getAsJsonArray();  

Answer 1

这是 C++ 中的一种直接方法：

#include <fstream>
#include "JSON.hpp"
#include <boost/algorithm/string/regex.hpp>
#include <boost/range/adaptors.hpp>
#include <boost/phoenix.hpp>

static std::vector<std::wstring> readRareWordList()
{
    std::vector<std::wstring> result;

    std::wifstream ifs("testcases/rarewords.txt");
    std::wstring line;
    while (std::getline(ifs, line))
        result.push_back(std::move(line));

    return result;
}

struct RareWords : boost::static_visitor<> {

    /////////////////////////////////////
    // do nothing by default
    template <typename T> void operator()(T&&) const { /* leave all other things unchanged */ }

    /////////////////////////////////////
    // recurse arrays and objects
    void operator()(JSON::Object& obj) const { 
        for(auto& v : obj.values) {
            //RareWords::operator()(v.first); /* to replace in field names (?!) */
            boost::apply_visitor(*this, v.second);
        }
    }

    void operator()(JSON::Array& arr) const {
        int i = 0;
        for(auto& v : arr.values) {
            if (i++) // skip the first element in all arrays
                boost::apply_visitor(*this, v);
        }
    }

    /////////////////////////////////////
    // do replacements on strings
    void operator()(JSON::String& s) const {
        using namespace boost;

        const static std::vector<std::wstring> rareWords = readRareWordList();
        const static std::wstring replacement = L"__RARE__";

        for (auto&& word : rareWords)
            if (word == s.value)
                s.value = replacement;
    }
};

int main()
{
    auto document = JSON::readFrom(std::ifstream("testcases/test3.json"));

    boost::apply_visitor(RareWords(), document);

    std::cout << document;
}

这假设您想要对所有字符串值进行替换，并且只匹配整个字符串。您可以通过更改正则表达式或正则表达式标志轻松地使这种不区分大小写、匹配字符串中的单词等。根据 cmets 稍作调整。

包含 JSON.hpp/cpp 的完整代码在这里：https://github.com/sehe/spirit-v2-json/tree/16093940