java - 用java中的另一个字符串替换JSON字符串

Question

String str = "{"id":"4ebd7e4f","start_page_ui_id":"","business_unit":["5b65aced"],"props":{"metadata":"[]","postsPerPage":"20","network_id":"1b375ffd"},"render_engine":"twig"}"

这里我想将 "metadata":"[]"替换为 "metadata":"["key":"value,value1","key1":"value2"]"

为此我尝试替换为

str =str.replace("\"metadata\":\"[\"", "\"metadata\": \"[{\"key\":\"key\",\"val\":\"value,value1\"},{\"key\":\"key1\",\"val\":\"value2\"}");

但它并没有被取代。我不明白为什么？？任何人都可以帮我解决这个问题吗？

我想将另一个字符串 "postsPerPage":"20"替换为 "postsPerPage":"6"

为此我尝试过

str = str .replace("\"postsPerPage\": \"20\",", "\"postsPerPage\": \"9\",");

这里的值也没有改变。

Answer 1

为此使用 JSON 第三方库，GSON或Jackson是最受欢迎的。

例如使用 GSON(仅适用于小样本!对于大块 JSON，您应该考虑使用流 API):

import com.google.gson.Gson;
import com.google.gson.JsonArray;
import com.google.gson.JsonObject;

public class Main {

    public static void main(String[] args) {
        Gson gson = new Gson();
        String str = "{\"id\":\"4ebd7e4f\",\"start_page_ui_id\":\"\",\"business_unit\":[\"5b65aced\"],\"props\":{\"metadata\":\"[]\",\"postsPerPage\":\"20\",\"network_id\":\"1b375ffd\"},\"render_engine\":\"twig\"}";
        String metadataReplacementJson = "[{\"key\":\"key\",\"val\":\"value,value1\"},{\"key\":\"key1\",\"val\":\"value2\"}]";
        JsonObject jsonObject = gson.fromJson(str, JsonObject.class);

        jsonObject
                .get("props")
                .getAsJsonObject()
                .remove("metadata");

        jsonObject
                .get("props")
                .getAsJsonObject()
                .add("metadata", gson.fromJson(metadataReplacementJson, JsonArray.class));

        System.out.println(gson.toJson(jsonObject));
    }
}

控制台输出:

{"id":"4ebd7e4f","start_page_ui_id":"","business_unit":["5b65aced"],"props":{"metadata":[{"key":"key","val":"value,value1"},{"key":"key1","val":"value2"}],"postsPerPage":"20","network_id":"1b375ffd"},"render_engine":"twig"}