如何从Java中的txt文件读取JSON数据? [英] How to Read JSON data from txt file in Java?

问题描述

我现在想从本地txt文件(如下所示，NODES.txt)中读取一系列JSON数据(节点数据).我使用javax.json来做到这一点.

I am now want to read a series of JSON data(Nodes data) from local txt file(shown below, NODES.txt ). I use javax.json to do this.

当前，我有一个 Node类，其中包含以下属性:type, id, geometry class(contains type, coordinates), properties class (contains name);

Currently, I have a Node class which contains the attributes:type, id, geometry class(contains type, coordinates), properties class (contains name);

这是我需要检索的数据，其中包含500多个节点，在这里我只列出了其中的3个节点，因此我需要使用循环来做到这一点，对此我还是很陌生的，请帮忙！

NODES.txt中的示例JSON数据

The sample JSON data in NODES.txt

[
 {
   "type" : "Feature",
   "id" : 8005583,
   "geometry" : {
    "type" : "Point",
    "coordinates" : [
     -123.2288,
     48.7578
    ]
   },
   "properties" : {
    "name" : 1
   }
  },
  {
   "type" : "Feature",
   "id" : 8005612,
   "geometry" : {
    "type" : "Point",
    "coordinates" : [
     -123.2271,
     48.7471
    ]
   },
   "properties" : {
    "name" : 2
   }
  },
  {
   "type" : "Feature",
   "id" : 8004171,
   "geometry" : {
    "type" : "Point",
    "coordinates" : [
     -123.266,
     48.7563
    ]
   },
   "properties" : {
    "name" : 3
   }
  },
     ****A Lot In the Between****
{
   "type" : "Feature",
   "id" : 8004172,
   "geometry" : {
    "type" : "Point",
    "coordinates" : [
     -113.226,
     45.7563
    ]
   },
   "properties" : {
    "name" : 526
   }
  }
]

推荐答案

创建代表条目的类:

Feature.java:

Feature.java:

import java.util.Map;

public class Node {
    public String type;
    public String id;
    public Geometry geometry;
    public Properties properties;
}

Geometry.java:

Geometry.java:

import java.util.List;

public class Geometry {
    public String type;
    public List<Double> coordinates;
}

Properties.java:

Properties.java:

public class Properties {
     public String name;
}

和一个用于驱动处理的应用程序主类.

And an application main class to drive the processing.

Main.java:

Main.java:

import com.google.gson.Gson;
import java.io.FileReader;
import java.io.Reader;

public class Main {
    public static void main(String[] args) throws Exception {
        try (Reader reader = new FileReader("NODES.txt")) {
            Gson gson = new Gson();
            Node[] features = gson.fromJson(reader, Node[].class);
             // work with features
        }
    }
}

这篇关于如何从Java中的txt文件读取JSON数据?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！