java读取JSON文件的多种实现方式
在开发过程中有时会遇到需要读取本地.json文件的需求,通常会自己写Reader代码去读,但是这么做写出来的代码有些繁琐(需要关流、创建StringBuilder对象等操作)。
最近发现几个小工具可以让需求代码变得更加简洁。
准备
json文件:F:\halon.json
{ "ID": 10001, "detail": "detail", "json_format_version": 1.0, "other_info": { "array_one": [ [855, 410], [854, 411], [847, 411], [846, 410], [845, 410], [844, 409] ], "array_two": [ [832, 303], [829, 303], [828, 302], [825, 302], [824, 301] ], "array_three": [ [1013, 224], [1012, 225], [1010, 225], [1009, 226], [1023, 224] ], "point": [853, 310], "boolean": true } }
1.使用FileReader读取json文件
package com.tool; import com.alibaba.fastjson.JSON; import com.alibaba.fastjson.JSONObject; import com.fasterxml.jackson.databind.ObjectMapper; import java.io.*; import java.nio.file.Files; import java.nio.file.Paths; import java.util.Map; /** * @Author halon * @create 2021/9/ */ public class ReadLocalJsonFileDemo { public static void main(String[] args) throws IOException { File file = new File("F:\\halon.json"); readerMethod(file); } private static void readerMethod(File file) throws IOException { FileReader fileReader = new FileReader(file); Reader reader = new InputStreamReader(new FileInputStream(file), "Utf-8"); int ch = 0; StringBuffer sb = new StringBuffer(); while ((ch = reader.read()) != -1) { sb.append((char) ch); } fileReader.close(); reader.close(); String jsonStr = sb.toString(); System.out.println(JSON.parseObject(jsonStr)); } }
控制台输出:
{"other_info":{"array_two":[[832,303],[829,303],[828,302],[825,302],[824,301]],"array_three":[[1013,224],[1012,225],[1010,225],[1009,226],[1023,224]],"boolean":true,"array_one":[[855,410],[854,411],[847,411],[846,410],[845,410],[844,409]],"point":[853,310]},"ID":10001,"detail":"detail","json_format_version":1.0}
2.使用jacksonAPI读取json文件
package com.tool; import com.alibaba.fastjson.JSON; import com.alibaba.fastjson.JSONObject; import com.fasterxml.jackson.databind.ObjectMapper; import java.io.*; import java.nio.file.Files; import java.nio.file.Paths; import java.util.Map; /** * @Author halon * @create 2021/9/ */ public class ReadLocalJsonFileDemo { public static void main(String[] args) throws IOException { File file = new File("F:\\halon.json"); jacksonMethod(file); } private static void jacksonMethod(File file) throws IOException { ObjectMapper objectMapper = new ObjectMapper(); System.out.println(objectMapper.readValue(file, Map.class)); }
控制台输出:
{ID=10001, detail=detail, json_format_version=1.0, other_info={array_one=[[855, 410], [854, 411], [847, 411], [846, 410], [845, 410], [844, 409]], array_two=[[832, 303], [829, 303], [828, 302], [825, 302], [824, 301]], array_three=[[1013, 224], [1012, 225], [1010, 225], [1009, 226], [1023, 224]], point=[853, 310], boolean=true}}
3.使用nio读取json文件
package com.tool; import com.alibaba.fastjson.JSON; import com.alibaba.fastjson.JSONObject; import com.fasterxml.jackson.databind.ObjectMapper; import java.io.*; import java.nio.file.Files; import java.nio.file.Paths; import java.util.Map; /** * @Author halon * @create 2021/9/ */ public class ReadLocalJsonFileDemo { public static void main(String[] args) throws IOException { File file = new File("F:\\halon.json"); nioMethod(file); } private static void nioMethod(File file) throws IOException { String jsonString = new String(Files.readAllBytes(Paths.get(file.getPath()))); System.out.println(JSONObject.parseObject(jsonString)); }
控制台输出:
{"other_info":{"array_two":[[832,303],[829,303],[828,302],[825,302],[824,301]],"array_three":[[1013,224],[1012,225],[1010,225],[1009,226],[1023,224]],"boolean":true,"array_one":[[855,410],[854,411],[847,411],[846,410],[845,410],[844,409]],"point":[853,310]},"ID":10001,"detail":"detail","json_format_version":1.0}
未完待续。。。。
总结
以上为个人经验,希望能给大家一个参考,也希望大家多多支持脚本之家。
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