从json文件读取json string或者自定义json string，将其转为object。下面采用的object为map，根据map读取json的某个数据，可以读取第一级的数据name，后来发现想转成JsonArray读取”red“时没撤了，只好用了其他方法。

最后用org.json包解决了（readJsonArray函数），有空再看看有没有更好的办法。

JSON文件如下：

{ "name":"name", "id":"id", "color":[ {"red":"red","blue":"blue"}, {"white":"white"} ]}

代码如下：

package com;import org.codehaus.jackson.map.ObjectMapper;import org.json.JSONArray;import org.json.JSONObject;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import java.io.*;import java.util.Map;/** * Hello world! * */public class JsonAnalysis{ private static final Logger LOG = LoggerFactory.getLogger(JsonAnalysis.class); public static void main(String[] args) throws FileNotFoundException { String jsonString = "{\"address\":\"address\",\"name\":\"name\",\"id\":\"1\",\"email\":\"email\"}"; FileReader fileReader = new FileReader("E:\\JsonAnalysis\\src\\test.json"); String fileString = readFile(fileReader); //Json字符串转java对象,比如转为Map对象读取其中数据 Map map = null; Map mapFile = null; try { map = readValue(jsonString, Map.class); mapFile = readValue(fileString, Map.class); } catch (Exception e) { e.printStackTrace(); LOG.error("ReadValue occur exception when switch json string to map"); } System.out.println(map != null ? map.get("id") : null); if (mapFile==null){ LOG.info("Json map form file is empty"); return; } System.out.println(mapFile.get("name")); try { readJsonArray(fileString); } catch (Exception e) { e.printStackTrace(); } } //Json string to object private static <T> T readValue(String jsonStr, Class<T> valueType) throws Exception{ ObjectMapper objectMapper = new ObjectMapper(); try {// Object object = objectMapper.readValue(jsonStr,Object.class); return objectMapper.readValue(jsonStr,valueType); } catch (IOException e) { e.printStackTrace(); } return null; } //Read file and to string private static String readFile(FileReader fileReader){ BufferedReader bufferedReader = new BufferedReader(fileReader); StringBuilder fileStr = new StringBuilder(); try { String eachLine; while ((eachLine=bufferedReader.readLine())!=null){ fileStr.append(eachLine); } return fileStr.toString(); } catch (IOException e1) { e1.printStackTrace(); LOG.error("Occur exception when read file,file={}",fileReader); return null; } } //根据json string 获取json array,读取数据（ 注意该部分引用的是org.json 包） private static void readJsonArray(String jsonStr) throws Exception { JSONObject jsonObject = new JSONObject(jsonStr); JSONArray jsonArray = jsonObject.getJSONArray("color"); JSONObject jsonObject1 = jsonArray.getJSONObject(0); System.out.println(jsonObject1.get("red")); }}

以上这篇Jackson将json string转为Object,org.json读取json数组的实例就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持。