详解java生成json字符串的方法
发布时间:2020-12-14 14:37:20 所属栏目:Java 来源:网络整理
导读:例1:将map对象添加一次元素(包括字符串对、数组),转换成json对象一次。 代码: package com.json; //这是使用org.json的程序:import java.util.HashMap;import java.util.Map; import org.json.JSONException;import org.json.JSONObject; public class
例1:将map对象添加一次元素(包括字符串对、数组),转换成json对象一次。 代码: package com.json; //这是使用org.json的程序: import java.util.HashMap; import java.util.Map; import org.json.JSONException; import org.json.JSONObject; public class jsontest { public static void main(String[] args) throws JSONException { String json = "{'name':'reiz'}"; JSONObject jsonObj = new JSONObject(json); String name = jsonObj.getString("name"); System.out.println(jsonObj); jsonObj.put("initial",name.substring(0,1).toUpperCase()); String[] likes = new String[] { "JavaScript","Skiing","Apple Pie" }; jsonObj.put("likes",likes); System.out.println(jsonObj); Map <String,String> ingredients = new HashMap <String,String>(); ingredients.put("apples","3kg"); ingredients.put("sugar","1kg"); ingredients.put("pastry","2.4kg"); ingredients.put("bestEaten","outdoors"); jsonObj.put("ingredients",ingredients); System.out.println(jsonObj); } } 运行结果: {"name":"reiz"} {"initial":"R","likes":["JavaScript","Apple Pie"],"name":"reiz"} {"ingredients":{"apples":"3kg","pastry":"2.4kg","bestEaten":"outdoors","sugar":"1kg"},"initial":"R","name":"reiz"} (需要用到的包可在官网下载:http://www.json.org/java/index.html) 例2:list转换成json的三种参数形式。 import java.util.ArrayList; import java.util.List; import net.sf.json.JSONArray; import net.sf.json.JSONObject; public class listToJson { public static void main(String[] args) { boolean[] boolArray = new boolean[]{true,false,true}; JSONArray jsonArray1 = JSONArray.fromObject( boolArray ); System.out.println( jsonArray1 ); // prints [true,true] List list = new ArrayList(); list.add( "first" ); list.add( "second" ); JSONArray jsonArray2 = JSONArray.fromObject( list ); System.out.println( jsonArray2 ); // prints ["first","second"] JSONArray jsonArray3 = JSONArray.fromObject( "['json','is','easy']" ); System.out.println( jsonArray3 ); // prints ["json","is","easy"] } } 运行结果: [true,true] ["first","second"] ["json","easy"] 例3:json转换成list和map。 package com.json; import java.util.Collection; import java.util.Map; import java.util.Map.Entry; import net.sf.json.JSONArray; import net.sf.json.JSONObject; public class jsonToListandMap { public static void main(String[] args) { // TODO Auto-generated method stub String listStr = "["apple","orange"]"; Collection<String> strlist = JSONArray.toCollection(JSONArray.fromObject(listStr)); for (String str : strlist) { System.out.println(str); } String mapStr = "{"age":30,"name":"Michael","baby":["Lucy","Lily"]}"; Map<String,Object> map = (Map) JSONObject.toBean(JSONObject .fromObject(mapStr),Map.class); for (Entry<String,Object> entry : map.entrySet()) { System.out.println(entry.getKey() + " " + entry.getValue()); } } } 运行结果: apple orange name Michael baby [Lucy,Lily] 以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持编程小技巧。 (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |