[转]java生成json字符串的方法

本文主要是介绍[转]java生成json字符串的方法，对大家解决编程问题具有一定的参考价值，需要的程序猿们随着小编来一起学习吧！

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","Skiing","Apple Pie"],"name":"reiz"}{"ingredients":{"apples":"3kg","pastry":"2.4kg","bestEaten":"outdoors","sugar":"1kg"},"initial":"R","likes":["JavaScript","Skiing","Apple Pie"],"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,false,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,false,true]["first","second"]["json","is","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：

appleorangename Michaelage 30baby [Lucy, Lily]

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作者：星辰之力
来源：CNBLOGS
原文：https://www.cnblogs.com/zhujiabin/p/5498555.html
版权声明：本文为作者原创文章，转载请附上博文链接！

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