基于json-lib.jar包 创建JSONObject的四个常用方法
基于json-lib.jar包Json实例程序1.从头或者从零开始，创建一个JSONObject(Creating a JSONObject from scratch)实例1： JSONObject jsonObject = new JSONObject(); jsonObject.element("name", "周星星"); jsonObject.element("sex", "male"); jsonObject.element("age", 18); jsonObject.element("job", "student"); System.out.println(jsonObject.get("name"));// 周星星 System.out.println(jsonObject.get("job"));// student System.out.println(jsonObject.getString("sex"));// male System.out.println(jsonObject.getInt("age"));// 18实例2： JSONObject jsonObject = new JSONObject().element("string", "JSON").element("integer", "1").element("double", "2.0").element("boolean", "true"); assertEquals("JSON", jsonObject.getString("string")); assertEquals(1, jsonObject.getInt("integer")); assertEquals(2.0d, jsonObject.getDouble("double"), 0d); assertTrue(jsonObject.getBoolean("boolean")); 注：这是对实例1的一个简化版 2.使用一个JSON格式化字符串来创建一个JSONObject(Creating a JSONObject from a JSON formatted string) 实例1： String json = "{name:"周星星",sex:"male",age:18,job:"student"}"; JSONObject jsonObject = JSONObject.fromObject(json); //或者使用 JSONObject jsonObject = (JSONObject) JSONSerializer.toJSON(json); System.out.println(jsonObject.get("name"));// 周星星 System.out.println(jsonObject.get("job"));// student System.out.println(jsonObject.getString("sex"));// male System.out.println(jsonObject.getInt("age"));// 18实例2： String str = "{'string':'JSON', 'integer': 1, 'double': 2.0, 'boolean': true}"; JSONObject jsonObject = (JSONObject) JSONSerializer.toJSON(str); assertEquals("JSON", jsonObject.getString("string")); assertEquals(1, jsonObject.getInt("integer")); assertEquals(2.0d, jsonObject.getDouble("double"), 0d); assertTrue(jsonObject.getBoolean("boolean")); 3.使用一个Map来创建一个JSONObject(Creating a JSONObject from a Map)实例1： Map map = new HashMap(); map.put( "string", "JSON" ); map.put( "integer", "1" ); map.put( "double", "2.0" ); map.put( "boolean", "true" ); JSONObject jsonObject = (JSONObject) JSONSerializer.toJSON( map ); assertEquals( "JSON", jsonObject.getString("string") ); assertEquals( 1, jsonObject.getInt("integer") ); assertEquals( 2.0d, jsonObject.getDouble("double"), 0d ); assertTrue( jsonObject.getBoolean("boolean") );4.使用一个JavaBean来创建一个JSONObject(Creating a JSONObject from a JavaBean)实例1：public class Mybean { private String string; private int integer; private double dooble; private boolean bool; // getters & setters}Mybean bean = new Mybean();bean.setString("JSON");bean.setInteger(1);bean.setDooble(2.0d);bean.setBool(true);JSONObject jsonObject = (JSONObject) JSONSerializer.toJSON(bean);assertEquals("JSON", jsonObject.getString("string"));assertEquals(1, jsonObject.getInt("integer"));assertEquals(2.0d, jsonObject.getDouble("dooble"), 0d);assertTrue(jsonObject.getBoolean("bool"));由此可见，无论要转换的源是哪种类型，都可以使用(JSONObject) JSONSerializer.toJSON()或JSONObject.fromObject()来转换;?