JSON字符串转换为对象

约定不等于承诺〃 2022-06-08 00:28 270阅读 0赞

首先理解JSONObject 和JSONArray,JSONObject就代表\{“key”:"value","key":"value"\}格式，不管多么复杂都是这种格式，JSONArray代表\[\{"key":"value"\},\{"key":"value"\}\]格式，原理一样，不管多么复杂，都是这种格式。

</dependency>

下面例子展示了怎么把对象转换成字符串，把复杂字符串解析成对象

package JSON.JSONObjectAndJSONArray;
    
    import org.junit.Before;
    
    import JSON.entity.Student;
    import junit.framework.Test;
    import junit.framework.TestCase;
    import junit.framework.TestSuite;
    import net.sf.json.JSONArray;
    import net.sf.json.JSONObject;
    
    /**
     * Unit test for simple App.
     */
    public class AppTest extends TestCase {
    	/**
    	 * Create the test case
    	 *
    	 * @param testName
    	 *            name of the test case
    	 */
    	public AppTest(String testName) {
    		super(testName);
    	}
    
    	/**
    	 * @return the suite of tests being tested
    	 */
    	public static Test suite() {
    		return new TestSuite(AppTest.class);
    	}
    
    	/**
    	 * Rigourous Test :-)
    	 */
    	@org.junit.Test
    	public void testApp() {
    		Student stu1 = new Student("001", "小红", "24");
    		Student stu2 = new Student("002", "小黄", "25");
    		Student stu3 = new Student("003", "小绿", "23");
    		JSONObject jsonObject = new JSONObject();
    		JSONArray jsonArray = new JSONArray();
    
    		jsonObject.put("stu1", stu1);
    		jsonObject.put("stu2", stu2);
    		jsonObject.put("stu3", stu3);
    
    		String jsonString = jsonObject.toString();
    		System.out.println(jsonString);
    		// {"stu1":{"age":"24","id":"001","name":"小红"},"stu2":{"age":"25","id":"002","name":"小黄"},"stu3":{"age":"23","id":"003","name":"小绿"}}
    
    		jsonArray.add(stu1);
    		jsonArray.add(stu2);
    		jsonArray.add(stu3);
    		System.out.println(jsonArray.toString());
    		// [{"age":"24","id":"001","name":"小红"},{"age":"25","id":"002","name":"小黄"},{"age":"23","id":"003","name":"小绿"}]
    
    		jsonObject = new JSONObject();
    		jsonObject.put("student", jsonArray);
    		System.out.println(jsonObject);
    		// {"student":[{"age":"24","id":"001","name":"小红"},{"age":"25","id":"002","name":"小黄"},{"age":"23","id":"003","name":"小绿"}]}
    
    		System.out.println("----------------");
    
    		String str = "{\"stu1\":{\"age\":\"24\",\"id\":\"001\",\"name\":\"小红\"},\"stu2\":{\"age\":\"25\",\"id\":\"002\",\"name\":\"小黄\"},\"stu3\":{\"age\":\"23\",\"id\":\"003\",\"name\":\"小绿\"}}";
    		JSONObject jsonObject2 = JSONObject.fromObject(str);
    		Object object = jsonObject2.get("stu1");
    		System.out.println(object);
    		// {"age":"24","id":"001","name":"小红"}
    
    		JSONObject jsonBean = JSONObject.fromObject(object);
    		System.out.println("jsonBean---" + jsonBean);
    		// jsonBean---{"age":"24","id":"001","name":"小红"}
    
    		Object bean = JSONObject.toBean(jsonBean, Student.class);
    		if (bean instanceof Student) {
    			System.out.println(bean);
    			// Student [id=001, name=小红, age=24]
    		}
    		System.out.println("--------------");
    
    		String str2 = "{\"student\":[{\"age\":\"24\",\"id\":\"001\",\"name\":\"小红\"},{\"age\":\"25\",\"id\":\"002\",\"name\":\"小黄\"},{\"age\":\"23\",\"id\":\"003\",\"name\":\"小绿\"}]}";
    		JSONObject jsonObject3 = JSONObject.fromObject(str2);
    		Object object2 = jsonObject.get("student");
    		JSONArray jsonArray2 = JSONArray.fromObject(object2);
    		for (int i = 0; i < jsonArray2.size(); i++) {
    			Object object3 = jsonArray2.get(i);
    			JSONObject object4 = jsonObject.fromObject(object3);
    			Object bean2 = JSONObject.toBean(object4, Student.class);
    			if (bean2 instanceof Student) {
    				System.out.println(bean2);
    				/*
    				 * Student [id=001, name=小红, age=24] 
    				 * Student [id=002, name=小黄, age=25] 
    				 * Student [id=003, name=小绿, age=23]
    				 */
    			}
    		}
    
    	}
    }

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