json与xml比较
可读性
解码难度
流行度
课时13 13.json-lib的应用
继承关系
public final class JSONArray extends AbstractJSON
implements JSON, List, Comparable
public final class JSONObject extends AbstractJSON
implements JSON, Map, Comparable
依赖
<dependency> <groupId>net.sf.json-lib</groupId> <artifactId>json-lib</artifactId> <version>2.4</version> <classifier>jdk15</classifier> </dependency>
示例
import net.sf.json.JSONObject; class Demo { public static void main(String[] args) { JSONObject map = new JSONObject(); map.put("name", "Tom"); map.put("age", 23); String str = map.toString(); System.out.println(str); // {"name":"Tom","age":23} } }
java对象转为json
Person.java
public class Person { private String name; private int age; public Person(String name, int age) { this.name = name; this.age = age; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } }
Demo.java
import net.sf.json.JSONArray; import net.sf.json.JSONObject; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; class Demo { public static void main(String[] args) { // 对象转JSONObject Person person = new Person("Tom", 23); JSONObject obj = JSONObject.fromObject(person); System.out.println(obj.toString()); // {"name":"Tom","age":23} // List转 JSONArray List<Person> list = new ArrayList<Person>(); list.add(new Person("Tom", 23)); list.add(new Person("Jack", 23)); JSONArray array = JSONArray.fromObject(list); System.out.println(array.toString()); // [{"age":23,"name":"Tom"},{"age":23,"name":"Jack"}] // map转JSONObject Map<String ,String> map = new HashMap<String ,String>(); map.put("name", "Tom"); map.put("sex", "male"); System.out.println(JSONObject.fromObject(map).toString()); // {"sex":"male","name":"Tom"} } }
课时14 14.打包ajax生成小工具
参数
option{
method
url
asyn
type
callback
params
data
}
xml
text
json
后端接口
from flask import Flask, request, jsonify from flask_cors import CORS app = Flask(__name__) CORS(app, supports_credentials=True) @app.route("/json", methods=["GET", "POST"]) def json(): username = request.args.get("username") if request.method == "POST": username = request.form.get("username") if request.is_json: username = request.json.get("username") return jsonify({"name": username}) if __name__ == '__main__': app.run(debug=True)
封装的工具 ajax-util.js
// 获取XMLHttpRequest对象 function createXMLHttpRequest() { try { // 大多数浏览器 return new XMLHttpRequest(); } catch (e) { try { // IE6.0 new ActiveXObject("Msxml2.XMLHTTP"); } catch (e) { try { // IE<=5.5 new ActiveXObject("Microsoft.XMLHTTP"); } catch (e) { console.log("浏览器版本太老了！"); throw e; } } } } // 判断是否为IE浏览器 function isIE() { if (window.addEventListener) { return false; } else { return true; } } /** * 将对象转为url查询参数 * @param {*} data * { "name": "Tom", "age": 23 } * -> name=Tom&age=23 */ function encodeData(data) { if (!data) { return null; } let list = []; for (let [key, value] of Object.entries(data)) { list.push(`${key}=${value}`); } return list.join("&"); } const CONTENT_TYPE = "Content-Type"; const contentTypeMap = { html: "text/html; charset=utf-8", xml: "text/xml; charset=utf-8", json: "application/json; charset=utf-8", form: "application/x-www-form-urlencoded" } /** * * @param {*} option: * method * url * asyn * type * callback * params * data */ function ajax(option) { // 必传参数 let url = option.url; let callback = option.callback; // 可选参数 let method = option.method || "GET"; let asyn = option.asyn || true; let params = option.params || {}; let type = option.type || "html"; let data = option.data || {}; let xmlHttp = createXMLHttpRequest(); // 处理响应数据 xmlHttp.onreadystatechange = function () { // 双重判断 xmlHttp状态为服务器响应结束，服务器状态响应结束 if (xmlHttp.readyState == 4 && xmlHttp.status == 200) { // 获取响应结果 let responseData = null; if (xmlHttp.responseXML) { responseData = xmlHttp.responseXML; } else { responseData = xmlHttp.responseText; try { responseData = JSON.parse(responseData); } catch (e) { } } callback(responseData); } } // 处理请求数据 if (params) { url = url + "?" + encodeData(params); } xmlHttp.open(method, url, asyn); xmlHttp.setRequestHeader(CONTENT_TYPE, contentTypeMap[type]); let sendData = null; if (type == "json") { sendData = JSON.stringify(data); } else { sendData = encodeData(data); } xmlHttp.send(sendData); } // console.log(encodeData(undefined));
