ajax響應json字串和json數組

最後更新：2015-05-20 來源：互聯網

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標籤：ajax json json字串 json數組

最近上班太忙，晚上抽空整理一下ajax請求中，後台返回json字串和json數組的情境，以及前台的處理樣本。

直接看代碼。

json字串的後台響應

package com.ajax;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;@WebServlet("/jsonStr")public class JsonStr extends HttpServlet {/** *  */private static final long serialVersionUID = 1L;@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {// 構造json對象String resStr = "{" + "name:" + "\"zhangsan\"," + "id:" + "\"id001\"" + "}";// 輸出json對象到前台PrintWriter out = resp.getWriter();out.write(resStr);out.flush();out.close();}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {doGet(req, resp);}}

json數組的後台響應

package com.ajax;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;@WebServlet("/jsonArr")public class JsonArr extends HttpServlet {/** *  */private static final long serialVersionUID = 1L;@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {// 構造json對象String resStr1 = "{" + "name:" + "\"zhangsan\"," + "id:" + "\"id001\"" + "}";String resStr2 = "{" + "name:" + "\"lisi\"," + "id:" + "\"id002\"" + "}";String resStr3 = "{" + "name:" + "\"wangwu\"," + "id:" + "\"id003\"" + "}";// 構造json數組String jsonArr = "[" + resStr1 + "," + resStr2 + "," + resStr3 + "]";// 輸出json數組到前台PrintWriter out = resp.getWriter();out.write(jsonArr);out.flush();out.close();}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {doGet(req, resp);}}

前台頁面

<%@ page language="java" contentType="text/html; charset=UTF-8"    pageEncoding="UTF-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Json</title></head><body><br><br><input type="button" value="JsonStr" onclick="jsonStr()" /><br><br><table><tr><td>username</td><td><input id="username"></td></tr><tr><td>id</td><td><input id="id"></td></tr></table><br><br><br><input type="button" value="JsonArr" onclick="jsonArr()" /><br><br><table border="1" bordercolor="red"><caption>Json Array</caption><thead><tr><th>Username</th><th>Id</th></tr></thead><tbody id="tb"></tbody></table></body><script type="text/javascript">// json字串處理方法function jsonStr() {var xhr = new XMLHttpRequest();xhr.open("get", "jsonStr");xhr.onreadystatechange = function(data) {if (xhr.readyState == 4 && xhr.status == 200) {// 將json字串轉換為json對象var obj = eval("(" + data.target.responseText + ")");document.getElementById("username").value = obj.name;document.getElementById("id").value = obj.id;}};xhr.send(null);}// json數組處理方法function jsonArr() {var xhr = new XMLHttpRequest();xhr.open("get", "jsonArr");xhr.onreadystatechange = function(data) {if (xhr.readyState == 4 && xhr.status == 200) {// 將json字串轉換為json數組var obj = eval("(" + data.target.responseText + ")");// 建立程式碼片段，用於存放表格行var oFragment = document.createDocumentFragment();// 根據json數組長度，產生行資料for (var i=0; i<obj.length; i++) {var trObj = document.createElement("tr");trObj.innerHTML = "<td>" + obj[i].name + "</td><td>" + obj[i].id + "</td>";oFragment.appendChild(trObj);}// 將行資料添加在表格的tBody部分document.getElementById("tb").appendChild(oFragment);}};xhr.send(null);}</script></html>

頁面

點擊 JsonStr 和 JsonArr 按鈕後的效果

好了，整理完畢，樣本僅供學習。

對了，有一點疑惑，之前回呼函數中，擷取響應資料的時候，都是直接通過data.responseText 來擷取的，今天的代碼中必須使用data.target.responseText，不知道為什嗎？有知道的朋友煩請告知一聲，非常感謝。

ajax響應json字串和json數組

本文章原先以中文撰寫並發佈於 aliyun.com，亦設英文版本，僅作資訊用途。本網站不對文章的準確性，完整性或可靠性或其任何翻譯作出任何明示或暗示的陳述或保證。如對該文章有任何疑慮或投訴，請傳送電郵至 info-contact@alibabacloud.com 並提供相關疑慮或投訴的詳細說明。職員會於 5 個工作天內與您聯絡，一經驗證之後，即會刪除該侵權內容。

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