將數據轉成JSON

前言

前面咱們在使用Strus2的時候，Struts2自帶了組件可以讓JavaBean對象、集合轉成是JSON，不用咱們本身拼接…這是很是方便的。可是，咱們不必定使用Struts2框架來作開發呀。所以，咱們還得學習使用第三方庫來將JavaBean對象、集合轉成JSON

導入開發包

• commons-io-2.0.1.jar
• commons-lang-2.5.jar
• commons-collections-3.1.jar
• commons-beanutils-1.7.0.jar
• ezmorph-1.0.3.jar
• json-lib-2.1-jdk15.jar

事例代碼

package cn.itcast.javaee.js.bean2json;

import net.sf.json.JSONArray;

import java.util.*;

/** * 使用第三方工具，將JavaBean對象/List或Set或Map對象轉成JSON * @author AdminTC */
public class TestBean2Json {
    private static void javabean2json() {
        City city = new City(1,"廣州");
        JSONArray jSONArray = JSONArray.fromObject(city);
        String jsonJAVA = jSONArray.toString();
        System.out.println(jsonJAVA);
        //[{"id":1,"name":"廣州"}]
    }
    private static void list2json() {
        List<City> cityList = new ArrayList<City>();
        cityList.add(new City(1,"廣州"));
        cityList.add(new City(2,"珠海"));
        JSONArray jSONArray = JSONArray.fromObject(cityList);
        String jsonJAVA = jSONArray.toString();
        System.out.println(jsonJAVA);
        //[{"id":1,"name":"廣州"},{"id":2,"name":"珠海"}]
    }
    private static void set2json() {
        Set<City> citySet = new LinkedHashSet<City>();
        citySet.add(new City(1,"廣州"));
        citySet.add(new City(2,"珠海"));
        JSONArray jSONArray = JSONArray.fromObject(citySet);
        String jsonJAVA = jSONArray.toString();
        System.out.println(jsonJAVA);
        //[{"id":1,"name":"廣州"},{"id":2,"name":"珠海"}]
    }
    private static void javabeanlist2json() {
        List<City> cityList = new ArrayList<City>();
        cityList.add(new City(1,"中山"));
        cityList.add(new City(2,"佛山"));
        Province province = new Province(1,"廣東",cityList);

        JSONArray jSONArray = JSONArray.fromObject(province);
        String jsonJAVA = jSONArray.toString();
        System.out.println(jsonJAVA);
        /* [ { "id":1, "name":"廣東" "cityList":[{"id":1,"name":"中山"},{"id":2,"name":"佛山"}], } ] */
    }
    private static void map2json() {

        List<City> cityList = new ArrayList<City>();
        cityList.add(new City(1,"中山"));
        cityList.add(new City(2,"佛山"));

        Map<String,Object> map = new LinkedHashMap<String,Object>();
        map.put("total",cityList.size());//表示集合的長度
        map.put("rows",cityList);//rows表示集合

        JSONArray jSONArray = JSONArray.fromObject(map);
        String jsonJAVA = jSONArray.toString();
        System.out.println(jsonJAVA);
        //[{"total":2,"rows":[{"id":1,"name":"中山"},{"id":2,"name":"佛山"}]}]

        jsonJAVA = jsonJAVA.substring(1,jsonJAVA.length()-1);
        System.out.println(jsonJAVA);
    }

}

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總結

把要解析成JSON 的javaBena對象、集合放進下面這段代碼便可！

 JSONArray jSONArray = JSONArray.fromObject(map);

不管放進去什麼，返回的都是數組

<script type="text/javascript"> $(function () { $('pre.prettyprint code').each(function () { var lines = $(this).text().split('\n').length; var $numbering = $('<ul/>').addClass('pre-numbering').hide(); $(this).addClass('has-numbering').parent().append($numbering); for (i = 1; i <= lines; i++) { $numbering.append($('<li/>').text(i)); }; $numbering.fadeIn(1700); }); }); </script>