Android - 手动解析Json数据（学习笔记一）

腾讯课堂 —> 尚硅谷Android视频《JSON解析》

布局

activity_main.xml <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/bt1" android:text="json格式的字符串转Java对象"/> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/bt2" android:text="json格式的字符串转Java对象的list"/> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/bt3" android:text="复杂json数据解析"/> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/bt4" android:text="特殊json数据解析"/> <ScrollView android:layout_width="match_parent" android:layout_height="match_parent"> <LinearLayout android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="显示原始数据" android:textColor="@color/colorAccent"/> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/tvJson"/> <View android:layout_width="match_parent" android:layout_height="1.5dp" android:background="#A9A9A9"/> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="解析后的数据" android:textColor="@color/colorAccent"/> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/tvJava"/> </LinearLayout> </ScrollView>

先行准备

1. 创建一个ShopInfo.java（快捷键：Alt+Insert）

/** * User: hu * Date: 2020/9/3 * title: 商店的实体类 */ public class ShopInfo { private int id; private String name; private double price; private String imagePath; public ShopInfo(int id, String name, double price, String imagePath) { this.id = id; this.name = name; this.price = price; this.imagePath = imagePath; } public ShopInfo() { } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public double getPrice() { return price; } public void setPrice(double price) { this.price = price; } public String getImagePath() { return imagePath; } public void setImagePath(String imagePath) { this.imagePath = imagePath; } @Override public String toString() { return "ShopInfo{" + "\n\tid=" + id + ", \n\tname='" + name + '\'' + ", \n\tprice=" + price + ", \timagePath='" + imagePath + '\'' + '}'; } }

2. 创建一个DataInfo.java（安装插件GsonFormat）

Android Studio 安装插件GsonFormat (Json数据转换实体类)

import java.util.List; /** * User: hu * Date: 2020/9/3 * title: DataInfo实体类 */ public class DataInfo { /** * data : {"count":5,"items":[{"id":45,"title":"小麦","titile":"大米"},{"id":134,"titile":"大米"},{"id":115,"title":"小米"},{"id":15,"title":"苹果"},{"id":68,"title":"三只松鼠"}]} * rs_code : 1000 * rs_msg : success */ private DataBean data; private String rs_code; private String rs_msg; @Override public String toString() { return "DataInfo{" + "\ndata=" + data + ", \nrs_code='" + rs_code + '\'' + ", \nrs_msg='" + rs_msg + '\'' + '}'; } public DataBean getData() { return data; } public void setData(DataBean data) { this.data = data; } public String getRs_code() { return rs_code; } public void setRs_code(String rs_code) { this.rs_code = rs_code; } public String getRs_msg() { return rs_msg; } public void setRs_msg(String rs_msg) { this.rs_msg = rs_msg; } public static class DataBean { /** * count : 5 * items : [{"id":45,"title":"小麦"},{"id":134,"titile":"大米"},{"id":115,"title":"小米"},{"id":15,"title":"苹果"},{"id":68,"title":"三只松鼠"}] */ private int count; private List<ItemsBean> items; @Override public String toString() { return "DataBean{" + "\ncount=" + count + ", \nitems=" + items + '}'; } public int getCount() { return count; } public void setCount(int count) { this.count = count; } public List<ItemsBean> getItems() { return items; } public void setItems(List<ItemsBean> items) { this.items = items; } public static class ItemsBean { /** * id : 45 * title : 小麦 * titile : 大米 */ private int id; private String title; private String titile; @Override public String toString() { return "\n\tItemsBean{" + "id=" + id + ", title='" + title + '\'' + '}'; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public String getTitile() { return titile; } public void setTitile(String titile) { this.titile = titile; } } } }

3. 创建一个FilmInfo.java

import java.util.List; /** * User: hu * Time: 19:59 * title: */ public class FilmInfo { private int code; private List<FilmBean> list; @Override public String toString() { return "FilmInfo{" + "\ncode=" + code + ", \nlist=" + list + '}'; } public int getCode() { return code; } public void setCode(int code) { this.code = code; } public List<FilmBean> getList() { return list; } public void setList(List<FilmBean> list) { this.list = list; } public static class FilmBean{ private String aid; private String author; private int coins; private String copyright; private String create; @Override public String toString() { return "\n\tFilmBean{" + "\n\t\taid='" + aid + '\'' + ", \n\t\tauthor='" + author + '\'' + ", \n\t\tcoins=" + coins + ", \n\t\tcopyright='" + copyright + '\'' + ", \n\t\tcreate='" + create + '\'' + '}'; } public String getAid() { return aid; } public void setAid(String aid) { this.aid = aid; } public String getAuthor() { return author; } public void setAuthor(String author) { this.author = author; } public int getCoins() { return coins; } public void setCoins(int coins) { this.coins = coins; } public String getCopyright() { return copyright; } public void setCopyright(String copyright) { this.copyright = copyright; } public String getCreate() { return create; } public void setCreate(String create) { this.create = create; } } }

一、json格式的字符串转Java对象

Json数据 { "id":2,"name":"小米煎饼", "price":11.2, "imagePath":"https://pics3.baidu.com/feed/960a304e251f95caf3db58a3973c4639670952af.jpeg?token=6d173c37740f4bcd401c8c44632b87d6" } MainActivity.java //json格式的字符串转Java对象 bt1.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { jsonToJavaObjectByNative(); } }); //json格式的字符串转Java对象 private void jsonToJavaObjectByNative(){ //获取或创建json数据 String json = "{\n" + "\t\"id\":2,\"name\":\"小米煎饼\",\n" + "\t\"price\":11.2,\n" + "\t\"imagePath\":\"https://pics3.baidu.com/feed/960a304e251f95caf3db58a3973c4639670952af.jpeg?token=6d173c37740f4bcd401c8c44632b87d6\"\n" + "}"; //解析json JSONObject jsonObject = null; ShopInfo shopInfo = null; try { jsonObject = new JSONObject(json); int id1 = jsonObject.getInt("id"); //方法一：这个有可能出现空指针异常 int id2 = jsonObject.optInt("id"); //方法二：推荐使用这个方法 String name = jsonObject.optString("name"); double price = jsonObject.optDouble("price"); String imagePath = jsonObject.optString("imagePath"); shopInfo = new ShopInfo(id2, name, price, imagePath); } catch (JSONException e) { e.printStackTrace(); } //显示Json数据 tvJson.setText(json); tvJava.setText(shopInfo.toString()); } 实现图

二、json格式的字符串转Java对象的list

Json数据 [ { "id":1,"name":"小米煎饼", "price":11.2, "imagePath":"https://pics3.baidu.com/feed/960a304e251f95caf3db58a3973c4639670952af.jpeg?token=6d173c37740f4bcd401c8c44632b87d6" }, { "id":2,"name":"芒果干", "price":10.2, "imagePath":"https://pics3.baidu.com/feed/960a304e251f95caf3db58a3973c4639670952af.jpeg?token=6d173c37740f4bcd401c8c44632b87d6" } ] MainActivity.java //json格式的字符串转Java对象的list bt2.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { jsonToJavaListByNative(); } }); //json格式的字符串转Java对象的list private void jsonToJavaListByNative() { //获取或创建json数据 String json = "[\n" + "\t{\n" + "\t\t\"id\":1,\"name\":\"小米煎饼\",\n" + "\t\t\"price\":11.2,\n" + "\t\t\"imagePath\":\"https://pics3.baidu.com/feed/960a304e251f95caf3db58a3973c4639670952af.jpeg?token=6d173c37740f4bcd401c8c44632b87d6\"\n" + "\t},\n" + "\t{\n" + "\t\t\"id\":2,\"name\":\"芒果干\",\n" + "\t\t\"price\":10.2,\n" + "\t\t\"imagePath\":\"https://pics3.baidu.com/feed/960a304e251f95caf3db58a3973c4639670952af.jpeg?token=6d173c37740f4bcd401c8c44632b87d6\"\n" + "\t}\n" + "]"; List<ShopInfo> shops = new ArrayList<>(); //解析json try { JSONArray jsonArray = new JSONArray(json); for (int i = 0; i < jsonArray.length(); i++){ JSONObject jsonObject = jsonArray.getJSONObject(i); //避免空指针异常 if (jsonObject != null){ int id = jsonObject.getInt("id"); String name = jsonObject.optString("name"); double price = jsonObject.optDouble("price"); String imagePath = jsonObject.optString("imagePath"); //封装Java对象 ShopInfo shopInfo = new ShopInfo(id, name, price, imagePath); shops.add(shopInfo); } } } catch (JSONException e) { e.printStackTrace(); } //显示Json数据 tvJson.setText(json); tvJava.setText(shops.toString()); } 实现图

三、复杂json数据解析

Json数据 { "data":{ "count":5, "items":[ { "id":45, "title":"小麦" }, { "id":134, "title":"大米" }, { "id":115, "title":"小米" }, { "id":15, "title":"苹果" }, { "id":68, "title":"三只松鼠" } ] }, "rs_code":"1000", "rs_msg":"success" } MainActivity.java //复杂json数据解析 bt3.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { jsonToJavaOfComplex(); } }); //复杂json数据解析 private void jsonToJavaOfComplex() { //获取或创建json数据 String json = "{\n" + "\t\"data\":{\n" + "\t\t\"count\":5,\n" + "\t\t\"items\":[\n" + "\t\t\t{\n" + "\t\t\t\t\"id\":45,\n" + "\t\t\t\t\"title\":\"小麦\"\n" + "\t\t\t},\n" + "\t\t\t{\n" + "\t\t\t\t\"id\":134,\n" + "\t\t\t\t\"titile\":\"大米\"\n" + "\t\t\t},\n" + "\t\t\t{\n" + "\t\t\t\t\"id\":115,\n" + "\t\t\t\t\"title\":\"小米\"\n" + "\t\t\t},\n" + "\t\t\t{\n" + "\t\t\t\t\"id\":15,\n" + "\t\t\t\t\"title\":\"苹果\"\n" + "\t\t\t},\n" + "\t\t\t{\n" + "\t\t\t\t\"id\":68,\n" + "\t\t\t\t\"title\":\"三只松鼠\"\n" + "\t\t\t}\n" + "\t\t]\n" + "\t},\n" + "\t\"rs_code\":\"1000\",\n" + "\t\"rs_msg\":\"success\"\n" + "}"; //封装Java对象 DataInfo dataInfo = new DataInfo(); //解析json try { JSONObject jsonObject = new JSONObject(json); //第一层解析 JSONObject data = jsonObject.optJSONObject("data"); String rs_code = jsonObject.optString("rs_code"); String rs_msg = jsonObject.optString("rs_msg"); //第一层封装 dataInfo.setRs_code(rs_code); dataInfo.setRs_msg(rs_msg); DataInfo.DataBean dataBean = new DataInfo.DataBean(); dataInfo.setData(dataBean); //第二层解析 int count = data.optInt("count"); JSONArray items = data.getJSONArray("items"); //第二层封装 dataBean.setCount(count); List<DataInfo.DataBean.ItemsBean> itemsBean = new ArrayList<>(); dataBean.setItems(itemsBean); //第三层解析 for (int i = 0; i < items.length(); i++){ JSONObject jsonObject1 = items.optJSONObject(i); if (jsonObject1 != null){ int id = jsonObject1.optInt("id"); String title = jsonObject1.optString("title"); //第三层封装 DataInfo.DataBean.ItemsBean bean = new DataInfo.DataBean.ItemsBean(); bean.setId(id); bean.setTitle(title); itemsBean.add(bean); } } } catch (JSONException e) { e.printStackTrace(); } //显示Json数据 tvJson.setText(json); tvJava.setText(dataInfo.toString()); } 实现图

四、特殊json数据解析

json数据 { "code":0, "list":{ "0":{ "aid":"6008965", "author":"滴滴滴", "coins":170, "copyright":"Copy", "create":"2020-09-25 19:25" }, "1":{ "aid":"12532654", "author":"啧啧啧", "coins":404, "copyright":"Copy", "create":"2020-09-26 20:25" } } } //特殊json数据解析 bt4.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { jsonToJavaOfSpecial(); } }); //特殊json数据解析 private void jsonToJavaOfSpecial() { //获取或创建json数据 String json = "{\n" + "\t\"code\":0,\n" + "\t\"list\":{\n" + "\t\t\"0\":{\n" + "\t\t\t\"aid\":\"6008965\",\n" + "\t\t\t\"author\":\"滴滴滴\",\n" + "\t\t\t\"coins\":170,\n" + "\t\t\t\"copyright\":\"Copy\",\n" + "\t\t\t\"create\":\"2020-09-25 19:25\"\n" + "\t\t},\n" + "\t\t\"1\":{\t\t\t\n" + "\t\t\t\"aid\":\"12532654\",\n" + "\t\t\t\"author\":\"啧啧啧\",\n" + "\t\t\t\"coins\":404,\n" + "\t\t\t\"copyright\":\"Copy\",\n" + "\t\t\t\"create\":\"2020-09-26 20:25\"\n" + "\t\t}\n" + "\t}\n" + "}"; //创建封装java对象 FilmInfo filmInfo = new FilmInfo(); //解析json try { JSONObject jsonObject = new JSONObject(json); //第一层解析 int code = jsonObject.optInt("code"); JSONObject list = jsonObject.optJSONObject("list"); //第一层封装 filmInfo.setCode(code); List<FilmInfo.FilmBean> lists = new ArrayList<>(); filmInfo.setList(lists); //第二层解析 for (int i = 0; i < list.length(); i++){ JSONObject jsonObject1 = list.optJSONObject(i + ""); if (jsonObject1 != null){ String aid = jsonObject1.optString("aid"); String author = jsonObject1.optString("author"); int coins = jsonObject1.optInt("coins"); String copyright = jsonObject1.optString("copyright"); String create = jsonObject1.optString("create"); //第二层封装 FilmInfo.FilmBean filmBean = new FilmInfo.FilmBean(); filmBean.setAid(aid); filmBean.setAuthor(author); filmBean.setCoins(coins); filmBean.setCopyright(copyright); filmBean.setCreate(create); lists.add(filmBean); } } } catch (JSONException e) { e.printStackTrace(); } //显示Json数据 tvJson.setText(json); tvJava.setText(filmInfo.toString()); } 实现图