gson的JsonTreeReader和JsonReader一起使用代码详解例子

package com.app.json;import java.io.IOException;import java.util.HashMap;import java.util.Map;import com.google.gson.Gson;import com.google.gson.JsonElement;import com.google.gson.JsonParser;import com.google.gson.internal.bind.JsonTreeReader;import com.google.gson.stream.JsonReader;/** *@DEMO:napp *@Author:jilongliang *@Date:2013-7-21 */public class GsonTreeReader {private static Gson gson = new Gson();public static void main(String[] args) throws Exception {/**  * 组装address对象的数据  */ Map<String, String> address = new HashMap <String, String>();  address.put("province", "广东省"); address.put("city", "广州市"); address.put("district", "天河区"); address.put("street", "棠东");  /**  * 组装users对象的数据  */ Map<String, String> users = new HashMap <String, String>();  users.put("username", "liangjilong"); users.put("age", "25"); users.put("tel", "12396878"); users.put("email", "jilongliang@sina.com");   Map<Object, Object> listsObj = new HashMap <Object, Object>();  listsObj.put("address",address);//address节点 listsObj.put("users",users);//users节点  Object obj=listsObj;//转换成对象  Map<Object, Object> info = new HashMap <Object, Object>();  info.put("info", obj);//json的根节点          String json=gson.toJson(info);//转换成json数据        System.out.println(json);//打印json数据readJsonData(json);}/**JsonReader * JsonTreeReader从文件读取json数据 * @param in * @throws Exception */public static void readJsonData(String json) throws Exception {//创建JsonParser对象JsonParser parser = new JsonParser();JsonElement jsonEl = parser.parse(json);//创建一个JsonTreeReader对像用JsonReaderJsonReader reader = new JsonTreeReader(jsonEl);try {reader.beginObject();String tagName = reader.nextName();if (tagName.equals("info")) {readInfo(reader);}reader.endObject();} finally {reader.close();}}/** * 读取json的父(根,第一个)节点 * @param reader * @throws Exception */public static void readInfo(JsonReader reader) throws Exception {reader.beginObject();while (reader.hasNext()) {String tagName = reader.nextName();if (tagName.equals("address")) {readAddress(reader);} else if (tagName.equals("users")) {readUsers(reader);} }reader.endObject();}/** * 读取用户信息值 * @param reader * @throws IOException */public static void readUsers(JsonReader reader) throws IOException {reader.beginObject();while (reader.hasNext()) {String tag = reader.nextName();if (tag.equals("username")) {String username = reader.nextString();System.out.println("用户名:" + username);} else if (tag.equals("email")) {String email = reader.nextString();System.out.println("Email:" + email);} else if (tag.equals("tel")) {String tel = reader.nextString();System.out.println("电话:" + tel);}else if (tag.equals("age")) {String age = reader.nextString();System.out.println("年龄:" + age);} else {reader.skipValue();//忽略值/跳过break}}reader.endObject();}/** * 读取地区值 * @param reader * @throws IOException */public static void readAddress(JsonReader reader) throws IOException {reader.beginObject();while (reader.hasNext()) {String tag = reader.nextName();if (tag.equals("province")) {String province = reader.nextString();System.out.println("省份:" + province);} else if (tag.equals("city")) {String city = reader.nextString();System.out.println("街道:" + city);} else if (tag.equals("street")) {String street = reader.nextString();System.out.println("街道:" + street);}else if (tag.equals("district")) {String district = reader.nextString();System.out.println("区:" + district);} else {reader.skipValue();//忽略值/跳过break}}reader.endObject();}}

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package com.app.entity.duapp;import java.io.Serializable;import com.google.gson.annotations.Expose;/** * Gson gson=new GsonBuilder().excludeFieldsWithoutExposeAnnotation().create(); * 创建Gson对象,没有@Expose注释的属性将不会被序列化 * serialize序列化 默认 true * deserialize反序列化 默认 true */public class Address implements Serializable{@Expose(serialize=false)// 序列化  /Address类已经序列化private int id;@Expose(deserialize=false)// 反序列化private String country;//国家private String province;//省份private String city;//城市private String street;//街道private String district;//地区private String cityCode;//邮政编码private String streetNumber;//街道号public Address() {}public Address(int id,String country) {this.id=id;this.country=country;}public String getCityCode() {return cityCode;}public void setCityCode(String cityCode) {this.cityCode = cityCode;}public String getStreetNumber() {return streetNumber;}public void setStreetNumber(String streetNumber) {this.streetNumber = streetNumber;}public String getStreet() {return street;}public void setStreet(String street) {this.street = street;}public String getDistrict() {return district;}public void setDistrict(String district) {this.district = district;}public String getCity() {return city;}public void setCity(String city) {this.city = city;}public String getProvince() {return province;}public void setProvince(String province) {this.province = province;}public int getId() {return id;}public void setId(int id) {this.id = id;}public String getCountry() {return country;}public void setCountry(String country) {this.country = country;}}

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