用Gson解析复杂的天气Json数据

对于结构简单的Json数据用android集成的JSONArray和JSONObject就可以解析出来，当遇到比较比较复杂的数据时可以考虑用Gson，最近刚好在做一个关于天气的app，要从如下Json数据中得到自己想要的数据。Json数据如下：

{
"error_code":0,
"reason":"成功",
"result":{
"sk":{
"temp":"27",
"wind_direction":"西南风",
"wind_strength":"3级",
"humidity":"44",
"time":"19:42"
},
"today":{
"city":"北京",
"date_y":"2015年08月18日",
"week":"星期二",
"temperature":"20~30",
"weather":"雷阵雨",
"fa":"04",
"fb":"21",
"wind":"无持续风向 微风",
"dressing_index":"热",
"dressing_advice":"天气热，建议着短裙、短裤、短薄外套、T恤等夏季服装。",
"uv_index":"弱",
"comfort_index":"--",
"wash_index":"不宜",
"travel_index":"较不宜",
"exercise_index":"较不宜",
"drying_index":"--"
},
"future":[
{
"temperature":"20~28",
"weather":"雷阵雨",
"fa":"04",
"fb":"04",
"wind":"无持续风向 微风",
"week":"星期三",
"date":"20150819"
},
{
"temperature":"22~33",
"weather":"多云",
"fa":"01",
"fb":"01",
"wind":"无持续风向 微风",
"week":"星期四",
"date":"20150820"
},
{
"temperature":"21~31",
"weather":"雷阵雨",
"fa":"04",
"fb":"04",
"wind":"无持续风向 微风",
"week":"星期五",
"date":"20150821"
},
{
"temperature":"20~29",
"weather":"雷阵雨",
"fa":"04",
"fb":"03",
"wind":"无持续风向 微风",
"week":"星期六",
"date":"20150822"
},
{
"temperature":"20~28",
"weather":"阵雨",
"fa":"03",
"fb":"03",
"wind":"无持续风向 微风",
"week":"星期日",
"date":"20150823"
},
{
"temperature":"20~29",
"weather":"阴",
"fa":"02",
"fb":"02",
"wind":"无持续风向 微风",
"week":"星期一",
"date":"20150824"
}
]
}
}

方法是写一个序列化的Bean类，需要注意以下几点

1、内部嵌套的类必须是static的，要不然解析会出错；

2、类里面的属性名必须跟Json字段里面的Key是一模一样的；

3、内部嵌套的用[]括起来的部分是一个List，所以定义为 public List<B> b，而只用{}嵌套的就定义为 public C c。

根据上面Json数据最外层的的结构可分为三个对象error_code、reason、result，注意属性名和Json里是一样的：

public class Status {
private Integer error_code;
private String reason;
private MyResult result;

public Integer getError_code() {
return error_code;
}

public void setError_code(Integer error_code) {
this.error_code = error_code;
}

public String getReason() {
return reason;
}

public void setReason(String reason) {
this.reason = reason;
}

public MyResult getResult() {
return result;
}

public void setResult(MyResult result) {
this.result = result;
}
}

其中result里还有两个对象Sk、today和一个数组future，数组用List集合包装起来：

public class MyResult {
private MySk sk;
private MyToday today;
private List<MyFuture> future;

public MySk getSk() {
return sk;
}

public void setSk(MySk sk) {
this.sk = sk;
}

public MyToday getToday() {
return today;
}

public void setToday(MyToday today) {
this.today = today;
}

public List<MyFuture> getFuture() {
return future;
}

public void setFuture(List<MyFuture> future) {
this.future = future;
}
}

如此类推，sk类

public class MySk {
private String temp;
private String wind_direction;
private String wind_strength;
private String humidity;
private String time;

public String getTemp() {
return temp;
}

public void setTemp(String temp) {
this.temp = temp;
}

public String getWind_direction() {
return wind_direction;
}

public void setWind_direction(String wind_direction) {
this.wind_direction = wind_direction;
}

public String getWind_strength() {
return wind_strength;
}

public void setWind_strength(String wind_strength) {
this.wind_strength = wind_strength;
}

public String getHumidity() {
return humidity;
}

public void setHumidity(String humidity) {
this.humidity = humidity;
}

public String getTime() {
return time;
}

public void setTime(String time) {
this.time = time;
}
}

today类：

public class MyToday {
private String city;
private String date_y;
private String week;
private String temperature;
private String weather;
private String fa;
private String fb;
private String wind;
private String dressing_index;
private String dressing_advice;
private String uv_index;
private String comfort_index;
private String wash_index;
private String travel_index;
private String exercise_index;
private String drying_index;

public String getCity() {
return city;
}

public void setCity(String city) {
this.city = city;
}

public String getDate_y() {
return date_y;
}

public void setDate_y(String date_y) {
this.date_y = date_y;
}

public String getWeek() {
return week;
}

public void setWeek(String week) {
this.week = week;
}

public String getTemperature() {
return temperature;
}

public void setTemperature(String temperature) {
this.temperature = temperature;
}

public String getWeather() {
return weather;
}

public void setWeather(String weather) {
this.weather = weather;
}

public String getFa() {
return fa;
}

public void setFa(String fa) {
this.fa = fa;
}

public String getFb() {
return fb;
}

public void setFb(String fb) {
this.fb = fb;
}

public String getWind() {
return wind;
}

public void setWind(String wind) {
this.wind = wind;
}

public String getDressing_index() {
return dressing_index;
}

public void setDressing_index(String dressing_index) {
this.dressing_index = dressing_index;
}

public String getDressing_advice() {
return dressing_advice;
}

public void setDressing_advice(String dressing_advice) {
this.dressing_advice = dressing_advice;
}

public String getUv_index() {
return uv_index;
}

public void setUv_index(String uv_index) {
this.uv_index = uv_index;
}

public String getComfort_index() {
return comfort_index;
}

public void setComfort_index(String comfort_index) {
this.comfort_index = comfort_index;
}

public String getWash_index() {
return wash_index;
}

public void setWash_index(String wash_index) {
this.wash_index = wash_index;
}

public String getTravel_index() {
return travel_index;
}

public void setTravel_index(String travel_index) {
this.travel_index = travel_index;
}

public String getExercise_index() {
return exercise_index;
}

public void setExercise_index(String exercise_index) {
this.exercise_index = exercise_index;
}

public String getDrying_index() {
return drying_index;
}

public void setDrying_index(String drying_index) {
this.drying_index = drying_index;
}
}

future类：

public class MyFuture {
private String temperature;
private String weather;
private String fa;
private String fb;
private String wind;
private String week;
private String date;

public String getTemperature() {
return temperature;
}

public void setTemperature(String temperature) {
this.temperature = temperature;
}

public String getWeather() {
return weather;
}

public void setWeather(String weather) {
this.weather = weather;
}

public String getFa() {
return fa;
}

public void setFa(String fa) {
this.fa = fa;
}

public String getFb() {
return fb;
}

public void setFb(String fb) {
this.fb = fb;
}

public String getWind() {
return wind;
}

public void setWind(String wind) {
this.wind = wind;
}

public String getWeek() {
return week;
}

public void setWeek(String week) {
this.week = week;
}

public String getDate() {
return date;
}

public void setDate(String date) {
this.date = date;
}
}

这样就完成了全部Bean类的编码，然后是如何解析自己想要的数据，其中的Gson和Volley要导入jar包，主界面是一个Button和一个Testview，点击按钮加载自己要的数据并显示，不要忘了在Manifest中加入internet的权限

public class MainActivity extends AppCompatActivity {

private TextView textView;
private RequestQueue queue;
private Button button;
private Gson gson;
private String url;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//Volley实例化
queue = Volley.newRequestQueue(this);
textView = (TextView) findViewById(R.id.content_text);
button = (Button) findViewById(R.id.button);

gson = new Gson();

try {
//这个URL是自己在网上申请的一个天气接口
String addressCode = URLEncoder.encode("北京", "UTF-8");
url = "http://apis.haoservice.com/weather?cityname=" + addressCode + "&key=b2827fdb1ceb477684fdd442b0100fa9";
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}

//Volley的StringRequest方法
final StringRequest stringRequest = new StringRequest(url,
new Response.Listener<String>() {
@Override
public void onResponse(String s) {
if (!TextUtils.isEmpty(s)) {
Log.d("TAG", s);
System.out.println(s);
Status status = gson.fromJson(s, Status.class);
MyResult myResult = status.getResult();
MyToday myToday = myResult.getToday();
//这是我想要得到的数据城市+日期+温度+天气情况+穿衣建议
String msg = myToday.getCity() + myToday.getDate_y() + myToday.getTemperature() + myToday.getWeather() + "\n" + myToday.getDressing_advice();
textView.setText(msg);
} else {
Toast.makeText(MainActivity.this, "加载失败", Toast.LENGTH_SHORT).show();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError volleyError) {
Log.e("TAG", volleyError.getMessage(), volleyError);
}
});

button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//点击触发下载
queue.add(stringRequest);

}
});

}

}

结果如下