使用JSONObject解析
- 還是在Apache\htdocs目錄中新建一個(gè)get_data.json的文件癞尚,然后編輯一下代碼:
[{"id":"5","version":"5.5","name":"Clash of Clans"},
{"id":"6","version":"7.0","name":"Boom Beach"},
{"id":"7","version":"8.0","name":"Clash Royale"},]
- 在瀏覽器中輸入http://127.0.0.1/get_data.json,就會(huì)出現(xiàn)一下的頁(yè)面
瀏覽器中的JSON數(shù)據(jù).png
- 還是使用上一節(jié)中的知識(shí)澎埠,使用OkHttp進(jìn)行網(wǎng)絡(luò)連接虽缕,activity頁(yè)面就一個(gè)按鈕
public class MainActivity extends AppCompatActivity implements View.OnClickListener{
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button but = (Button)findViewById(R.id.but);
but.setOnClickListener(this);
}
@Override
public void onClick(View view) {
switch (view.getId()){
case R.id.but:
sendRequestOkHttp();
break;
default:
break;
}
}
private void sendRequestOkHttp(){
new Thread(new Runnable() {
@Override
public void run() {
try {
OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder()
// 指定訪問(wèn)的服務(wù)器地址是電腦本機(jī),使用的夜神
.url("http://172.17.100.2/get_data.json")
.build();
Response response = client.newCall(request).execute();
String responseData = response.body().string();
// 把返回的數(shù)據(jù)進(jìn)行解析
parseJSONWithJSONObject(responseData);
} catch (Exception e) {
e.printStackTrace();
}
}
}).start();
}
// 自定義方法進(jìn)行JSON數(shù)據(jù)的解析
private void parseJSONWithJSONObject(String jsonData){
try {
JSONArray jsonArray = new JSONArray(jsonData);
for (int i = 0;i<jsonArray.length();i++){
JSONObject jsonObject = jsonArray.getJSONObject(i);
String id = jsonObject.getString("id");
String name = jsonObject.getString("name");
String version = jsonObject.getString("version");
Log.d("MainActivity","id is "+id);
Log.d("MainActivity","name is "+name);
Log.d("MainActivity","version is "+version);
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
- 請(qǐng)求到的是
http://172.17.100.2/get_data.json
這個(gè)始藕,從服務(wù)器返回的是JSON數(shù)據(jù),調(diào)用parseJSONWithJSONObject()方法進(jìn)行解析 - 在這個(gè)方法中氮趋,把傳入的對(duì)象放入到JSONArray對(duì)象中伍派,進(jìn)行遍歷,取出每一個(gè)元素都是JSONArray對(duì)象剩胁,每個(gè)JSONArray對(duì)象中又包含id诉植,name,version這些數(shù)據(jù)昵观,這個(gè)時(shí)候使用getString()方法把這些數(shù)據(jù)取出
-
運(yùn)行程序晾腔,點(diǎn)擊按鈕就可以看到下面這些數(shù)據(jù)
json解析的數(shù)據(jù).png
使用GSON
使用JSONObject來(lái)解析JSON數(shù)據(jù)已經(jīng)非常簡(jiǎn)單了,但是這個(gè)GSON更加簡(jiǎn)單啊犬,
- 在項(xiàng)目中添加GSON庫(kù)的依賴灼擂,編輯app/build.gradlew嗯見(jiàn),在dependencies中添加內(nèi)容
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.android.support:appcompat-v7:26.1.0'
implementation 'com.android.support.constraint:constraint-layout:1.0.2'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.1'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
compile 'com.squareup.okhttp3:okhttp:3.4.1'
// 添加這一行代碼
compile 'com.google.code.gson:gson:2.7'
}
- GSON之所以這么簡(jiǎn)單觉至,是因?yàn)榭梢詫son格式的字符串自動(dòng)映射成一個(gè)對(duì)象剔应,從而不需要我們手動(dòng)去編碼進(jìn)行解析,比如有這一段json
{"name":"TOM","age":20}
- 這個(gè)時(shí)候就可以定義一個(gè)Person類语御,并加入name和age這兩個(gè)字段峻贮,然后簡(jiǎn)單地調(diào)用下面的代碼就可以將json數(shù)據(jù)自動(dòng)解析成person對(duì)象了
Gson gson = new Gson();
Person person = gson.fromJson(jsonData,Person.class);
- 如果解析的一段JSON數(shù)組就會(huì)稍微麻煩一點(diǎn),這個(gè)時(shí)候需要借助TypeToken將期望解析成的數(shù)據(jù)類型傳入到fromJson()方法中应闯,如下
List<Person> people = gson.fromJson(jsonData,new TYpeToken<List<Person>>(){}.getType());
- 基本就是這樣用的纤控,接下來(lái)實(shí)戰(zhàn)一下就可以了,新建一個(gè)app類碉纺,添加3個(gè)字段
public class App {
private String id;
private String name;
private String version;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getVersion() {
return version;
}
public void setVersion(String version) {
this.version = version;
}
}
- 修改MainActiviy中的代碼
public class MainActivity extends AppCompatActivity implements View.OnClickListener{
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button but = (Button)findViewById(R.id.but);
but.setOnClickListener(this);
}
@Override
public void onClick(View view) {
if (view.getId() == R.id.but){
sendRequestOkHttp();
}
}
private void sendRequestOkHttp(){
new Thread(new Runnable() {
@Override
public void run() {
try {
OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder()
// 指定訪問(wèn)的服務(wù)器地址是電腦本機(jī)船万,此時(shí)用的是
.url("http://10.0.2.2/get_data.json")
.build();
Response response = client.newCall(request).execute();
String responseData = response.body().string();
// 把返回的數(shù)據(jù)進(jìn)行解析
parseJSONWithJSONObject(responseData);
} catch (Exception e) {
e.printStackTrace();
}
}
}).start();
}
// 自定義方法進(jìn)行JSON數(shù)據(jù)的解析
private void parseJSONWithJSONObject(String jsonData){
Gson gson = new Gson();
List<App> applist = gson.fromJson(jsonData,new TypeToken<List<App>>(){}.getType());
for (App app:applist){
Log.d("MainActivity","id is "+app.getId());
Log.d("MainActivity","name is "+app.getName());
Log.d("MainActivity","version is "+app.getVersion());
}
}
}
- 這個(gè)時(shí)候運(yùn)行程序细层,你會(huì)看到和上面一樣的打印日志