Java Gson和谷歌
我有以下代码:Java Gson和谷歌,java,android,Java,Android,我有以下代码: public String test(){ URL url = null; try { url = new URL("http://api.heroesofnewerth.com/player_statistics/ranked/nickname/Hieratic/?token=0CZGH8ZI7UR8J2GN"); } catch (MalformedURLException e1) {
public String test(){
URL url = null;
try {
url = new URL("http://api.heroesofnewerth.com/player_statistics/ranked/nickname/Hieratic/?token=0CZGH8ZI7UR8J2GN");
} catch (MalformedURLException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
BufferedReader reader = null;
String x = "";
try {
reader = new BufferedReader(new InputStreamReader(url.openStream(), "UTF-8"));
for (String line; (line = reader.readLine()) != null;) {
System.out.println(line);
x = line;
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally{
if (reader !=null) try{reader.close();} catch (IOException ignore) {
}{}
}
JsonElement root = new JsonParser().parse(x);
return x;
}
}
现在我想将文本插入到下面的文本视图中
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_create_competetion);
TextView tv = (TextView) findViewById(R.id.competetion_text);
JsonCollector jc = new JsonCollector();
tv.setText(jc.test());
然而,当我尝试运行它时。我得到以下错误:
FATAL EXCEPTION: main
E/AndroidRuntime(1800): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.konkurrencesigner/com.example.konkurrencesigner.CreateCompetetion}: android.os.NetworkOnMainThreadException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
E/AndroidRuntime(1800): at android.app.ActivityThread.access$600(ActivityThread.java:141)
E/AndroidRuntime(1800): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
E/AndroidRuntime(1800): at android.os.Handler.dispatchMessage(Handler.java:99)
E/AndroidRuntime(1800): at android.os.Looper.loop(Looper.java:137)
E/AndroidRuntime(1800): at android.app.ActivityThread.main(ActivityThread.java:5039)
E/AndroidRuntime(1800): at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime(1800): at java.lang.reflect.Method.invoke(Method.java:511)
E/AndroidRuntime(1800): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
E/AndroidRuntime(1800): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
E/AndroidRuntime(1800): at dalvik.system.NativeStart.main(Native Method)
E/AndroidRuntime(1800): Caused by: android.os.NetworkOnMainThreadException
E/AndroidRuntime(1800): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117)
E/AndroidRuntime(1800): at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
E/AndroidRuntime(1800): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
E/AndroidRuntime(1800): at java.net.InetAddress.getAllByName(InetAddress.java:214)
E/AndroidRuntime(1800): at libcore.net.http.HttpConnection.<init>(HttpConnection.java:70)
E/AndroidRuntime(1800): at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50)
E/AndroidRuntime(1800): at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:340)
E/AndroidRuntime(1800): at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87)
E/AndroidRuntime(1800): at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
E/AndroidRuntime(1800): at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:316)
E/AndroidRuntime(1800): at libcore.net.http.HttpEngine.connect(HttpEngine.java:311)
E/AndroidRuntime(1800): at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290)
E/AndroidRuntime(1800): at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:240)
E/AndroidRuntime(1800): at libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:282)
致命异常:main
E/AndroidRuntime(1800):java.lang.RuntimeException:无法启动活动组件信息{com.example.konkurrencesigner/com.example.konkurrencesigner.createCompetition}:android.os.NetworkOnMainThreadException
在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)上
位于android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
E/AndroidRuntime(1800):位于android.app.ActivityThread.access$600(ActivityThread.java:141)
E/AndroidRuntime(1800):位于android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
E/AndroidRuntime(1800):位于android.os.Handler.dispatchMessage(Handler.java:99)
E/AndroidRuntime(1800):位于android.os.Looper.loop(Looper.java:137)
E/AndroidRuntime(1800):位于android.app.ActivityThread.main(ActivityThread.java:5039)
E/AndroidRuntime(1800):位于java.lang.reflect.Method.Invokenactive(本机方法)
E/AndroidRuntime(1800):位于java.lang.reflect.Method.invoke(Method.java:511)
E/AndroidRuntime(1800):位于com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
E/AndroidRuntime(1800):位于com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
E/AndroidRuntime(1800):位于dalvik.system.NativeStart.main(本机方法)
E/AndroidRuntime(1800):由以下原因引起:android.os.NetworkOnMainThreadException
E/AndroidRuntime(1800):位于android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117)
E/AndroidRuntime(1800):位于java.net.InetAddress.lookupHostByName(InetAddress.java:385)
E/AndroidRuntime(1800):位于java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
E/AndroidRuntime(1800):位于java.net.InetAddress.getAllByName(InetAddress.java:214)
E/AndroidRuntime(1800):位于libcore.net.http.HttpConnection(HttpConnection.java:70)
E/AndroidRuntime(1800):位于libcore.net.http.HttpConnection(HttpConnection.java:50)
E/AndroidRuntime(1800):位于libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:340)
E/AndroidRuntime(1800):位于libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87)
E/AndroidRuntime(1800):位于libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
E/AndroidRuntime(1800):位于libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:316)
E/AndroidRuntime(1800):位于libcore.net.http.HttpEngine.connect(HttpEngine.java:311)
E/AndroidRuntime(1800):位于libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290)
E/AndroidRuntime(1800):位于libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:240)
E/AndroidRuntime(1800):位于libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:282)
谁能告诉我为什么会这样
请注意,我已经在我的android清单中添加了以下行:
<uses-permission android:name="android.permission.INTERNET" />
您正在主线程上进行HTTP通信,这就是为什么会出现
NetworkOnMainThreadException
。在单独的线程中执行,使用将是一个理想的解决方案,下面是一个如何实现它的示例:
private TextView tv;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_create_competetion);
tv = (TextView) findViewById(R.id.competetion_text);
JsonCollector jc = new JsonCollector();
// Create and execute a new AsyncTask, the TextView will
// be updated asynchronously when the task has finished.
updateTextView();
}
private void updateTextView() {
new AsyncTask<Void, Void, String>() {
@Override
/* Runs on a separate thread */
protected String doInBackground(Void... params) {
String result = null;
BufferedReader reader = null;
try {
URL url = new URL("http://api.heroesofnewerth.com/player_statistics/ranked/nickname/Hieratic/?token=0CZGH8ZI7UR8J2GN");
reader = new BufferedReader(new InputStreamReader(url.openStream(), "UTF-8"));
for (String line; (line = reader.readLine()) != null;) {
System.out.println(line);
result = line;
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
// Ignore
}
}
}
return result;
}
@Override
/* Runs on the UI/Main thread when doInBackground()
* has finished */
protected void onPostExecute(String result) {
if(result != null) {
// Update the TextView only if we got a result
// from the HTTP request
tv.setText(result);
}
}
}.execute();
}
private TextView电视;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity\u create\u competition);
tv=(文本视图)findViewById(R.id.Competition_text);
JsonCollector jc=新的JsonCollector();
//创建并执行新的AsyncTask,TextView将
//在任务完成后异步更新。
updateTextView();
}
私有void updateTextView(){
新建异步任务(){
@凌驾
/*在单独的线程上运行*/
受保护字符串doInBackground(无效…参数){
字符串结果=null;
BufferedReader reader=null;
试一试{
URL=新URL(“http://api.heroesofnewerth.com/player_statistics/ranked/nickname/Hieratic/?token=0CZGH8ZI7UR8J2GN");
reader=新的BufferedReader(新的InputStreamReader(url.openStream(),“UTF-8”);
for(字符串行;(line=reader.readLine())!=null;){
系统输出打印项次(行);
结果=直线;
}
}捕获(例外e){
e、 printStackTrace();
}最后{
if(读卡器!=null){
试一试{
reader.close();
}捕获(IOE异常){
//忽略
}
}
}
返回结果;
}
@凌驾
/*doInBackground()时在UI/主线程上运行
*完成*/
受保护的void onPostExecute(字符串结果){
如果(结果!=null){
//仅当我们得到结果时才更新TextView
//从HTTP请求
tv.setText(结果);
}
}
}.execute();
}
您正在主线程上进行HTTP通信,这就是为什么会出现NetworkOnMainThreadException
。在单独的线程中执行,使用将是一个理想的解决方案,下面是一个如何实现它的示例:
private TextView tv;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_create_competetion);
tv = (TextView) findViewById(R.id.competetion_text);
JsonCollector jc = new JsonCollector();
// Create and execute a new AsyncTask, the TextView will
// be updated asynchronously when the task has finished.
updateTextView();
}
private void updateTextView() {
new AsyncTask<Void, Void, String>() {
@Override
/* Runs on a separate thread */
protected String doInBackground(Void... params) {
String result = null;
BufferedReader reader = null;
try {
URL url = new URL("http://api.heroesofnewerth.com/player_statistics/ranked/nickname/Hieratic/?token=0CZGH8ZI7UR8J2GN");
reader = new BufferedReader(new InputStreamReader(url.openStream(), "UTF-8"));
for (String line; (line = reader.readLine()) != null;) {
System.out.println(line);
result = line;
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
// Ignore
}
}
}
return result;
}
@Override
/* Runs on the UI/Main thread when doInBackground()
* has finished */
protected void onPostExecute(String result) {
if(result != null) {
// Update the TextView only if we got a result
// from the HTTP request
tv.setText(result);
}
}
}.execute();
}
private TextView电视;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity\u create\u competition);
tv=(文本视图)findViewById(R.id.Competition_text);
JsonCollector jc=新的JsonCollector();
//创建并执行新的AsyncTask,TextView将
//在任务完成后异步更新。
updateTextView();
}
私有void updateTextView(){
新建异步任务(){
@凌驾
/*在单独的线程上运行*/
保护