google places api android返回java..lang.nullpointerexception

我试图实现GooglePlacesAPI，但它一直发送java.lang.nullpointerexception。我从这个网站上得到了代码：

根据我所能收集到的信息，我将URL发送到某个Google服务器并得到响应。该响应是JSON格式的，然后被解析为我的特定“位置”对象。我认为在这个解析阶段会发生一些事情。在站点中，他们使用了一些中间对象PlacesList，我认为这就是问题所在，因为我不理解它

砂石：

        public class PlacesList implements Serializable {

    @Key
    public String status;

    @Key
    public List<Locations> results;

主要来自主要活动 System.err（6447）：atcom.example.mapmapreach.MainActivity.onCreate（MainActivity.java:86）==

以下是日志：

              04-26 19:10:52.839: W/System.err(4156): android.os.NetworkOnMainThreadException
              04-26 19:10:52.899: W/System.err(4156):   at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117)
              04-26 19:10:52.899: W/System.err(4156):   at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
              04-26 19:10:52.899: W/System.err(4156):   at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
              04-26 19:10:52.899: W/System.err(4156):   at java.net.InetAddress.getAllByName(InetAddress.java:214)
              04-26 19:10:52.899: W/System.err(4156):   at libcore.net.http.HttpConnection.<init>(HttpConnection.java:70)
              04-26 19:10:52.899: W/System.err(4156):   at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50)
              04-26 19:10:52.899: W/System.err(4156):   at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:340)
              04-26 19:10:52.899: W/System.err(4156):   at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87)
              04-26 19:10:52.899: W/System.err(4156):   at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
              04-26 19:10:52.899: W/System.err(4156):   at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:316)
              04-26 19:10:52.899: W/System.err(4156):   at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.makeSslConnection(HttpsURLConnectionImpl.java:461)
             04-26 19:10:52.899: W/System.err(4156):    at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.connect(HttpsURLConnectionImpl.java:433)
             04-26 19:10:52.899: W/System.err(4156):    at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290)
             04-26 19:10:52.899: W/System.err(4156):    at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:240)
             04-26 19:10:52.899: W/System.err(4156):    at libcore.net.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:81)
             04-26 19:10:52.899: W/System.err(4156):    at libcore.net.http.HttpsURLConnectionImpl.connect(HttpsURLConnectionImpl.java:165)
             04-26 19:10:52.899: W/System.err(4156):    at com.google.api.client.http.javanet.NetHttpRequest.execute(NetHttpRequest.java:88)
             04-26 19:10:52.899: W/System.err(4156):    at com.google.api.client.http.HttpRequest.execute(HttpRequest.java:814)
             04-26 19:10:52.909: W/System.err(4156):    at com.example.mapmapagain.PlaceSearch.search(PlaceSearch.java:64)
             04-26 19:10:52.909: W/System.err(4156):    at com.example.mapmapagain.MainActivity.onCreate(MainActivity.java:86)
             04-26 19:10:52.909: W/System.err(4156):    at android.app.Activity.performCreate(Activity.java:5104)
             04-26 19:10:52.909: W/System.err(4156):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
             04-26 19:10:52.909: W/System.err(4156):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
             04-26 19:10:52.909: W/System.err(4156):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
             04-26 19:10:52.909: W/System.err(4156):    at android.app.ActivityThread.access$600(ActivityThread.java:141)
             04-26 19:10:52.909: W/System.err(4156):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
             04-26 19:10:52.909: W/System.err(4156):    at android.os.Handler.dispatchMessage(Handler.java:99)
             04-26 19:10:52.909: W/System.err(4156):    at android.os.Looper.loop(Looper.java:137)
             04-26 19:10:52.909: W/System.err(4156):    at android.app.ActivityThread.main(ActivityThread.java:5039)
             04-26 19:10:52.909: W/System.err(4156):    at java.lang.reflect.Method.invokeNative(Native Method)
             04-26 19:10:52.909: W/System.err(4156):    at java.lang.reflect.Method.invoke(Method.java:511)
             04-26 19:10:52.909: W/System.err(4156):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
             04-26 19:10:52.909: W/System.err(4156):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
             04-26 19:10:52.909: W/System.err(4156):    at dalvik.system.NativeStart.main(Native Method)

04-26 19:10:52.839:W/System.err（4156）：android.os.NetworkOnMainThreadException
04-26 19:10:52.899:W/System.err（4156）：在android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork（StrictMode.java:1117）
04-26 19:10:52.899:W/System.err（4156）：位于java.net.InetAddress.lookupHostByName（InetAddress.java:385）
04-26 19:10:52.899:W/System.err（4156）：位于java.net.InetAddress.getAllByNameImpl（InetAddress.java:236）
04-26 19:10:52.899:W/System.err（4156）：位于java.net.InetAddress.getAllByName（InetAddress.java:214）
04-26 19:10:52.899:W/System.err（4156）：位于libcore.net.http.HttpConnection.（HttpConnection.java:70）
04-26 19:10:52.899:W/System.err（4156）：位于libcore.net.http.HttpConnection.（HttpConnection.java:50）
04-26 19:10:52.899:W/System.err（4156）：位于libcore.net.http.HttpConnection$Address.connect（HttpConnection.java:340）
04-26 19:10:52.899:W/System.err（4156）：位于libcore.net.http.HttpConnectionPool.get（HttpConnectionPool.java:87）
04-26 19:10:52.899:W/System.err（4156）：位于libcore.net.http.HttpConnection.connect（HttpConnection.java:128）
04-26 19:10:52.899:W/System.err（4156）：位于libcore.net.http.HttpEngine.openSocketConnection（HttpEngine.java:316）
04-26 19:10:52.899:W/System.err（4156）：在libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.makeSslConnection（HttpsURLConnectionImpl.java:461）
04-26 19:10:52.899:W/System.err（4156）：在libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.connect（HttpsURLConnectionImpl.java:433）
04-26 19:10:52.899:W/System.err（4156）：位于libcore.net.http.HttpEngine.sendSocketRequest（HttpEngine.java:290）
04-26 19:10:52.899:W/System.err（4156）：位于libcore.net.http.HttpEngine.sendRequest（HttpEngine.java:240）
04-26 19:10:52.899:W/System.err（4156）：位于libcore.net.http.HttpURLConnectionImpl.connect（HttpURLConnectionImpl.java:81）
04-26 19:10:52.899:W/System.err（4156）：位于libcore.net.http.HttpsURLConnectionImpl.connect（HttpsURLConnectionImpl.java:165）
04-26 19:10:52.899:W/System.err（4156）：位于com.google.api.client.http.javanet.NetHttpRequest.execute（NetHttpRequest.java:88）
04-26 19:10:52.899:W/System.err（4156）：位于com.google.api.client.http.HttpRequest.execute（HttpRequest.java:814）
04-26 19:10:52.909:W/System.err（4156）：位于com.example.mapmapreach.PlaceSearch.search（PlaceSearch.java:64）
04-26 19:10:52.909:W/System.err（4156）：位于com.example.mapmapreach.MainActivity.onCreate（MainActivity.java:86）
04-26 19:10:52.909:W/System.err（4156）：位于android.app.Activity.performCreate（Activity.java:5104）
04-26 19:10:52.909:W/System.err（4156）：在android.app.Instrumentation.callActivityOnCreate（Instrumentation.java:1080）
04-26 19:10:52.909:W/System.err（4156）：在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2144）
04-26 19:10:52.909:W/System.err（4156）：位于android.app.ActivityThread.handleLaunchActivity（ActivityThread.java:2230）
04-26 19:10:52.909:W/System.err（4156）：在android.app.ActivityThread.access$600（ActivityThread.java:141）
04-26 19:10:52.909:W/System.err（4156）：在android.app.ActivityThread$H.handleMessage（ActivityThread.java:1234）
04-26 19:10:52.909:W/System.err（4156）：位于android.os.Handler.dispatchMessage（Handler.java:99）
04-26 19:10:52.909:W/System.err（4156）：位于android.os.Looper.loop（Looper.java:137）
04-26 19:10:52.909:W/System.err（4156）：位于android.app.ActivityThread.main（ActivityThread.java:5039）
04-26 19:10:52.909:W/System.err（4156）：位于java.lang.reflect.Method.invokenactive（本机方法）
04-26 19:10:52.909:W/System.err（4156）：位于java.lang.reflect.Method.invoke（Method.java:511）
04-26 19:10:52.909:W/System.err（4156）：在com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run（ZygoteInit.java:793）
04-26 19:10:52.909:W/System.err（4156）：位于com.android.internal.os.ZygoteInit.main（ZygoteInit.java:560）
04-26 19:10:52.909:W/System.err（4156）：在dalvik.System.NativeStart.main（本机方法）

---

感谢您的帮助。

您正在主UI线程上进行联网，Android框架现在禁止该线程，正如您的

Android.os.NetworkOnMainThreadException

异常所示

这是禁止的，因为假设您的服务器无法访问，或者您的用户的internet连接非常慢。当程序启动您的

搜索

功能时，UI将完全冻结，直到它返回，因为UI线程将忙于尝试联系该服务器

---

将搜索函数放入一个

异步任务

，或将其包装在一个

可运行的

中，以便它在自己的线程中执行。请看看这个问题，看一个很好的例子

您是否正在使用emulator？请发布准确的stacktrace和其他内容，然后将粘贴的代码与行号进行映射？像是Activity.java:5104==“Places

              try {
        PlacesList places = ps.search(curr_lat, curr_longitude, 100.0);
    } catch (Exception e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();

              04-26 19:10:52.839: W/System.err(4156): android.os.NetworkOnMainThreadException
              04-26 19:10:52.899: W/System.err(4156):   at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117)
              04-26 19:10:52.899: W/System.err(4156):   at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
              04-26 19:10:52.899: W/System.err(4156):   at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
              04-26 19:10:52.899: W/System.err(4156):   at java.net.InetAddress.getAllByName(InetAddress.java:214)
              04-26 19:10:52.899: W/System.err(4156):   at libcore.net.http.HttpConnection.<init>(HttpConnection.java:70)
              04-26 19:10:52.899: W/System.err(4156):   at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50)
              04-26 19:10:52.899: W/System.err(4156):   at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:340)
              04-26 19:10:52.899: W/System.err(4156):   at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87)
              04-26 19:10:52.899: W/System.err(4156):   at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
              04-26 19:10:52.899: W/System.err(4156):   at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:316)
              04-26 19:10:52.899: W/System.err(4156):   at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.makeSslConnection(HttpsURLConnectionImpl.java:461)
             04-26 19:10:52.899: W/System.err(4156):    at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.connect(HttpsURLConnectionImpl.java:433)
             04-26 19:10:52.899: W/System.err(4156):    at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290)
             04-26 19:10:52.899: W/System.err(4156):    at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:240)
             04-26 19:10:52.899: W/System.err(4156):    at libcore.net.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:81)
             04-26 19:10:52.899: W/System.err(4156):    at libcore.net.http.HttpsURLConnectionImpl.connect(HttpsURLConnectionImpl.java:165)
             04-26 19:10:52.899: W/System.err(4156):    at com.google.api.client.http.javanet.NetHttpRequest.execute(NetHttpRequest.java:88)
             04-26 19:10:52.899: W/System.err(4156):    at com.google.api.client.http.HttpRequest.execute(HttpRequest.java:814)
             04-26 19:10:52.909: W/System.err(4156):    at com.example.mapmapagain.PlaceSearch.search(PlaceSearch.java:64)
             04-26 19:10:52.909: W/System.err(4156):    at com.example.mapmapagain.MainActivity.onCreate(MainActivity.java:86)
             04-26 19:10:52.909: W/System.err(4156):    at android.app.Activity.performCreate(Activity.java:5104)
             04-26 19:10:52.909: W/System.err(4156):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
             04-26 19:10:52.909: W/System.err(4156):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
             04-26 19:10:52.909: W/System.err(4156):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
             04-26 19:10:52.909: W/System.err(4156):    at android.app.ActivityThread.access$600(ActivityThread.java:141)
             04-26 19:10:52.909: W/System.err(4156):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
             04-26 19:10:52.909: W/System.err(4156):    at android.os.Handler.dispatchMessage(Handler.java:99)
             04-26 19:10:52.909: W/System.err(4156):    at android.os.Looper.loop(Looper.java:137)
             04-26 19:10:52.909: W/System.err(4156):    at android.app.ActivityThread.main(ActivityThread.java:5039)
             04-26 19:10:52.909: W/System.err(4156):    at java.lang.reflect.Method.invokeNative(Native Method)
             04-26 19:10:52.909: W/System.err(4156):    at java.lang.reflect.Method.invoke(Method.java:511)
             04-26 19:10:52.909: W/System.err(4156):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
             04-26 19:10:52.909: W/System.err(4156):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
             04-26 19:10:52.909: W/System.err(4156):    at dalvik.system.NativeStart.main(Native Method)