您好，我想创建一个活动，在该活动中，我想根据所选位置更改列表的内容，因此我编写了一个覆盖类
class MapOverlay extends com.google.android.maps.Overlay
{
@Override
public boolean draw(Canvas canvas, MapView mapView, boolean shadow, long when)
{
super.draw(canvas, mapView, shadow);
//---translate the GeoPoint to screen pixels---
return false;
}
@Override
public boolean onTouchEvent(MotionEvent event, MapView mapView)
{
//---when user lifts his finger---
if (event.getAction() == 1) {
GeoPoint p = mapView.getProjection().fromPixels(
(int) event.getX(),
(int) event.getY());
double x = p.getLatitudeE6() / 1E6 ;
double y= p.getLongitudeE6() /1E6 ;
String url="http://api.v3.factual.com/t/global?geo={\"$circle\":{\"$center\":["+x+","+y+"],\"$meters\":5000}}&KEY=uZSowx1CRS4oD2R8kQGGgjkbFoDMHlriDl1IAoQc";
url=URLEncoder.encode(url);
HttpGet get=new HttpGet(url);
try {
HttpResponse response=client.execute(get);
Log.i("hello",EntityUtils.toString(response.getEntity()));
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return true;
}
}
但是当我单击任何项目时，它显示我被强制关闭并显示错误
Java.lang.IllegalStateException目标主机不得为null，并且在参数中进行设置，请帮助解决该错误。
这是错误的日志猫
03-30 12:30:52.267: E/AndroidRuntime(692): Uncaught handler: thread main exiting due to uncaught exception
03-30 12:30:52.277: E/AndroidRuntime(692): java.lang.IllegalStateException: Target host must not be null, or set in parameters.
03-30 12:30:52.277: E/AndroidRuntime(692): at org.apache.http.impl.client.DefaultRequestDirector.determineRoute(DefaultRequestDirector.java:561)
03-30 12:30:52.277: E/AndroidRuntime(692): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:292)
03-30 12:30:52.277: E/AndroidRuntime(692): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
03-30 12:30:52.277: E/AndroidRuntime(692): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
03-30 12:30:52.277: E/AndroidRuntime(692): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
03-30 12:30:52.277: E/AndroidRuntime(692): at factual.box.android.Factual_Mapping$MapOverlay.onTouchEvent(Factual_Mapping.java:91)
03-30 12:30:52.277: E/AndroidRuntime(692): at com.google.android.maps.OverlayBundle.onTouchEvent(OverlayBundle.java:63)
03-30 12:30:52.277: E/AndroidRuntime(692): at com.google.android.maps.MapView.onTouchEvent(MapView.java:625)
03-30 12:30:52.277: E/AndroidRuntime(692): at android.view.View.dispatchTouchEvent(View.java:3709)
03-30 12:30:52.277: E/AndroidRuntime(692): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:852)
03-30 12:30:52.277: E/AndroidRuntime(692): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
03-30 12:30:52.277: E/AndroidRuntime(692): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
03-30 12:30:52.277: E/AndroidRuntime(692): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
03-30 12:30:52.277: E/AndroidRuntime(692): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
03-30 12:30:52.277: E/AndroidRuntime(692): at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1659)
03-30 12:30:52.277: E/AndroidRuntime(692): at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1107)
03-30 12:30:52.277: E/AndroidRuntime(692): at android.app.Activity.dispatchTouchEvent(Activity.java:2061)
03-30 12:30:52.277: E/AndroidRuntime(692): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1643)
03-30 12:30:52.277: E/AndroidRuntime(692): at android.view.ViewRoot.handleMessage(ViewRoot.java:1691)
03-30 12:30:52.277: E/AndroidRuntime(692): at android.os.Handler.dispatchMessage(Handler.java:99)
03-30 12:30:52.277: E/AndroidRuntime(692): at android.os.Looper.loop(Looper.java:123)
03-30 12:30:52.277: E/AndroidRuntime(692): at android.app.ActivityThread.main(ActivityThread.java:4363)
03-30 12:30:52.277: E/AndroidRuntime(692): at java.lang.reflect.Method.invokeNative(Native Method)
03-30 12:30:52.277: E/AndroidRuntime(692): at java.lang.reflect.Method.invoke(Method.java:521)
03-30 12:30:52.277: E/AndroidRuntime(692): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
03-30 12:30:52.277: E/AndroidRuntime(692): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
03-30 12:30:52.277: E/AndroidRuntime(692): at dalvik.system.NativeStart.main(Native Method)
03-30 12:30:52.297: I/dalvikvm(692): threadid=7: reacting to signal 3
03-30 12:30:52.317: I/dalvikvm(692): Wrote stack trace to '/data/anr/traces.txt'
最佳答案
不编码，请使用以下代码。
String url = "http://api.v3.factual.com/t/global?KEY=uZSowx1CRS4oD2R8kQGGgjkbFoDMHlriDl1IAoQc";
HttpParams params = new BasicHttpParams();
params.setParameter("geo", "{\"$circle\":{\"$center\":[\" + x + \",\" + y + \"],\"$meters\":5000}}");
HttpGet get = new HttpGet(url);