Java Can'；无法获取PHP脚本的结果

我有一个PHP脚本，它应该从我的数据库返回一个小的ID列表，它在浏览器中运行良好，但当我尝试在我的应用程序中执行它时，我得到了一个错误

这是我的密码：

public static String makeCall(String scriptName) {
    String address = "http://10.0.2.2/" + scriptName + ".php";

    HttpPost httpPost = new HttpPost(address);
    HttpClient httpClient = new DefaultHttpClient();
    StringBuilder total = new StringBuilder();
    try {
        //httpPost.setEntity(new UrlEncodedFormEntity(params));

        // Execute HTTP Post Request
        HttpResponse response = httpClient.execute(httpPost);
        InputStream is = response.getEntity().getContent();
        BufferedReader rd = new BufferedReader(new InputStreamReader(is));
        String line = "";
        // Read response until the end
        while ((line = rd.readLine()) != null) {
            total.append(line);
        }

        // Return full string
        //System.out.println(total.toString());

        return total.toString();
    } catch (Exception e) {
        System.out.println(total == null ? "null" : "notnull");
        Log.d("error", e.getMessage());
        Log.e("main", "connection error");
    }
    return "empty";
}

堆栈跟踪：

02-24 19:30:08.583: I/System.out(1220): notnull 02-24 19:30:08.594:
D/AndroidRuntime(1220): Shutting down VM 02-24 19:30:08.594:
W/dalvikvm(1220): threadid=1: thread exiting with uncaught exception
(group=0x40a70930) 

E/AndroidRuntime(1220): FATAL EXCEPTION: main

java.lang.RuntimeException: Unable to start activity

ComponentInfo{com.example.phptest/com.example.phptest.MainActivity}:

java.lang.NullPointerException: println needs a message
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
at android.app.ActivityThread.access$600(ActivityThread.java:141) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
at android.os.Handler.dispatchMessage(Handler.java:99) 
at android.os.Looper.loop(Looper.java:137)      
at android.app.ActivityThread.main(ActivityThread.java:5039) 
at java.lang.reflect.Method.invokeNative(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:511)      
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560) 
at dalvik.system.NativeStart.main(Native Method)      

Caused by: java.lang.NullPointerException:
println needs a message       
at android.util.Log.println_native(Native Method)      
at android.util.Log.d(Log.java:138) 
at com.example.phptest.MainActivity.makeCall(MainActivity.java:61) 
at com.example.phptest.MainActivity.onCreate(MainActivity.java:25) 
at android.app.Activity.performCreate(Activity.java:5104) 
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
 ... 11 more

当我删除日志语句或首先检查它们是否为null时，我得到以下错误：

02-24 20:29:27.523: E/ActivityThread(648): Service
com.android.exchange.ExchangeService has leaked ServiceConnection
com.android.emailcommon.service.ServiceProxy$ProxyConnection@40d0ce98
that was originally bound here

E/ActivityThread(648): android.app.ServiceConnectionLeaked: Service
com.android.exchange.ExchangeService has leaked ServiceConnection
com.android.emailcommon.service.ServiceProxy$ProxyConnection@40d0ce98

that was originally bound here     

at android.app.LoadedApk$ServiceDispatcher.<init>(LoadedApk.java:969)
at android.app.LoadedApk.getServiceDispatcher(LoadedApk.java:863)
at android.app.ContextImpl.bindService(ContextImpl.java:1418)
at android.app.ContextImpl.bindService(ContextImpl.java:1407) 
at android.content.ContextWrapper.bindService(ContextWrapper.java:473)
at com.android.emailcommon.service.ServiceProxy.setTask(ServiceProxy.java:157)
at com.android.emailcommon.service.ServiceProxy.setTask(ServiceProxy.java:145)
at com.android.emailcommon.service.ServiceProxy.test(ServiceProxy.java:191)
at com.android.exchange.ExchangeService$7.run(ExchangeService.java:1850)
at com.android.emailcommon.utility.Utility$2.doInBackground(Utility.java:551)
at com.android.emailcommon.utility.Utility$2.doInBackground(Utility.java:549)
at android.os.AsyncTask$2.call(AsyncTask.java:287)     
at java.util.concurrent.FutureTask.run(FutureTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
at java.lang.Thread.run(Thread.java:856)

02-24 20:29:27.523:E/ActivityThread（648）：服务
com.android.exchange.ExchangeService已泄漏ServiceConnection
com.android.emailcommon.service.ServiceProxy$ProxyConnection@40d0ce98
原来是订在这里的
E/ActivityThread（648）：android.app.ServiceConnectionLeaked:服务
com.android.exchange.ExchangeService已泄漏ServiceConnection
com.android.emailcommon.service.ServiceProxy$ProxyConnection@40d0ce98
原来是订在这里的
在android.app.LoadedApk$ServiceDispatcher上。（LoadedApk.java:969）
位于android.app.LoadedApk.getServiceDispatcher（LoadedApk.java:863）
位于android.app.ContextImpl.bindService（ContextImpl.java:1418）
位于android.app.ContextImpl.bindService（ContextImpl.java:1407）
位于android.content.ContextWrapper.bindService（ContextWrapper.java:473）
位于com.android.emailcommon.service.ServiceProxy.setTask（ServiceProxy.java:157）
位于com.android.emailcommon.service.ServiceProxy.setTask（ServiceProxy.java:145）
位于com.android.emailcommon.service.ServiceProxy.test（ServiceProxy.java:191）
位于com.android.exchange.ExchangeService$7.run（ExchangeService.java:1850）
位于com.android.emailcommon.utility.utility$2.doInBackground（utility.java:551）
位于com.android.emailcommon.utility.utility$2.doInBackground（utility.java:549）
在android.os.AsyncTask$2.call（AsyncTask.java:287）
在java.util.concurrent.FutureTask.run（FutureTask.java:234）处
位于java.util.concurrent.ThreadPoolExecutor.runWorker（ThreadPoolExecutor.java:1080）
位于java.util.concurrent.ThreadPoolExecutor$Worker.run（ThreadPoolExecutor.java:573）
运行（Thread.java:856）

更改

Log.d("error", e.getMessage());

到

if (e.getMessage() != null) {
    Log.d("error", e.getMessage());
}