如何从android应用程序调用java web服务？

Question

I've made simple web service where you have to provide your name.我制作了简单的网络服务，您必须在其中提供您的姓名。 It will return "Hello "+your_Name.它将返回“Hello”+your_Name。

At Server Side在服务器端

myWebService.java我的WebService.java

package pkg;

import javax.jws.WebService;
import javax.jws.WebMethod;
import javax.jws.WebParam;


@WebService(serviceName = "myWebService")
public class myWebService {


    @WebMethod(operationName = "hello")
    public String hello(@WebParam(name = "name") String txt) {
        return "Hello " + txt + " !";
    }
}

At Client Side在客户端

Index.jsp索引.jsp

<%@page import="java.io.Writer"%>
<%@page import="org.json.JSONObject"%>
<%@page import="org.json.JSONArray"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="application/json; charset=UTF-8">
        <title>JSP Page</title>
    </head>
    <body>
        <form action="#">
            <input type="text" name="t1">
            <input type="submit" value="CLICK"><br>
        </form>
    </body>
</html>
    <%-- start web service invocation --%><hr/>
    <%
    try {
    pkg.MyWebService_Service service = new pkg.MyWebService_Service();
    pkg.MyWebService port = service.getMyWebServicePort();
    java.lang.String name = request.getParameter("t1");
    java.lang.String result = port.hello(name);

        out.write(result);

    } catch (Exception ex) 
    {

    }
    %>
    <%-- end web service invocation --%><hr/>

Output on Browser浏览器输出

So Web Service works fine when I call it from Browser.所以当我从浏览器调用它时，Web 服务工作正常。 But problem occurs when I try to call it from Android.但是当我尝试从 Android 调用它时出现问题。

build.gradle(Module: app) build.gradle（模块：app）

apply plugin: 'com.android.application'

android {
    compileSdkVersion 26
    defaultConfig {
        applicationId "com.example.akshay.httpclientdemo"
        minSdkVersion 14
        targetSdkVersion 26
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    packagingOptions {
        exclude 'META-INF/DEPENDENCIES'
        exclude 'META-INF/LICENSE'
        exclude 'META-INF/LICENSE.txt'
        exclude 'META-INF/license.txt'
        exclude 'META-INF/NOTICE'
        exclude 'META-INF/NOTICE.txt'
        exclude 'META-INF/notice.txt'
        exclude 'META-INF/ASL2.0'
    }
}

dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation 'com.android.support:appcompat-v7:26.1.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    implementation files('libs/httpclient-4.5.9.jar')
    implementation files('libs/httpcore-4.4.11.jar')
}

AndroidManifest.xml AndroidManifest.xml

    <?xml version="1.0" encoding="utf-8"?>
    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
        package="com.example.akshay.httpclientdemo">

        <uses-permission android:name="android.permission.INTERNET"/>
        <application
            android:allowBackup="true"
            android:icon="@mipmap/ic_launcher"
            android:label="@string/app_name"
            android:roundIcon="@mipmap/ic_launcher_round"
            android:supportsRtl="true"
            android:theme="@style/AppTheme">
            <activity android:name=".MainActivity">
                <intent-filter>
                    <action android:name="android.intent.action.MAIN" />

                    <category android:name="android.intent.category.LAUNCHER" />
                </intent-filter>
            </activity>
        </application>

    </manifest>

**activity_main.xml**
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/t1"
        android:layout_width="293dp"
        android:layout_height="wrap_content"
        android:layout_marginEnd="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:ems="10"
        android:inputType="textPersonName"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <EditText
        android:id="@+id/t2"
        android:layout_width="289dp"
        android:layout_height="wrap_content"
        android:layout_marginEnd="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:ems="10"
        android:inputType="textPersonName"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/t1" />

    <Button
        android:id="@+id/btn"
        android:layout_width="132dp"
        android:layout_height="wrap_content"
        android:layout_marginEnd="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:text="Button"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/t2" />

    <ProgressBar
        android:id="@+id/pBar"
        style="?android:attr/progressBarStyle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>

MainActivity.java主活动.java

public class MainActivity extends AppCompatActivity
{

    Button btn;
    EditText t1,t2;
    ProgressBar pBar;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        btn=(Button)findViewById(R.id.btn);
        t1=(EditText)findViewById(R.id.t1);
        t2=(EditText)findViewById(R.id.t2);
        pBar=(ProgressBar)findViewById(R.id.pBar);

        pBar.setVisibility(View.GONE);

        btn.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View view)
            {
                pBar.setVisibility(View.VISIBLE);
                new ExecuteTask().execute();
            }
        });
    }


    class ExecuteTask extends AsyncTask<String, Integer, String>
    {
        StringBuffer result;

        @Override
        protected String doInBackground(String... params) {

            try
            {
                String url = "http://localhost:8080/WebClient/index.jsp?t1="+t1.getText().toString();

                HttpClient client = new DefaultHttpClient();
                HttpGet request = new HttpGet(url);

                HttpResponse response = client.execute(request);

                BufferedReader rd = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));

                String line = "";
                result = new StringBuffer();

                while ((line = rd.readLine()) != null)
                {
                    result.append(line);
                }

                t2.setText(result.toString());
            }
            catch(Exception ex)
            {
                ex.printStackTrace();
            }

            return result.toString();
        }

        @Override
        protected void onPostExecute(String result) {
            pBar.setVisibility(View.GONE);
            t2.setText(result.toString());
        }
    }
}

Output输出

After Clicking Button, I get单击按钮后，我得到

Error Log错误日志

07-18 14:13:06.423 1394-1422/? W/audio_hw_generic: Not supplying enough data to HAL, expected position 9295997 , only wrote 9295920
07-18 14:13:06.442 8162-8185/com.example.akshay.httpclientdemo D/NetworkSecurityConfig: No Network Security Config specified, using platform default
07-18 14:13:06.452 8162-8185/com.example.akshay.httpclientdemo W/System.err: org.apache.http.conn.HttpHostConnectException: Connection to http://localhost:8080 refused
        at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:193)
        at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:169)
        at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:124)
        at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:366)
        at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:560)
        at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:492)
        at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:470)
07-18 14:13:06.453 8162-8185/com.example.akshay.httpclientdemo W/System.err:     at com.example.akshay.httpclientdemo.MainActivity$ExecuteTask.doInBackground(MainActivity.java:64)
        at com.example.akshay.httpclientdemo.MainActivity$ExecuteTask.doInBackground(MainActivity.java:50)
        at android.os.AsyncTask$2.call(AsyncTask.java:304)
        at java.util.concurrent.FutureTask.run(FutureTask.java:237)
        at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:243)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
        at java.lang.Thread.run(Thread.java:761)
    Caused by: java.net.ConnectException: Connection refused
        at java.net.PlainSocketImpl.socketConnect(Native Method)
        at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:334)
        at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:196)
        at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:178)
        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:356)
        at java.net.Socket.connect(Socket.java:586)
        at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:124)
        at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:149)
        ... 14 more

    --------- beginning of crash
07-18 14:13:06.454 8162-8185/com.example.akshay.httpclientdemo E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #1
    Process: com.example.akshay.httpclientdemo, PID: 8162
    java.lang.RuntimeException: An error occurred while executing doInBackground()
        at android.os.AsyncTask$3.done(AsyncTask.java:318)
        at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:354)
        at java.util.concurrent.FutureTask.setException(FutureTask.java:223)
        at java.util.concurrent.FutureTask.run(FutureTask.java:242)
        at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:243)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
        at java.lang.Thread.run(Thread.java:761)
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.StringBuffer.toString()' on a null object reference
        at com.example.akshay.httpclientdemo.MainActivity$ExecuteTask.doInBackground(MainActivity.java:83)
        at com.example.akshay.httpclientdemo.MainActivity$ExecuteTask.doInBackground(MainActivity.java:50)
        at android.os.AsyncTask$2.call(AsyncTask.java:304)
        at java.util.concurrent.FutureTask.run(FutureTask.java:237)
        at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:243) 
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133) 
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607) 
        at java.lang.Thread.run(Thread.java:761) 


    --------- beginning of system
07-18 14:13:06.455 1674-1829/system_process W/ActivityManager:   Force finishing activity com.example.akshay.httpclientdemo/.MainActivity
07-18 14:13:06.462 1674-1829/system_process W/ActivityManager:   Force finishing activity com.example.akshay.httpclientdemo/.MainActivity
    Duplicate finish request for ActivityRecord{fc02510 u0 com.example.akshay.httpclientdemo/.MainActivity t92 f}
07-18 14:13:06.496 1310-2049/? D/gralloc_ranchu: gralloc_alloc: Creating ashmem region of size 2691072
07-18 14:13:06.522 1310-1310/? E/EGL_emulation: tid 1310: eglCreateSyncKHR(1901): error 0x3004 (EGL_BAD_ATTRIBUTE)
07-18 14:13:06.667 1674-1691/system_process W/art: Long monitor contention with owner Binder:1674_2 (1686) at void com.android.server.am.ActivityManagerService.activityPaused(android.os.IBinder)(ActivityManagerService.java:6879) waiters=2 in void com.android.server.am.ActivityManagerService$3.handleMessage(android.os.Message) for 181ms
07-18 14:13:06.676 1674-2111/system_process W/art: Long monitor contention with owner Binder:1674_2 (1686) at void com.android.server.am.ActivityManagerService.activityPaused(android.os.IBinder)(ActivityManagerService.java:6879) waiters=3 in int com.android.server.am.ActivityManagerService.bindService(android.app.IApplicationThread, android.os.IBinder, android.content.Intent, java.lang.String, android.app.IServiceConnection, int, java.lang.String, int) for 188ms
07-18 14:13:06.811 6822-6839/com.example.akshay.todolist D/EGL_emulation: eglMakeCurrent: 0x997be600: ver 2 0 (tinfo 0xa6bf67e0)
07-18 14:13:06.846 8162-8178/com.example.akshay.httpclientdemo D/EGL_emulation: eglMakeCurrent: 0xb1a4e6a0: ver 2 0 (tinfo 0xa6b86880)
07-18 14:13:06.853 8162-8178/com.example.akshay.httpclientdemo D/OpenGLRenderer: endAllActiveAnimators on 0x99878300 (RippleDrawable) with handle 0x9953e240
07-18 14:13:06.872 1674-1752/system_process I/OpenGLRenderer: Initialized EGL, version 1.4
07-18 14:13:06.872 1674-1752/system_process D/OpenGLRenderer: Swap behavior 1
07-18 14:13:06.872 1674-1752/system_process W/OpenGLRenderer: Failed to choose config with EGL_SWAP_BEHAVIOR_PRESERVED, retrying without...
07-18 14:13:06.872 1674-1752/system_process D/OpenGLRenderer: Swap behavior 0
07-18 14:13:06.883 1674-1752/system_process D/EGL_emulation: eglCreateContext: 0x971032a0: maj 2 min 0 rcv 2
07-18 14:13:06.893 1674-1752/system_process D/EGL_emulation: eglMakeCurrent: 0x971032a0: ver 2 0 (tinfo 0x97d9b700)
07-18 14:13:06.902 1674-1752/system_process D/EGL_emulation: eglMakeCurrent: 0x971032a0: ver 2 0 (tinfo 0x97d9b700)
07-18 14:13:07.163 1394-1422/? W/audio_hw_generic: Not supplying enough data to HAL, expected position 9331460 , only wrote 9331200
    Not supplying enough data to HAL, expected position 9331210 , only wrote 9331200
07-18 14:13:07.181 1394-1422/? W/audio_hw_generic: Not supplying enough data to HAL, expected position 9332030 , only wrote 9331920
07-18 14:13:07.432 1674-4893/system_process I/WindowManager: Destroying surface Surface(name=com.example.akshay.httpclientdemo/com.example.akshay.httpclientdemo.MainActivity) called by com.android.server.wm.WindowStateAnimator.destroySurface:2016 com.android.server.wm.WindowStateAnimator.destroySurfaceLocked:882 com.android.server.wm.WindowState.removeLocked:1456 com.android.server.wm.WindowManagerService.removeWindowInnerLocked:2484 com.android.server.wm.WindowManagerService.removeWindowLocked:2442 com.android.server.wm.WindowManagerService.removeWindowLocked:2311 com.android.server.wm.WindowManagerService.removeWindow:2306 com.android.server.wm.Session.remove:202 
07-18 14:13:09.582 1394-1423/? W/audio_hw_generic: Not supplying enough data to HAL, expected position 9561758 , only wrote 9447120
07-18 14:13:23.586 1674-1758/system_process D/WifiNative-HAL: Failing getSupportedFeatureset because HAL isn't started
07-18 14:13:23.587 1674-1695/system_process E/BluetoothAdapter: Bluetooth binder is null
07-18 14:13:23.588 1674-1695/system_process E/BatteryStatsService: no controller energy info supplied
07-18 14:13:23.592 1674-1695/system_process E/KernelCpuSpeedReader: Failed to read cpu-freq: /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state (No such file or directory)
07-18 14:13:23.592 1674-1695/system_process E/KernelUidCpuTimeReader: Failed to read uid_cputime: /proc/uid_cputime/show_uid_stat (No such file or directory)
07-18 14:13:23.593 1674-1695/system_process E/BatteryStatsService: modem info is invalid: ModemActivityInfo{ mTimestamp=0 mSleepTimeMs=0 mIdleTimeMs=0 mTxTimeMs[]=[0, 0, 0, 0, 0] mRxTimeMs=0 mEnergyUsed=0}
07-18 14:14:00.138 1674-1674/system_process I/EntropyMixer: Writing entropy...
07-18 14:14:17.212 1674-1692/system_process I/ProcessStatsService: Prepared write state in 39ms

Answer 1

You're trying to connect to localhost.您正在尝试连接到本地主机。 Localhost is the machine the code is running on.本地主机是运行代码的机器。 But your server isn't on your phone (even if using an emulator, the emulator is a VM- it counts as a separate machine).但是你的服务器不在你的手机上（即使使用模拟器，模拟器也是一个虚拟机——它算作一台单独的机器）。 So its not connecting, and not getting any data.所以它没有连接，也没有得到任何数据。 Use the real url/ip address.使用真实的 url/ip 地址。

You also need to account for the case of a connection not working for some reason (for example, the server is down) and try to handle it more gracefully than a crash.您还需要考虑连接因某种原因（例如，服务器关闭）无法正常工作的情况，并尝试比崩溃更优雅地处理它。 Your problem here is that you depend on result being non-null in the return of doInBackground.您的问题是您在 doInBackground 的返回中依赖于非空的结果。 You can fix this by moving return result.toString into the try block, and putting return null where you have it now.您可以通过将 return result.toString 移动到 try 块中，并将 return null 放在您现在拥有的位置来解决此问题。

如何从android应用程序调用java web服务？

问题描述

1 个解决方案

解决方案1
1 已采纳 2019-07-18 08:57:51

如何从android应用程序调用java web服务？

问题描述

1 个解决方案

解决方案1 1 已采纳 2019-07-18 08:57:51

解决方案1
1 已采纳 2019-07-18 08:57:51