android - 尝试发送 Android 图像时应用程序崩溃

Question

我在尝试将图像从我的应用程序发送到服务器时遇到问题。我知道它在哪里崩溃。 这些是我的文件:

RestClient.java

package edu.gvsu.cis.masl.camerademo;

import android.util.Log;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpEntityEnclosingRequestBase;
import org.apache.http.client.methods.HttpPut;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.params.HttpParams;
import org.apache.http.util.EntityUtils;
import java.io.IOException;
import java.io.UnsupportedEncodingException;


public class RestClient {

private static final int DEFAULT_CONNECTION_TIMEOUT = 30000;
private static final int DEFAULT_RECEIVE_TIMEOUT = 60000;
//private static final String AUTHORIZATION = "Authorization";
private static final String CONTENT_TYPE = "Content-Type";
private static final String JSON_CONTENT_TYPE = "application/json; charset=utf-8";
private static final String UTF8 = "UTF8";
private static final String DEBUG = RestClient.class.getName();


public Result put(String url, String json) {
    return executeRequest(new HttpPut(url), json, DEFAULT_RECEIVE_TIMEOUT);
}



private Result executeRequest(HttpEntityEnclosingRequestBase request, String json, int timeout) {
    request.addHeader(CONTENT_TYPE, JSON_CONTENT_TYPE);
    try {
        request.setEntity(new StringEntity(json,UTF8));
    }catch(UnsupportedEncodingException e) {
        Log.e(DEBUG, e.getMessage());
        return Result.error();
    }
    return executeRequest(request,timeout);
}


private Result executeRequest(HttpUriRequest request, int timeout) {

    int responseCode = -1;
    String responseContent = null;
    //request.addHeader(AUTHORIZATION, encodeCredentials(userCredentials));
    HttpParams httpParams = new BasicHttpParams();
    HttpConnectionParams.setConnectionTimeout(httpParams, DEFAULT_CONNECTION_TIMEOUT);
    HttpConnectionParams.setSoTimeout(httpParams, timeout);
    HttpClient client = new DefaultHttpClient(httpParams);

    try {
        HttpResponse response = client.execute(request);
        HttpEntity entity = response.getEntity();
        responseCode = response.getStatusLine().getStatusCode();
        if(entity!=null) {
            responseContent = EntityUtils.toString(entity, UTF8);
        }

    }catch(IOException e) {
        Log.e(DEBUG, e.getMessage());
        return Result.error();
    }
    return new Result(responseCode, responseContent);
}


}

ImageDTO.java:

public class ImageDTO {

public String id;
public String image;

public ImageDTO(String id, String image) {
    this.id = id;
    this.image=image;
}

}

结果.java:

package edu.gvsu.cis.masl.camerademo;

public class Result {

public static final int COMMUNICATION_ERROR = -1;
public static final int OK_SUCCESS = 200;
public static final int BAD_REQUEST = 400;
public static final int UNAUTHORIZED = 401;
public static final int NOT_FOUND = 404;
public static final int INTERNAL_SERVER_ERROR = 500;

private int responseCode;
private String resultContent;

public Result(int responseCode, String resultContent) {
    this.responseCode = responseCode;
    this.resultContent = resultContent;
}

public int getResponseCode() {
    return this.responseCode;
}

public String getResultContent() {
    return this.resultContent;
}

public static Result error() {
    return new Result(COMMUNICATION_ERROR, "ERROR");
}

}

我的 Activity 中的代码与此相关:

String strBase64 = Base64.encodeToString(imageBytes, Base64.DEFAULT);
            int id = 1;

            ImageDTO imdto = new ImageDTO(Integer.toString(id), strBase64);

            RestClient client = new RestClient();
            String jsonDTO = new Gson().toJson(imdto);

            Log.i("Pablo", jsonDTO);
            Result result = client.put(SERVICE_URL, jsonDTO);
            if (result.getResponseCode() != 200) Log.i("****************", "Oups! Smth went wrong!!!");
            else Log.i("****************", "Response = 200 , Connection Established :D");

我的应用程序在 RestClient.java 中失败:

HttpResponse response = client.execute(request);

我不知道为什么会失败，因为 RestClient 和 Result 文件在其他项目中工作正常。

另外我不得不说 Base64 代码在 IntelliJ Idea 中显示不完整。如果我询问最新的字符，它是正确的，但无法以日志模式显示所有字符。

这是显示失败的日志:

ERROR/AndroidRuntime(27028): FATAL EXCEPTION: main
    Process: edu.gvsu.cis.masl.camerademo, PID: 27028
    java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1888, result=-1, data=null} to activity {edu.gvsu.cis.masl.camerademo/edu.gvsu.cis.masl.camerademo.MyCameraActivity}: android.os.NetworkOnMainThreadException
    at android.app.ActivityThread.deliverResults(ActivityThread.java:3365)
    at android.app.ActivityThread.handleSendResult(ActivityThread.java:3408)
    at android.app.ActivityThread.access$1300(ActivityThread.java:135)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1244)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:136)
    at android.app.ActivityThread.main(ActivityThread.java:5017)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:515)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
    at dalvik.system.NativeStart.main(Native Method)
    Caused by: android.os.NetworkOnMainThreadException
    at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1145)
    at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
    at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
    at java.net.InetAddress.getAllByName(InetAddress.java:214)
    at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
    at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
    at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
    at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
    at edu.gvsu.cis.masl.camerademo.RestClient.executeRequest(RestClient.java:61)
    at edu.gvsu.cis.masl.camerademo.RestClient.executeRequest(RestClient.java:46)
    at edu.gvsu.cis.masl.camerademo.RestClient.put(RestClient.java:33)
    at edu.gvsu.cis.masl.camerademo.MyCameraActivity.onActivityResult(MyCameraActivity.java:78)
    at android.app.Activity.dispatchActivityResult(Activity.java:5423)
    at android.app.ActivityThread.deliverResults(ActivityThread.java:3361)
    ... 11 more

Answer 1

Caused by: android.os.NetworkOnMainThreadException

原因: 当应用程序尝试在其主线程上执行网络操作时引发的异常。

只有针对 Honeycomb SDK 或更高版本的应用程序才会抛出此错误。允许针对早期 SDK 版本的应用程序在其主事件循环线程上进行联网，但强烈建议不要这样做。

引用NetworkOnMainThreadException了解更多信息。

问题: 您正在主线程(UI 线程) 中执行与网络相关的任务/操作。

解决方案: 它应该在工作线程中完成。 这种情况可以使用android提供的AsyncTask。 在AsyncTask的doInbackground方法中执行所有与网络相关的任务。

注意: 您还可以使用StrictMode。

StrictMode 是一种开发人员工具，它可以检测您可能意外执行的操作并引起您的注意，以便您可以修复它们。

StrictMode 最常用于捕获应用程序主线程上的意外磁盘或网络访问，在该主线程中接收 UI 操作并发生动画。将磁盘和网络操作保持在主线程之外可以使应用程序更加流畅、响应更快。通过保持应用程序的主线程响应，您还可以防止向用户显示 ANR 对话框。

引用StrictMode了解更多信息。