将JSON填充到android Listview

时间：2016-05-10 09:06:37

标签： android json listview

运行应用时出现此错误：

05-10 01：44：39.243 11047-11047 / com.efe.efeAlumni E / AndroidRuntime：FATAL EXCEPTION：main进程：com.efe.efeAlumni，PID：11047 java.lang.RuntimeException：无法启动活动ComponentInfo {com.efe.efeAlumni / com.efe.efeAlumni.ui.MainActivity}：java.lang.NullPointerException：尝试在android.app的android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2325）获取null数组的长度android.app.Handler的android.app.ActivityThread $ H.handleMessage（ActivityThread.java:1303）上的android.app.ActivityThread.access $ 800（ActivityThread.java:151）的.ActivityThread.handleLaunchActivity（ActivityThread.java:2387） android.app.Looper.loop（Looper.java:135）的.dispatchMessage（Handler.java:102）位于android.app.ActivityThread.main（ActivityThread.java:5254）的java.lang.reflect.Method.invoke（原始方法）在com.android.internal.os的com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:903）的java.lang.reflect.Method.invoke（Method.java:372）。 ZygoteInit.main （ZygoteInit.java:698）引起：java.lang.NullPointerException：尝试在android.widget.ListView.setAdapter的com.efe.efeAlumni.Adaptors.JobAdaptor.getCount（JobAdaptor.java:28）获取null数组的长度（ListView.java:487）位于android.app.A活动中的com.efe.efeAlumni.ui.MainActivity.onCreate（MainActivity.java:74）上的android.app.ListActivity.setListAdapter（ListActivity.java:265） Activity.java:5990）在Android.app.ActivityThread.handleLaunchActivity（ActivityThread.java:2387）的android.app.Instrumentation.callActivityOnCreate（Instrumentation.java:1106）android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2278） ）在Android.app.Handler.dispatchMessage（Handler.java:102）的android.app.ActivityThread.access $ 800（ActivityThread.java:151）android.app.ActivityThread $ H.handleMessage（ActivityThread.java:1303） android.os.Looper.loop（Looper.java:135）在android.app.ActivityThread.main（ActivityThread.java:5254）java.lang.reflect.Method.invoke（Native Method） ）在com.android.internal.os.ZygoteInit的com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:903）的java.lang.reflect.Method.invoke（Method.java:372）中。主（ZygoteInit.java:698）

MainActivity：

import android.app.ListActivity;
import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.util.Log;
import android.widget.ListView;

package com.efe.efeAlumni.ui;

import android.app.ListActivity;
import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.util.Log;

import com.efe.efeAlumni.Adaptors.JobAdaptor;
import com.efe.efeAlumni.Model.Config;
import com.efe.efeAlumni.Model.JobDetails;
import com.efe.efeAlumni.Model.Jobs;
import com.efe.efeAlumni.R;
import com.squareup.okhttp.Call;
import com.squareup.okhttp.Callback;
import com.squareup.okhttp.OkHttpClient;
import com.squareup.okhttp.Request;
import com.squareup.okhttp.Response;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.IOException;

public class MainActivity extends ListActivity {

    public static final String TAG = MainActivity.class.getSimpleName();

    private Jobs mJobs;
    private JobDetails[] mJobDetails;

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

        getJobsDetails();

        JobAdaptor adaptor = new JobAdaptor(this, mJobDetails);
        setListAdapter(adaptor);

        Log.d(TAG," OkHttp success ");

    }

    private void getJobsDetails() {
        if(isNetworkAvailable()) {
            OkHttpClient client = new OkHttpClient();
            Request request = new Request.Builder()
                    .url(Config.jobsURL)
                    .build();

            Call call = client.newCall(request);

            call.enqueue(new Callback() {
                @Override
                public void onFailure(Request request, IOException e) {

                }

                @Override
                public void onResponse(Response response) throws IOException {
                    try {
                        String jsonData = response.body().string();
                        Log.v(TAG, jsonData);
                        if (response.isSuccessful()) {
                            mJobs = parseJobsDetails(jsonData);
                        } else {
                            AlertUserAboutError();
                        }
                    } catch (IOException e) {
                        Log.v(TAG, "Exception caught: ", e);
                   } catch (JSONException e) {
                        Log.v(TAG, "Exception caught: ", e);
                    }
                }

            });

        }else {
            AlertUserAboutError();
        }
    }

    private Jobs parseJobsDetails (String jsonData) throws JSONException{
        Jobs jobs = new Jobs();
        jobs.setJobDetailses(getCurrentJobDetails(jsonData));
        return jobs;
    }

    private JobDetails[] getCurrentJobDetails(String jsonData) throws JSONException {
        JSONObject jsonObject = new JSONObject(jsonData);
        JSONArray result = jsonObject.getJSONArray("result");

        JobDetails[] jobDetails = new JobDetails[result.length()];

        for (int i = 0; i < result.length(); i++) {
            JSONObject jsonDetail = result.getJSONObject(i);
            JobDetails jobDetail = new JobDetails();

            jobDetail.setIds(jsonDetail.getString("id"));
            jobDetail.setSalary(jsonDetail.getString("title"));
            jobDetail.setTitles(jsonDetail.getString("salary"));

            jobDetails[i] = jobDetail;

            Log.d(TAG, jobDetail.getIds());

        }

        return jobDetails;
    }

    private boolean isNetworkAvailable() {
        ConnectivityManager manger = (ConnectivityManager)
                getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo  networkInfo =  manger.getActiveNetworkInfo();
        boolean isAvailable = false;

        if(networkInfo != null && networkInfo.isConnected()){
            isAvailable = true;
        }
        return  isAvailable;
    }

    private void AlertUserAboutError() {
        AlertDialogFragment dialog = new AlertDialogFragment();
        dialog.show(getFragmentManager(),"error_dailog");
    }
}

JobAdaptor类：

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import com.efe.efeAlumni.Model.JobDetails;
import com.efe.efeAlumni.R;

public class JobAdaptor extends BaseAdapter {

    private JobDetails[] mJobs;
    private Context mContext;

    public JobAdaptor(Context context, JobDetails[] jobs) {
        mContext = context;
        mJobs = jobs;
    }

    @Override
    public int getCount() {
        return mJobs.length;
    }

    @Override
    public Object getItem(int i) {
        return mJobs[i];
    }

    @Override
    public long getItemId(int i) {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;

        if (convertView == null) {
            convertView = LayoutInflater.from(mContext).inflate(R.layout.job_list_items, null);
            holder = new ViewHolder();
            holder.titleLabel = (TextView) convertView.findViewById(R.id.titleTextView);
            holder.salaryLabel = (TextView) convertView.findViewById(R.id.salaryTextView);

            convertView.setTag(holder);
        }
        else {
            holder = (ViewHolder) convertView.getTag();
        }

        JobDetails job = mJobs[position];

        holder.titleLabel.setText(job.getTitles() + "");
        holder.salaryLabel.setText(job.getSalary() + "");

        if (position == 0) {
            holder.titleLabel.setText("Noting to show ");
            holder.titleLabel.setText(" ");
        }

        return convertView;
    }

    private static class ViewHolder {
        TextView titleLabel;
        TextView salaryLabel;
    }

}

JobDetails类：

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import com.efe.efeAlumni.Model.JobDetails;
import com.efe.efeAlumni.R;

public class JobAdaptor extends BaseAdapter {

    private JobDetails[] mJobs;
    private Context mContext;

    public JobAdaptor(Context context, JobDetails[] jobs) {
        mContext = context;
        mJobs = jobs;
    }

    @Override
    public int getCount() {
        return mJobs.length;
    }

    @Override
    public Object getItem(int i) {
        return mJobs[i];
    }

    @Override
    public long getItemId(int i) {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;

        if (convertView == null) {
            // brand new
            convertView = LayoutInflater.from(mContext).inflate(R.layout.job_list_items, null);
            holder = new ViewHolder();
            holder.titleLabel = (TextView) convertView.findViewById(R.id.titleTextView);
            holder.salaryLabel = (TextView) convertView.findViewById(R.id.salaryTextView);

            convertView.setTag(holder);
        }
        else {
            holder = (ViewHolder) convertView.getTag();
        }

        JobDetails job = mJobs[position];

        holder.titleLabel.setText(job.getTitles() + "");
        holder.salaryLabel.setText(job.getSalary() + "");

        if (position == 0) {
            holder.titleLabel.setText("Noting to show ");
            holder.titleLabel.setText(" ");
        }

        return convertView;
    }

    private static class ViewHolder {
        TextView titleLabel;
        TextView salaryLabel;
    }

}

0 个答案:

没有答案
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