Question

我用于解析JSON值的代码。

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;

import android.util.Log;

public class JSONParser {

static InputStream is = null;
static JSONObject jObj = null;
static String json ="";

// constructor
public JSONParser() {

}

public JSONObject getJSONFromUrl(String url) {

    // Making HTTP request
    try {
        // defaultHttpClient
        DefaultHttpClient httpClient = new DefaultHttpClient();
        HttpPost httpPost = new HttpPost(url);

        HttpResponse httpResponse = httpClient.execute(httpPost);
        HttpEntity httpEntity = httpResponse.getEntity();
        is = httpEntity.getContent();           

    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

    try {
        BufferedReader reader = new BufferedReader(new InputStreamReader(
                is, "utf-8"), 8);
        StringBuilder sb = new StringBuilder();
        String line = null;
        while ((line = reader.readLine()) != null) {
            sb.append(line + "\n");
        }
        is.close();
        json = sb.toString();
        Log.i("JSON Parser", json);
    } catch (Exception e) {
        Log.e("Buffer Error", "Error converting result " + e.toString());
    }

    // try parse the string to a JSON object
    try {
        jObj = new JSONObject(json);
    } catch (JSONException e) {
        Log.e("JSON Parser", "Error parsing data " + e.toString());
    }

    // return JSON String
    return jObj;

}

}

Actvity类代码

    private static final String TAG_UserLoginsResult = "UserLoginsResult";
private static final String TAG_BRANCH_ID = "BRANCH_ID";
private static final String TAG_USER_NAME = "USER_NAME";
private static final String TAG_User_ID = "User_ID";
private static final String TAG_msg = "msg";

// contacts JSONArray
JSONArray loginsResult = null;
String url = null;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    /*
     * try { String URL = URLEncoder.encode(url1, "utf-8"); } catch
     * (UnsupportedEncodingException e1) { // TODO Auto-generated catch
     * block e1.printStackTrace(); }
     */
    /*
     * try{ String url =
     * "http://etosxmldev.ctdi.com/WS/WCF/AVAYA-MOBILE-    SERVICE/Service.svc/UserLogins"
     * + URLEncoder.encode("?","UTF-8") + "LoginId" +
     * URLEncoder.encode("=","UTF-8") + "samalorp" +
     * URLEncoder.encode("&","UTF-8") + "passWord" +
     * URLEncoder.encode("=","UTF-8") + "pass"; }catch (Exception e) { //
     * TODO: handle exception }
     */
    // Hashmap for ListView
    ArrayList<HashMap<String, String>> contactList = new ArrayList<HashMap<String, String>>();

    // Creating JSON Parser instance
    JSONParser jParser = new JSONParser();
    // getting JSON string from URL
    // http://etosxmldev.ctdi.com/WS/WCF/AVAYA-MOBILE-SERVICE/Service.svc/UserLogins?LoginId=samalorp&passWord=pass
    JSONObject json = jParser
            .getJSONFromUrl("http://etosxmldev.ctdi.com/WS/WCF/AVAYA-MOBILE-SERVICE/Service.svc/UserLogins");
    try {
        // Getting Array of Contacts
        loginsResult = json.getJSONArray(TAG_UserLoginsResult);

        // looping through All Contacts
        for (int i = 0; i < loginsResult.length(); i++) {
            JSONObject c = loginsResult.getJSONObject(i);

            String BRANCH_ID = c.getString(TAG_BRANCH_ID);
            String USER_NAME = c.getString(TAG_USER_NAME);
            String User_ID = c.getString(TAG_User_ID);
            String msg = c.getString(TAG_msg);
            System.out.println("===========>>>" + BRANCH_ID);
            System.out.println("===========>>>" + USER_NAME);
            System.out.println("===========>>>" + User_ID);
            System.out.println("===========>>>" + msg);

            // creating new HashMap
            HashMap<String, String> map = new HashMap<String, String>();

            // adding each child node to HashMap key => value
            map.put(TAG_BRANCH_ID, BRANCH_ID);
            map.put(TAG_USER_NAME, USER_NAME);
            map.put(TAG_User_ID, User_ID);
            map.put(TAG_msg, msg);

            // adding HashList to ArrayList
            contactList.add(map);

            // Intent i2 = new Intent(AndroidJSONParsingActivity.this,
            // otherActivity.class);
            // startActivity(i2);
        }
    } catch (JSONException e) {
        e.printStackTrace();
    }

}

根据JSONLInt，JSON值有效。

Json值

  {
    "UserLoginsResult": [
      {
        "BRANCH_ID": "R28",
        "USER_NAME": "saranya",
        "User_ID": "5677",
        "msg": null
     }
  ]
 }

甚至用于url编码也使用了各种选项。无法在android中找到解决方案。请给出一些想法。我知道有很多问题就像这样。但是那里给出了解决方案，但没有为我工作。

    09-09 09:03:37.956: I/JSON Parser(266): <HTML><HEAD><STYLE type="text/css">#content{     FONT-SIZE: 0.7em; PADDING-BOTTOM: 2em; MARGIN-LEFT: 30px}BODY{MARGIN-TOP: 0px; MARGIN-LEFT:    0px; COLOR: #000000; FONT-FAMILY: Verdana; BACKGROUND-COLOR: white}P{MARGIN-TOP: 0px; MARGIN-BOTTOM: 12px; COLOR: #000000; FONT-FAMILY: Verdana}PRE{BORDER-RIGHT: #f0f0e0 1px solid; PADDING-RIGHT: 5px; BORDER-TOP: #f0f0e0 1px solid; MARGIN-TOP: -5px; PADDING-LEFT: 5px; FONT-SIZE: 1.2em; PADDING-BOTTOM: 5px; BORDER-LEFT: #f0f0e0 1px solid; PADDING-TOP: 5px; BORDER-BOTTOM: #f0f0e0 1px solid; FONT-FAMILY: Courier New; BACKGROUND-COLOR: #e5e5cc}.heading1{MARGIN-TOP: 0px; PADDING-LEFT: 15px; FONT-WEIGHT: normal; FONT-SIZE: 26px; MARGIN-BOTTOM: 0px; PADDING-BOTTOM: 3px; MARGIN-LEFT: -30px; WIDTH: 100%; COLOR: #ffffff; PADDING-TOP: 10px; FONT-FAMILY: Tahoma; BACKGROUND-COLOR: #003366}.intro{MARGIN-LEFT: -15px}</STYLE>
09-09 09:03:37.956: I/JSON Parser(266): <TITLE>Service</TITLE></HEAD><BODY>
09-09 09:03:37.956: I/JSON Parser(266): <DIV id="content">
09-09 09:03:37.956: I/JSON Parser(266): <P class="heading1">Service</P>
09-09 09:03:37.956: I/JSON Parser(266): <BR/>
09-09 09:03:37.956: I/JSON Parser(266): <P class="intro">Method not allowed.</P>
09-09 09:03:37.956: I/JSON Parser(266): </DIV>
09-09 09:03:37.956: I/JSON Parser(266): </BODY></HTML>
09-09 09:03:37.966: E/JSON Parser(266): Error parsing data org.json.JSONException: Value <HTML><HEAD><STYLE of type java.lang.String cannot be converted to JSONObject
09-09 09:03:37.993: D/AndroidRuntime(266): Shutting down VM
09-09 09:03:37.993: W/dalvikvm(266): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
09-09 09:03:38.006: E/AndroidRuntime(266): FATAL EXCEPTION: main
09-09 09:03:38.006: E/AndroidRuntime(266): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.testapp/com.example.testapp.AndroidJSONParsingActivity}: java.lang.NullPointerException
09-09 09:03:38.006: E/AndroidRuntime(266):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
09-09 09:03:38.006: E/AndroidRuntime(266):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
09-09 09:03:38.006: E/AndroidRuntime(266):  at android.app.ActivityThread.access$2300(ActivityThread.java:125)
09-09 09:03:38.006: E/AndroidRuntime(266):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
09-09 09:03:38.006: E/AndroidRuntime(266):  at android.os.Handler.dispatchMessage(Handler.java:99)
09-09 09:03:38.006: E/AndroidRuntime(266):  at android.os.Looper.loop(Looper.java:123)
09-09 09:03:38.006: E/AndroidRuntime(266):  at android.app.ActivityThread.main(ActivityThread.java:4627)
09-09 09:03:38.006: E/AndroidRuntime(266):  at java.lang.reflect.Method.invokeNative(Native Method)
09-09 09:03:38.006: E/AndroidRuntime(266):  at java.lang.reflect.Method.invoke(Method.java:521)
09-09 09:03:38.006: E/AndroidRuntime(266):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
09-09 09:03:38.006: E/AndroidRuntime(266):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
09-09 09:03:38.006: E/AndroidRuntime(266):  at dalvik.system.NativeStart.main(Native Method)
09-09 09:03:38.006: E/AndroidRuntime(266): Caused by: java.lang.NullPointerException
09-09 09:03:38.006: E/AndroidRuntime(266):  at com.example.testapp.AndroidJSONParsingActivity.onCreate(AndroidJSONParsingActivity.java:66)
09-09 09:03:38.006: E/AndroidRuntime(266):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
09-09 09:03:38.006: E/AndroidRuntime(266):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
09-09 09:03:38.006: E/AndroidRuntime(266):  ... 11 more

Answer 1

在你的pasrser中构建一个JSON格式的字符串并将其传递给JSON对象

 try {
        jObj = new JSONObject(json);
    } catch (JSONException e) {
        Log.e("JSON Parser", "Error parsing data " + e.toString());
    }

遗憾的是，该字符串不是JSON格式的，它属于异常，因此整个方法返回null，并在您的活动中调用

JSONObject json = jParser
            .getJSONFromUrl("http://etosxmldev.ctdi.com/WS/WCF/AVAYA-MOBILE-SERVICE/Service.svc/UserLogins");
    try {
        // Getting Array of Contacts
        loginsResult = json.getJSONArray(TAG_UserLoginsResult);
....
}

当你的json为null时，它将落入该catch块中，
我的建议重新检查你的JSON数据，这是一个很好的JSON validator

修改你应该设置标题来定义你需要json

public JSONObject getJSONFromUrl（String url）{

// Making HTTP request try { // defaultHttpClient DefaultHttpClient httpClient = new DefaultHttpClient(); HttpPost httpPost = new HttpPost(url);
之后
添加

httpPost.setHeader("Content-Type", "application/json"); httpPost.setHeader("Accept", "JSON");

Answer 2

@Override
    protected String doInBackground(String... params) {
        String response="";

        try{
             String url="your ulr";
             response = sendRequest(url);

        }catch(Exception e){
            e.printStackTrace();
            return "";
        }

        return response;
    }






//String Method to fetech data from server
public String sendRequest(String url) {
    String result = "";
    try {

        HttpClient client = new DefaultHttpClient();
        HttpParams httpParameters = client.getParams();
        HttpConnectionParams.setConnectionTimeout(httpParameters, 5000);
        HttpConnectionParams.setSoTimeout(httpParameters, 5000);
        HttpConnectionParams.setTcpNoDelay(httpParameters, true);
        HttpGet request = new HttpGet();
        request.setURI(new URI(url));
        HttpResponse response = client.execute(request);
        InputStream ips = response.getEntity().getContent();

        BufferedReader buf = new BufferedReader(new InputStreamReader(ips,
                "UTF-8"));

        StringBuilder sb = new StringBuilder();
        String s;
        while (true) {
            s = buf.readLine();
            if (s == null || s.length() == 0)
                break;
            sb.append(s);

        }
        buf.close();
        ips.close();
        result = sb.toString();

    } catch (Exception e) {
        e.printStackTrace();
    }

    return result;
}

Just used this method to fetch the valued for api.just permission on Manifest.xml for internel

Answer 3

您正在一次读取8个字节的响应，并为每个8个字节添加换行符。

，如

BufferedReader reader = new BufferedReader(new InputStreamReader(
            is, "utf-8"), 8);
    StringBuilder sb = new StringBuilder();
    String line = null;
    while ((line = reader.readLine()) != null) {
        sb.append(line + "\n");
    }

删除这两个问题，它应该有效。

解析数据时出错org.json.JSONException：Value

3 个答案: