如何从线程获取返回值? [英] How get return value from Thread?
本文介绍了如何从线程获取返回值?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我正在将Thread
用于Webservice
,但是我无法从Thread
获取数据,因为我无法从Thread
返回数据.
I am using Thread
for Webservice
but i cant get the data from Thread
because i cant return data from Thread
.
这是我的WebService.java
:
public class Webservice {
static String result;
public static String readUrl(final String url) {
Thread thread = new Thread(new Runnable() {
@Override
public void run() {
try {
HttpClient client = new DefaultHttpClient();
HttpPost method = new HttpPost(url);
HttpResponse response = client.execute(method);
InputStream stream = response.getEntity().getContent();
result = ConvertInputStreamToString(stream);
Log.i("xxx","OK" + result);
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
});
thread.start();
return result;
}
private static String ConvertInputStreamToString(InputStream inputstteam) {
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
inputstteam));
StringBuilder builder = new StringBuilder();
String line = "";
while ((line = reader.readLine()) != null) {
builder.append(line);
}
return builder.toString();
}
catch (IOException e) {
e.printStackTrace();
}
return null;
}
}
这是NotesActivity.java
:
public class NotesActivity extends Activity {
private ArrayList<StructTask> nettasks = new ArrayList<StructTask>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Thread thread = new Thread(new Runnable() {
@Override
public void run() {
String result = Webservice.readUrl("http://192.168.200.101:8081/note-server/");
if (result != null) {
try {
JSONArray tasks = new JSONArray(result);
for (int i = 0; i < tasks.length(); i++) {
JSONObject object = tasks.getJSONObject(i);
//Log.i("LOG", "Task: " + object.getString("task_title"));
StructTask task = new StructTask();
task.id = object.getLong("task_id");
task.title = object.getString("task_title");
task.desc = object.getString("task_desc");
task.done = object.getBoolean("task_done");
nettasks.add(task);
for (StructTask taskes : nettasks) {
Log.i("LOG", "Taskes: " + taskes.id + "|" + taskes.title + "|" + taskes.desc + "|" + taskes.done);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
}
else
{
Log.i("OK", "TaskesOK: " + result);
Log.i("LOG", "Task: " + "NULL");
}
}
});
thread.start();
}
}
这是我的StructTask.java
:
public class StructTask {
public long id;
public String title;
public String desc;
public boolean done;
}
此代码为我返回NULL.
This code return for me NULL .
推荐答案
只需尝试这种方式
1)Webservice.java
public class Webservice {
public interface WebCallListener{
void onCallComplete(String result);
}
public static void readUrl(final String url,final WebCallListener callListener) {
Thread thread = new Thread(new Runnable() {
@Override
public void run() {
try {
HttpClient client = new DefaultHttpClient();
HttpPost method = new HttpPost(url);
HttpResponse response = client.execute(method);
InputStream stream = response.getEntity().getContent();
callListener.onCallComplete(ConvertInputStreamToString(stream));
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
});
thread.start();
}
private static String ConvertInputStreamToString(InputStream inputstteam) {
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
inputstteam));
StringBuilder builder = new StringBuilder();
String line = "";
while ((line = reader.readLine()) != null) {
builder.append(line);
}
return builder.toString();
}
catch (IOException e) {
e.printStackTrace();
}
return null;
}
}
2)NotesActivity.java
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Webservice.readUrl("http://192.168.200.101:8081/note-server/",new WebCallListener() {
@Override
public void onCallComplete(String result) {
if (result != null) {
try {
JSONArray tasks = new JSONArray(result);
for (int i = 0; i < tasks.length(); i++) {
JSONObject object = tasks.getJSONObject(i);
//Log.i("LOG", "Task: " + object.getString("task_title"));
StructTask task = new StructTask();
task.id = object.getLong("task_id");
task.title = object.getString("task_title");
task.desc = object.getString("task_desc");
task.done = object.getBoolean("task_done");
nettasks.add(task);
}
for (StructTask taskes : nettasks) {
Log.i("LOG", "Taskes: " + taskes.id + "|" + taskes.title + "|" + taskes.desc + "|" + taskes.done);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
else
{
Log.i("OK", "TaskesOK: " + result);
Log.i("LOG", "Task: " + "NULL");
}
}
});
}
这篇关于如何从线程获取返回值?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文