我在java中创建了一个web服务
@Path（ “/应用程序”） 公共类WebServiceApp {
MainClass mc = null;
@Path("/login")
@POST
@Consumes(MediaType.APPLICATION_JSON)
@Produces(MediaType.APPLICATION_JSON)
public User authenticateLoginWebService(Login log){
mc = new MainClass();
return mc.authenticateLogin(log.getUsername(), log.getPassword());
}
}
此方法包含网址：http://localhost:8080/webapi/api/app/login“，
现在在android上调用它我使用了以下代码：
JSONParser：
public class JSONParser {
String charset = "UTF-8";
HttpURLConnection conn;
DataOutputStream wr;
StringBuilder result;
URL urlObj;
JSONObject jObj = null;
StringBuilder sbParams;
String paramsString;
public JSONObject makeHttpRequest(String url, String method, JSONObject params) {
if (method.equals("POST")) {
try {
urlObj = new URL(url);
conn = (HttpURLConnection) urlObj.openConnection();
conn.setDoOutput(true);
conn.setRequestMethod("POST");
conn.setRequestProperty("content-type", "application/json");
conn.setReadTimeout(10000);
conn.setConnectTimeout(15000);
conn.connect();
OutputStream o = conn.getOutputStream();
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(o, "UTF-8"));
writer.write(params.toString());
writer.flush();
writer.close();
o.close();
***Log.e("Req code", String.valueOf(conn.getResponseCode()));
Log.e("Req Value", conn.getContent().toString())***;
} catch (IOException e) {
e.printStackTrace();
}
} else if (method.equals("GET")) {
try {
urlObj = new URL(url);
conn = (HttpURLConnection) urlObj.openConnection();
conn.setDoOutput(false);
conn.setRequestMethod("GET");
conn.setRequestProperty("Accept-Charset", charset);
conn.setConnectTimeout(15000);
conn.connect();
} catch (IOException e) {
e.printStackTrace();
}
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
Log.e("Reader", reader.readLine());
StringBuilder result = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null){
result.append(line + "\n");
Log.e("Line", line);
}
reader.close();
Log.d("JSON Parser", "result: " + result.toString());
} catch (IOException e) {
e.printStackTrace();
}
conn.disconnect();
try {
jObj = new JSONObject(result.toString());
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
return jObj;
}
}
LoginActivity：
public class LoginActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
final EditText username = (EditText) findViewById(R.id.username);
final EditText password = (EditText) findViewById(R.id.password);
TextView linkToSignup = (TextView) findViewById(R.id.linktosignup);
linkToSignup.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent it = new Intent(LoginActivity.this, SignUpActivity.class);
startActivity(it);
finish();
}
});
Button login = (Button) findViewById(R.id.login_button);
login.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
new HelperAsync().execute(username.getText().toString(), password.getText().toString());
}
});
TextView mainMenu = (TextView) findViewById(R.id.mainMenu);
mainMenu.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent it = new Intent(LoginActivity.this, HotelActivity.class);
startActivity(it);
finish();
}
});
}
public class HelperAsync extends AsyncTask<String, Void, User>{
@Override
protected User doInBackground(String... params) {
try {
JSONObject inputParam = new JSONObject();
inputParam.put("username", params[0]);
inputParam.put("password", params[1]);
Log.e("inpt",inputParam.toString());
JSONObject obj = new JSONParser().makeHttpRequest("http://10.0.3.2:8080/webapi/api/app/login", "POST", inputParam);
Log.e("jOsn", obj.toString());
if (obj != null) {
try {
String username = obj.getString("username");
int phoneNumber = obj.getInt("phoneNumber");
String role = obj.getString("role");
String name = obj.getString("name");
Log.e("username", username + " " + phoneNumber + " " + role + " " + name);
} catch (JSONException e) {
e.printStackTrace();
}
}
return null;
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(User user) {
super.onPostExecute(user);
}
@Override
protected void onPreExecute() {
super.onPreExecute();
}
}
}
我收到请求代码415，错误消息为Unsupported Media Type。
stacktrace如下：
05-03 00:40:16.256 1252-1829/com.whiteboard.aajkamenu W/System.err: java.io.FileNotFoundException: http://10.0.3.2:8080/webapi/api/app/login
05-03 00:40:16.260 1252-1829/com.whiteboard.aajkamenu W/System.err: at com.android.okhttp.internal.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:186)
05-03 00:40:16.264 1252-1829/com.whiteboard.aajkamenu W/System.err: at com.whiteboard.httpresource.JSONParser.makeHttpRequest(JSONParser.java:77)
05-03 00:40:16.264 1252-1829/com.whiteboard.aajkamenu W/System.err: at com.whiteboard.aajkamenu.LoginActivity$HelperAsync.doInBackground(LoginActivity.java:71)
05-03 00:40:16.264 1252-1829/com.whiteboard.aajkamenu W/System.err: at com.whiteboard.aajkamenu.LoginActivity$HelperAsync.doInBackground(LoginActivity.java:62)
05-03 00:40:16.264 1252-1829/com.whiteboard.aajkamenu W/System.err: at android.os.AsyncTask$2.call(AsyncTask.java:288)
05-03 00:40:16.264 1252-1829/com.whiteboard.aajkamenu W/System.err: at java.util.concurrent.FutureTask.run(FutureTask.java:237)
05-03 00:40:16.264 1252-1829/com.whiteboard.aajkamenu W/System.err: at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
05-03 00:40:16.264 1252-1829/com.whiteboard.aajkamenu W/System.err: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
05-03 00:40:16.264 1252-1829/com.whiteboard.aajkamenu W/System.err: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
05-03 00:40:16.264 1252-1829/com.whiteboard.aajkamenu W/System.err: at java.lang.Thread.run(Thread.java:841)
05-03 00:40:16.264 1252-1829/com.whiteboard.aajkamenu W/dalvikvm: threadid=14: thread exiting with uncaught exception (group=0xa4d02b20)
05-03 00:40:16.272 1252-1829/com.whiteboard.aajkamenu E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #3
Process: com.whiteboard.aajkamenu, PID: 1252
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:300)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
Caused by: java.lang.NullPointerException
at com.whiteboard.httpresource.JSONParser.makeHttpRequest(JSONParser.java:91)
at com.whiteboard.aajkamenu.LoginActivity$HelperAsync.doInBackground(LoginActivity.java:71)
at com.whiteboard.aajkamenu.LoginActivity$HelperAsync.doInBackground(LoginActivity.java:62)
at android.os.AsyncTask$2.call(AsyncTask.java:288)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
05-03 00:40:16.280 546-813/system_process W/ActivityManager: Force finishing activity com.whiteboard.aajkamenu/.LoginActivity
如何解决此错误？
答案 0 :(得分：1)
请修改HelperAsync中的doInBackground代码，如下所示：
@Override
protected String doInBackground(String... args)
{
String login_url="http://localhost:8080/webapi/api/app/login";
try {
URL ur = new URL(login_url);
HttpURLConnection httpURLConnection = (HttpURLConnection) ur.openConnection();
OutputStream outputStream = httpURLConnection.getOutputStream();
httpURLConnection.setRequestMethod("POST");
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>;
nameValuePairs.add(new BasicNameValuePair("username, "Sarvesh"));
nameValuePairs.add(new BasicNameValuePair("password", "12345"));
}