AngularJS调用Java中的Restful Webservice返回错误

Question

I have a restful webservice that returns a list of users .I am calling the method using AngularJS My Restful Webservice:

package webservice;
import java.sql.Connection;
import java.util.ArrayList;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import model.ProjectManager;
import com.google.gson.Gson;
import dto.Users;
@Path("/WebService")
public class UsersService {
@GET
@Path("/GetUsers")
@Produces("application/json")
public String user()
{
  String users = null;
  try 
  {
    ArrayList<Users> usersList = null;
    ProjectManager projectManager= new ProjectManager();
    usersList = projectManager.GetUsers();
    Gson gson = new Gson();
    System.out.println(gson.toJson(usersList));
    users = gson.toJson(usersList);
  }
  catch (Exception e)
  {
    System.out.println("Exception Error"); //Console 
  }
   return users;
 }
}

and the output is:

[{"userId":1,"userName":"sdsouza"},{"userId":3,"userName":"administrator"}]

The http url is yielding the results just fine.

My controllers.js in Angular Js:

angular.module('starter.controllers', [])
.controller('DashCtrl', ['$scope', '$http', function($scope, $http) {
$http.get( 
'http://localhost:8081/TestDataRestful/REST/WebService/GetUsers'
).success(function(data) {          
    $scope.$apply(function () {
     $scope.users = data;
     });
      })
   .error(function(data) {
    $scope.message="error";
    });
  }])

When I run the html page,I see that the call is getting made.The console prints out the result but the html page prints out the error message and there is no sight of the users.I am a noob.I would be grateful if anyone can spot the error.I have been battling with it for quite some time.Thanks in advance.

 <ion-view view-title="Dashboard">
 <ion-content class="padding">
 <div class="list card">
 <div class="item item-divider">Recent Updates</div>
 <div class="item item-body">
 {{message}}
 </div>
 <div class="item item-body" ng-repeat="user in users">
 {{user}}
 </div>
 </div>
 </ion-content>
 </ion-view>

Answer 1

It was not the code.I needed to add CORS filter in the webapp's web.xml file. If you are using Tomcat 7 and above,there is no need to add cors jars,just include the filters in the xml file.

http://tomcat.apache.org/tomcat-7.0-doc/config/filter.html#CORS_Filter

<filter>
<filter-name>CorsFilter</filter-name>
<filter-class>org.apache.catalina.filters.CorsFilter</filter-class>
<init-param>
<param-name>cors.allowed.origins</param-name>
<param-value>*</param-value>
</init-param>
<init-param>
<param-name>cors.allowed.methods</param-name>
<param-value>GET,POST,HEAD,OPTIONS,PUT</param-value>
</init-param>
<init-param>
<param-name>cors.allowed.headers</param-name>
<param-value>Content-Type,X-Requested-With,accept,Origin,Access-Control-  
Request-Method,Access-Control-Request-Headers</param-value>
</init-param>
<init-param>
<param-name>cors.exposed.headers</param-name>
<param-value>Access-Control-Allow-Origin,Access-Control-Allow-
Credentials</param-value>
</init-param>
<init-param>
<param-name>cors.support.credentials</param-name>
<param-value>true</param-value>
</init-param>
<init-param>
<param-name>cors.preflight.maxage</param-name>
<param-value>10</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>CorsFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

Special thanks to Mike's article.I used ionic.So I could skip the first configuration of including the httpProvider in the js file.

http://mikesknowledgebase.azurewebsites.net/pages/Services/WebServices-Page8.5.htm