Page factory is not working for android

Hi All,

I was trying to access pagefactory concept for android & ios app using appium 1.5.3 (java-client-4.1.3). It was working fine for iOS ,but android giving below error,

FAILED: loginWithValidUser on [LoginTest passed=0 failed=0 skipped=0]
java.lang.IllegalArgumentException: @$Proxy7: one of [uiAutomator, accessibility, className, id, tagName, name, xpath, linkText, partialLinkText] should be filled
at io.appium.java_client.pagefactory.bys.builder.AppiumByBuilder.getFilledValue(AppiumByBuilder.java:105)
at io.appium.java_client.pagefactory.bys.builder.AppiumByBuilder.createBy(AppiumByBuilder.java:145)
at io.appium.java_client.pagefactory.DefaultElementByBuilder.buildMobileNativeBy(DefaultElementByBuilder.java:137)
at io.appium.java_client.pagefactory.DefaultElementByBuilder.buildBy(DefaultElementByBuilder.java:186)
at io.appium.java_client.pagefactory.AppiumElementLocatorFactory.createLocator(AppiumElementLocatorFactory.java:57)
at io.appium.java_client.pagefactory.AppiumElementLocatorFactory.createLocator(AppiumElementLocatorFactory.java:44)
at io.appium.java_client.pagefactory.AppiumElementLocatorFactory.createLocator(AppiumElementLocatorFactory.java:1)
at org.openqa.selenium.support.pagefactory.DefaultFieldDecorator.decorate(DefaultFieldDecorator.java:56)
at io.appium.java_client.pagefactory.AppiumFieldDecorator.decorate(AppiumFieldDecorator.java:172)
at org.openqa.selenium.support.PageFactory.proxyFields(PageFactory.java:113)
at org.openqa.selenium.support.PageFactory.initElements(PageFactory.java:105)
at com.tej.pages.LoginPage.(LoginPage.java:34)
at com.tej.tests.LoginTest.loginWithValidUser(LoginTest.java:32)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:86)
at org.testng.internal.Invoker.invokeMethod(Invoker.java:643)
at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:820)
at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1128)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:129)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:112)
at org.testng.TestRunner.privateRun(TestRunner.java:782)
at org.testng.TestRunner.run(TestRunner.java:632)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:366)
at org.testng.SuiteRunner.access$000(SuiteRunner.java:39)
at org.testng.SuiteRunner$SuiteWorker.run(SuiteRunner.java:400)
at org.testng.internal.thread.ThreadUtil$2.call(ThreadUtil.java:64)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)

and used POM like below ,

public class LoginPageObjects {

@AndroidFindBy(uiAutomator= "login_username")
@iOSFindBy(id = "login_username")
public MobileElement username;

@AndroidFindBy(uiAutomator = “login_password”)
@iOSFindBy(id = “pwd_textfield”)
public MobileElement password;

}
public class LoginPage extends CommonAppiumTest {

public LoginPageObjects loginPageObjects = new LoginPageObjects();


public LoginPage(AppiumDriver<MobileElement> driver) {
    super(driver);
    PageFactory.initElements(new AppiumFieldDecorator(driver, 5, TimeUnit.SECONDS), loginPageObjects);
}

}

Please let me know whether i am using perfectly or not, but same working for ios.

Thanks in advance,
Senthilkumar K