title: How to add external library project to android studio 1.2.2? with solution
body: <p>I am facing problem to use external library project's in android studio version 1.2.2 .</p>
  
  <p>steps i did to add external library projects are:-</p>
  
  <ol>
  <li><p>I created a new project exPagerSliding.</p></li>
  <li><p>I Add a new directory(libs) in root directory of the app. and paste the library there.</p></li>
  <li><p>I open my apps setting.gradle. and add following lines of code</p>
  
  <pre><code>include ':app' ':PagerSlidingTabStrip'
  project(':PagerSlidingTabStrip').projectDir=new File('libs/PagerSlidingTabStrip')
  </code></pre></li>
  <li><p>then I open my build.gradle file 
  add following lines of code</p>
  
  <pre><code>dependencies {
  classpath 'com.android.tools.build:gradle:1.2.3'
  compile fileTree(dir: 'libs', include: ['*.jar'])
  compile 'com.android.support:appcompat-v7:21.0.3'
  compile project(":PagerSlidingTabStrip")
  }
  </code></pre></li>
  </ol>
  
  <p>5.Next i go to gradle.properties and write following lines of code.</p>
  
  <pre><code>    ANDROID_BUILD_MIN_SDK_VERSION=14
      ANDROID_BUILD_TARGET_SDK_VERSION=21
      ANDROID_BUILD_TOOLS_VERSION=21.1.3
      ANDROID_BUILD_SDK_VERSION=21
  </code></pre>
  
  <ol start="6">
  <li><p>and last in build.gradle i add</p>
  
  <p>android {</p>
  
  <p>compileSdkVersion Integer.parseInt(project.ANDROID_BUILD_SDK_VERSION)
          buildToolsVersion project.ANDROID_BUILD_TOOLS_VERSION</p>
  
  <pre><code>        defaultConfig {
          minSdkVersion    Integer.parseInt(project.ANDROID_BUILD_MIN_SDK_VERSION)
          targetSdkVersion     Integer.parseInt(project.ANDROID_BUILD_TARGET_SDK_VERSION)
      }
  </code></pre>
  
  <p>}</p></li>
  </ol>
  
  <p>I am getting a message "Error:Cannot get property <code>':PagerSlidingTabStrip'</code> on null object"</p>
  
  <p>When i open my build.gradle file from library . their i am getting this message</p>
  
  <p>you must use a newer version of android gradle plugin.current version is 1.0 and recomended version is 1.2.3</p>
  
  <hr>
  
  <p>well now problem is solved,</p>
  
  <p>so i am writing for those who was still facing this mess.</p>
  
  <p>step's to use external library project in android studio are:-</p>
  
  <ol>
  <li><p>go to file-new -import module.</p></li>
  <li><p>select your library project folder.</p></li>
  <li><p>after importing module.</p></li>
  <li><p>go to file->project structure->select app ->select dependency-> click on + sign in right side->module dependencies-> select your module name and press ok.</p></li>
  <li><p>4th step was the final step , but you can get two type of error. Ex. no such property GROUP... for handle this go to select build.gradle of your library , and remove line like this apply from: <code>'https://raw.github.com/twotoasters/gradle-mvn-push/master/gradle-mvn-push.gradle'</code></p></li>
  </ol>