butterknife: java.lang.NullPointerException


1. @BindView(R.id.email_sign_in_button)
2. Button emailSignInButton;
3. 
4. @Override
5. protected void onCreate(Bundle savedInstanceState) {
6.         super.onCreate(savedInstanceState);
7.         setContentView(R.layout.activity_login);
8. 
9.         ButterKnife.bind(this);
10. 
11.         // @OnClick()点击事件失效,所以采用该方式测试
12.         // @OnClick() Click event failure, so the test using this way
13.         emailSignInButton.setOnClickListener(new View.OnClickListener() {
14.             @Override
15.             public void onClick(View view) {
16.                 ToastUtils.showShort(LoginActivity.this, "Can help me? thanks.");
17.             }
18.       });
19. }
20.
21.@OnClick(R.id.email_sign_in_button)
22.public void onClick() {
23.        ToastUtils.showLong(this, "output");
24.}

But 13 line error： java.lang.NullPointerException

Module gradle:

dependencies {
    // 编译ButterKnife注解框架(Compile ButterKnife annotation framework)
    compile 'com.jakewharton:butterknife:8.4.0'
    annotationProcessor 'com.jakewharton:butterknife-compiler:8.4.0'
}

是我的配置出错了么？(Is my configuration error?)

About this issue

Original URL
State: closed
Created 8 years ago
Comments: 33 (3 by maintainers)

Most upvoted comments

dependencies { compile ‘com.jakewharton:butterknife:8.4.0’ annotationProcessor ‘com.jakewharton:butterknife-compiler:8.4.0’ }

我发现添加以上代码到 app‘s build.gradle 是正确的。但是添加到library’s build.gradle 就会java.lang.NullPointerException.

LeifDong on Nov 15, 2016

@LeifDong
apply plugin: ‘com.android.library’ apply plugin: ‘com.jakewharton.butterknife’ classpath ‘com.jakewharton:butterknife-gradle-plugin:8.4.0’ 这三个是使用本地库的时候需要的 compile ‘com.jakewharton:butterknife:8.4.0’ annotationProcessor ‘com.jakewharton:butterknife-compiler:8.4.0’ 这两个是使用gradle库需要的

分开使用，别一起用

Khaos116 on Nov 15, 2016

In my above everyone whos like me beacuse i am every biger and longer and handsome, look at this !!! replace the 'annotationProcessor ’ with ‘apt’. sample: dependencies { compile ‘com.jakewharton:butterknife:8.4.0’ apt ‘com.jakewharton:butterknife-compiler:8.4.0’ }

i am your brother.

davistsin on Nov 21, 2016

@maoxiandemeng 改你主 Module 中的 build.gradle 和项目中的 build.gradle

1.在你主 Module 下 build.gradle 中的 apply plugin: ‘com.android.application’ 的下面加入

apply plugin: 'android-apt'
...

在你主 Module 下 build.gradle 中的 dependencies 里加入

compile 'com.jakewharton:butterknife:8.4.0'
apt 'com.jakewharton:butterknife-compiler:8.4.0'

3.在你项目下的 build.gradle 中的 dependencies 里加入 classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8'

ljf1172361058 on Dec 23, 2016

use classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8 in your root build.gradle dependencies, add apply plugin: 'android-apt' in your app.gradle, Then use compile 'com.jakewharton:butterknife:8.4.0' apt 'com.jakewharton:butterknife-compiler:8.4.0' as the app.gradle dependencies. Get it!

gmyboy on Dec 5, 2016

@ljf1172361058 我测试发现如果使用apply plugin: 'com.neenbedankt.android-apt’会造成空指针

Khaos116 on Nov 15, 2016

第一阶段：下面配置可以正常工作，生成对应的xxxActivity_ViewBinding dependencies{ implementation ‘com.jakewharton:butterknife:9.0.0-SNAPSHOT’ annotationProcessor ‘com.jakewharton:butterknife-compiler:9.0.0-SNAPSHOT’ }

第二阶段：新项目添加了kotlin环境，在app.gradle中添加了下面的代码，就不能编译自动生成xxxActivity_ViewBinding了，到了指定界面就报NullPointerException

apply plugin: ‘kotlin-android’ apply plugin: ‘kotlin-kapt’ // 经过排查是这段代码产生了影响

解决办法有两种： 1、apply plugin: ‘kotlin-kapt’ 这行代码注释，（不推荐） 2、把annotationProcessor这一块改成kapt。就可以了。kapt 也能够处理Java 文件，所以不需要再保留 annotationProcessor 的依赖 dependencies{ implementation ‘com.jakewharton:butterknife:9.0.0-SNAPSHOT’ kapt ‘com.jakewharton:butterknife-compiler:9.0.0-SNAPSHOT’ }

GreenPepperForPotato on May 20, 2018

I got this problem too,and i use it in app’s build like this: compile ‘com.jakewharton:butterknife:8.5.1’ annotationProcessor ‘com.jakewharton:butterknife-compiler:8.5.1’; My solution is delete ‘apt’ in project’s build and app’s build,I think the ‘apt’ is conflicted with ‘annotationProcessor’,only one can be retained.

rch0903 on Feb 16, 2017