[Java] major version 51 is newer than 50, the highest major version supported by this compiler.

!markdown

#Java (자바)

### Error (오류)

```

warning: javax\servlet\http\HttpServletRequest.class(javax\servlet\http:HttpServletRequest.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\http\HttpServletResponse.class(javax\servlet\http:HttpServletResponse.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\http\HttpSession.class(javax\servlet\http:HttpSession.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\Filter.class(javax\servlet:Filter.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\FilterChain.class(javax\servlet:FilterChain.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\FilterConfig.class(javax\servlet:FilterConfig.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\ServletContext.class(javax\servlet:ServletContext.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\ServletException.class(javax\servlet:ServletException.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\ServletRequest.class(javax\servlet:ServletRequest.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\ServletResponse.class(javax\servlet:ServletResponse.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\http\HttpServletRequest.class(javax\servlet\http:HttpServletRequest.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\http\HttpServletResponse.class(javax\servlet\http:HttpServletResponse.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\http\HttpSession.class(javax\servlet\http:HttpSession.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\Filter.class(javax\servlet:Filter.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\FilterChain.class(javax\servlet:FilterChain.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\FilterConfig.class(javax\servlet:FilterConfig.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\ServletContext.class(javax\servlet:ServletContext.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\ServletException.class(javax\servlet:ServletException.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\ServletRequest.class(javax\servlet:ServletRequest.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\ServletResponse.class(javax\servlet:ServletResponse.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\http\HttpServletRequest.class(javax\servlet\http:HttpServletRequest.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\http\HttpServletResponse.class(javax\servlet\http:HttpServletResponse.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\http\HttpSession.class(javax\servlet\http:HttpSession.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\Filter.class(javax\servlet:Filter.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\FilterChain.class(javax\servlet:FilterChain.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\FilterConfig.class(javax\servlet:FilterConfig.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\ServletContext.class(javax\servlet:ServletContext.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\ServletException.class(javax\servlet:ServletException.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\ServletRequest.class(javax\servlet:ServletRequest.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

warning: javax\servlet\ServletResponse.class(javax\servlet:ServletResponse.class): major version 51 is newer than 50, the highest major version supported by this compiler.

It is recommended that the compiler be upgraded.

```

### Problem (문제)

JDK1.7을 지원하는 클래스가 존재하는데,

`JDK1.6 환경`에서 `컴파일(Compile)`하여 경고를 하는 것이다.

### Solved (해결)

나의 경우에는 JDK1.6환경을 기준으로 컴파일하는 것이 목표였기 때문에, 

경고가 뜬 `javax.servlet를 다운그레이드(Down Grade)`하였다.

3.1 => 2.4

Gradle(그래들)로 예를 들면 다음과 같다.

#### 1. Gradle Depedencies설정 (build.gradle)

BEFORE

```gradle

providedCompile  group: 'javax.servlet', name: 'javax.servlet-api', version: '3.1.0'

```

AFTER

```gradle

providedCompile  group: 'javax.servlet', name: 'servlet-api', version: '2.4'

```

#### 2. War Build

```bash

$ gradle clean war

```