<div id="readability-page-1" class="page"><div>            <h3 data-ke-size="size23"><b>문제상황</b></h3>
<hr contenteditable="false" data-ke-type="horizontalRule" data-ke-style="style6">
<p data-ke-size="size16">개발하면서 특정 정보를 필터링할 Predicate를 동적으로 생성하고 싶은 마음에 다음과 같이 개발을 진행했었다.</p>

<p data-ke-size="size16">WedulFilterPredicate</p>
<p data-ke-size="size16">- 필터로 사용할 조건을 보관하고 Predicate를 반환하는 클래스</p>
<pre id="code_1654353915107" data-ke-language="java" data-ke-type="codeblock"><code>package com.wedul.springtest;

import lombok.Builder;
import lombok.Getter;

import java.util.function.Predicate;

@Getter
public class WedulFilterPredicate {

    private Boolean hasName;
    private Boolean hasPicture;
    private String teamNo;

    @Builder
    public WedulFilterPredicate(Boolean hasName, Boolean hasPicture, String teamNo) {
        this.hasName = hasName;
        this.hasPicture = hasPicture;
        this.teamNo = teamNo;
    }

    public Predicate createPredicate() {
        if (hasPicture &amp;&amp; teamNo != null) {
            return data -&gt; data.equals(teamNo);
        }
        return data -&gt; false;
    }
}</code></pre>

<p data-ke-size="size16">WedulFilter</p>
<p data-ke-size="size16">- 조건별 필터(WedulFilterPredicate)를 생성할 수 있도록 static builder를 반환하는 메소드를 정의한 인터페이스</p>
<pre id="code_1654353929144" data-ke-language="java" data-ke-type="codeblock"><code>package com.wedul.springtest.filter;

import com.wedul.springtest.WedulFilterPredicate;

public interface WedulFilter {
    WedulFilterPredicate.WedulFilterPredicateBuilder predicateBuilder();
}</code></pre>

<p data-ke-size="size16">WedulPosPredicate</p>
<p data-ke-size="size16">- 조건 별 Enum value로 value에 따라 WedulFilterPredicate 클래스를 생성할 수 있도록 하는 static WedulFilterPredicateBuilder를 반환할 수 있도록 하는 enum 클래스</p>
<pre id="code_1654353942359" data-ke-language="java" data-ke-type="codeblock"><code>package com.wedul.springtest;

import com.wedul.springtest.filter.WedulFilter;

public enum WedulPosPredicate implements WedulFilter {
    HAS_NAME {
        @Override
        public WedulFilterPredicate.WedulFilterPredicateBuilder predicateBuilder() {
            return WedulFilterPredicate.builder()
                    .hasName(true);
        }
    },
    HAS_PHOTOS {
        @Override
        public WedulFilterPredicate.WedulFilterPredicateBuilder predicateBuilder() {
            return WedulFilterPredicate.builder()
                    .hasPicture(true);
        }
    }
}</code></pre>

<p data-ke-size="size16">WedulPosDomainService</p>
<p data-ke-size="size16">- HAS_PHOTO조건에 맞는 Predicate를 WedulPosPredicate에서 받고 입력받은 teamNo를 사용하여 WedulFilterPredicate를 만들어서 predicate를 반환하는 서비스</p>
<pre id="code_1654353955508" data-ke-language="java" data-ke-type="codeblock"><code>package com.wedul.springtest;

import org.springframework.stereotype.Service;

import java.util.function.Predicate;

@Service
public class WedulPosDomainService {

    public Predicate getHasPhotoWedulPosPredicate(String teamNo) {
        WedulFilterPredicate wedulFilterPredicate = WedulPosPredicate.HAS_PHOTOS
                .predicateBuilder()
                .teamNo(teamNo)
                .build();

        return wedulFilterPredicate.createPredicate();
    }

}</code></pre>

<p data-ke-size="size16">동일하지는 않지만 이런식으로 요청받은 filter값을 사용해서 Predicate를 생성하는 로직이었다. 크게 문제가 없이 동작할 것으로 보이지만 해당 코드를 돌려보면 <span><b>error: cannot find symbol 에러가 발생한다.</b></span></p>

<pre id="code_1654354430305" data-ke-language="java" data-ke-type="codeblock"><code>/Users/jeongcheol/Documents/project/springtest/src/main/java/com/wedul/springtest/filter/WedulFilter.java:6: error: cannot find symbol
    WedulFilterPredicate.WedulFilterPredicateBuilder predicateBuilder();
                        ^
  symbol:   class WedulFilterPredicateBuilder
  location: class WedulFilterPredicate</code></pre>

<h3 data-ke-size="size23"><b>원인파악</b></h3>
<hr contenteditable="false" data-ke-type="horizontalRule" data-ke-style="style6">
<p data-ke-size="size16">위 코드에서 다른 부분이 중요한 것이 아니라 WedulFilter에서 WedulFilterPredicate.WedulFilterPredicateBuilder를 반환하고 있는 이부분에서 WedulFilterPredicateBuilder를 못찾는다는 것이다.&nbsp;</p>

<p data-ke-size="size16">왜 못찾는 것인가? 그냥 봤을때는 lombok의 builder 애노테이션을 사용하게 되면 static 클래스를 생성해서 접근해서 사용할 수 있도록 하기 때문에 큰 문제가 없을거라고 생각하게된다. 실제 Delombok을 해서 생성되는 코드를 봐도 WedulFilterPredicateBuilder클래스가 만들어져서 큰 문제없이 접근이 가능할것이라고 보인다.&nbsp;</p>
<pre id="code_1654354786621" data-ke-language="java" data-ke-type="codeblock"><code>public static class WedulFilterPredicateBuilder {
        private Boolean hasName;
        private Boolean hasPicture;
        private String teamNo;

        WedulFilterPredicateBuilder() {
        }

        public WedulFilterPredicateBuilder hasName(Boolean hasName) {
            this.hasName = hasName;
            return this;
        }

        public WedulFilterPredicateBuilder hasPicture(Boolean hasPicture) {
            this.hasPicture = hasPicture;
            return this;
        }

        public WedulFilterPredicateBuilder teamNo(String teamNo) {
            this.teamNo = teamNo;
            return this;
        }

        public WedulFilterPredicate build() {
            return new WedulFilterPredicate(hasName, hasPicture, teamNo);
        }

        public String toString() {
            return "WedulFilterPredicate.WedulFilterPredicateBuilder(hasName=" + this.hasName + ", hasPicture=" + this.hasPicture + ", teamNo=" + this.teamNo + ")";
        }
    }</code></pre>


<p data-ke-size="size16">하지만 동작하지 않았던 원인은 lombok의 동작방식을 보면 알 수 있는데 lombok을 사용할 때 AnnotationProcessor를 사용해서 코드를 생성해서 사용한다는것을 알고 있다.&nbsp;</p>

<p data-ke-size="size16">하지만 static import는 annotation processor가 동작하기전에 진행되기 때문에 javac 컴파일 시점에 WedulFilterPredicateBuilder를 찾지 못하기 때문에 발생하는 문제였다.&nbsp;</p>


<h3 data-ke-size="size23"><b>해결방법</b></h3>
<hr contenteditable="false" data-ke-type="horizontalRule" data-ke-style="style6">
<h3 data-ke-size="size23"><b>WedulFilterPredicateBuilder static class 미리 생성</b></h3>
<p data-ke-size="size16">위 에러의 문제가 static import 작업 시 lombok의 생성내용을 알지 못하기 때문에 발생하는 것으로 lombok이 생성하는 static class 껍데기를 미리 생성하는 것이다. 그럼 의문이 들수 있는 부분이 나중에 Lombok이 코드를 생성할 때 문제가 되는거 아니야? 라고 생각할 수 있다. 하지만 실제 롬복에 의해서 코드가 생성되는 시점에 해당 클래스에 내용물을 채워지기 때문에 동작에 문제가 없다.&nbsp;</p>
<pre id="code_1654356245992" data-ke-language="java" data-ke-type="codeblock"><code>package com.wedul.springtest;

import lombok.Builder;
import lombok.Getter;

import java.util.function.Predicate;

@Getter
public class WedulFilterPredicate {

    private Boolean hasName;
    private Boolean hasPicture;
    private String teamNo;

    @Builder
    public WedulFilterPredicate(Boolean hasName, Boolean hasPicture, String teamNo) {
        this.hasName = hasName;
        this.hasPicture = hasPicture;
        this.teamNo = teamNo;
    }

    public static class WedulFilterPredicateBuilder {}

    public Predicate createPredicate() {
        if (hasPicture &amp;&amp; teamNo != null) {
            return data -&gt; data.equals(teamNo);
        }
        return data -&gt; false;
    }

}</code></pre>



<p data-ke-size="size16"><a href="http://www.miredot.com/docs/faq/q/cannot-find-symbol-during-javadoc-phase/" target="_blank" rel="noopener">http://www.miredot.com/docs/faq/q/cannot-find-symbol-during-javadoc-phase/</a></p>
<figure id="og_1654356150935" contenteditable="false" data-ke-type="opengraph" data-ke-align="alignCenter" data-og-type="website" data-og-title="Miredot | Lombok's @Builder annotation causes a cannot find symbol error during the javadoc phase." data-og-description="documentation home FAQ&nbsp;&nbsp;Lombok's @Builder annotation causes a cannot find symbol error during the javadoc phase. Problem You get the following error during the javadoc phase when using Lombok's @Builder annotation. javadoc: Constructing Javadoc informati" data-og-host="www.miredot.com" data-og-source-url="http://www.miredot.com/docs/faq/q/cannot-find-symbol-during-javadoc-phase/" data-og-url="http://www.miredot.com/docs/faq/q/cannot-find-symbol-during-javadoc-phase/" data-og-image=""><a href="http://www.miredot.com/docs/faq/q/cannot-find-symbol-during-javadoc-phase/" target="_blank" rel="noopener" data-source-url="http://www.miredot.com/docs/faq/q/cannot-find-symbol-during-javadoc-phase/">

<div>
<p data-ke-size="size16">Miredot | Lombok's @Builder annotation causes a cannot find symbol error during the javadoc phase.</p>
<p data-ke-size="size16">documentation home FAQ&nbsp;&nbsp;Lombok's @Builder annotation causes a cannot find symbol error during the javadoc phase. Problem You get the following error during the javadoc phase when using Lombok's @Builder annotation. javadoc: Constructing Javadoc informati</p>
<p data-ke-size="size16">www.miredot.com</p>
</div>
</a></figure>


<p data-ke-size="size16"><a href="https://github.com/projectlombok/lombok/issues/979" target="_blank" rel="noopener">https://github.com/projectlombok/lombok/issues/979</a></p>
<figure id="og_1654356162405" contenteditable="false" data-ke-type="opengraph" data-ke-align="alignCenter" data-og-type="object" data-og-title="Static import of builder class breaks bytecode generation in Maven · Issue #979 · projectlombok/lombok" data-og-description="I have a class Foo annotated with @builder. @Builder public class Foo { ... } I use the generated class Foo.FooBuilder in Bar, but I statically import Foo.Builder so that I can refer directly to Fo..." data-og-host="github.com" data-og-source-url="https://github.com/projectlombok/lombok/issues/979" data-og-url="https://github.com/projectlombok/lombok/issues/979" data-og-image="https://scrap.kakaocdn.net/dn/xPVvW/hyOEgGbo6i/9ZjbHxRYEjvCacR41OJ4IK/img.png?width=1200&amp;height=600&amp;face=76_84_1072_521"><a href="https://github.com/projectlombok/lombok/issues/979" target="_blank" rel="noopener" data-source-url="https://github.com/projectlombok/lombok/issues/979">

<div>
<p data-ke-size="size16">Static import of builder class breaks bytecode generation in Maven · Issue #979 · projectlombok/lombok</p>
<p data-ke-size="size16">I have a class Foo annotated with @builder. @Builder public class Foo { ... } I use the generated class Foo.FooBuilder in Bar, but I statically import Foo.Builder so that I can refer directly to Fo...</p>
<p data-ke-size="size16">github.com</p>
</div>
</a><img src="https://scrap.kakaocdn.net/dn/xPVvW/hyOEgGbo6i/9ZjbHxRYEjvCacR41OJ4IK/img.png?width=1200&amp;height=600&amp;face=76_84_1072_521"></figure>
<p data-ke-size="size16"><a href="https://stackoverflow.com/questions/34358689/maven-build-cannot-find-symbol-when-accessing-project-lombok-annotated-methods" target="_blank" rel="noopener">https://stackoverflow.com/questions/34358689/maven-build-cannot-find-symbol-when-accessing-project-lombok-annotated-methods</a></p>
<figure id="og_1654356169369" contenteditable="false" data-ke-type="opengraph" data-ke-align="alignCenter" data-og-type="website" data-og-title="Maven build cannot find symbol when accessing project lombok annotated methods," data-og-description="I'm using project lombok for the first time and I have problems compiling the project via maven when I run the build I receive errors where methods annotated with project lombok annotations are cal..." data-og-host="stackoverflow.com" data-og-source-url="https://stackoverflow.com/questions/34358689/maven-build-cannot-find-symbol-when-accessing-project-lombok-annotated-methods" data-og-url="https://stackoverflow.com/questions/34358689/maven-build-cannot-find-symbol-when-accessing-project-lombok-annotated-methods" data-og-image="https://scrap.kakaocdn.net/dn/dCmRAl/hyOEiquq5m/8z4qrfRXv5MbxlYDuAOUg0/img.png?width=316&amp;height=316&amp;face=0_0_316_316"><a href="https://stackoverflow.com/questions/34358689/maven-build-cannot-find-symbol-when-accessing-project-lombok-annotated-methods" target="_blank" rel="noopener" data-source-url="https://stackoverflow.com/questions/34358689/maven-build-cannot-find-symbol-when-accessing-project-lombok-annotated-methods">

<div>
<p data-ke-size="size16">Maven build cannot find symbol when accessing project lombok annotated methods,</p>
<p data-ke-size="size16">I'm using project lombok for the first time and I have problems compiling the project via maven when I run the build I receive errors where methods annotated with project lombok annotations are cal...</p>
<p data-ke-size="size16">stackoverflow.com</p>
</div>
</a><img src="https://scrap.kakaocdn.net/dn/dCmRAl/hyOEiquq5m/8z4qrfRXv5MbxlYDuAOUg0/img.png?width=316&amp;height=316&amp;face=0_0_316_316"></figure>
<p data-ke-size="size16"><a href="https://stackoverflow.com/questions/47674264/static-import-not-working-in-lombok-builder-in-intellij" target="_blank" rel="noopener">https://stackoverflow.com/questions/47674264/static-import-not-working-in-lombok-builder-in-intellij</a></p>
<figure id="og_1654356173779" contenteditable="false" data-ke-type="opengraph" data-ke-align="alignCenter" data-og-type="website" data-og-title="static import not working in lombok builder in intelliJ" data-og-description="I am using Lombok in IntelliJ. Though everything else is working fine when I try to do the static import of the Lombok builder, IntelliJ build project doesn't find the builder class. If you don't use" data-og-host="stackoverflow.com" data-og-source-url="https://stackoverflow.com/questions/47674264/static-import-not-working-in-lombok-builder-in-intellij" data-og-url="https://stackoverflow.com/questions/47674264/static-import-not-working-in-lombok-builder-in-intellij" data-og-image="https://scrap.kakaocdn.net/dn/eHSZa/hyOEeInRdE/0rpY3kODRxaVtClv0B0nN1/img.png?width=316&amp;height=316&amp;face=0_0_316_316"><a href="https://stackoverflow.com/questions/47674264/static-import-not-working-in-lombok-builder-in-intellij" target="_blank" rel="noopener" data-source-url="https://stackoverflow.com/questions/47674264/static-import-not-working-in-lombok-builder-in-intellij">

<div>
<p data-ke-size="size16">static import not working in lombok builder in intelliJ</p>
<p data-ke-size="size16">I am using Lombok in IntelliJ. Though everything else is working fine when I try to do the static import of the Lombok builder, IntelliJ build project doesn't find the builder class. If you don't use</p>
<p data-ke-size="size16">stackoverflow.com</p>
</div>
</a><img src="https://scrap.kakaocdn.net/dn/eHSZa/hyOEeInRdE/0rpY3kODRxaVtClv0B0nN1/img.png?width=316&amp;height=316&amp;face=0_0_316_316"></figure>
            
</div></div>

wedul

문제상황
개발하면서 특정 정보를 필터링할 Predicate를 동적으로 생성하고 싶은 마음에 다음과 같이 개발을 진행했었다.
 
WedulFilterPredicate
- 필터로 사용할 조건을 보관하고 Predicate를 반환하는 클래스
package com.wedul.springtest;
import lombok.Builder;
import lombok.Getter;
import java.util.function.Predicate;
@Getter
public class WedulFilterPredicate {
    private Boolean hasName;
    private Boolean hasPicture;
    private String teamNo;
    @Builder
    public WedulFilterPredicate(Boolean hasName, Boolean hasPicture, String teamNo) {
        this.hasName = hasName;
        this.hasPicture = hasPicture;
        this.teamNo = teamNo;
    }
    public Predicate createPredicate() {
        if (hasPicture && teamNo != null) {
            return data -> data.equals(teamNo);
        }
        return data -> false;
    }
}
 
WedulFilter
- 조건별 필터(WedulFilterPredicate)를 생성할 수 있도록 static builder를 반환하는 메소드를 정의한 인터페이스
package com.wedul.springtest.filter;
import com.wedul.springtest.WedulFilterPredicate;
public interface WedulFilter {
    WedulFilterPredicate.WedulFilterPredicateBuilder predicateBuilder();
}
 
WedulPosPredicate
- 조건 별 Enum value로 value에 따라 WedulFilterPredicate 클래스를 생성할 수 있도록 하는 static WedulFilterPredicateBuilder를 반환할 수 있도록 하는 enum 클래스
package com.wedul.springtest;
import com.wedul.springtest.filter.WedulFilter;
public enum WedulPosPredicate implements WedulFilter {
    HAS_NAME {
        @Override
        public WedulFilterPredicate.WedulFilterPredicateBuilder predicateBuilder() {
            return WedulFilterPredicate.builder()
                    .hasName(true);
        }
    },
    HAS_PHOTOS {
        @Override
        public WedulFilterPredicate.WedulFilterPredicateBuilder predicateBuilder() {
            return WedulFilterPredicate.builder()
                    .hasPicture(true);
        }
    }
}
 
WedulPosDomainService
- HAS_PHOTO조건에 맞는 Predicate를 WedulPosPredicate에서 받고 입력받은 teamNo를 사용하여 WedulFilterPredicate를 만들어서 predicate를 반환하는 서비스
package com.wedul.springtest;
import org.springframework.stereotype.Service;
import java.util.function.Predicate;
@Service
public class WedulPosDomainService {
    public Predicate getHasPhotoWedulPosPredicate(String teamNo) {
        WedulFilterPredicate wedulFilterPredicate = WedulPosPredicate.HAS_PHOTOS
                .predicateBuilder()
                .teamNo(teamNo)
                .build();
        return wedulFilterPredicate.createPredicate();
    }
}
 
동일하지는 않지만 이런식으로 요청받은 filter값을 사용해서 Predicate를 생성하는 로직이었다. 크게 문제가 없이 동작할 것으로 보이지만 해당 코드를 돌려보면 error: cannot find symbol 에러가 발생한다.
 
/Users/jeongcheol/Documents/project/springtest/src/main/java/com/wedul/springtest/filter/WedulFilter.java:6: error: cannot find symbol
    WedulFilterPredicate.WedulFilterPredicateBuilder predicateBuilder();
                        ^
  symbol:   class WedulFilterPredicateBuilder
  location: class WedulFilterPredicate
 
원인파악
위 코드에서 다른 부분이 중요한 것이 아니라 WedulFilter에서 WedulFilterPredicate.WedulFilterPredicateBuilder를 반환하고 있는 이부분에서 WedulFilterPredicateBuilder를 못찾는다는 것이다. 
 
왜 못찾는 것인가? 그냥 봤을때는 lombok의 builder 애노테이션을 사용하게 되면 static 클래스를 생성해서 접근해서 사용할 수 있도록 하기 때문에 큰 문제가 없을거라고 생각하게된다. 실제 Delombok을 해서 생성되는 코드를 봐도 WedulFilterPredicateBuilder클래스가 만들어져서 큰 문제없이 접근이 가능할것이라고 보인다. 
public static class WedulFilterPredicateBuilder {
        private Boolean hasName;
        private Boolean hasPicture;
        private String teamNo;
        WedulFilterPredicateBuilder() {
        }
        public WedulFilterPredicateBuilder hasName(Boolean hasName) {
            this.hasName = hasName;
            return this;
        }
        public WedulFilterPredicateBuilder hasPicture(Boolean hasPicture) {
            this.hasPicture = hasPicture;
            return this;
        }
        public WedulFilterPredicateBuilder teamNo(String teamNo) {
            this.teamNo = teamNo;
            return this;
        }
        public WedulFilterPredicate build() {
            return new WedulFilterPredicate(hasName, hasPicture, teamNo);
        }
        public String toString() {
            return "WedulFilterPredicate.WedulFilterPredicateBuilder(hasName=" + this.hasName + ", hasPicture=" + this.hasPicture + ", teamNo=" + this.teamNo + ")";
        }
    }
 
 
하지만 동작하지 않았던 원인은 lombok의 동작방식을 보면 알 수 있는데 lombok을 사용할 때 AnnotationProcessor를 사용해서 코드를 생성해서 사용한다는것을 알고 있다. 
 
하지만 static import는 annotation processor가 동작하기전에 진행되기 때문에 javac 컴파일 시점에 WedulFilterPredicateBuilder를 찾지 못하기 때문에 발생하는 문제였다. 
 
 
해결방법
WedulFilterPredicateBuilder static class 미리 생성
위 에러의 문제가 static import 작업 시 lombok의 생성내용을 알지 못하기 때문에 발생하는 것으로 lombok이 생성하는 static class 껍데기를 미리 생성하는 것이다. 그럼 의문이 들수 있는 부분이 나중에 Lombok이 코드를 생성할 때 문제가 되는거 아니야? 라고 생각할 수 있다. 하지만 실제 롬복에 의해서 코드가 생성되는 시점에 해당 클래스에 내용물을 채워지기 때문에 동작에 문제가 없다. 
package com.wedul.springtest;
import lombok.Builder;
import lombok.Getter;
import java.util.function.Predicate;
@Getter
public class WedulFilterPredicate {
    private Boolean hasName;
    private Boolean hasPicture;
    private String teamNo;
    @Builder
    public WedulFilterPredicate(Boolean hasName, Boolean hasPicture, String teamNo) {
        this.hasName = hasName;
        this.hasPicture = hasPicture;
        this.teamNo = teamNo;
    }
    public static class WedulFilterPredicateBuilder {}
    public Predicate createPredicate() {
        if (hasPicture && teamNo != null) {
            return data -> data.equals(teamNo);
        }
        return data -> false;
    }
}
 
 
 
http://www.miredot.com/docs/faq/q/cannot-find-symbol-during-javadoc-phase/
 
 
https://github.com/projectlombok/lombok/issues/979
https://stackoverflow.com/questions/34358689/maven-build-cannot-find-symbol-when-accessing-project-lombok-annotated-methods
https://stackoverflow.com/questions/47674264/static-import-not-working-in-lombok-builder-in-intellij

lombok에서 @builder annotation 사용 후 static 접근 시 cannot find symbol 에러 문제

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