[FIXED] Desserialization of + (plus) in Spring Request Param

Issue

I have a simple HTTP GET request like this:

http://localhost:8080/search?page=0&size=20&sort=id,asc&description=1+3

And a RestController:

@RequestMapping(value = "/search", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity<List<TestEntity>> search(Pageable pageable, @RequestParam("description") String description) {

    Page<TestEntity> page = service.search(pageable, description);
    HttpHeaders headers = PaginationUtil.generatePaginationHttpHeaders(page);
    return ResponseEntity
            .ok()
            .headers(headers)
            .body(page.getContent());

}

But the value of @RequestParam "description" is getting "1 3".

What am I doing wrong?

Or what should I do so that signals like "+" are deserialized to "+" in the Spring @RequestParam?

This is my pom.xml

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.0.5.RELEASE</version>
</parent>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <java.version>1.8</java.version>
    <maven.build.timestamp.format>yyyyMMddHHmmss</maven.build.timestamp.format>
    <project.http.version>1.23.0</project.http.version>
    <project.oauth.version>1.23.0</project.oauth.version>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-tomcat</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>
    <dependency>
        <groupId>com.zaxxer</groupId>
        <artifactId>HikariCP</artifactId>
        <version>3.1.0</version>
    </dependency>
    <dependency>
        <groupId>org.liquibase</groupId>
        <artifactId>liquibase-core</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-security</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-mail</artifactId>
    </dependency>

    <dependency>
        <groupId>javax.xml.bind</groupId>
        <artifactId>jaxb-api</artifactId>
        <version>2.3.0</version>
    </dependency>
    <dependency>
        <groupId>com.sun.xml.bind</groupId>
        <artifactId>jaxb-core</artifactId>
        <version>2.3.0</version>
    </dependency>
    <dependency>
        <groupId>com.sun.xml.bind</groupId>
        <artifactId>jaxb-impl</artifactId>
        <version>2.3.0</version>
    </dependency>
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-lang3</artifactId>
        <version>3.8.1</version>
    </dependency>

</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>

Solution

Everything is as expected. As per RFC3986 in URL encoding + is a reserved character. As per point 2.2. Reserved Characters:

If a reserved character is found in a URI component and no delimiting role is known for that character, then it must be interpreted as representing the data octet corresponding to that character's encoding in US-ASCII.

To use + as a value you need to encode it as %2B as explained in Percent-encoding reserved characters. This will make your URL:

http://localhost:8080/search?page=0&size=20&sort=id,asc&description=1%2B3

Do note that sometimes Spring is inconsistent when it comes to + handling e.g. SPR-16860 Spring is inconsistent in the encoding/decoding of URLs bug.

Answered By - Karol Dowbecki
Answer Checked By - Mildred Charles (JavaFixing Admin)