Consuming a RESTful Web Service: Controller Springboot error
Solution 1
The problem is in this line
package hello;
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
// Below you are importing wrong Value class
import com.fasterxml.jackson.annotation.JsonIgnoreProperties.Value;
You are importing com.fasterxml.jackson.annotation.JsonIgnoreProperties.Value instead of your hello.Value class in Quote.java file
Replace your Quote.java file with the below code.
package hello;
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import hello.Value;
@JsonIgnoreProperties(ignoreUnknown = true)
public class Quote {
private String type;
private Value value;
public Quote() {
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public Value getValue() {
return value;
}
public void setValue(Value value) {
this.value = value;
}
@Override
public String toString() {
return "Quote{" +
"type='" + type + '\'' +
", value=" + value +
'}';
}
}
Solution 2
The problem is that Spring can't create properly object because you don't have matching constructor in your classess
Add constructors to your classes:
Value.java
public Value(Long id, String quote) {
this.id = id;
this.quote = quote;
}
Quote.java
public Quote(String type, Value value) {
this.type= type;
this.value= value;
}
Last time I had the same problem: Invoke REST controller method returns 404 null
Dean Huang
Updated on October 17, 2020Comments
-
Dean Huang over 3 years
i'm studying how to consume rest controller in spring, i'm using eclipse to run the java/spring , I want to ask i got error like this when running the java. i already tried to search about the caused,etc still dont find the solutions. anyone know how to fix it?
Exception in thread "main" org.springframework.http.converter.HttpMessageConversionException: Type definition error: [simple type, class com.fasterxml.jackson.annotation.JsonIgnoreProperties$Value]; nested exception is com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Cannot construct instance of `com.fasterxml.jackson.annotation.JsonIgnoreProperties$Value` (no Creators, like default construct, exist): cannot deserialize from Object value (no delegate- or property-based Creator) at [Source: (PushbackInputStream); line: 1, column: 28] (through reference chain: hello.Quote["value"]) at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.readJavaType(AbstractJackson2HttpMessageConverter.java:238) at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.read(AbstractJackson2HttpMessageConverter.java:223) at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:100) at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:725) at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:680) at org.springframework.web.client.RestTemplate.getForObject(RestTemplate.java:332) at hello.Application.main(Application.java:15) Caused by: com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Cannot construct instance of `com.fasterxml.jackson.annotation.JsonIgnoreProperties$Value` (no Creators, like default construct, exist): cannot deserialize from Object value (no delegate- or property-based Creator) at [Source: (PushbackInputStream); line: 1, column: 28] (through reference chain: hello.Quote["value"]) at com.fasterxml.jackson.databind.exc.InvalidDefinitionException.from(InvalidDefinitionException.java:67) at com.fasterxml.jackson.databind.DeserializationContext.reportBadDefinition(DeserializationContext.java:1451) at com.fasterxml.jackson.databind.DeserializationContext.handleMissingInstantiator(DeserializationContext.java:1027) at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.deserializeFromObjectUsingNonDefault(BeanDeserializerBase.java:1290) at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:326) at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:159) at com.fasterxml.jackson.databind.deser.impl.MethodProperty.deserializeAndSet(MethodProperty.java:127) at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:369) at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:159) at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4001) at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3072) at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.readJavaType(AbstractJackson2HttpMessageConverter.java:235) ... 6 more
My Application Java
package hello; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.web.client.RestTemplate; public class Application { private static final Logger log = LoggerFactory.getLogger(Application.class); public static void main(String args[]) { RestTemplate restTemplate = new RestTemplate(); Quote quote = restTemplate.getForObject("http://gturnquist-quoters.cfapps.io/api/random", Quote.class); log.info(quote.toString()); } }
Quote Java:
package hello; import com.fasterxml.jackson.annotation.JsonIgnoreProperties; import com.fasterxml.jackson.annotation.JsonIgnoreProperties.Value; @JsonIgnoreProperties(ignoreUnknown = true) public class Quote { private String type; private Value value; public Quote() { } public String getType() { return type; } public void setType(String type) { this.type = type; } public Value getValue() { return value; } public void setValue(Value value) { this.value = value; } @Override public String toString() { return "Quote{" + "type='" + type + '\'' + ", value=" + value + '}'; } }
Value Java
package hello; import com.fasterxml.jackson.annotation.JsonIgnoreProperties; @JsonIgnoreProperties(ignoreUnknown = true) public class Value { private Long id; private String quote; public Value() { } public Long getId() { return this.id; } public String getQuote() { return this.quote; } public void setId(Long id) { this.id = id; } public void setQuote(String quote) { this.quote = quote; } @Override public String toString() { return "Value{" + "id=" + id + ", quote='" + quote + '\'' + '}'; } }
Pom XML :
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.resttemplate</groupId> <artifactId>hello1</artifactId> <packaging>war</packaging> <version>0.0.1-SNAPSHOT</version> <name>hello1 Maven Webapp</name> <url>http://maven.apache.org</url> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.0.2.RELEASE</version> </parent> <properties> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>