com.fasterxml.jackson.databind.JsonMappingException：无法从START_ARRAY标记中反序列化TestAcceptanceCriteria的实例
[英]com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of TestAcceptanceCriteria out of START_ARRAY token
问题描述
Given the following JSON file: 
给出以下JSON文件：
[
{"name":"test_12345_54321",
"acceptanceCriteria":
[
{
"given":"I am a developer",
"and":"I have some test case to write",
"when":"I run my test",
"then":"I get a report generated about its details."
}
]
},
{"name":"test_2",
"acceptanceCriteria":
[
{
"given":"I am a developer test 2",
"and":"I have some test case to write test 2",
"when":"I run my test test 2",
"then":"I get a report generated about its details.2"
}
]
}
]
I am trying to access values within a JSON file using Jackson Object Mapper. 我试图使用Jackson Object Mapper访问JSON文件中的值。 As follows: 如下：
File jsonFile = new File("results/acceptanceCriteria.json");
ObjectMapper mapper = new ObjectMapper();
TestAcceptanceCriteria acceptanceCriteria = null;
acceptanceCriteria = mapper.readValue(jsonFile, TestAcceptanceCriteria.class);
System.out.println(acceptanceCriteria.getAcceptanceCriteria());
Each time I try to access any variable I get the following error: 每次我尝试访问任何变量时，都会收到以下错误：
com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of file.readers.TestAcceptanceCriteria out of START_ARRAY token at [Source: results\\acceptanceCriteria.json;
My classes are as follows: 我的课程如下：
public class AcceptanceCriteria{
private String given;
private String and;
private String when;
private String then;
public String getGiven(){
return given;
}
public void setGiven(String given){
this.given = given;
}
public String getAnd(){
return and;
}
public void setAnd(String and){
this.and = and;
}
public String getWhen(){
return when;
}
public void setWhen(String when){
this.when = when;
}
public String getThen(){
return then;
}
public void setThen(String then){
this.then = then;
}
}
... ...
import java.util.List;
public class TestAcceptanceCriteria {
private String name;
private List<AcceptanceCriteria> acceptanceCriteria;
public String getName(){
return name;
}
public void setName(String name){
this.name = name;
}
public List<AcceptanceCriteria> getAcceptanceCriteria(){
return acceptanceCriteria;
}
public void setAcceptanceCriteria(List<AcceptanceCriteria> acceptanceCriteria){
this.acceptanceCriteria = acceptanceCriteria;
}
}
1 个解决方案
解决方案1
0 2017-04-14 16:48:36
You are trying deserialize array of entities to single object, what cause a problem. 您正在尝试将实体数组反序列化为单个对象，这是导致问题的原因。 Let's try: 我们试试吧：
List<TestAcceptanceCriteria> acceptanceCriteria = null;
acceptanceCriteria = mapper.readValue(json, new TypeReference<List<TestAcceptanceCriteria>>(){});
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