CSV生成器不支持属性的数组值 [英] CSV generator does not support Array values for properties
问题描述
我正在开发一个将 JSON 转换为 CSV 的应用程序。
JACKSON 解析 JSON 并写入 CSV 。
：
$ b <$ p>
{_id ：0，
name：aimee Zank，
scores：
[
{type：exam，score：1.463179736705023} b $ b {type：quiz，score：11.78273309957772}，
{type：homework，score：6.676176060654615}，
{type： ，score：35.8740349954354}
]
}
{_id：1，
name：Aurelia Menendez，
scores：
[
{type：exam，score：60.06045071030959}，
{type：quiz，score：52.79790691903873} b $ b {type：homework，score：71.76133439165544}，
{type：homework，score：34.85718117893772}
]
}
{_id：2，
name：Corliss Zuk，
scores：
[
{type： ，score：67.03077096065002}，
{type：quiz，score：6.301851677835235}，
{type：homework，score：20.18160621941858} b $ b {type：homework，score：66.28344683278382}
]
}
这两个Java类：
JsonNode类
public class JsonNode {
private String _id;
private String name;
private Collection< ScoreType>分数;
/ **
* @返回_id
* /
public String get_id（）{
return _id;
}
/ **
* @param _id _id设置
* /
public void set_id（String _id）{
this._id = _ID;
}
/ **
* @返回名称
* /
public String getName（）{
return name;
}
/ **
* @param命名要设置的名称
* /
public void setName（String name）{
this.name =名称;
}
/ **
* @返回分数
* /
public Collection< ScoreType> getScores（）{
return scores;
}
/ **
* @param对得分设置
* /
public void setScores（Collection< ScoreType> scores）{
this .scores = score;
}
}
ScoreType类
public class ScoreType {
private String type;
private String score;
/ **
* @返回类型
* /
public String getType（）{
return type;
}
/ **
* @param键入要设置的类型
* /
public void setType（String type）{
this.type =类型;
}
/ **
* @返回分数
* /
public String getScore（）{
return score;
}
/ **
* @param得分设置
* /
public void setScore（String score）{
this.score =得分了;
}
}
JSON 到 CSV
ObjectMapper mapper = new ObjectMapper
JsonNode jsonNode = mapper.readValue（new File（C：\\ ... \\ ... \\ ... \\test.json ），JsonNode.class）;
CsvMapper csvMapper = new CsvMapper（）;
CsvSchema schema = csvMapper.schemaFor（JsonNode.class）;
schema = schema.withColumnSeparator（';'）;
ObjectWriter myObjectWriter = csvMapper.writer（schema）;
FileOutputStream tempFileOutputStream = new FileOutputStream（out +\\jsontocsv.csv）;
BufferedOutputStream bufferedOutputStream = new BufferedOutputStream（tempFileOutputStream）;
OutputStreamWriter writerOutputStream = new OutputStreamWriter（bufferedOutputStream，UTF-8）;
myObjectWriter.writeValue（writerOutputStream，jsonNode）;
控制台输出：
com.fasterxml.jackson.core.JsonGenerationException：CSV生成器不支持
属性的数组值
CSV输出：
0 ;aimee Zank;
这是我到目前为止做的。
因此，我在这里面临两个问题：
1）输出CSV不完整，它只创建一行，不写分数。 >
2）控制台中的错误。
我使用这些 JACKSON
< dependency>
< groupId> com.fasterxml.jackson.dataformat< / groupId>
< artifactId> jackson-dataformat-csv< / artifactId>
< version> 2.4.0< / version>
< / dependency>
任何人都可以帮助我解决这些问题吗？
编辑 CSV我希望：
_id; name; scores.type; scores.score; scores.type; scores.score; scores.type; scores.score
0; aimee Zank; exam; 1.46; quiz; 11.78;家庭作业; 6.67;家庭作业; 35.87
Ismail
由于CSV是一个简单值的元组，它不支持集合（JSON数组）作为列值。您有一个集合< ScoreType> 作为您的bean的属性之一，这是导致您的错误。
添加 String getter，将您的集合转换为字符串，并手动构建CSV模式，以避免自动使用Collection-值列。 p>
I'm trying to develop an application that convert JSON to CSV.
I'm using JACKSON to parse JSON and write CSV.
Here is an example of a JSON I'm trying to parse :
{ "_id" : 0,
"name" : "aimee Zank",
"scores" :
[
{ "type" : "exam", "score" : 1.463179736705023 },
{ "type" : "quiz", "score" : 11.78273309957772 },
{ "type" : "homework", "score" : 6.676176060654615 },
{ "type" : "homework", "score" : 35.8740349954354 }
]
}
{ "_id" : 1,
"name" : "Aurelia Menendez",
"scores" :
[
{ "type" : "exam", "score" : 60.06045071030959 },
{ "type" : "quiz", "score" : 52.79790691903873 },
{ "type" : "homework", "score" : 71.76133439165544 },
{ "type" : "homework", "score" : 34.85718117893772 }
]
}
{ "_id" : 2,
"name" : "Corliss Zuk",
"scores" :
[
{ "type" : "exam", "score" : 67.03077096065002 },
{ "type" : "quiz", "score" : 6.301851677835235 },
{ "type" : "homework", "score" : 20.18160621941858 },
{ "type" : "homework", "score" : 66.28344683278382 }
]
}
The two Java Classes :
JsonNode class
public class JsonNode {
private String _id;
private String name;
private Collection<ScoreType> scores;
/**
* @return the _id
*/
public String get_id() {
return _id;
}
/**
* @param _id the _id to set
*/
public void set_id(String _id) {
this._id = _id;
}
/**
* @return the name
*/
public String getName() {
return name;
}
/**
* @param name the name to set
*/
public void setName(String name) {
this.name = name;
}
/**
* @return the scores
*/
public Collection<ScoreType> getScores() {
return scores;
}
/**
* @param scores the scores to set
*/
public void setScores(Collection<ScoreType> scores) {
this.scores = scores;
}
}
ScoreType class
public class ScoreType {
private String type;
private String score;
/**
* @return the type
*/
public String getType() {
return type;
}
/**
* @param type the type to set
*/
public void setType(String type) {
this.type = type;
}
/**
* @return the score
*/
public String getScore() {
return score;
}
/**
* @param score the score to set
*/
public void setScore(String score) {
this.score = score;
}
}
The method that convert JSON to CSV
ObjectMapper mapper=new ObjectMapper();
JsonNode jsonNode=mapper.readValue(new File("C:\\...\\...\\...\\test.json"), JsonNode.class);
CsvMapper csvMapper=new CsvMapper();
CsvSchema schema=csvMapper.schemaFor(JsonNode.class);
schema=schema.withColumnSeparator(';');
ObjectWriter myObjectWriter=csvMapper.writer(schema);
FileOutputStream tempFileOutputStream=new FileOutputStream(out+"\\jsontocsv.csv");
BufferedOutputStream bufferedOutputStream=new BufferedOutputStream(tempFileOutputStream);
OutputStreamWriter writerOutputStream=new OutputStreamWriter(bufferedOutputStream,"UTF-8");
myObjectWriter.writeValue(writerOutputStream,jsonNode);
The console output :
com.fasterxml.jackson.core.JsonGenerationException: CSV generator does not support
Array values for properties
The CSV output :
"0";"aimee Zank";
That's what I have done so far.
So I'm facing two issues here :
1) The output CSV is not complete, it creates only one line and don't write scores.
2) The error in the console.
I'm using these JACKSON depandencies :
<dependency>
<groupId>com.fasterxml.jackson.dataformat</groupId>
<artifactId>jackson-dataformat-csv</artifactId>
<version>2.4.0</version>
</dependency>
Can anyone help me solving these issues ?
I hope I was clear enough.
Edits CSV I'm expecting :
_id;name;scores.type;scores.score;scores.type;scores.score;scores.type;scores.score
0;aimee Zank;exam;1.46;quiz;11.78;homework;6.67;homework;35.87
Ismail
Since a CSV is a tuple of simple values, it does indeed not support collections (JSON arrays) as column values. You have a Collection<ScoreType> as one of your bean's properties and this is causing your error.
Suggestion: add a String getter which turns your collection into a string, and build a CSV schema manually to avoid automatically using the Collection-valued column.
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